Highly Efficient Interface Modification between Poly(Propylene Carbonate)-Based Solid Electrolytes and a Lithium Anode by Facile Graphite Coating
Luke Zhang, Mao‐xiang Jing, Hua Yang, Quan-yao Liu, Fei Chen, Weiyong Yuan, Ming-quan Liu, Yongsheng Ji, Xiangqian Shen
Abstract
Solid-state lithium metal batteries attract much attention for their high theoretical specific capacity and safety. However, the poor interfacial combination between the solid electrolyte (SE) and Li anode usually results in unavoidable growth of Li dendrites and interfacial side reactions. In this work, we propose a simple and effective strategy to modify the interface of the electrolyte/Li anode by scraping a graphite layer on the electrolyte surface facing the anode. The graphite-modified solid electrolyte (G-SE) has a high electrochemical potential window exceeding 4.6 V and high ion conductivity of 3.08 × 10–4 S·cm–2 at ambient temperature. This G-SE membrane is suitable for high-voltage solid-state lithium metal batteries, the assembled NCM622/G-SE/Li cell shows an initial capacity of 160 mAh/g at 0.5 C and a retention capacity of 100 mAh/g after 200 cycles. The good electrochemical performance is attributed to the graphite interfacial modification; the graphite coating and Li can spontaneously react to form a LiC6 layer, which improves the SE/Li interfacial combination and suppresses the growth of lithium dendrites and interfacial side reactions.