Realizing Persistent Lithium Protection and Revival with Dissolution‐Equilibrium‐Driven Sustainable Additives Reservoir
Xiaoxi Luo, Shuang‐Jie Tan, Juan Zhang, Junchen Guo, Chaohui Zhang, Yuhao Wang, Wanli Wang, Jiansong Wu, Xing‐Long Wu, Yu‐Guo Guo
Abstract
Abstract Additive chemistry plays a pivotal role in enhancing the cycling stability of lithium metal batteries. Conventional additives with high solubility facilitate the formation of a stable interface in the early stages of cycling, yet typically act as “sacrificial agents”, failing to maintain a durable interface over long time. Herein, we demonstrate a sustainable lithium protection and retrieval strategy based on additive reservoirs driven by chemical dissolution equilibrium. A sparingly soluble AgI coating on the separator provides a continuous supply of constant concentration of Ag + and I − , where Ag + contributes to the formation of a Li–Ag alloy interphase, promoting uniform Li deposition, while I − assisting in the recovery of inactive Li. With this strategy, symmetric Li||Li batteries deliver an extended cycle life over of 1000 h at 5 mA cm −2 with a capacity of 5 mAh cm −2 . Additionally, practical pouch cells demonstrate a prolonged cycle life of over 200 cycles with 82% capacity retention. This work offers new insights into additive chemistry and paves the way for the development of durable lithium metal batteries.