Influence of the Li–Ge–P–S based solid electrolytes on NCA electrochemical performances in all-solid-state lithium batteries

• The synthesized Li10GeP2S12 shows higher ionic conductivity than Li3.25Ge0.25P0.75S4.
• All-solid-state lithium batteries containing NCA cathode and LGPS were demonstrated.
• NCA/Li10GeP2S12/Li-In battery shows superior electrochemical performances.
• Li10GeP2S12 exhibits low interfacial resistance with NCA cathode materials.

The effect of solid electrolytes, i.e. Li10GeP2S12 and Li3.25Ge0.25P0.75S4, on the rate and low temperature performances of LiNi0.8Co0.15Al0.05O2 (NCA) cathode in all solid state lithium batteries is investigated. The ionic conductivities for the synthesized Li10GeP2S12 and Li3.25Ge0.25P0.75S4 at room temperature (RT) are 8.27 × 10− 3 and 2.03 × 10− 3 S cm− 1, respectively. These solid electrolytes are demonstrated as electrolytes for all solid state lithium batteries containing NCA cathode for the first time. The results show that Li10GeP2S12 based battery exhibits superior rate performance (72.3 mAh g− 1 at 1 C, RT), cycling stability (capacity retention of 87.1% after 30 cycles at 0.1 C, RT) and low temperature performance (79.2 mAh g− 1 at 0.1 C and − 10 °C), which can be ascribed to its higher ionic conductivity and lower interfacial resistance between Li10GeP2S12 and NCA cathode. It is indicated that all solid state lithium batteries with NCA cathode and Li10GeP2S12 solid electrolyte can realize its potential application in high power and low temperature conditions.