Single crystal cathodes enabling high-performance all-solid-state lithium-ion batteries

All-solid-state lithium-ion batteries (ASSLIBs) are receiving significant attention owing to their improved safety and energy density over liquid counterparts. However, single-crystal cathodes have never been investigated in ASSLIBs. In this work, single-crystal Li(Ni0.5Mn0.3Co0.2)O-2 (SC-NMC532) is used as the cathode material for ASSLIBs, which exhibits 6-14 times higher Li+ diffusion coefficient than polycrystalline Li(Ni0.5Mn0.3Co0.2)O-2 (PC-NMC532). As a result, SC-NMC532 exhibits an initial specific capacity of 156.4 mAh.g(-1) while PC-NMC532 shows an initial capacity of only 127.5 mAh.g(-1). After 150 cycles, SC-NMC532 retains the capacity of 94.5 mAh.g(-1). More impressively, under a high current density of 1.3 mA cm(-2), SC-NMC532 exhibits a capacity of 82 mAh.g(-1), much higher than that of PC-NMC532 (2.1 mAh.g(-1)). This work demonstrates that single-crystal NMC cathodes could enable both high power density and high energy density of ASSLIBs.