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Zr-doping in Li₃InCl₆enhances ionic conductivity by 2.4%viathe creation of lithium vacancies. Zr-F co-doped Li₃InCl₆electrolyte improves electrochemical stability through the formation of a LiF protective layer. 

Environmentally friendly processes to recapture critical metals and supplement markets are vital to overall sustainability in the energy sector. This work outlines a precise methodology for the electrochemical study of extraction performance in hydrometallurgical recycling. To demonstrate this method, the battery cathode material NMC532 is exposed to hydrochloric acid solutions at varying concentrations, rotation rates, current densities, and hydrogen peroxide contents. A dispersion of NMC532 and Nafion™ in water is deposited onto a rotating disc electrode surface to form a thin-film composite. The solution is sampled over time and relevant component concentrations are measured using inductively coupled plasma mass spectrometry (ICP-MS). The solution volume is maintained by replacing the sampled volume with the initial solution and a correction equation is used to account for dilution. After electrochemical extraction, the NMC532 residue is collected for further analysis using scanning electron microscopy (SEM). This methodology requires minimal recyclable material to assess extraction conditions and provide high-precision results. It can also facilitate the development of advanced electrochemical systems and provide valuable insight into key mechanisms for various hydrometallurgical and electrochemical processes. 

Over the past years, lithium-ion solid-state batteries have demonstrated significant advancements regarding such properties as safety, long-term endurance, and energy density. Solid-state electrolytes based on lithium halides offer new opportunities due to their unique features such as a broad electrochemical stability window, high lithium-ion conductivity, and elasticity at close to melting point temperatures that could enhance lithium-ion transport at interfaces. A comparative study of lithium indium halide (Li3InCl6) electrolytes synthesized through a mechano-thermal method with varying optimization parameters revealed a significant effect of temperature and pressure on lithium-ion transport. An analysis of Electrochemical Impedance Spectroscopy (EIS) data within the temperature range of 25–100 °C revealed that the optimized Li3InCl6 electrolyte reveals high ionic conductivity, reaching 1.0 mS cm−1 at room temperature. Herein, we present the utilization of in situ/operando X-ray Photoelectron Spectroscopy (XPS) and in situ X-ray powder diffraction (XRD) to investigate the temperature-dependent behavior of the Li3InCl6 electrolyte. Confirmed by these methods, significant changes in the Li3InCl6 ionic conductivity at 70 °C were observed due to phase transformation. The observed behavior provides critical information for practical applications of the Li3InCl6 solid-state electrolyte in a broad temperature range, contributing to the enhancement of lithium-ion solid-state batteries through their improved morphology, chemical interactions, and structural integrity. 

Ionic diffusivity plays a central role in battery performance. A cathode material for lithium-ion (Li-ion) batteries, LiFePO4 (LFP), performs poorly at high current rates due to low Li-ion diffusivity. An increase in ionic diffusivity is essential to enhance battery performance for high-power-density applications such as hybrid and electric vehicles. Here, we use molecular dynamics simulations with machine learning force field and climbing-image nudged elastic band calculations to show that Li-ion diffusivity in LFP increases when doped with the transition-metal dopant ruthenium. This increase is associated with a reduction in Li diffusion energy barrier, diffusion length, and Li-vacancy formation energy, and it is accompanied by changes in the electronic band structure, specifically the appearance of electronic states in the middle of the band gap and the vicinity of the conduction band.