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Effects of emissions caps on the costs and feasibility of low-carbon hydrogen in the European ammonia industry. Nat Commun 2024; 15:3753. [PMID: 38704394 PMCID: PMC11069508 DOI: 10.1038/s41467-024-48145-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 04/19/2024] [Indexed: 05/06/2024] Open
Abstract
The European ammonia industry emits 36 million tons of carbon dioxide annually, primarily from steam methane reforming (SMR) hydrogen production. These emissions can be mitigated by producing hydrogen via water electrolysis using dedicated renewables with grid backup. This study investigates the impact of decarbonization targets for hydrogen synthesis on the economic viability and technical feasibility of retrofitting existing European ammonia plants for on-site, semi-islanded electrolytic hydrogen production. Results show that electrolytic hydrogen cuts emissions, on average, by 85% (36%-100% based on grid price and carbon intensity), even without enforcing emission limits. However, an optimal lifespan average well-to-gate emission cap of 1 kg carbon dioxide equivalent (CO2e)/kg H2 leads to a 95% reduction (92%-100%) while maintaining cost-competitiveness with SMR in renewable-rich regions (mean levelized cost of hydrogen (LCOH) of 4.1 euro/kg H2). Conversely, a 100% emissions reduction target dramatically increases costs (mean LCOH: 6.3 euro/kg H2) and land area for renewables installations, likely hindering the transition to electrolytic hydrogen in regions with poor renewables and limited land. Increasing plant flexibility effectively reduces costs, particularly in off-grid plants (mean reduction: 32%). This work guides policymakers in defining cost-effective decarbonization targets and identifying region-based strategies to support an electrolytic hydrogen-fed ammonia industry.
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Ultra-fast green hydrogen production from municipal wastewater by an integrated forward osmosis-alkaline water electrolysis system. Nat Commun 2024; 15:2617. [PMID: 38521862 PMCID: PMC10960855 DOI: 10.1038/s41467-024-46964-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Accepted: 03/15/2024] [Indexed: 03/25/2024] Open
Abstract
Recent advancements in membrane-assisted seawater electrolysis powered by renewable energy offer a sustainable path to green hydrogen production. However, its large-scale implementation faces challenges due to slow power-to-hydrogen (P2H) conversion rates. Here we report a modular forward osmosis-water splitting (FOWS) system that integrates a thin-film composite FO membrane for water extraction with alkaline water electrolysis (AWE), denoted as FOWSAWE. This system generates high-purity hydrogen directly from wastewater at a rate of 448 Nm3 day-1 m-2 of membrane area, over 14 times faster than the state-of-the-art practice, with specific energy consumption as low as 3.96 kWh Nm-3. The rapid hydrogen production rate results from the utilisation of 1 M potassium hydroxide as a draw solution to extract water from wastewater, and as the electrolyte of AWE to split water and produce hydrogen. The current system enables this through the use of a potassium hydroxide-tolerant and hydrophilic FO membrane. The established water-hydrogen balance model can be applied to design modular FO and AWE units to meet demands at various scales, from households to cities, and from different water sources. The FOWSAWE system is a sustainable and an economical approach for producing hydrogen at a record-high rate directly from wastewater, marking a significant leap in P2H practice.
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Real-world experience with fluocinolone acetonide intravitreal implant in patients with diabetic macular edema. Eur J Ophthalmol 2024:11206721241235266. [PMID: 38396370 DOI: 10.1177/11206721241235266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2024]
Abstract
OBJECTIVES to evaluate long-term effectiveness and safety of fluocinolone acetonide (FAc) implant used as second-line treatment in patients with persistent diabetic macular edema (DME). METHODS retrospective data chart review of 241 pseudophakic eyes of 178 patients treated with FAc from July 2017 to December 2021 in 10 medical retinal units in Italy. The primary endpoint was the change of best-corrected visual acuity (BCVA) and central macular thickness (CMT) at 2 years. A Student's paired t-test was used. Additional therapies for DME and intraocular pressure (IOP)-related events were also evaluated. RESULTS efficacy of FAc was assessed in a subset of 111 eyes with at least 24 months of follow-up. Mean BCVA increased at 2 years by 5.1 ETDRS letters (95%CI = 2.6-7.5; p < 0.001) while mean CMT decreased by 189 µm (95% CI 151-227; p < 0.001). Thirty-eight of these eyes (34.2%) needed additional intravitreal treatments, mainly anti-VEGF. Safety was evaluated on the entire cohort of 241 eyes treated with FAc. Overall, 66 eyes (27.4%) required emergent IOP-lowering medications (typically within the first-year post FAc) while 14 eyes (5.8%) underwent trabeculectomy, mostly during the second year of follow-up. CONCLUSION FAc implant provides a substantial long-term functional and anatomical benefit when used as second-line treatment in eyes with DME. IOP rise can be adequately managed with topical agents although some eyes may require IOP-lowering surgery.
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Sintering-induced cation displacement in protonic ceramics and way for its suppression. Nat Commun 2023; 14:7984. [PMID: 38042884 PMCID: PMC10693594 DOI: 10.1038/s41467-023-43725-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 11/17/2023] [Indexed: 12/04/2023] Open
Abstract
Protonic ceramic fuel cells with high efficiency and low emissions exhibit high potential as next-generation sustainable energy systems. However, the practical proton conductivity of protonic ceramic electrolytes is still not satisfied due to poor membrane sintering. Here, we show that the dynamic displacement of Y3+ adversely affects the high-temperature membrane sintering of the benchmark protonic electrolyte BaZr0.1Ce0.7Y0.1Yb0.1O3-δ, reducing its conductivity and stability. By introducing a molten salt approach, pre-doping of Y3+ into A-site is realized at reduced synthesis temperature, thus suppressing its further displacement during high-temperature sintering, consequently enhancing the membrane densification and improving the conductivity and stability. The anode-supported single cell exhibits a power density of 663 mW cm-2 at 600 °C and long-term stability for over 2000 h with negligible performance degradation. This study sheds light on protonic membrane sintering while offering an alternative strategy for protonic ceramic fuel cells development.
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Improving Room-Temperature Li-Metal Battery Performance by In Situ Creation of Fast Li + Transport Pathways in a Polymer-Ceramic Electrolyte. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2302691. [PMID: 37279776 DOI: 10.1002/smll.202302691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Indexed: 06/08/2023]
Abstract
Composite polymer-ceramic electrolytes have shown considerable potential for high-energy-density Li-metal batteries as they combine the benefits of both polymers and ceramics. However, low ionic conductivity and poor contact with electrodes limit their practical usage. In this study, a highly conductive and stable composite electrolyte with a high ceramic loading is developed for high-energy-density Li-metal batteries. The electrolyte, produced through in situ polymerization and composed of a polymer called poly-1,3-dioxolane in a poly(vinylidene fluoride)/ceramic matrix, exhibits excellent room-temperature ionic conductivity of 1.2 mS cm-1 and high stability with Li metal over 1500 h. When tested in a Li|electrolyte|LiFePO4 battery, the electrolyte delivers excellent cycling performance and rate capability at room temperature, with a discharge capacity of 137 mAh g-1 over 500 cycles at 1 C. Furthermore, the electrolyte not only exhibits a high Li+ transference number of 0.76 but also significantly lowers contact resistance (from 157.8 to 2.1 Ω) relative to electrodes. When used in a battery with a high-voltage LiNi0.8 Mn0.1 Co0.1 O2 cathode, a discharge capacity of 140 mAh g-1 is achieved. These results show the potential of composite polymer-ceramic electrolytes in room-temperature solid-state Li-metal batteries and provide a strategy for designing highly conductive polymer-in-ceramic electrolytes with electrode-compatible interfaces.
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Achieving Net-Zero Emissions with Solid Oxide Electrolysis Cells: The Power-to-X Approach. J Phys Chem Lett 2023; 14:4688-4695. [PMID: 37171053 DOI: 10.1021/acs.jpclett.3c00140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Replacing fossil fuels with renewable energy sources is a crucial step for mitigating global warming. However, the intermittent nature of the most prevalent renewable sources, such as solar and wind, poses a significant challenge to their widespread deployment. One potential solution for renewable sources of storage is power-to-X, which involves the production of chemicals from electricity using solid oxide electrolysis cells. This process offers a flexible and efficient means of energy storage. This Perspective offers an overview of the characteristics, capabilities, and fundamental mechanisms of solid oxide electrolysis cells. It also examines the latest research progress and explores the prospects and challenges in this field.
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Metal Oxide-Supported Metal Catalysts for Electrocatalytic Oxygen Reduction Reaction: Characterization Methods, Modulation Strategies, and Recent Progress. SMALL METHODS 2023:e2201714. [PMID: 37029582 DOI: 10.1002/smtd.202201714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 02/25/2023] [Indexed: 06/19/2023]
Abstract
The sluggish kinetics of the oxygen reduction reaction (ORR) with complex multielectron transfer steps significantly limits the large-scale application of electrochemical energy devices, including metal-air batteries and fuel cells. Recent years witnessed the development of metal oxide-supported metal catalysts (MOSMCs), covering single atoms, clusters, and nanoparticles. As alternatives to conventional carbon-dispersed metal catalysts, MOSMCs are gaining increasing interest due to their unique electronic configuration and potentially high corrosion resistance. By engineering the metal oxide substrate, supported metal, and their interactions, MOSMCs can be facilely modulated. Significant progress has been made in advancing MOSMCs for ORR, and their further development warrants advanced characterization methods to better understand MOSMCs and precise modulation strategies to boost their functionalities. In this regard, a comprehensive review of MOSMCs for ORR is still lacking despite this fast-developing field. To eliminate this gap, advanced characterization methods are introduced for clarifying MOSMCs experimentally and theoretically, discuss critical methods of boosting their intrinsic activities and number of active sites, and systematically overview the status of MOSMCs based on different metal oxide substrates for ORR. By conveying methods, research status, critical challenges, and perspectives, this review will rationally promote the design of MOSMCs for electrochemical energy devices.
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High-Entropy Perovskites for Energy Conversion and Storage: Design, Synthesis, and Potential Applications. SMALL METHODS 2023; 7:e2201138. [PMID: 36843320 DOI: 10.1002/smtd.202201138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 12/17/2022] [Indexed: 06/18/2023]
Abstract
Perovskites have shown tremendous promise as functional materials for several energy conversion and storage technologies, including rechargeable batteries, (electro)catalysts, fuel cells, and solar cells. Due to their excellent operational stability and performance, high-entropy perovskites (HEPs) have emerged as a new type of perovskite framework. Herein, this work reviews the recent progress in the development of HEPs, including synthesis methods and applications. Effective strategies for the design of HEPs through atomistic computations are also surveyed. Finally, an outlook of this field provides guidance for the development of new and improved HEPs.
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Gaussian Processes for the Analysis of Electrochemical Impedance Spectroscopy Data: Prediction, Filtering, and Active Learning. Electrochim Acta 2022. [DOI: 10.1016/j.electacta.2022.141688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Ni-Doped CuO Nanoarrays Activate Urea Adsorption and Stabilizes Reaction Intermediates to Achieve High-Performance Urea Oxidation Catalysts. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2204800. [PMID: 36266984 PMCID: PMC9731696 DOI: 10.1002/advs.202204800] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Revised: 09/15/2022] [Indexed: 05/14/2023]
Abstract
Urea oxidation reaction (UOR) with a low equilibrium potential offers a promising route to replace the oxygen evolution reaction for energy-saving hydrogen generation. However, the overpotential of the UOR is still high due to the complicated 6e- transfer process and adsorption/desorption of intermediate products. Herein, utilizing a cation exchange strategy, Ni-doped CuO nanoarrays grown on 3D Cu foam are synthesized. Notably, Ni-CuO NAs/CF requires a low potential of 1.366 V versus a reversible hydrogen electrode to drive a current density of 100 mA cm-2 , outperforming various benchmark electrocatalysts and maintaining robust stability in alkaline media. Theoretical and experimental studies reveal that Ni as the driving force center can effectively enhance the urea adsorption and stabilize CO*/NH* intermediates toward the UOR. These findings suggest a new direction for constructing nanostructures and modulating electronic structures, ultimately developing promising Cu-based electrode catalysts.
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Simultaneously Improved Surface and Bulk Participation of Evolved Perovskite Oxide for Boosting Oxygen Evolution Reaction Activity Using a Dynamic Cation Exchange Strategy. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2204109. [PMID: 36228095 DOI: 10.1002/smll.202204109] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 08/24/2022] [Indexed: 06/16/2023]
Abstract
Perovskite oxides are intriguing electrocatalysts for the oxygen evolution reaction, but both surface (e.g., composition) and bulk (e.g., lattice oxygen) properties should be optimized to maximize their participation in offering favorable activity and durability. In this work, it is demonstrated that through introducing exogenous Fe3+ ( Fe exo 3 + ${\rm{Fe}}_{{\rm{exo}}}^{3 + }$ ) into the liquid electrolyte, not only is the reconstructed surface stabilized and optimized, but the lattice oxygen diffusion is also accelerated. As a result, compared to that in Fe-free 0.1 m KOH, PrBa0.5 Sr0.5 Co2 O5+δ in 0.1 m KOH + 0.1 mm Fe3+ demonstrates a tenfold increment in activity, an extremely low Tafel slope of ≈50 mV dec-1 , and outstanding stability at 10.0 mA cm-2 for 10 h. The superior activity and stability are further demonstrated in Zn-air batteries by presenting high open-circuit voltage, narrow potential gap, high power output, and long-term cycle stability (500 cycles). Based on experimental and theoretical calculations, it is discovered that the dynamical interaction between the Co hydr(oxy)oxide from surface reconstruction and intentional Fe3+ from the electrolyte plays an important role in the enhanced activity and durability, while the generation of a perovskite-hydr(oxy)oxide heterostructure improves the lattice oxygen diffusion to facilitate lattice oxygen participation and enhances the stability.
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Deconvolution of Electrochemical Impedance Spectroscopy Data Using the Deep-Neural-Network-Enhanced Distribution of Relaxation Times. Electrochim Acta 2022. [DOI: 10.1016/j.electacta.2022.141499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Nano film Pr2Ni0.8Cu0.2O4+δ decorated La0.6Sr0.4Co0.2Fe0.8O3-δ oxygen electrode for highly efficient and stable reversible solid oxide cells. Electrochim Acta 2022. [DOI: 10.1016/j.electacta.2022.141032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Rational design of perovskite ferrites as high-performance proton-conducting fuel cell cathodes. Nat Catal 2022. [DOI: 10.1038/s41929-022-00829-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Precise Modulation of Triple‐Phase Boundaries towards a Highly Functional Exsolved Catalyst for Dry Reforming of Methane under a Dilution‐Free System. Angew Chem Int Ed Engl 2022; 61:e202204990. [PMID: 35638132 PMCID: PMC9542147 DOI: 10.1002/anie.202204990] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Indexed: 11/06/2022]
Abstract
Dry reforming of methane (DRM) has been emerging as a viable solution to achieving carbon neutrality enhanced by the Paris Agreement as it converts the greenhouse gases of CO2 and CH4 into industrially useful syngas. However, there have been limited studies on the DRM catalyst under mild operating conditions with a high dilution gas ratio due to their deactivation from carbon coking and metal sintering. Herein, we apply the triple‐phase boundary (TPB) concept to DRM catalyst via exsolution phenomenon that can secure elongated TPB by controlling the Fe‐doping ratio in perovskite oxide. Remarkably, the exsolved catalyst with prolongated TPB shows exceptional CO2 and CH4 conversion rates of 95.9 % and 91.6 %, respectively, stable for 1000 hours under a dilution‐free system. DFT calculations confirm that the Lewis acid of support and Lewis base of metal at the TPB promote the adsorption of reactants, resulting in lowering the overall CO2 dissociation and CH4 dehydrogenation energy.
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Precise Modulation of Triple‐Phase Boundaries towards Highly Functional Exsolved Catalyst for Dry Reforming of Methane under A Dilution‐Free System. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202204990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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PERSEUS-IT 24-month analysis: a prospective observational study to assess the effectiveness of intravitreal aflibercept in routine clinical practice in Italy in patients with neovascular age-related macular degeneration. Graefes Arch Clin Exp Ophthalmol 2022; 260:3185-3195. [PMID: 35511286 PMCID: PMC9477902 DOI: 10.1007/s00417-022-05679-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 03/30/2022] [Accepted: 04/15/2022] [Indexed: 11/05/2022] Open
Abstract
Purpose PERSEUS-IT (NCT02289924) was a prospective, observational, 2-year study evaluating the effectiveness and treatment patterns of intravitreal aflibercept (IVT-AFL) in patients with neovascular age-related macular degeneration (nAMD) in routine clinical practice in Italy. Methods Treatment-naïve patients with nAMD receiving IVT-AFL per routine clinical practice were enrolled. The primary endpoint was mean change in visual acuity (VA; decimals) from baseline to month (M) 12 and M24. Outcomes were evaluated for the overall study population and independently for the 2 treatment cohorts: regular (3 initial monthly doses, ≥ 7 injections by M12, and ≥ 4 injections between M12 and M24) and irregular (any other pattern). Results Of 813 patients enrolled, 709 were included in the full analysis set (FAS); VA assessments were available for 342 patients at M12 (FAS1Y, 140 regular and 202 irregular) and 233 patients at M24 (FAS2Y, 37 regular and 196 irregular). In the overall FAS, the mean ± SD change in VA from baseline to M12 and M24 was + 0.09 ± 0.24 and + 0.02 ± 0.25 decimals, and there was a statistically significant difference between the regular and irregular cohorts in both FAS1Y (p = 0.0034) and FAS2Y (p = 0.0222). Ocular treatment-emergent adverse events were reported in 4.1% (n = 33/810 [safety set]) of patients. Conclusion In PERSEUS-IT, clinically relevant functional and anatomic improvements were observed within the first 12 months of IVT-AFL treatment in routine clinical practice in Italy in patients with treatment-naïve nAMD. These gains were generally maintained across the 2-year study. The safety profile of IVT-AFL was consistent with prior studies. Trial registration number ClinicalTrials.gov Identifier: NCT02289924. Date of registration November 13, 2014. ![]() Supplementary Information The online version contains supplementary material available at 10.1007/s00417-022-05679-6.
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The probabilistic deconvolution of the distribution of relaxation times with finite Gaussian processes. Electrochim Acta 2022. [DOI: 10.1016/j.electacta.2022.140119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Nonflammable, robust and flexible electrolytes enabled by phosphate coupled polymer-polymer for Li-metal batteries. J Colloid Interface Sci 2022; 621:222-231. [PMID: 35461137 DOI: 10.1016/j.jcis.2022.04.051] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 04/01/2022] [Accepted: 04/07/2022] [Indexed: 02/06/2023]
Abstract
Liquid organic electrolytes commonly employed in commercial Li-ion batteries suffer from safety issues such as flammability and explosions. Replacing liquid electrolytes with nonflammable electrolytes has become increasingly attractive in the development of safe, high-energy Li-metal batteries (LMBs). In this work, nonflammable, robust, and flexible composite polymer-polymer electrolytes (PPEs) were successfully fabricated by flame-retardant solution casting with polyimide (PI) and polyvinylidene fluoride (PVDF). The optimized nonflammable PPEs (e.g., PPE-50) demonstrate not only good mechanical properties (i.e., a high tensile strength of 29.6 MPa with an elongation at break of 87.2%), but also high Li salts dissolubility, the former of which ensures the suppression of Li dendrites, while the latter further improves the ionic conductivity (∼1.86 × 10-4 S cm-1 at 30 °C). The resulting symmetric cells (Li|PPE-50|Li) offer excellent Li stripping and plating stability for 1000 h at 0.5 mA cm-2/0.25 mAh cm-2 and 600 h at 2.0 mA cm-2/1.0 mAh cm-2. In addition, the LiFePO4|PPE-50|Li half cells show high cycling performance (e.g., a reversible discharge capacity of 135.9 mAh g-1 after 300 cycles at 1C) and rate capability (e.g., 117.2 mAh g-1 at 4C). The PPE-50 is also compatible with a high-voltage cathode (e.g., LiNi0.5Mn0.3Co0.2O2), and the resulting batteries demonstrate long-term cycling stability with a high cut-off voltage of 4.5 V vs. Li/Li+. Because of the incorporation of a mechanically robust and thermally stable PI, a polar PVDF, and flame-retardant trimethyl phosphate (TMP) within PPEs, as well as the coordination between Li salts and TMP, and the interaction between Li salts and polymers (especially between Li bis(oxalato)borate) and PI, as well as the bis(oxalato)borate anion and PI), PPEs show great potential for practical and high-energy LMBs without safety concerns.
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Realizing Simultaneous Detrimental Reactions Suppression and Multiple Benefits Generation from Nickel Doping toward Improved Protonic Ceramic Fuel Cell Performance. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2200450. [PMID: 35277919 DOI: 10.1002/smll.202200450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 02/18/2022] [Indexed: 06/14/2023]
Abstract
Anode-supported protonic ceramic fuel cells (PCFCs) are highly promising and efficient energy conversion systems. However, several challenges need to be overcome before these systems are used more widely, including the poor sintering of recently developed proton-conducting oxides and the decreased proton conductivity due to detrimental reactions between the nickel from anode and the electrolyte occurring during high-temperature co-sintering. Herein, a Ni doping strategy to increase the electrolyte sintering, suppress the detrimental phase reactions, and generate stable Ni nanoparticles for enhanced performance is proposed. A nickel-doped perovskite oxide is developed with the nominal composition of Ba(Zr0.1 Ce0.7 Y0.1 Yb0.1 )0.95 Ni0.05 O3- δ . Acting as a sintering aid, such a small amount of nickel effectively improves the sintering of the electrolyte. Concomitantly, reactions between nickel and the Ni-doped ceramic phase are suppressed, turning detrimental phase reactions into benefits. The nickel doping further promotes the formation of Ni nanoparticles, which enhance the electrocatalytic activity of the anode toward the hydrogen oxidation reaction and improve the charge transfer across the anode-electrolyte interface. As a result, highly efficient PCFCs are developed. The innovative anode developed in this work also shows favorable activity toward ammonia decomposition, making it highly promising for use in direct ammonia fuel cells.
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Hierarchical Structure of CuO Nanowires Decorated with Ni(OH) 2 Supported on Cu Foam for Hydrogen Production via Urea Electrocatalysis. SMALL METHODS 2022; 6:e2101017. [PMID: 35041274 DOI: 10.1002/smtd.202101017] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 11/01/2021] [Indexed: 06/14/2023]
Abstract
Owing to the low theoretical potential of the urea oxidation reaction (UOR), urea electrolysis is an energy-saving technique for the generation of hydrogen. Herein, a hierarchical structure of CuO nanowires decorated with nickel hydroxide supported on 3D Cu foam is constructed. Combined theoretical and experimental analyses demonstrate the high reactivity and selectivity of CuO and Ni(OH)2 toward the UOR instead of the oxygen evolution reaction. The hierarchical structure creates a synergistic effect between the two highly active sites, enabling an exceptional UOR activity with a record low potential of 1.334 V (vs the reversible hydrogen electrode) to reach 100 mA cm-2 and a low Tafel slope of 14 mV dec-1 in 1 m KOH and 0.5 m urea electrolyte. Assembling full urea electrolysis driven by this developed UOR electrocatalyst as the anode and a commercial Pt/C electrocatalyst as the cathode provides a current density of 20 mA cm-2 at a cell voltage of ≈1.36 V with promising operational stability for at least 150 h. This work not only enriches the UOR material family but also significantly advances energy-saving hydrogen production.
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Enhancing the Intrinsic Activity and Stability of Perovskite Cobaltite at Elevated Temperature Through Surface Stress. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2104144. [PMID: 34605170 DOI: 10.1002/smll.202104144] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 08/27/2021] [Indexed: 06/13/2023]
Abstract
Perovskite-based oxides attract great attention as catalysts for energy and environmental devices. Nanostructure engineering is demonstrated as an effective approach for improving the catalytic activity of the materials. The mechanism for the enhancement, nevertheless, is still not fully understood. In this study, it is demonstrated that compressive strain can be introduced into freestanding perovskite cobaltite La0.8 Sr0.2 CoO3- δ (LSC) nanofibers with sufficient small size. Crystal structure analysis suggests that the LSC fiber is characterized by compressive strain along the ab plane and less distorted CoO6 octahedron compared to the bulk powder sample. Accompanied by such structural changes, the nanofiber shows significantly higher oxygen reduction reaction (ORR) activity and better stability at elevated temperature, which is attributed to the higher oxygen vacancy concentration and suppressed Sr segregation in the LSC nanofibers. First-principle calculations further suggest that the compressive strain in LSC nanofibers effectively shortens the distance between the Co 3d and O 2p band center and lowers the oxygen vacancy formation energy. The results clarify the critical role of surface stress in determining the intrinsic activity of perovskite oxide nanomaterials. The results of this work can help guide the design of highly active and durable perovskite catalysts via nanostructure engineering.
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The deep-DRT: A deep neural network approach to deconvolve the distribution of relaxation times from multidimensional electrochemical impedance spectroscopy data. Electrochim Acta 2021. [DOI: 10.1016/j.electacta.2021.139010] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Central retinal thickness fluctuations in patients treated with anti-VEGF for neovascular age related macular degeneration. Eur J Ophthalmol 2021; 32:2388-2394. [PMID: 34392710 DOI: 10.1177/11206721211037820] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
PURPOSE This is a retrospective, single-center, non randomized interventional real life study, investigating the correlation between variability of central retinal thickness (CRT) and functional outcomes during 2 years of anti-VEGF therapy in patients treated for neovascular age related macular degeneration (nAMD). BACKGROUND CRT fluctuations can depend on various factors such as the correct timing of injections, the therapeutic algorithm, and the number of injections (NI) performed; it is important to understand if CRT fluctuations are responsible for worse visual outcomes and consequently to identify the correct ways to avoid or reduce them. METHODS Forty-one patients were treated for nAMD with aflibercept: 0.5 mg intravitreal aflibercept was administered every 4 weeks during the first 3 months, then bimonthly over the first year, and after the first year adopting a PRN regimen. Standard deviation of CRT (CRT/SD), BCVA, and NI were recorded. Correlation studies were performed by Pearson's test, Ancova, and Principal Component Analysis. RESULTS A negative correlation was found between CRT/SD and final BCVA. In patients who lost more than 15 letters, CRT/SD mean was significantly higher in comparison with patients who lost less than 15 letters. Patients with final BCVA >65 letters showed lower CRT/SD values compared to patients with final BCVA ⩽65 letters. Multivariate analysis confirmed that in patients with higher baseline BCVA, improvement of BCVA was correlated to NI, and lower values of CRT fluctuations were observed. CONCLUSIONS CRT fluctuations, even after an appropriate NI given per year, significantly influence BCVA; a proactive treatment algorithm appears crucial when treating patients with nAMD.
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Exploring Transport Behavior in Hybrid Perovskites Solar Cells via Machine Learning Analysis of Environmental-Dependent Impedance Spectroscopy. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:e2002510. [PMID: 34155825 PMCID: PMC8336513 DOI: 10.1002/advs.202002510] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 04/14/2021] [Indexed: 06/13/2023]
Abstract
Hybrid organic-inorganic perovskites are one of the promising candidates for the next-generation semiconductors due to their superlative optoelectronic properties. However, one of the limiting factors for potential applications is their chemical and structural instability in different environments. Herein, the stability of (FAPbI3 )0.85 (MAPbBr3 )0.15 perovskite solar cell is explored in different atmospheres using impedance spectroscopy. An equivalent circuit model and distribution of relaxation times (DRTs) are used to effectively analyze impedance spectra. DRT is further analyzed via machine learning workflow based on the non-negative matrix factorization of reconstructed relaxation time spectra. This exploration provides the interplay of charge transport dynamics and recombination processes under environment stimuli and illumination. The results reveal that in the dark, oxygen atmosphere induces an increased hole concentration with less ionic character while ionic motion is dominant under ambient air. Under 1 Sun illumination, the environment-dependent impedance responses show a more striking effect compared with dark conditions. In this case, the increased transport resistance observed under oxygen atmosphere in equivalent circuit analysis arises due to interruption of photogenerated hole carriers. The results not only shed light on elucidating transport mechanisms of perovskite solar cells in different environments but also offer an effective interpretation of impedance responses.
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Spark Plasma Sintering of LiFePO 4: AC Field Suppressing Lithium Migration. MATERIALS 2021; 14:ma14112826. [PMID: 34070590 PMCID: PMC8198947 DOI: 10.3390/ma14112826] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 05/21/2021] [Indexed: 11/16/2022]
Abstract
Our work proposes a comparison between Spark Plasma Sintering of LiFePO4 carried out using an Alternating Current (AC) and Direct Current (DC). It quantifies the Li-ion migration using DC, and it validates such hypothesis using impedance spectroscopy, X-ray photoelectron spectroscopy and inductively coupled plasma optical emission spectroscopy. The use of an AC field seems effective to inhibit undesired Li-ion migration and achieve high ionic conductivity as high as 4.5 × 10−3 S/cm, which exceeds by one order of magnitude samples processed under a DC field. These results anticipate the possibility of fabricating a high-performance all-solid-state Li-ion battery by preventing undesired Li loss during SPS processing.
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Positive/Negative Phototropism: Controllable Molecular Actuators with Different Bending Behavior. CCS CHEMISTRY 2021. [DOI: 10.31635/ccschem.020.202000350] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Nanoparticle Ex-solution for Supported Catalysts: Materials Design, Mechanism and Future Perspectives. ACS NANO 2021; 15:81-110. [PMID: 33370099 DOI: 10.1021/acsnano.0c07105] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Supported metal catalysts represent one of the major milestones in heterogeneous catalysis. Such catalytic systems are feasible for use in a broad range of applications, including renewable energy devices, sensors, automotive emission control systems, and chemical reformers. The lifetimes of these catalytic platforms depend strongly on the stability of the supported nanoparticles. With this regard, nanoparticles synthesized via ex-solution process emphasize exceptional robustness as they are socketed in the host oxide. Ex-solution refers to a phenomenon which yields selective growth of fine and uniformly distributed metal nanocatalysts on oxide supports upon partial reduction. This type of advanced structural engineering is a game-changer in the field of heterogeneous catalysis with numerous studies showing the benefits of ex-solution process. In this review, we highlight the latest research efforts regarding the origin of the ex-solution phenomenon and the mechanism underpinning particle formation. We also propose research directions to expand the utility and functionality of the current ex-solution techniques.
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Stability, Elastic Properties, and the Li Transport Mechanism of the Protonated and Fluorinated Antiperovskite Lithium Conductors. ACS APPLIED MATERIALS & INTERFACES 2020; 12:55011-55022. [PMID: 33242955 DOI: 10.1021/acsami.0c17975] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Lithium-rich antiperovskites (APs) have attracted significant research attention due to their ionic conductivity above 1 mS cm-1 at room temperature. However, recent experimental reports suggest that proton-free lithium-rich APs, such as Li3OCl, may not be synthesized using conventional methods. While Li2OHCl has a lower conductivity of about 0.1 mS cm-1 at 100 °C, its partially fluorinated counterpart, Li2(OH)0.9F0.1Cl, is a significantly better ionic conductor. In this article, using density functional theory simulations, we show that it is easier to synthesize Li2OHCl and two of its fluorinated variants, i.e., Li2(OH)0.9F0.1Cl and Li2OHF0.1Cl0.9, than Li3OCl. The transport properties and electrochemical windows of Li2OHCl and the fluorinated variants are also studied. The ab initio molecular dynamics simulations suggest that the greater conductivity of Li2(OH)0.9F0.1Cl is due to structural distortion of the lattice and correspondingly faster OH reorientation dynamics. Partially fluorinating the Cl site to obtain Li2OHF0.1Cl0.9 leads to an even greater ionic conductivity without impacting the electrochemical window and synthesizability of the materials. This study motivates further research on the correlation between local structure distortion, OH dynamics, and increased Li mobility. Furthermore, it introduces Li2OHF0.1Cl0.9 as a novel Li conductor.
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A Bayesian view on the Hilbert transform and the Kramers-Kronig transform of electrochemical impedance data: Probabilistic estimates and quality scores. Electrochim Acta 2020. [DOI: 10.1016/j.electacta.2020.136864] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Sodiophilically Graded Gold Coating on Carbon Skeletons for Highly Stable Sodium Metal Anodes. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2020; 16:e2003815. [PMID: 32875749 DOI: 10.1002/smll.202003815] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 08/10/2020] [Indexed: 06/11/2023]
Abstract
Metallic sodium (Na) is an appealing anode material for high-energy Na batteries. However, Na metal suffers from low coulombic efficiencies and severe dendrite growth during plating/stripping cycles, causing short circuits. As an effective strategy to improve the deposition behavior of Na metal, a 3D carbon foam is developed that is sputter-coated with gold nanoparticles (Au/CF), forming a functional gradient through its thickness. The highly porous Au/CF host is proven to have gradually varying sodiophilicity, which in turn facilitates initially preferential Na deposition on the gold-rich, sodiophilic region in a "bottom-up growth" mode, leading to uniform plating over the entire Au/CF host. This finding contrasts with dendrite formation in the pristine CF host, as proven by in situ microscopy. The Na-predeposited Au/CF (Na@Au/CF) composite anode operates steadily for 1000 h at a low overpotential of ≈20 mV at 2 mA cm-2 in a symmetric cell. When the composite anode is coupled with a Na3 V2 (PO4 )2 F3 cathode, the full cell has a high capacity of 102.1 mAh g-1 after 500 cycles at 2 C. The sodiophilicity gradient design that is explored in this study offers new insight into developing porous Na metal hosts with highly stable plating/stripping performance for next-generation Na batteries.
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Frontispiece: Molybdenum Disulfide Based Nanomaterials for Rechargeable Batteries. Chemistry 2020. [DOI: 10.1002/chem.202082961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Molybdenum Disulfide Based Nanomaterials for Rechargeable Batteries. Chemistry 2020; 26:6296-6319. [DOI: 10.1002/chem.201905524] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Revised: 01/19/2020] [Indexed: 12/31/2022]
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Non-precious-metal catalysts for alkaline water electrolysis: operando characterizations, theoretical calculations, and recent advances. Chem Soc Rev 2020; 49:9154-9196. [DOI: 10.1039/d0cs00575d] [Citation(s) in RCA: 197] [Impact Index Per Article: 49.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Advances of non-precious-metal catalysts for alkaline water electrolysis are reviewed, highlighting operando techniques and theoretical calculations in their development.
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Metallic MoS 2 nanosheets: multifunctional electrocatalyst for the ORR, OER and Li-O 2 batteries. NANOSCALE 2018; 10:22549-22559. [PMID: 30480696 DOI: 10.1039/c8nr07106c] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Lithium-oxygen batteries (LOBs) possess the highest theoretical specific density among all types of lithium batteries, making them ideal candidates to replace the current Li ion batteries for next-generation electric vehicle applications. However, designing highly active catalysts with high electronic conductivities to kinetically accelerate the sluggish oxygen reduction/evolution reactions (ORR/OER) is still a big challenge. This work was dedicated to developing two-dimensional (2D) trigonal phase MoS2 (1T-MoS2) nanosheets as a highly active electrocatalyst for LOBs for the first time. Metallic 1T-MoS2 prepared via in situ liquid-redox intercalation and exfoliation was hybridized with functionalized carbon nanotubes (CNTs) to form freestanding, binder-free oxygen electrodes. The 1T-MoS2/CNT electrode exhibited excellent electrochemical performances with a high reversible capacity of 500 mA h g-1 at a current density of 200 mA g-1 for more than 100 cycles owing to the catalytically active surfaces of 1T-MoS2 accessible by Li+ ions and O2. Density functional theory (DFT) calculations identified the catalytically active basal planes in 1T-MoS2 during the ORR as well as the initial ORR path during LOB cycles. The results based on the rotational ring disk electrode (RRDE) experiments also supported the findings from the DFT calculations, where the 1T-MoS2 basal planes are active for both the ORR and OER, not the semiconducting hexagonal MoS2 (2H-MoS2) whose edges are only electrocatalytically active. This study sheds light on the use of metallic 1T-MoS2 as a multifunctional oxygen electrocatalyst for LOB applications with enhanced ORR and OER activities.
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Model development and comparison of low hemorrhage-risk endoluminal patch thrombolytic treatment for ischemic stroke. Med Eng Phys 2018; 61:32-40. [PMID: 30177419 DOI: 10.1016/j.medengphy.2018.08.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 06/28/2018] [Accepted: 08/13/2018] [Indexed: 11/16/2022]
Abstract
Clot dissolution drugs delivered into the systemic circulation can dissolve intracranial blood clots in 90 min with 20-50% hemorrhage rate. Immobilizing <5% of the intravenous dosage on an endoluminal patch can reduce the dissolution time to <20 min with negligible hemorrhage risk. The thrombus dissolution behavior in endoluminal patch thrombolytic treatment is modeled and compared with experimental results from a companion study. Analyses showed that the thrombus dissolution time decreases with increasing dosage, but the dissolution time reaches a dosage-independent minimum when uPA dosage on the patch is >800 IU. Model analyses showed that dissolution time in the plateau regime is controlled by diffusion. Further results showed that dissolution time could be reduced in this regime by reducing thrombus thickness. This suggests that a stented endoluminal thrombolytic >800 IU patch that compresses the thrombus to thin the clot thickness can help reduce dissolution time. This ultra-low transition dosage (i.e., 800 IU), compared to 0.6-2.4 million IU in conventional thrombolysis suggests that hemorrhage risk in endoluminal patch thrombolytic treatment is low. The low hemorrhagic-risk endoluminal patch can be considered for use in patients who are ineligible for conventional thrombolytic treatment because of high hemorrhagic treatment risk.
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Mesoporous MnCo 2S 4 nanosheet arrays as an efficient catalyst for Li-O 2 batteries. NANOSCALE 2018; 10:15588-15599. [PMID: 30090885 DOI: 10.1039/c8nr03942a] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Ternary metal sulfides and ternary metal oxides have received much attention as potential electrodes for high performance rechargeable batteries. Herein, MnCo2S4 nanosheets are grown on carbon paper (MCS/CP) via facile electrodeposition followed by low temperature vulcanization for application in Li-O2 batteries for the first time. The electrochemical performance of freestanding, binder-free MCS/CP oxygen electrodes is compared with those prepared from MnCo2O4 nanosheets on CP (MCO/CP). The MCS/CP electrode delivers an extremely high initial specific capacity of 10 760 mA h g-1, twice that of MCO/CP. The former electrode sustains 96 cycles at an upper limit capacity of 500 mA h g-1 at 200 mA g-1, whereas the latter counterpart survives only a few cycles with a poor round trip efficiency. The superior performance of MCS/CP is in part proven by the four times higher electrical conductivity and 250% higher lithium diffusion coefficient than MCO/CP. In addition, the 3D interconnected web of 2D MCS nanosheets offers a few micrometer open voids to accommodate discharge products and a large surface area with internal mesopores providing abundant active sites. The density functional theory calculations reveal a lower adsorption energy for LiO2 on the surface of MCS than on MCO, which is responsible for the lower OER overpotential and the higher catalytic ability of MCS/CP. The predicted density of states signifies metallic properties of MCS in agreement with the high electrical conductivity of MCS/CP.
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Dietary linseed supplementation affects the fatty acid composition of the sn-2 position of triglycerides in sheep milk. J Dairy Sci 2018; 101:6742-6751. [DOI: 10.3168/jds.2017-14188] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Accepted: 04/06/2018] [Indexed: 11/19/2022]
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A Ceramic-PVDF Composite Membrane with Modified Interfaces as an Ion-Conducting Electrolyte for Solid-State Lithium-Ion Batteries Operating at Room Temperature. ChemElectroChem 2018. [DOI: 10.1002/celc.201800643] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Abstract
The presence of active metal nanoparticles on the surface significantly increases the electrochemical performance of ABO3 perovskite oxide materials. While conventional deposition methods can improve the activity, in situ exsolution produces nanoparticles with far greater stability. The migration of transition metal atoms toward the surface is expected to affect the exsolution process. To study the energetics, we use ab initio computations combined with experiments in a SrTiO3-based model system. Our calculations show that Ni preferentially segregates toward the (100)-oriented and SrTiO-terminated surfaces, note that this orientation is identical to one reported by the Irvine and Gorte groups. Vacancies in the Sr-site and O-site promote the segregation of Ni, while placing La on the Sr-site has an opposite effect. The corresponding experiments are in agreement with the computational predictions. Fast nanoparticle growth and activity enhancement are found in STO system with Sr vacancies and without La. The approach developed in this Letter could be used to study the mechanism of exsolution in other material systems, and possibly lead to the development of new compositions capable of nanoparticle exsolution with higher activity and stability.
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Promotion of Oxygen Reduction with Both Amorphous and Crystalline MnO
x
through the Surface Engineering of La0.8
Sr0.2
MnO3-δ
Perovskite. ChemElectroChem 2018. [DOI: 10.1002/celc.201701248] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Boosting oxygen reduction/evolution reaction activities with layered perovskite catalysts. Chem Commun (Camb) 2018; 52:10739-42. [PMID: 27507001 DOI: 10.1039/c6cc04895a] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Layered PrBaMn2O5+δ (H-PBM) was simply prepared by annealing pristine Pr0.5Ba0.5MnO3-δ in H2. The oxygen reduction/evolution reaction activities are remarkably enhanced by employing H-PBM. The improvement can be ascribed to the introduction of additional oxygen vacancies, an optimized eg filling of Mn ions, and the facile incorporation of oxygen into layered H-PBM.
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Optical Coherence Tomography Findings in a Case of Acute Multifocal Posterior Placoid Pigment Epitheliopathy (AMPPPE). Eur J Ophthalmol 2018. [DOI: 10.1177/112067210501500125] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Activating the Bifunctionality of a Perovskite Oxide toward Oxygen Reduction and Oxygen Evolution Reactions. ACS APPLIED MATERIALS & INTERFACES 2017; 9:35829-35836. [PMID: 28948763 DOI: 10.1021/acsami.7b10216] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
This article presents a facile and effective approach to activate the bifunctionality of calcium-manganese perovskites toward the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). We substituted Nb into the Mn site of CaMnO3 (CMO) and treated the material with H2. The as-obtained CaMn0.75Nb0.25O3-δ (H2-CMNO) displays the same structure as that of CMO, and compared to that of CMO, H2-CMNO exhibits significantly improved OER performance, including a lower overpotential, a reduced Tafel slope, a higher mass activity, and enhanced stability. In addition, the ORR performance of H2-CMNO is also greatly enhanced, relative to CMO, with a higher ORR activity and a more efficient electron-transfer pathway. H2-CMNO shows an even higher activity-per-catalyst cost and superior stability than that of state-of-the-art materials, such as IrO2 and Pt/C. This great enhancement in ORR and OER activity of H2-CMNO is attributed to several factors, including phase stabilization, optimized eg filling, better OH- adsorption, and improved electrical conductivity.
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Chestnut or quebracho tannins in the diet of grazing ewes supplemented with soybean oil: Effects on animal performances, blood parameters and fatty acid composition of plasma and milk lipids. Small Rumin Res 2017. [DOI: 10.1016/j.smallrumres.2017.05.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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49
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Boosting Bifunctional Oxygen Electrolysis for N-Doped Carbon via Bimetal Addition. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2017; 13:1604103. [PMID: 28199051 DOI: 10.1002/smll.201604103] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 01/10/2017] [Indexed: 05/20/2023]
Abstract
The addition of transition metals, even in a trace amount, into heteroatom-doped carbon (M-N/C) is intensively investigated to further enhance oxygen reduction reaction (ORR) activity. However, the influence of metal decoration on the electrolysis of the reverse reaction of ORR, that is, oxygen evolution reaction (OER), is seldom reported. Moreover, further improving the bifunctional activity and corrosion tolerance for carbon-based materials remains a big challenge, especially in OER potential regions. Here, bimetal-decorated, pyridinic N-dominated large-size carbon tubes (MM'-N/C) are proposed for the first time as highly efficient and durable ORR and OER catalysts. FeFe-N/C, CoCo-N/C, NiNi-N/C, MnMn-N/C, FeCo-N/C, NiFe-N/C, FeMn-N/C, CoNi-N/C, MnCo-N/C, and NiMn-N/C are systematically investigated in terms of their structure, composition, morphology, surface area, and active site densities. In contrast to conventional monometal and N-decorated carbon, small amounts of bimetal (≈2 at%) added during the one-step template-free synthesis contribute to increased pyridinic N content, much longer and more robust carbon tubes, reduced metal particle size, and stronger coupling between the encapsulated metals and carbon support. The synergy of those factors accounts for the dramatically improved ORR and OER activity and stability. By comparison, NiFe-N/C and MnCo-N/C stand out and achieve superior bifunctional oxygen catalytic performance, exceeding most of state-of-the-art catalysts.
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Data mining of molecular dynamics data reveals Li diffusion characteristics in garnet Li 7La 3Zr 2O 12. Sci Rep 2017; 7:40769. [PMID: 28094317 PMCID: PMC5240091 DOI: 10.1038/srep40769] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 12/12/2016] [Indexed: 11/26/2022] Open
Abstract
Understanding Li diffusion in solid conductors is essential for the next generation Li batteries. Here we show that density-based clustering of the trajectories computed using molecular dynamics simulations helps elucidate the Li diffusion mechanism within the Li7La3Zr2O12 (LLZO) crystal lattice. This unsupervised learning method recognizes lattice sites, is able to give the site type, and can identify Li hopping events. Results show that, while the cubic LLZO has a much higher hopping rate compared to its tetragonal counterpart, most of the Li hops in the cubic LLZO do not contribute to the diffusivity due to the dominance of back-and-forth type jumps. The hopping analysis and local Li configuration statistics give evidence that Li diffusivity in cubic LLZO is limited by the low vacancy concentration. The hopping statistics also shows uncorrelated Poisson-like diffusion for Li in the cubic LLZO, and correlated diffusion for Li in the tetragonal LLZO in the temporal scale. Further analysis of the spatio-temporal correlation using site-to-site mutual information confirms the weak site dependence of Li diffusion in the cubic LLZO as the origin for the uncorrelated diffusion. This work puts forward a perspective on combining machine learning and information theory to interpret results of molecular dynamics simulations.
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