Lithium Fluoride Embedded Prelithiated Graphite Interface Layer Enables Stable All‐solid‐state Lithium Ion Batteries

Abstract All‐solid‐state rechargeable batteries are regarded as one of the most promising next‐generation energy storage devices, while their cycling stability is still a great challenge due to the nonuniform lithium ion transportation and the loss of active lithium during cycling. Herein, a LiF embedded prelithiated graphite interface layer is designed and inserted between Li₆PS₅Cl solid electrolyte layer and graphite anode layer. The presence of LiF, C−F bonds and prelithiated graphite in this unique interface layer can facilitate uniform lithium ion migration and compensate the loss of active lithium, thus significantly improving the cyclic performances of both monopolar and bipolar all‐solid‐state lithium ion batteries. After 100 cycles at 0.1 C, the capacity retention increases from 58 % to 78.5 % for the monopolar LiNi_0.5Co_0.2Mn_0.3O₂|Li₆PS₅Cl|LiF@2.5 %Li@G|graphite all‐solid‐state lithium ion battery. Besides, the bipolar all‐solid‐state lithium ion batteries show a high discharge plateau of ~7.6 V with a capacity retention of 60.2 % after 190 cycles at 0.1 C. This work demonstrates the effectiveness of LiF embedded prelithiated graphite interface layer for improving the electrochemical performances of all‐solid‐state lithium ion batteries.