Solvate ionic liquid boosting favorable interfaces kinetics to achieve the excellent performance of Li4Ti5O12 anodes in Li10GeP2S12 based solid-state batteries

Solid-state lithium batteries (SSLBs) exhibit numerous advantages including high safety, high energy density and power density, etc., and therefore become the most promising candidate for next-generation batteries. However, constructing an intimate contact within the composite electrode and the electrode/electrolyte interface via simple mixing and cold-pressing processes is still challenging. Herein, a novel fabrication process for homogeneous composite electrodes used in SSLBs is successfully demonstrated. An in-situ liquid-phase approach employing the [Li(triglyme)] + [TFSI] - (LiG3) solvent-salt complex with excellent stability to modify the sulfide-based solid-state electrolyte interfaces, is introduced into the SSLBs system, which enables SSLBs to work efficiently at lower external pressures. The quasi-solid-state prototype cells with Li 4 Ti 5 O 12 (LTO) active material deliver excellent room-temperature performance, generating a super high capacity of 160 mA h g −1 and high capacity retention of 91.4% for 1500 cycles under 0.25 C. This work gives new insight into the interface engineering, processing and more positive impact on the industrial production of SSLBs.