Hao Qingfei, Yan Jiawei, Gao Ying, Chen Fei, Chen Xiangtao, Qi Yang, Li Na
Key Laboratory for Anisotropy and Texture of Materials, Ministry of Education, School of Materials Science and Engineering, Northeastern University, Shenyang 110819, China.
ACS Appl Mater Interfaces. 2024 Aug 28;16(34):44689-44696. doi: 10.1021/acsami.4c06856. Epub 2024 Aug 13.
Carbonate-based electrolytes show distinct advantages in high-voltage cathodes but generate nonuniform and mechanically fragile solid-electrolyte interphase (SEI) in lithium (Li) metal batteries. Herein, we propose a LiF-rich SEI incorporating an in situ polymerized poly(hexamethylene diisocyanate)-based gel polymer electrolyte (GPE) to improve the homogeneity and mechanical stability of SEI. Fluoroethylene carbonate (FEC) as a fluorine-based additive for building LiF-rich SEI on Li metal electrodes. With this strategy, the assembled Li symmetric batteries cycled stably for 700 h, and the formation of byproducts on the Li electrode surface was significantly inhibited. The Li/LiFePO battery delivered significant capacity retention (91% retention after 800 cycles) at 1 C. With high-voltage LiNiCoMnO (NCM811) as cathode, the Li/GPE-FEC/NCM811 cell delivered a discharge capacity of 168.9 mAh g with a capacity retention of 82% after 300 cycles at 0.5 C. From the above, the work could assist the rapid development of high-energy-density rechargeable Li metal batteries toward remarkable performance.
基于碳酸盐的电解质在高压阴极中显示出明显优势，但在锂金属电池中会产生不均匀且机械脆弱的固体电解质界面（SEI）。在此，我们提出一种富含LiF的SEI，其包含原位聚合的基于聚六亚甲基二异氰酸酯的凝胶聚合物电解质（GPE），以改善SEI的均匀性和机械稳定性。碳酸亚乙酯（FEC）作为一种氟基添加剂，用于在锂金属电极上构建富含LiF的SEI。采用这种策略，组装的锂对称电池稳定循环700小时，并且锂电极表面副产物的形成受到显著抑制。Li/LiFePO电池在1 C下具有显著的容量保持率（800次循环后保持91%）。以高压LiNiCoMnO（NCM811）作为阴极，Li/GPE-FEC/NCM811电池在0.5 C下300次循环后放电容量为168.9 mAh g，容量保持率为82%。综上所述，这项工作有助于高能量密度可充电锂金属电池快速发展并实现卓越性能。
