Batteries

The development of stable and efficient solid electrolytes is essential for advancing solid-state battery technologies. In this study, we present a comparative study of three sulfide-based electrolytes, Li₆PS₅Cl (LPSCl), Li₆PS₅Br (LPSBr), and Li₁₀GeP₂S₁₂ (LGPS), combining Density Functional Theory (DFT) and hybrid (HSE06) simulations for electrochemical, charge carrier transport, and structural characterization. DFT and HSE06 simulations revealed semiconductor-like direct band gaps for LPSCl, with a 2.45 eV (DFT) −3.30 eV (HSE06) and 2.32 eV (DFT) −3.34 eV (HSE06) for LPSBr, and indirect band gap with 2.13 eV (DFT) −3.22 eV (HSE06) for LGPS, along with work functions of 3.40 eV for the argyrodites and 3.67 eV for LGPS. Scanning Kelvin Probe (SKP) analyses, performed at both micrometric and nanometric resolution, showed consistently negative surface potentials and interfacial polarons associated with electron tunneling through the surface of the electrolyte. Potentiostatic electrochemical impedance spectroscopy (PEIS) and cyclic voltammetry (CV) confirmed enhanced ionic conductivity with increasing temperature. While LPSCl and LGPS exhibited stable behavior at almost all temperatures, from −20 to 60 °C, LPSBr displayed noise-like activity at 0 °C with Au symmetric electrodes. This integrated experimental/theoretical approach highlights differences in electronic structure, interfacial charge distribution, and electrochemical stability, all showing affinity to react with lithium, providing key insights for the design and optimization of solid electrolytes for next-generation batteries.

An innovative ionic liquid–organic hybrid electrolyte technology was developed to obtain safer and more reliable sodium-ion battery (SIB) systems. The formulation is based on the 1-ethyl-3-methyl-imidazolium bis(flurosulfonyl)imide (EMIFSI) ionic liquid combined with the Diglyme cosolvent, which showed good performance in SIBs. The hybrid electrolyte formulation was qualified in terms of thermal and ion transport properties and electrochemical stability. The results, reported and discussed in the present manuscript, showed how it is feasible to improve conductivity without decreasing the safety and electrochemical stability of ionic liquid-based electrolytes.

Lithium-ion batteries are widely used in electrochemical energy storage due to their advantages such as fast response and good scalability, but they are prone to thermal runaway (TR) under abusive conditions. Liquid nitrogen has been proven effective in suppressing lithium-ion cell TR in previous studies owing to its excellent cooling capacity. To further enhance the suppression capability of liquid nitrogen on lithium-ion cell TR, a method combining liquid nitrogen with fire-resistant materials was proposed. All experiments were conducted under strictly controlled conditions to ensure result comparability. Experiments on the synergistic suppression of lithium-ion cell TR propagation were conducted with the type and thickness of the fire-resistant materials as variables. The results demonstrated that installing porous fire-resistant materials inside the lithium-ion battery module significantly enhanced the efficacy of liquid nitrogen in suppressing TR propagation. The maximum rebound temperature of the cell after nitrogen injection cessation was reduced by up to 32.7% compared to the condition without fire-resistant materials. Both material characteristics and thickness influenced the heat exchange process—ceramic fiber aerogel, with its low thermal conductivity, achieved a maximum cooling rate of 2.45 °C/s on the TR cell surface, exhibiting the optimal enhancement effect; as the material thickness increased, the synergistic fire suppression performance was further enhanced with increasing material thickness, with the 9 mm thick ceramic fiber aerogel performing better than the thinner (6 mm and 3 mm) variants. The research findings provide a valuable reference for module-level thermal runaway suppression in energy storage systems.