Intercalated montmorillonite fabricating highly-conductive and overall-stable solid composite electrolyte for advanced lithium metal battery

Abstract

Solid-state lithium metal batteries are promising volunteers for next-generation energy storage. However, their widespread applications are greatly hindered by low ionic conductivity of solid electrolyte and unstable interface towards Li metal. Herein, a novel organic molecule’s pre-intercalation strategy is proposed for modifying layered-structure montmorillonite (MMT) as a functional filler of solid composite electrolyte (SCE). Research results reveal that polar dimethyl sulfoxide (DMSO) successfully inserts into MMT interlayers by hydrogen bonding interaction, which effectively expands the interlayer spacing without disrupting inherent structure of the MMT. The modified filler not only creates continuous and ordered channels to conduct Li+ rapidly, but also minimizes the detrimental effects of residual solvent by strong adsorption effect, thereby achieving overall enhancements of the SCE in ionic transport properties and electrochemical/thermal/mechanical stability. Consequently, excellent cycling capabilities with lessened polarization are illustrated in both Li|Li symmetrical cell and LiFePO4|Li full cell.