浙江大学范修林团队报道了配体通道实现的超快锂离子传导。相关研究成果于2024年2月28日发表于国际顶尖学术期刊《自然》。

用于电动汽车和航空的锂离子电池（LIBs）需要高能量密度、快速充电和宽的工作温度范围，这几乎是不可能的，因为它们需要电解质同时具有高离子电导率、低溶剂化能和低熔点，并形成阴离子衍生的无机界面。

该文中，研究人员报道了通过使用低溶剂化能的小尺寸溶剂来设计这种电解质的指南。二次溶剂化鞘中的微小溶剂拉出一次溶剂化环中的Li⁺，形成快速离子传导配体通道，以增强Li⁺的传输，而具有低溶剂化能的小尺寸溶剂也使阴离子进入一次Li⁺溶剂化壳层以形成富含无机物的界面。使用氟乙腈（FAN）溶剂来证明了电解质的设计概念。

FAN中1.3M双（氟磺酰基）酰亚胺锂（LiFSI）的电解质在25°C时表现出40.3mScm^-1的超高离子电导率，即使在70°C时也表现出11.9mScm^-1的超高电导率，从而使4.5-V石墨|| LiNi_0.8Mn_0.1Co_0.1O₂袋状电池（1.2Ah，2.85mAhcm^-2）在65°C下充放电时也能实现高可逆性（0.62Ah）。具有小尺寸溶剂的电解质使LIBs能够同时实现高能量密度、快速充电和宽的工作温度范围，这对于当前的电解质设计来说是无法实现的，但对于极端的LIBs来说是非常需要的。这种机理是可推广到其他金属离子电池电解质中。

附：英文原文

Title: Ligand-channel-enabled ultrafast Li-ion conduction

Author: 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

Issue&Volume: 2024-02-28

Abstract: 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 interphase1,2,3,4,5. 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 1.3M lithium bis(fluorosulfonyl)imide (LiFSI) in FAN exhibits ultrahigh ionic conductivity of 40.3mScm1 at 25°C and 11.9mScm1 even at 70°C, thus enabling 4.5-V graphite||LiNi0.8Mn0.1Co0.1O2 pouch cells (1.2Ah, 2.85mAhcm2) to achieve high reversibility (0.62Ah) when the cells are charged and discharged even at 65°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.

DOI: 10.1038/s41586-024-07045-4

Source: https://www.nature.com/articles/s41586-024-07045-4