High Specific Power Dual-Metal-Ion Rechargeable Microbatteries Based on LiMn2O4 and Zinc for Miniaturized Applications

2D VS2 @MXene Based Zinc Ion Batteries with SPANI-Contained Electrolyte Enables Dendrite-Free Anode for Stable Cycling

Regarded as one of the popular cathode materials in aqueous zinc ion batteries (ZIBs), VS₂ has unsatisfied cycling stability and relatively low capacity owing to its poor conductivity and low mechanical properties. To this regard, compositing VS₂ with high-conductive 2D transition metal carbide (MXene) has been an effective method recently. However, the Zn dendrite on the anode electrode derived from the uncontrollable sluggish migration of solvated Zn²⁺ /H₂ O ions seriously threatens the application safety of ZIB batteries. To effectively regulate the diffusion of zinc ions, in this work a conductive polymeric electrolyte of sulfonated polyaniline (SPANI) is added in the electrolyte solution. Under the Zn²⁺ /SPANI interactions confirmed by X-ray diffraction, Raman, and zeta potential experiments, the Zn²⁺ /H₂ O combination is weakened, and the deposition rate of Zn²⁺ is increased evaluated by the galvanostatic intermittent titration technique. Theoretical simulation shows that the electrostatic shielding by SPANI combining Zn^2- at the zinc/electrolyte interface has important contribution to the significant suppression of Zn dendrite. Accordingly, the fabricated VS₂ @MXene||ZnSO₄ +SPANI||Zn battery shows high capacity (368.0 mAh g^-1 at 0.1 A g^-1 ), which remains 96% after 5000 cyclic charge-discharge operations. This work develops an available strategic idea for suppressing growth of metallic dendrites to improve the ZIB performances.

Zn Microbatteries Explore Ways for Integrations in Intelligent Systems

As intelligent microsystems develop, many revolutionary applications, such as the swallowing surgeon proposed by Richard Feynman, are about to evolve. Nonetheless, integrable energy storage satisfying the demand for autonomous operations has emerged as a major obstacle to the deployment of intelligent microsystems. A reason for the lagging development of integrable batteries is the challenge of miniaturization through microfabrication procedures. Lithium batteries, generated by the most successful battery chemistry, are not stable in the air, thus creating major manufacturing challenges. Other cations (Na⁺ , Mg²⁺ , Al³⁺ , K⁺ ) are still in the early stages of development. In contrast, the superior stability of zinc batteries in the air brings high compatibility to microfabrication protocols and has already demonstrated excellent practicability in full-sized devices. To obtain energy-dense and high-power zinc microbatteries within square-millimeter or smaller footprints, sandwich, pillar, and Swiss-roll configurations are developed. Thin interdigital and fiber microbatteries find their applications being integrated into wearable devices and electronic skin. It is foreseeable that zinc microbatteries will find their way into highly integrated microsystems unlocking their full potential for autonomous operation. This review summarizes the material development, configuration innovation, and application-oriented integration of zinc microbatteries.

Electrochemical Methods for Lithium Recovery: A Comprehensive and Critical Review

Due to the ubiquitous presence of lithium-ion batteries in portable applications, and their implementation in the transportation and large-scale energy sectors, the future cost and availability of lithium is currently under debate. Lithium demand is expected to grow in the near future, up to 900 ktons per year in 2025. Lithium utilization would depend on a strong increase in production. However, the currently most extended lithium extraction method, the lime-soda evaporation process, requires a period of time in the range of 1-2 years and depends on weather conditions. The actual global production of lithium by this technology will soon be far exceeded by market demand. Alternative production methods have recently attracted great attention. Among them, electrochemical lithium recovery, based on electrochemical ion-pumping technology, offers higher capacity production, it does not require the use of chemicals for the regeneration of the materials, reduces the consumption of water and the production of chemical wastes, and allows the production rate to be controlled, attending to the market demand. Here, this technology is analyzed with a special focus on the methodology, materials employed, and reactor designs. The state-of-the-art is reevaluated from a critical perspective and the viability of the different proposed methodologies analyzed.

Production of a NiO/Al primary battery employing powder-based electrodes

This paper describes the use of aluminum and zinc as anodic materials for a battery employing nickel (II) oxide (NiO) as cathode. Comparison of both materials resulted in the development of a compact, cost effective, and easy to use primary NiO/Al battery employing an alkaline electrolyte. The system features electrodes composed of powder forms of the active materials on modified paper substrates that are contained in a simple multilayer design utilizing thin laminated plastic materials to provide structure and flexibility to the battery as well as a paper separator. Various concentrations of potassium hydroxide (KOH) electrolyte were examined and maximum performance was observed at 6 M KOH. A maximum current density and power density of 1.94 mA/cm² and 1 mW/cm² , respectively was achieved. This user-friendly device was able to produce a maximum capacity of 2.33 mAh/g when 2 mA/g was applied. This work demonstrates the viability of a paper-based battery featuring powder electrodes as a possible power source for microelectronic devices.

Effect of Pt and Au current collector in LiMn2O4 thin film for micro-batteries

The crystal orientation and morphology of sputtered LiMn₂O₄ thin films is strongly affected by the current collector. By substituting Pt with Au, it is possible to observe in the x-ray diffraction pattern of LiMn₂O₄ a change in the preferential orientation of the grains from (111) to (400). In addition, LiMn₂O₄ thin films deposited on Au show a higher porosity than films deposited on Pt. These structural differences cause an improvement in the electrochemical performances of the thin films deposited on Au, with up to 50% more specific charge. Aqueous cells using thin film based on LiMn₂O₄ sputtered on Au or Pt as the cathode electrode present a similar retention of specific charge, delivering 85% and 100%, respectively, of the initial values after 100 cycles. The critical role of the nature of the substrate used in the morphology and electrochemical behaviour observed could permit the exploration of similar effects for other lithium intercalation electrodes.