Wang Yanru, Fang Timing, Wang Chao, Wang Siyu, Yang Ke, Biao Jie, Li Daohao, Yang Dongjiang, He Yan-Bing, Xia Yanzhi
State Key Laboratory of Biofibers and Eco-textiles, College of Materials Science and Engineering, Institute of Marine Bio-based Materials, Qingdao University, Qingdao, 266071, P. R. China.
Shenzhen All-Solid-State Lithium Battery Electrolyte Engineering Research Center, Institute of Materials Research (IMR), Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, P. R. China.
Adv Mater. 2025 Aug;37(32):e2505209. doi: 10.1002/adma.202505209. Epub 2025 May 22.
The low concentration and inhomogenous distribution of free lithium ion (Li) in composite polymer electrolytes (CPEs) greatly restrict the Li transport, cycle stability and rate performance of all solid-state batteries. In this work, lithium zirconate with superficial oxygen (O)-vacancies (O-LZO) is reported as a new Li conductors for polyethylene oxide (PEO)-based CPEs (PEO@O-LZO). The O-LZO demonstrates exceptional Li transport capability, and its superficial O-vacancies efficiently adsorb anions to facilitate the dissociation of lithium salts, leading a high concentration of free Li in CPEs. Furthermore, the electropositive equilibrium charge layer of O-vacancies avoids the aggregation of Li near the filler and achieves a stable interface to promote the efficient and continuous Li transport. These effects contribute to a high Li conductivity of 1.63 × 10 S cm and a Li migration number of 0.35 for PEO@O-LZO at 40 °C. The assembled battery (LiFePO/PEO@O-LZO/Li) exhibits a capacity of 120 mAh g at 3 C and stable cycling performance with an 80.5% capacity retention after 800 cycles at 1 C and 40 °C, maintaining excellent coulombic efficiency. This work provides a design principle of fillers to regulate Li concentration and distribution in CPEs for efficient solid-state lithium metal batteries.
复合聚合物电解质（CPEs）中游离锂离子（Li）的低浓度和不均匀分布极大地限制了全固态电池的Li传输、循环稳定性和倍率性能。在这项工作中，报道了一种具有表面氧（O）空位的锆酸锂（O-LZO）作为基于聚环氧乙烷（PEO）的CPEs（PEO@O-LZO）的新型Li导体。O-LZO表现出卓越的Li传输能力，其表面O空位有效地吸附阴离子以促进锂盐的解离，从而使CPEs中游离Li的浓度较高。此外，O空位的正电平衡电荷层避免了Li在填料附近的聚集，并形成稳定的界面以促进高效且连续的Li传输。这些效应使得PEO@O-LZO在40℃时具有1.63×10 S cm的高Li电导率和0.35的Li迁移数。组装的电池（LiFePO/PEO@O-LZO/Li）在3 C时表现出120 mAh g的容量，并且在1 C和40℃下循环800次后具有稳定的循环性能，容量保持率为80.5%，保持了优异的库仑效率。这项工作为调节CPEs中Li浓度和分布以实现高效固态锂金属电池提供了一种填料设计原则。
