Reviving the rock-salt phases in Ni-rich layered cathodes by mechano-electrochemistry in all-solid-state batteries

The rock-salt phase (RSP) formed on the surface of Ni-rich layered cathodes in liquid-electrolyte lithium-ion batteries is conceived to be electrochemically "dead". Here we show massive RSP forms interior LiNixMnyCo(1?x-y)O2 (NMC) crystals sulfide based all solid state (ASSBs), but remains active even after long cycles. and structure constitute a two-phase mixture, material architecture that distinctly different from liquid electrolytes. tensioned affords an effective percolation channel into which lithium squeezed out RSPs by compressive stress, rendering active. Consequently, ASSBs with predominant NMC cathode deliver remarkable cycle life 4000 cycles at high areal capacity 4.3 mAh/cm2. Our study unveils distinct mechano-electrochemistry can harnessed enable energy density durable ASSBs.