Tailoring electrolyte distributions to enable high-performance Li3PS4-based all-solid-state batteries under different operating temperatures.

Abstract

Li3PS4 shows great potential as solid electrolyte for all-solid-state lithium batteries (ASSLBs) due to its high conductivity and excellent mechanical properties. However, its poor interfacial stability with bare high-nickel materials in the cathode mixture inhibits the energy density and electrochemical performances of the correspondingLiNi0.6Mn0.2Co0.2O2/Li3PS4/Li-In battery. The Li3InCl6 electrolyte with good electrochemical/chemical stability with bare NCM622, which acts both as a Li-ion additive in the cathode and as an isolation layer to isolate the direct contact between the sulfide electrolytes and active materials, providing superior solid/solid interface stabilities in the assembled battery. XPS and TEM results confirm that this strategy can mitigate the side reactions.This grading utilization of different solid electrolytes can greatly alleviate the poor electrochemical stability, yielding smaller interfacial resistances. The corresponding battery delivers high discharge capacities at various C-rates under different operating temperatures. It delivers a much higher initial discharge capacity of 187.7 mAh g-1at 0.1C with a coulombic efficiency of 87.6% at RT. Moreover, it can show highly reversible capacity with excellent cyclability when operated at 0 and -20 oC. This work provides a hierarchical utilization strategy to fabricate sulfide electrolytes-based ASSLBs with high energy density and superior cycling performance combined with highly-oxidation cathode materials.