LiBF_(4)和LiDFOB双盐电解液实现硬碳负极的室温和低温电化学性能优化调控  

Optimal Regulation of Electrochemical Performance of Hard Carbon Anode at Room Temperature and Low Temperature by LiBF_(4) and LiDFOB Double Salt Electrolyte

作　　者：林虎 刘芳延 谢英鹏 吴忠帅[2] LIN Hu;LIU Fangyan;XIE Yingpeng;WU Zhongshuai(College of Chemical Engineering,Shenyang University of Chemical Technology,Shenyang Liaoning 110142,China;State Key Laboratory of Catalysis,Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian Liaoning 116023,China)

机构地区：[1]沈阳化工大学化学工程学院,辽宁沈阳110142 [2]中国科学院大连化学物理研究所催化基础国家重点实验室,辽宁大连116023

出　　处：《辽宁化工》2024年第7期984-989,共6页Liaoning Chemical Industry

基　　金：国家重点研发计划(项目编号:2022YFA1504100);中科院洁净能源创新研究院合作基金(项目编号:DNL202016、DNL202019);大连化物所基金(项目编号:DICP I2020032、DICP I202222)。

摘　　要：为克服商用六氟磷酸锂(LiPF_6)基电解液无法使锂离子电池在0℃下正常工作的问题,开发低温锂离子电池电解液成为领域研究重点。其中,四氟硼酸锂(LiBF_(4))基电解液因其低温下电荷转移阻抗较小,二氟草酸硼酸锂(LiDFOB)基电解液因其良好的成膜性能都备受学者关注。开发了一种新型LiBF_(4)和LiDFOB双盐电解液,通过优化与调控,使硬碳负极在室温和低温条件下同时具有优异的电化学性能。通过循环伏安、倍率和循环性能测试,系统比较了LiBF_(4)和LiDFOB及其混合双盐电解液对硬碳负极室温及低温电化学性能的影响。结果表明:LiBF_(4)+LiDFOB双盐电解液在兼顾硬碳室温电化学性能的同时,仍能实现硬碳优异的低温循环性能,100圈循环后硬碳仍有134 mAh·g^(-1)的可逆容量,显著优于硬碳在商用LiPF_6基电解液中的循环性能(100圈循环后可逆容量仅为2 mAh·g^(-1))。To overcome the issue that commercial lithium hexafluorophosphate(LiPF6)-based electrolytes can’t operate properly below 0℃,the development of low-temperature lithium-ion battery electrolytes has become a key research priority.Among them,lithium tetrafluoroborate(LiBF_(4))-based electrolytes show their low charge transfer impedance at low temperature,and lithium difluoroborate(LiDFOB)-based electrolytes present their good film-forming properties.In this paper,a new LiBF_(4) and LiDFOB dual salt electrolyte was developed to provide excellent electrochemical performance of hard carbon anode at both room temperature and low temperature through optimization and modulation.The effects of LiBF_(4),LiDFOB and their mixed LiBF_(4)+LiDFOB double salt electrolytes on the electrochemical performance of hard carbon anodes at room temperature and low temperature were systematically compared by cyclic voltammetry,multiplicity and cycling performance tests.The results showed that the LiBF_(4)+LiDFOB double salt electrolytes could-1 achieve excellent low temperature cycling performance of hard carbon,showing a reversible capacity of 134 mAh·g after 100 cycles,which was significantly better than the cycling performance of hard carbon in commercial LiPF6-based electrolytes(reversible capacity after 100 cycles was only 2 mAh·g^(-1)).

关 键 词：锂离子电池 低温电解液 LiBF_(4) LiDFOB 

分 类 号：TQ152[化学工程—电化学工业]