Cation Defect-Engineered Boost Fast Kinetics of Two-Dimensional Topological Bi2 Se3 Cathode for High-Performance Aqueous Zn-Ion Batteries

Nickel silicate nanotubes modifying the surface of Zn anode tuning the uniform zinc deposition for high-performance Zn metal battery

Among many new types of ion batteries, aqueous Zn-ion batteries (AZIBs) have gained more and more interest because of their unique characteristics such as abundant metal Zn reserves and high capacity. Herein, a nickel silicate nanotube (NSO) is synthesized for protecting Zn metal anode by the surface modification strategy (NSO-Zn). On the one hand, the pores generated by the stacking of NSO nanotubes uniformly guide the deposition of Zn2+ on Zn plate, which greatly reduces the risk of the battery's short-circuit due to the dendrite growth puncturing the diaphragm. On the other hand, the hydrophilic nature of NSO is more conducive to the penetration of electrolyte. Thanks to the inherent material and structural properties of NSO nanotubes, the symmetric cells prepared with NSO-Zn electrodes have a long cycle life of more than 2500 h at 1 mA·cm-2. Finite element simulations of the electrical field and Zn2+ intensity demonstrate that the NSO-Zn electrodes can well reduce the local current density resulting in homogenizing electric field distribution. The present study not only provides a facile and large-grid synthesis of NSO nanotubes, but also demonstrates that NSO nanotubes can protect high-reversible zinc metal anodes and guide the uniform zinc deposition for long-cycle AZIBs.

In Situ Construction of Hierarchical Nickel-Cobalt Hydroxides Derived from Metal-Organic Frameworks for High-Performance Nickel-Zinc Batteries

Rechargeable nickel-zinc (Ni-Zn) batteries hold great promise for large-scale applications due to their relatively high voltage, cost-efficient zinc anode, and good safety. However, the commonly used cathode materials are susceptible to overcharging and experience irreversible capacity degradation, primarily as a result of low electrical conductivity and substantial limitations in volume-constrained proton diffusion. Here, we present a robust methodology for synthesizing hierarchical nickel-cobalt (Ni-Co) hydroxides characterized by hollow interiors and interconnected nanosheet shells with the help of in situ formed metal-organic frameworks (MOFs). The templating effect of the MOF induced the hierarchical structure, while the chemical etching of MOFs by Ni2+ ions resulted in a hollow structure, thereby enhancing the surface area. Theoretical calculations suggested that incorporation of cobalt reduces the band gap, thereby improving electronic conductivity, and lowered the deprotonation energy, which mitigated overcharge issues. These advantages conferred improved specific capacity, rate capability, and cyclic stability to the Ni-Co hydroxide. The Ni-Zn cell delivered specific energy values of 338 Wh kg-1 at 1.62 kW kg-1 and 142 Wh kg-1 at 29.89 kW kg-1. Our investigations undercoreed the critical role of MOFs as intermediates in the preparation of multi-component hydroxide and the construction of hiearchical structures to achieve superior performance.

In-situ conversion of BiOBr to Br-doped BiOCl nanosheets for "rocking chair" zinc-ion battery

Developing insertion-type anodes is essential for designing high-performance "rocking chair" zinc-ion batteries. BiOCl shows great potential as an insertion-type anode material for Zn2+ storage due to its high specific capacity and unique layered structure. However, the development of BiOCl has been significantly hampered by its poor stability and kinetics during cycling. In this study, Br-doped and carbon-coated BiOCl ultrathin nanosheets (Br-BiOCl@NC) are synthesized as high-performance anodes. The ultrathin nanosheet morphology facilitates Zn2+/H+ transfer and the Br doping reduces the Zn2+/H+ diffusion barrier. Additionally, the carbon coating enhances the electronic transfer. Furthermore, an insertion-conversion mechanism involving H+ and Zn2+ storage is revealed by ex-situ tests. Therefore, Br-BiOCl@NC exhibits a high discharge capacity of 174 mA h/g at 500 mA/g without capacity degradation after 1000 cycles. The Br-BiOCl@NC//MnO2 full cell presents a discharge capacity of ≈ 120 mA h/g at 200 mA/g. This work offers valuable insights for the design of high-performance insertion-type anode materials in zinc-ion batteries.

Stress Release of Zincophilic N-Doped Carbon@Sn Composite on High-Curvature Surface of Zinc Foam for Dendrite-Free 3D Zinc Anode

Commercial 3D zinc foam anodes with high deposition space and ion permeation have shown great potential in aqueous ion batteries. However, the local accumulated stress from its high-curvature surface exacerbates the Zn dendrite issue, leading to poor reversibility. Herein, we have employed zincophilic N-doped carbon@Sn composites (N-C@Sn) as nano-fillings to effectively release the local stress of high curvature surface of 3D Zn foams toward dendrite-free anode in aqueous zinc ion battery (AZIB). These electronegative and conductive N-C@Sn nano-fillings as supporters can provide a highly zincophilic channel for initial Zn nucleation and reduce local current density for regulating Zn deposition. Uniform Zn deposition further assists homogenous stress distribution on the platting surface, which gives a positive feedback loop to improve anode reversibility. As a result, zinc foam with N-C@Sn composite (ZCSn Foam) symmetric cell achieves a long cycle lifespan of 1100h at 0.5 mA cm-2, much more than that of Zn Foam (∼80 h lifespan). The full cell ZCSn Foam||MnO2 exhibits remarkable reversibility with 67% retention after 1000 cycles at 0.8 A g-1 and 76% after 1600 cycles at 2 Ag-1. This 3D-constructing strategy may offer a promising and practical pathway for metal anode application.

Recent Progress in Aqueous Zinc-ion Batteries at High Zinc Utilization

Aqueous zinc ion batteries (AZIBs) are promising candidates for next-generation energy storage systems due to their low cost, high safety, and environmental friendliness. As the critical component, Zn metal with high theoretical capacity (5855 mAh cm-3), low redox potential (-0.76 V vs. standard hydrogen electrode), and low cost has been widely applied in AZIBs. However, the low Zn utilization rate (ZUR) of Zn metal anode caused by the dendrite growth, hydrogen evolution, corrosion, and passivation require excess Zn installation in current AZIBs, thus leading to increased unnecessary battery weight and decreased energy density. Herein, approaches to the historical progress toward high ZUR AZIBs through the perspective of electrolyte optimization, anode protection, and substrate construction are comprehensively summarized, and an in-depth understanding of ZUR is highlighted. Specifically, the main challenges and failure mechanisms of Zn anode are analyzed. Then, the persisting issues and promising solutions in the reaction interface, aqueous electrolyte, and Zn anode are emphasized. Finally, the design of 100 % ZUR AZIBs free of Zn metal is presented in detail. This review aims to provide a better understanding and fundamental guidelines on the high ZUR AZIBs design, which can shed light on research directions for realizing high energy density AZIBs.

Boosting the Charge Storage Capability of Bi2TeO5 Cathode Using Iodide Ions in Aqueous Zinc-Based Batteries System

As insertion-type cathode materials of aqueous Zn-based batteries (ABs), bismuth chalcogenides/oxychalcogenides exhibits relatively limited capacities in ZnSO4 baseline electrolyte. This work finds that Bi2TeO5 (BTO) cathode with pre-added I- electrolyte additive can simultaneously achieve conversion and insertion chemistries, which enables aqueous BTO-Zn batteries to deliver an extraordinary electrochemical performance. As shown in the experiment results, the BTO cathode showcases an ultrahigh specific capacity of 534.9 mA h g-1 at 0.5 A g-1, excellent rate capability (237.3 mA h g-1 at 10 A g-1). In the estimation of cyclic durability, the capacity of the BTO cathode decreases from 271.2 to 171.1 mA h g-1 during 2000 cycles at 10 A g-1.

Bipolar Modulation in a Self-Powered Ultra-Wide Photodetector Based on Bi2Se3/AlInAsSb Heterojunction for Wavelength-Sensitive Imaging and Encrypted Optical Communication

Broadband photodetectors (PDs) have garnered significant attention due to their ability to detect optical signals across a wide wavelength range, with applications spanning military reconnaissance, environmental monitoring, and medical imaging. However, existing broadband detectors face several practical challenges, including limited detection range, uneven photoresponse, and difficult to distinguish multispectral signals. To address these limitations, this study presents a self-powered ultra-wide PD based on the Bi2Se3/AlInAsSb heterojunction. The device can detect signals across a wide wavelength range from 250 nm to 1900 nm, exhibiting outstanding optoelectronic performance with a maximum responsivity of 0.5 A W-1, a detectivity of 4.2 × 1012 Jones, a switching ratio of 1.1 × 104, and an external quantum efficiency of 71.4%. Furthermore, the detector achieves a detectivity greater than 1010 Jones across the entire broadband range, significantly improving photoresponse uniformity. Notably, due to the differential band alignment of the two materials across spectral ranges, this detector exhibits a photocurrent polarity reversal in the 650-680 nm range. Leveraging its broadband and bipolar characteristics, this PD successfully enables secure information encryption in communication systems. This study significantly advances broadband PD technology, enhancing its practical uses and introducing innovative solutions for secure communications, thus strengthening communication security and confidentiality.

Directing Zn Growth with Biased Adsorption of Straight-chain Molecules for Superior Zn Anode Stability

Aqueous zinc ion batteries (AZIBs), which have attracted attentions in the field of energy storage, is affected by dendrites and side reactions of Zn anode, resulting in an unsatisfactory performance of AZIBs. Herein, we propose a biased adsorption strategy mediated by straight-chain molecule (Scm) for stabilizing Zn anode. The dual polar termini of Scms guaranties securely anchor themselves in a parallel orientation upon the Zn anode surface. This provides a comprehensive coverage, effectively sequestering water molecules from the Zn anode and precipitating the formation of a water-depleted electric double layer (EDL). Furthermore, the Scms selectively adsorb along the crystallographic planes, guiding the deposition of Zn2+. Consequently, the incorporation of these Scms successfully mitigates anode corrosion, HER, and dendrites. The Zn||Zn, Zn||Cu and Zn||V6O13 cells with Scms display significantly enhanced electrochemical performance, especially at elevated temperature of 60 °C. This work highlights the potential of cost-effective, straight-chain electrolyte additives for enhancing Zn anode stability.

Unraveling the Ionic Storage Mechanism of Flexible Nitrogen-Doped MXene Films for High-Performance Aqueous Hybrid Supercapacitors

2D MXene nanomaterials have excellent potential for application in novel electrochemical energy storage technologies such as supercapacitors and batteries, but the existing pure MXene is difficult to meet the practical needs. Although the electrochemical properties of modified MXene have been improved, the unclear ion storage mechanism still hinders the development of MXene-based electrode materials. Herein, the study develops flexible self-supported nitrogen-doped Ti3C2 (Py-Ti3C2) films by the highly mobile, high nitrogen content, oxygen-free pyridine-assisted solvothermal method, and then deeply investigates the energy storage mechanism of hybrid supercapacitors in four aqueous electrolytes (H2SO4, Li2SO4, Na2SO4, and MgSO4). The experimental results suggest that the Py-Ti3C2 film electrode exhibits a pseudocapacitance-dominated energy storage mechanism. Particularly, the specific capacity of the Py-Ti3C2 in 1 M H2SO4 (506 F g-1 at 0.1 A g-1) is 4-5 times higher than other electrolytes (≈110 F g-1), which could be attributed to the substantially higher ionic diffusion coefficient of H+ than those of Li+, Na+, Mg2+ with small ionic size, high ionic conductivity, and fast pseudocapacitance response. Theoretical analysis further confirms that Py-Ti3C2 has strengthened conductivity and electrical double-layer capacitance performance. Meanwhile, it has lower free energy for protonation and deprotonation of functional groups, which gives excellent pseudocapacitance performance.

Spin Symmetry Breaking-Induced Hubbard Gap Near-Closure in N-Coordinated MnO2 for Enhanced Aqueous Zinc-Ion Battery Performance

Transition metal oxides (TMOs) are promising cathode materials for aqueous zinc ion batteries (ZIBs), however, their performance is hindered by a substantial Hubbard gap, which limits electron transfer and battery cyclability. Addressing this, we introduce a heteroatom coordination approach, using triethanolamine to induce axial N coordination on Mn centers in MnO2, yielding N-coordinated MnO2 (TEAMO). This approach leverages the change of electronegativity disparity between Mn and ligands (O and N) to disrupt spin symmetry and augment spin polarization. This enhancement leads to the closure of the Hubbard gap, primarily driven by the intensified occupancy of the Mn eg orbitals. The resultant TEAMO exhibit a significant increase in storage capacity, reaching 351 mAh g-1 at 0.1 A g-1. Our findings suggest a viable strategy for optimizing the electronic structure of TMO cathodes, enhancing the potential of ZIBs in energy storage technology.

Additives for Aqueous Zinc-Ion Batteries: Recent Progress, Mechanism Analysis, and Future Perspectives

Aqueous zinc-ion batteries (ZIBs) stand out as a promising next-generation electrochemical energy storage technology, offering notable advantages such as high specific capacity, enhanced safety, and cost-effectiveness. However, the application of aqueous electrolytes introduces challenges: Zn dendrite formation and parasitic reactions at the anode, as well as dissolution, electrostatic interaction, and by-product formation at the cathode. In addressing these electrode-centric problems, additive engineering has emerged as an effective strategy. This review delves into the latest advancements in electrolyte additives for ZIBs, emphasizing their role in resolving the existing issues. Key focus areas include improving morphology and reducing side reactions during battery cycling using synergistic effects of modulating anode interface regulation, zinc facet control, and restructuring of hydrogen bonds and solvation sheaths. Special attention is given to the efficacy of amino acids and zwitterions due to their multifunction to improve the cycling performance of batteries concerning cycle stability and lifespan. Additionally, the recent additive advancements are studied for low-temperature and extreme weather applications meticulously. This review concludes with a holistic look at the future of additive engineering, underscoring its critical role in advancing ZIB performance amidst the complexities and challenges of electrolyte additives.

Defect Engineering in Bi-Based Photo/Electrocatalysts for Nitrogen Reduction to Ammonia

Main group Bi-based materials have gained popularity as N2 reduction reaction (NRR) photo/electrocatalysts due to their ability to inhibit competitive H2 evolution reactions (HER) and the unique N2 adsorption activities. The introduction of defects in Bi-based catalysts represents a highly effective strategy for enhancing light absorption, promoting efficient separation of photogenerated carriers, optimizing the activity of free radicals, regulating electronic structure, and improving catalytic performance. In this review, we outline the various applications of state of the defect engineering in Bi-based catalysts and elucidate the impact of vacancies on NRR performance. In particular, the types of defects, methods of defects tailoring, advanced characterization techniques, as well as the Bi-based catalysts with abundant defects and their corresponding catalytic behavior in NRR were elucidated in detail. Finally, the main challenges and opportunities for future development of defective Bi-based NRR catalysts are discussed, which provides a comprehensive theoretical guidance for this field.

Two-dimensional/three-dimensional hierarchical self-supporting potassium ammonium vanadate@MXene hybrid film for superior performance aqueous zinc ion batteries

Currently, aqueous zinc ion batteries (AZIBs) have grown to be a good choice for large-scale energy storage systems due to their high theoretical specific capacity, low redox potential, low cost, and non-toxicity of the aqueous electrolyte. However, it is still challenging to obtain high specific capacity and stability suitable cathodes. Herein, hierarchical self-supporting potassium ammonium vanadate@MXene (KNVO@MXene) hybrid films were prepared by vacuum filtration method. Due to the three-dimensional nanoflower structure of KNVO with dual ions intercalation, high conductivity of two-dimensional Ti3C2Tx MXene, and the hierarchical self-supporting structure, the AZIB based on the KNVO@MXene hybrid film cathode possessed superior specific capacity (481 mAh/g at 0.3 A/g) and cycling stability (retaining 125 mAh/g after 1000 cycles at a high current density of 10 A/g). In addition, the storage mechanism was revealed by various ex-situ characterizations. Hence, a new viewpoint for the preparation of AZIB self-supporting cathode materials is presented.

Novel Zn0.079V2O5·0.53H2O/Graphene aerogel as high-rate and long-life cathode materials of aqueous zinc-ion batteries

Aqueous zinc-ion batteries (ZIBs) have attracted more and more attention due to their advantages of low cost, high safety and environmental protection. Unfortunately, the unsatisfactory capacity at high current density and long-term cycling performance of cathode materials hinder the development of ZIBs. Here, a novel Zn0.079V2O5·0.53H2O/graphene (ZVOH@rGO) hybrid aerogel composed of ultrathin Zn0.079V2O5·0.53H2O (ZVOH) nanoribbons and 3D continuous graphene conductive network was successfully prepared and used as cathode of ZIBs. Taking advantage of the synergistic effects associated with ion doping, morphology control and unique aerogel structure, the ZVOH@rGO electrode demonstrated ultrafast charge/discharge capability and remarkable cycling stability: A high reversible capacity of 286.7 mAh g-1 was achieved at a current density as large as 30 A g-1, and an impressive capacity retention ratio of 75.6 % was realized over 9800 ultra-long cycles at 12 A g-1. This work is of great significance for the synthesis modification of vanadium oxides and the development of high performance ultrafast charge-discharge ZIBs.

Insights into the cycling stability of manganese-based zinc-ion batteries: from energy storage mechanisms to capacity fluctuation and optimization strategies

Manganese-based materials are considered as one of the most promising cathodes in zinc-ion batteries (ZIBs) for large-scale energy storage applications owing to their cost-effectiveness, natural availability, low toxicity, multivalent states, high operation voltage, and satisfactory capacity. However, their intricate energy storage mechanisms coupled with unsatisfactory cycling stability hinder their commercial applications. Previous reviews have primarily focused on optimization strategies for achieving high capacity and fast reaction kinetics, while overlooking capacity fluctuation and lacking a systematic discussion on strategies to enhance the cycling stability of these materials. Thus, in this review, the energy storage mechanisms of manganese-based ZIBs with different structures are systematically elucidated and summarized. Next, the capacity fluctuation in manganese-based ZIBs, including capacity activation, degradation, and dynamic evolution in the whole cycle calendar are comprehensively analyzed. Finally, the constructive optimization strategies based on the reaction chemistry of one-electron and two-electron transfers for achieving durable cycling performance in manganese-based ZIBs are proposed.

Rapid Growth of Bi2Se3 Nanodots on MXene Nanosheets at Room Temperature for Promoting Sulfur Redox Kinetics

Li-S batteries are hampered by problems with their cathodes and anodes simultaneously. The improvement of Li-S batteries needs to consider both the anode and cathode. Herein, a Bi2Se3@MXene composite is prepared for the first time by rapidly growing Bi2Se3 nanodots on two-dimensional (2D) MXene nanosheets at room temperature through simply adding high-reactive hydroxyethylthioselenide in Bi3+/MXene aqueous solution. Bi2Se3@MXene exhibits a 2D structure due to the template effect of 2D MXene. Bi2Se3@MXene can not only facilitate the conversion of lithium polysulfides (LiPSs) but also inhibit their shuttling in the S cathode due to its catalytic effect and adsorption force with LiPSs. Bi2Se3@MXene can also be used as an interfacial lithiophilic layer to inhibit Li dendrite growth in the Li metal anode. Theoretical calculations reveal that Bi2Se3 nanodots in Bi2Se3@MXene can effectively boost the adsorption ability with LiPSs, and the MXene in Bi2Se3@MXene can accelerate the electron transport. Under the bidirectional regulation of Bi2Se3@MXene in the Li metal anode and S cathode, the Li-S battery shows an enhanced electrochemical performance.

Dynamically Ion-Coordinated Bipolar Organodichalcogenide Cathodes Enabling High-Energy and Durable Aqueous Zn Batteries

Bipolar organic cathode materials (OCMs) implementing cation/anion storage mechanisms are promising for high-energy aqueous Zn batteries (AZBs). However, conventional organic functional group active sites in OCMs usually fail to sufficiently unlock the high-voltage/capacity merits. Herein, we initially report dynamically ion-coordinated bipolar OCMs as cathodes with chalcogen active sites to solve this issue. Unlike conventional organic functional groups, chalcogens bonded with conjugated group undergo multielectron-involved positive-valence oxidation and negative-valence reduction, affording higher redox potentials and reversible capacities. With phenyl diselenide (PhSe-SePh, PDSe) as a proof of concept, it exhibits a conversion pathway from (PhSe)- to (PhSe-SePh)0 and then to (PhSe)+ as unveiled by characterization and theoretical simulation, where the diselenide bonds are periodically broken and healed, dynamically coordinating with ions (Zn2+ and OTF-). When confined into ordered mesoporous carbon (CMK-3), the dissolution of PDSe intermediates is greatly inhibited to obtain an ultralong lifespan without voltage/capacity compromise. The PDSe/CMK-3 || Zn batteries display high reversibility capacity (621.4 mAh gPDSe -1), distinct discharge plateau (up to 1.4 V), high energy density (578.3 Wh kgPDSe -1), and ultralong lifespan (12 000 cycles) at 10 A g-1, far outperforming conventional bipolar OCMs. This work sheds new light on conversion-type active site engineering for high-voltage/capacity bipolar OCMs towards high-energy AZBs.

The LiV3 O8 Superlattice Cathode with Optimized Zinc Ion Insertion Chemistry for High Mass-Loading Aqueous Zinc-Ion Batteries

Resolving the sluggish transport kinetics of divalent Zn2+ in the cathode lattice and improving mass-loading performance are crucial for advancing the zinc-ion batteries (AZIBs) application. Herein, PEO-LiV3 O8 superlattice nanosheets (PEO-LVO) with expanded interlayer spacing (1.16 nm) are fabricated to provide a high-rate, stable lifetime, and large mass-loading cathode. The steady in-plane expansion without shrinkage after the first cycle, but reversible H+ /Zn2+ co-insertion in PEO-LVO are demonstrated by operando synchrotron X-ray diffraction and ex situ characterizations. Moreover, the large capacity of PEO-LVO is traced back to the optimized Zn2+ insertion chemistry with increased Zn2+ storage ratio, which is facilitated by the interlayer PEO in lowering the Zn2+ diffusion barrier and increased number of active sites from additional interfaces, as anticipated by density functional theory. Due to the optimized ion insertion resulting in stalled interfacial byproducts and rapid kinetics, PEO-LVO achieves excellent high mass-loading performance (areal capacity up to 6.18 mAh cm-2 for freestanding electrode with 24 mg cm-2 mass-loading and 2.8 mAh cm-2 at 130 mA cm-2 for conventional electrode with 27 mg cm-2 mass-loading). As a proof-of-concept, the flexible all-solid-state fiber-shaped AZIBs with high mass-loading woven into a fabric can power an electronic watch, highlighting the application potential of PEO-LVO cathode.