Stabilizing the oxide cathode/sulfide solid electrolyte interface via a novel polyaniline coating prepared by ball milling

The thermodynamic instability of oxide cathode/sulfide solid electrolyte (SSE) interfaces leads to the large resistances of all-solid-state lithium-ion batteries (ASSLIBs). This work proposes a flexible polyaniline (PANI) coating instead of rigid lithium-containing oxides to stabilize the lithium cobalt oxide (LCO)/SSE interface. The PANI coating is prepared by a facile ball milling followed by annealing. Electrochemical tests demonstrated that the elastic PANI layer lowers and maintains the LCO/SSE interface resistance during cycling. Thus, the high capacity retention of 85.5% after 200 cycles was achieved for ASSLIBs with Li5.5PS4.5Cl1.5 electrolytes.