Argyrodite solid electrolyte-coated graphite as anode material for all-solid-state batteries

All-solid-state batteries based on sulfide solid electrolytes are potential candidates for applications such as electric vehicles. One of the challenges for the realization of the all-solid-state battery is the construction of composite electrodes with favorable lithium and electron conductive pathways. Here, we prepared an argyrodite type Li6PS5Cl-based solid electrolyte (LiPSCl)-coated graphite (Gr:LiPSCl, 64:36 weight ratio) by a dissolution-reprecipitation process and investigate its use as anode material for all-solid-state batteries. The addition of a carbon additive (acetylene black, 0.5, 1 and 2 weight ratio) to LiPSCl-coated graphite to form favorable electronic conductive pathways in the negative electrode was also investigated. The all-solid-state half-cell constructed using the argyrodite-coated graphite and carbon additive in 100:1 weight ratio exhibited a discharge capacity of 335 and 372 mAh g(-1) at a C-rate of C/8 and at 25 degrees C and 100 degrees C, respectively. The electrochemical performance of the all-solid-state cell at different C-rates was evaluated at 100 degrees C. A relatively high discharge capacity of 276 mAh g(-1) was retained at the high C-rate of 2C. Charge-discharge curves of an all-solid-state cell using the argyrodite-coated graphite, at the C-rates of C/8, C/4, C/2, C and 2C.