Curtailing the thermal runaway and ameliorating interfacial charge kinetics using electrolyte-cum-separator in Li-battery

Abstract

Recently, absolute requirements for high-performing energy storage devices with high thermal stability and superior safety features keep motivating to replace conventional liquid electrolyte systems with lithium-based secondary batteries. Instead, incorporating the solid-state electrolytes can be an elegant strategy; however, the solid electrolyte's poor interfacial kinetics and brutal ceramic nature are the significant hitches for commercial battery manufacturing. Considering these critical issues, an electrolyte cum separator (ECSP) membrane composed of robust polymer and high ion-conducting ceramic has been rationally designed to improve interfacial ion kinetics during electrochemical cycling. The electrolyte-cum-separator (ECSP) attains high thermal endurance (150 °C), superior mechanical strength, and excellent wettability to commercially available systems. Further, the ECSP ensures low interfacial resistance against the Li metal even at a high current density, that let to prevent the dendritic growth and short-circuiting of the battery. The ECSP membrane-enabled batteries demonstrate excellent discharge capacity with high potential cathode and metal anodes that outperform those batteries assembled from commercial electrolyte and separator systems. Moreover, the thermal stability of the ECSP membrane using the accelerating rate calorimeter (ARC) has also been investigated. The excess flammable solvent and lower thermal endurance of the commercial electrolyte separator system are responsible for the batteries' thermal runaway. Additionally, the full-cell performance composed of a commercial cathode (Li(NixCoxMnx)O2, x =1/3), anode (MCMB), and the ECSP membrane manifests good cycle life and stable capacity retention. Therefore, the fabrication of electrolyte-cum-separator is a prominent strategy to achieve flexible, dendrite-free, and high-performing solid-state Li metal as well as Li-ion battery technologies for high-end applications.