Interphase Optimum via Synergistic Effect of Poly(1,3‐dioxolane) Electrolytes and Lithium Difluorophosphate for Stable Lithium Metal Batteries

作者：Anyi Hu, Zhu Liao, Qirui Yang, Jun Huang, Zhuangzhuang Wei, Yukun Sun, Enyou Zhao, Zhengxi Zhang, Li Yang, Nagahiro Saito, Akihiro Orita · 发表于：Advanced Functional Materials · 年份：2024 · DOI：10.1002/adfm.202410282 · 被引用次数：24 · 研究领域：Advancements in Battery Materials、Advanced Battery Materials and Technologies、Advanced Battery Technologies Research

Abstract Solid polymer electrolytes (SPEs) hold great promise for future applications of high‐energy lithium metal batteries (LMBs). Unfortunately, inadequate room‐temperature ionic conductivity, sluggish interfacial charge transport, and uncontrolled electrode/electrolyte interface reactions severely limit their widespread applications. Herein, poly(1,3‐dioxolane) electrolytes (PDEs) are prepared in situ by introducing lithium difluorophosphate (LiDFP, LiPO 2 F 2 ) as a multifunctional additive, which not only achieves excellent ionic conductivity but facilitates interfacial charge transport. Meanwhile, a high‐mechanical‐stability organic–inorganic hybrid solid electrolyte interphase (SEI) is formed by the synergistic effect of PDEs and LiDFP. The enrichment of LiF and Li x PO y F z species in SEI formed by the preferential reduction of LiDFP ensures outstanding mechanical stability, and the ring‐opening polymerization of 1,3‐dioxolane provides the SEI excellent adaptability to the repetitive volume changes of lithium metal anode, which mitigates crack and regeneration of SEI and reduces side reactions between active Li and electrolytes. Therefore, based on PDEs, the symmetric Li cell enables steady cycling for 2000 h. The Li‐LiFePO 4 cell achieves superior long‐term cycling stability (over 1200 cycles) and wide operating temperature (−20 ∼ 60 °C). Also, the Li‐LiNi 0.6 Mn 0.2 Co 0.2 O 2 exhibits favorable cycling stability. This study provides solutions to ongoing pain poin...