Tailored electrolyte salt anion chemistry for enhanced high-nickel lithium-ion batteries

作者：Shitao Wang, Lixin Qiao, Jinlong Li, Shu Zhang, Shenghang Zhang, Xiangchun Zhuang, Yu Zhao, Xiaofan Du, Bin Xie, Kai Chen, Ruling Du, Qingrui Kong, Zhaolin Lv, Zili Cui, Shanmu Dong, Gaojie Xu, Michel Armand, Guanglei Cui · 发表于：Nature Communications · 年份：2025 · DOI：10.1038/s41467-025-65989-1 · 被引用次数：6 · 研究领域：Advancements in Battery Materials、Advanced Battery Materials and Technologies、Fiber-reinforced polymer composites

The instability of lithium salts within the electrolyte has consistently posed a significant challenge to next-generation lithium-ion batteries. The most commercialized lithium hexafluorophosphate (LiPF6) suffers from ligand abstraction, causing excessive formation of erosive HF at elevated temperatures. Another promising salt of lithium difluoro(oxalato)borate (LiDFOB), featuring hydrophilic/lithiophilic carbonyl groups, possesses high moisture sensitivity and insufficient dissociation in electrolytes. Herein, we propose an anion-skeleton editing strategy that increases the fluoride ion affinity of the parent Lewis acid while reducing its interaction with H+/Li+ by replacing the carbonyl groups in DFOB- anion with hydrophobic/lithiophobic -CF3 groups. The lithium salt alternative, lithium 2,2-difluoro-4,4,5,5-tetrakis(trifluoromethyl)−1,3,2-dioxaborolan-2-uide (LiDFTFB), has been successfully synthesized and serves as a well-balanced salt in terms of moisture stability, thermal stability, electrochemical stability, ionic conductivity, solubility, and aluminum foil passivation, outperforming LiPF6 and LiDFOB. Even at an elevated temperature of 50 °C, LiDFTFB endows 1 Ah graphite | |LiNi0.8Mn0.1Co0.1O2 pouch cells with enhanced cycling stability (81.7% retention after 650 cycles, 0.5 C charge and 0.5 C discharge, 1 C = 200 mA g-1). This work emphasizes the critical importance of strategically modulating anion chemistries to promote the development of the next-generation lithiu...