A Facile Methodology for the Development of a Printable and Flexible All-Solid-State Rechargeable Battery

Microwave-Assisted Synthesis of Water-Dispersible Humate-Coated Magnetite Nanoparticles: Relation of Coating Process Parameters to the Properties of Nanoparticles

Nowadays, there is a demand in the production of nontoxic multifunctional magnetic materials possessing both high colloidal stability in water solutions and high magnetization. In this work, a series of water-dispersible natural humate-polyanion coated superparamagnetic magnetite nanoparticles has been synthesized via microwave-assisted synthesis without the use of inert atmosphere. An impact of a biocompatible humate-anion as a coating agent on the structural and physical properties of nanoparticles has been established. The injection of humate-polyanion at various synthesis stages leads to differences in the physical properties of the obtained nanomaterials. Depending on the synthesis protocol, nanoparticles are characterized by improved monodispersity, smaller crystallite and grain size (up to 8.2 nm), a shift in the point of zero charge (6.4 pH), enhanced colloidal stability in model solutions, and enhanced magnetization (80 emu g⁻¹).

Review of the Design of Current Collectors for Improving the Battery Performance in Lithium-Ion and Post-Lithium-Ion Batteries

Current collectors (CCs) are an important and indispensable constituent of lithium-ion batteries (LIBs) and other batteries. CCs serve a vital bridge function in supporting active materials such as cathode and anode materials, binders, and conductive additives, as well as electrochemically connecting the overall structure of anodes and cathodes with an external circuit. Recently, various factors of CCs such as the thickness, hardness, compositions, coating layers, and structures have been modified to improve aspects of battery performance such as the charge/discharge cyclability, energy density, and the rate performance of a cell. In this paper, the details of interesting and useful attempts of preparing CCs for high battery performance in lithium-ion and post-lithium-ion batteries are reviewed. The advantages and disadvantages of these attempts are discussed.

LiCoO2 particles used in Li-ion batteries induce primary mutagenicity in lung cells via their capacity to generate hydroxyl radicals

BACKGROUND

Li-ion batteries (LIB) are used in most portable electronics. Among a wide variety of materials, LiCoO₂ (LCO) is one of the most used for the cathode of LIB. LCO particles induce oxidative stress in mouse lungs due to their Co content, and have a strong inflammatory potential. In this study, we assessed the mutagenic potential of LCO particles in lung cells in comparison to another particulate material used in LIB, LTO (Li₄Ti₅O₁₂), which has a low inflammatory potential compared to LCO particles.

RESULTS

We assessed the mutagenic potential of LCO and LTO particles in vitro by performing a cytokinesis-block micronucleus (MN) assay with rat lung epithelial cells (RLE), as well as in vivo in alveolar type II epithelial (AT-II) cells. LCO particles induced MN in vitro at non-cytotoxic concentrations and in vivo at non-inflammatory doses, indicating a primary genotoxic mechanism. LTO particles did not induce MN. Electron paramagnetic resonance and terephthalate assays showed that LCO particles produce hydroxyl radicals (•OH). Catalase inhibits this •OH production. In an alkaline comet assay with the oxidative DNA damage repair enzyme human 8-oxoguanine DNA glycosylase 1, LCO particles induced DNA strand breaks and oxidative lesions. The addition of catalase reduced the frequency of MN induced by LCO particles in vitro.

CONCLUSIONS

We report the mutagenic activity of LCO particles used in LIB in vitro and in vivo. Our data support the role of Co(II) ions released from these particles in their primary genotoxic activity which includes the formation of •OH by a Fenton-like reaction, oxidative DNA lesions and strand breaks, thus leading to chromosomal breaks and the formation of MN. Documenting the genotoxic potential of the other LIB particles, especially those containing Co and/or Ni, is therefore needed to guarantee a safe and sustainable development of LIB.

HIF-1α is a key mediator of the lung inflammatory potential of lithium-ion battery particles

Background

Li-ion batteries (LIB) are increasingly used worldwide. They are made of low solubility micrometric particles, implying a potential for inhalation toxicity in occupational settings and possibly for consumers. LiCoO₂ (LCO), one of the most used cathode material, induces inflammatory and fibrotic lung responses in mice. LCO also stabilizes hypoxia-inducible factor (HIF) -1α, a factor implicated in inflammation, fibrosis and carcinogenicity. Here, we investigated the role of cobalt, nickel and HIF-1α as determinants of toxicity, and evaluated their predictive value for the lung toxicity of LIB particles in in vitro assays.

Results

By testing a set of 5 selected LIB particles (LCO, LiNiMnCoO₂, LiNiCoAlO₂) with different cobalt and nickel contents, we found a positive correlation between their in vivo lung inflammatory activity, and (i) Co and Ni particle content and their bioaccessibility and (ii) the stabilization of HIF-1α in the lung. Inhibition of HIF-1α with chetomin or PX-478 blunted the lung inflammatory response to LCO in mice. In IL-1β deficient mice, HIF-1α was the upstream signal of the inflammatory lung response to LCO. In vitro, the level of HIF-1α stabilization induced by LIB particles in BEAS-2B cells correlated with the intensity of lung inflammation induced by the same particles in vivo.

Conclusions

We conclude that HIF-1α, stabilized in lung cells by released Co and Ni ions, is a mechanism-based biomarker of lung inflammatory responses induced by LIB particles containing Co/Ni. Documenting the Co/Ni content of LIB particles, their bioaccessibility and their capacity to stabilize HIF-1α in vitro can be used to predict the lung inflammatory potential of LIB particles.

Electronic supplementary material

The online version of this article (10.1186/s12989-019-0319-z) contains supplementary material, which is available to authorized users.

Facile Development Strategy of a Single Carbon-Fiber-Based All-Solid-State Flexible Lithium-Ion Battery for Wearable Electronics

Microsized and shape-versatile flexible and wearable lithium-ion batteries (LIBs) are promising and smart energy storage devices for next-generation electronics. In the present work, we design and fabricate the first prototype of microsized fibrous LIBs (thickness ≈ 22 μm) based on multilayered coaxial structure of solid-state battery components over flexible and electrically conductive carbon fibers (CFs). The micro coaxial batteries over the CF surface were fabricated via electrophoretic deposition and dip-coating methods. The microfiber battery showed a stable potential window of 2.5 V with an areal discharge capacity of ∼4.2 μA h cm^-2 at 13 μA cm^-2 of the current density. The as-assembled battery fiber delivered a comparable energy density (∼0.006 W h cm^-3) with solid-state lithium thin-film batteries at higher power densities (∼0.0312 W cm^-3). The fibrous batteries were also connected in parallel and in series to deliver large current and high voltage, respectively. The fibrous battery also retains up to 85% discharge capacity even after 100 charge-discharge cycles. Furthermore, these battery fibers performed well under both static and bending conditions, which shows the robustness of the battery fiber. Therefore, this type of fibrous microbattery can be used in advanced flexible and wearable microelectronics, bioelectronics, robotics, and textile applications.

A carbon foam-supported high sulfur loading composite as a self-supported cathode for flexible lithium-sulfur batteries

A binder-free, self-supported, flexible cathode is explored for application in flexible lithium-sulfur (Li-S) batteries. The cathode is constructed using nitrogen (N)-doped carbon foam/carbon nanotubes (CNTs) as the scaffold and filled with poly(3,4-ethylenedioxythiophene) (PEDOT)-encapsulated sulfur nanoparticles as the active material. The dense CNTs coated on the skeleton of the 3D N-doped foam enhance flexibility, and the highly conductive CNTs are crossed and twined together to create an interconnected skeleton for rapid electron transport. The conductive PEDOT shell of sulfur nanoparticles and the N-doping of the carbon foams restrain the dissolution of polysulfides through the enhanced chemisorption of lithium polysulfides. The best cathode with a sulfur loading of 2.6 mg cm-2 has an eminent capacity of 1395 mA h g-1 during the initial cycle at 0.1 C. Furthermore, freestanding cathodes are assembled into flexible Li-S batteries, which demonstrate significant achievement at various bending angles. The capacity fading rate is 0.16% per cycle at 30° after 120 cycles. Its high sulfur loading, high capacitance, and good flexibility make this cathode material a promising candidate for potential application in flexible electronics.

Issues and Challenges Facing Flexible Lithium-Ion Batteries for Practical Application

With the advent of flexible electronics, lithium-ion batteries have become a key component of high performance energy storage systems. Thus, considerable effort is made to keep up with the development of flexible lithium-ion batteries. To date, many researchers have studied newly designed batteries with flexibility, however, there are several significant challenges that need to be overcome, such as degradation of electrodes under external load, poor battery performance, and complicated cell preparation procedures. In addition, an in-depth understanding of the current challenges for flexible batteries is rarely addressed in a systematical and practical way. Herein, recent progress and current issues of flexible lithium-ion batteries in terms of battery materials and cell designs are reviewed. A critical overview of important issues and challenges for the practical application of flexible lithium-ion batteries is also provided. Finally, the strategies are discussed to overcome current limitations of the practical use of flexible lithium-based batteries, providing a direction for future research.

Robust Succinonitrile-Based Gel Polymer Electrolyte for Lithium-Ion Batteries Withstanding Mechanical Folding and High Temperature

Fabrication of a gel polymer electrolyte containing succinonitrile (GPE-SN) with high mechanical strength is quite challenging because the SN electrolyte always suppresses the formation of polymer networks during in situ polymerization. In this work, a mechanically robust GPE-SN was successfully prepared by using a solution immersion method. During fabrication, the paste-like SN electrolyte was transformed into a liquid SN electrolyte with low viscosity by heating at 50 °C and then infiltrated into the UV-cured highly cross-linked polyurethane acrylate (PUA) skeleton. The resulted GPE-SN film exhibits superior tensile strength (6.5 MPa) compared to the one (0.5 MPa) prepared by in situ polymerization (GPE-SN-IN). The high mechanical strength of the GPE-SN-IM film enables the LiCoO₂/Li₄Ti₅O₁₂ film battery to withstand 100-cycle folding without electrolyte damage and capacity loss. Besides, the GPE-SN presents a high ionic conductivity (1.63 × 10^-3 S·cm^-1 at 25 °C), which is comparable to GPE with a commercial liquid electrolyte (GPE-LE). Because of good thermal stability of the GPE-SN, the LiCoO₂/Li cell with this electrolyte shows better charge-discharge cycling stability than that with GPE-LE at high temperature (55 °C). Thus, the GPE-SN prepared by our method could be a promising polymer electrolyte offering better safety and reliability for lithium-ion batteries.

Respiratory hazard of Li-ion battery components: elective toxicity of lithium cobalt oxide (LiCoO2) particles in a mouse bioassay

Rechargeable Li-ion batteries (LIB) are increasingly produced and used worldwide. LIB electrodes are made of micrometric and low solubility particles, consisting of toxicologically relevant elements. The health hazard of these materials is not known. Here, we investigated the respiratory hazard of three leading LIB components (LiFePO₄ or LFP, Li₄Ti₅O₁₂ or LTO, and LiCoO₂ or LCO) and their mechanisms of action. Particles were characterized physico-chemically and elemental bioaccessibility was documented. Lung inflammation and fibrotic responses, as well as particle persistence and ion bioavailability, were assessed in mice after aspiration of LIB particles (0.5 or 2 mg); crystalline silica (2 mg) was used as reference. Acute inflammatory lung responses were recorded with the 3 LIB particles and silica, LCO being the most potent. Inflammation persisted 2 m after LFP, LCO and silica, in association with fibrosis in LCO and silica lungs. LIB particles persisted in the lungs after 2 m. Endogenous iron co-localized with cobalt in LCO lungs, indicating the formation of ferruginous bodies. Fe and Co ions were detected in the broncho-alveolar lavage fluids of LFP and LCO lungs, respectively. Hypoxia-inducible factor (HIF) -1α, a marker of fibrosis and of the biological activity of Co ions, was upregulated in LCO and silica lungs. This study identified, for the first time, the respiratory hazard of LIB particles. LCO was at least as potent as crystalline silica to induce lung inflammation and fibrosis. Iron and cobalt, but not lithium, ions appear to contribute to LFP and LCO toxicity, respectively.

Preparation and performance study of a PVDF–LATP ceramic composite polymer electrolyte membrane for solid-state batteries

Recently, safety issues in conventional organic liquid electrolytes and the interface resistance between the electrode and electrolyte have been the most challenging barriers for the expansion of lithium batteries to a wide range of applications. Here, an ion-conductive PVDF-based composite polymer electrolyte (CPE) consisting of lithium aluminum germanium phosphate (Li_1.3Al_0.3Ti_1.7(PO₄)₃) and polyvinylidene fluoride (PVDF) is prepared on a Li metal anode via a facile casting method. The ionic conductivity and electrochemical stability were enhanced by incorporating an appropriate amount of LATP into the PVDF-based composite polymer electrolyte, and the optimum content of LATP in the hybrid solid electrolyte was approximately 90 wt%. The corresponding solid-state battery based on an SEI-protected Li anode, the PVDF–LATP electrolyte, and a LiMn₂O₄ (LMO) cathode exhibited excellent rate capability and long-term cycling performance, with an initial discharge capacity of 107.4 mA h g⁻¹ and a retention of 91.4% after 200 cycles.

Recently, safety issues in conventional organic liquid electrolytes and the interface resistance between the electrode and electrolyte have been the most challenging barriers for the expansion of lithium batteries to a wide range of applications.