Ligand-channel-enabled ultrafast Li-ion conduction

• 成果类型: Article
• 署名作者: Lu, Di; Li, Ruhong; Rahman, Muhammad Mominur; Yu, Pengyun; Lv, Ling; Yang, Sheng; Huang, Yiqiang; Sun, Chuangchao; Zhang, Shuoqing; Zhang, Haikuo; Zhang, Junbo; Xiao, Xuezhang; Deng, Tao; Fan, Liwu; Chen, Lixin; Wang, Jianping; Hu, Enyuan; Wang, Chunsheng; Fan, Xiulin
• 署名单位: Zhejiang University; United States Department of Energy (DOE); Brookhaven National Laboratory; Chinese Academy of Sciences; Institute of Chemistry, CAS; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS; Zhejiang University; University System of Maryland; University of Maryland College Park
• 刊物名称: Nature
• ISSN/ISSBN: 0028-6754
• DOI: 10.1038/s41586-024-07045-4
• 发表日期: 2024-03-07
• 关键词: electrolytes; transport; association; CHALLENGES; diffusion; mechanism; battery

摘要

Li-ion batteries (LIBs) for electric vehicles and aviation demand high energy density, fast charging and a wide operating temperature range, which are virtually impossible because they require electrolytes to simultaneously have high ionic conductivity, low solvation energy and low melting point and form an anion-derived inorganic interphase1-5. Here we report guidelines for designing such electrolytes by using small-sized solvents with low solvation energy. The tiny solvent in the secondary solvation sheath pulls out the Li+ in the primary solvation sheath to form a fast ion-conduction ligand channel to enhance Li+ transport, while the small-sized solvent with low solvation energy also allows the anion to enter the first Li+ solvation shell to form an inorganic-rich interphase. The electrolyte-design concept is demonstrated by using fluoroacetonitrile (FAN) solvent. The electrolyte of 1.3 M lithium bis(fluorosulfonyl)imide (LiFSI) in FAN exhibits ultrahigh ionic conductivity of 40.3 mS cm-1 at 25 degrees C and 11.9 mS cm-1 even at -70 degrees C, thus enabling 4.5-V graphite||LiNi0.8Mn0.1Co0.1O2 pouch cells (1.2 Ah, 2.85 mAh cm-2) to achieve high reversibility (0.62 Ah) when the cells are charged and discharged even at -65 degrees C. The electrolyte with small-sized solvents enables LIBs to simultaneously achieve high energy density, fast charging and a wide operating temperature range, which is unattainable for the current electrolyte design but is highly desired for extreme LIBs. This mechanism is generalizable and can be expanded to other metal-ion battery electrolytes. An electrolyte design using small-sized fluoroacetonitrile solvents to form a ligand channel produces lithium-ion batteries simultaneously achieving high energy density, fast charging and wide operating temperature range, desirable features for batteries working in extreme conditions.