Branch-Chain-Rich Diisopropyl Ether with Steric Hindrance Facilitates Stable Cycling of Lithium Batteries at-20℃  

作　　者：Houzhen Li Yongchao Kang Wangran Wei Chuncheng Yan Xinrui Ma Hao Chen Yuanhua Sang Hong Liu Shuhua Wang 

机构地区：[1]State Key Laboratory of Crystal Materials,Shandong University,Jinan 250100,People's Republic of China

出　　处：《Nano-Micro Letters》2024年第10期121-135,共15页纳微快报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant nos.92372118,52072224);the Youth Innovation Team Project of Shandong Provincial Education Department(2021KJ093);the Natural Science Foundation of Shandong Province(ZR2020YQ35);the Qilu Young Scholar Funding of Shandong University;the Young Elite Scientists Sponsorship Program by CAST(YESS,2019QNRC001);the Natural Science Foundation of Shandong Provincial(ZR2023ZD52)。

摘　　要：Li metal batteries(LMBs)offer signifi-cant potential as high energy density alternatives;nev-ertheless,their performance is hindered by the slow desolvation process of electrolytes,particularly at low temperatures(LT),leading to low coulombic efficiency and limited cycle stability.Thus,it is essential to opti-mize the solvation structure thereby achieving a rapid desolvation process in LMBs at LT.Herein,we introduce branch chain-rich diisopropyl ether(DIPE)into a 2.5 M Li bis(fluorosulfonyl)imide dipropyl ether(DPE)elec-trolyte as a co-solvent for high-performance LMBs at-20℃.The incorporation of DIPE not only enhances the disorder within the electrolyte,but also induces a steric hindrance effect form DIPE’s branch chain,excluding other solvent molecules from Li+solvation sheath.Both of these factors contribute to the weak interactions between Li^(+)and solvent molecules,effectively reducing the desolvation energy of the electrolyte.Consequently,Li(50μm)||LFP(mass loading~10 mg cm^(-2))cells in DPE/DIPE based electrolyte demonstrate stable performance over 650 cycles at-20℃,delivering 87.2 mAh g^(-1),and over 255 cycles at 25℃ with 124.8 mAh g^(-1).DIPE broadens the electrolyte design from molecular structure considera-tions,offering a promising avenue for highly stable LMBs at LT.

关 键 词：Solvation structure Li metal battery Low temperature Steric hindrance DISORDER 

分 类 号：TM912[电气工程—电力电子与电力传动]