Revealing the Electrochemistry of All-Solid-State Li-SeS2 Battery via Transmission Electron Microscopy

Li-SeS2 batteries balance the opposing and complimentary qualities of Li-S Li-Se by having a high specific capacity electrical conductivity. However, there is still lack knowledge regarding electrochemical characteristics all-solid-state (ASSB). Herein, transmission electron microscopy (TEM) used to reveal electrochemistry battery. It discovered that, without Polyethylene glycol (PEG), amorphous SeS2 in ASSB change into crystalline selenium small amount sulfur. The continuous loss sulfur from active material may be related failure cell at 15 cycles severe instability Coulombic efficiency. was found that PEG coating disulfide graphene composite (PEG@rGO-SeS2) cathode maintained 258 mAh g−1 stable efficiency about 97% after 50 cycles. TEM analysis shows charging product remains as granular with constant Se/S ratio during cycling. PEG-protected can effectively limit elemental regulate reaction mechanism batteries.