摘要
聚合物基固态电解质得益于其易加工性,最有希望应用于下一代固态锂金属电池.目前,聚合物基态电解质的离子电导率提升策略多为加入导锂陶瓷以构建离子传输通道,其提升程度有限.电场在锂离子输运过程中存在重要影响,目前研究中有关电场对锂离子传输的影响机制尚不明确.本文将兼具高离子电导率和高介电常数的铌酸锂嵌入聚偏氟乙烯基体中,设计了一种新型复合固态电解质.铌酸锂颗粒有效调节电解质内部电场结构,增强了离子输运方向电场强度,实现了离子电导率的大幅提升(7.39×10^(-4)S cm^(-1),25℃).该电解质匹配高镍正极和锂金属负极的固态电池可稳定循环1000次以上,容量保持率为72%.该研究为设计下一代固态锂电池用高离子电导复合固态电解质提供了新的策略.
The composite solid-state electrolytes(CSEs)are one of the most promising electrolytes for advanced solid-state Li metal batteries.However,it is unclear for the effect of the induced electric field inside CSEs on the Li-ion transport.Herein,we design a compact CSE by imbedding the lithium niobate(LiNbO3)with both high ionic conductivity and di-electric constant into poly(vinylidene fluoride)matrix(NPC).The LiNbO3 significantly enhances the internal electric field of NPC along the LiNbO3 particles and establishes uniform in-terfacial electric field between NPC and electrodes,which fundamentally facilitates the Li-ion transport,weakens the space-charge layer and inhibits the growth of Li dendrites.Continuous fast ion-conducting channels with high con-centration of Li-ions are constructed inside NPC,which con-tributes to a quite high ionic conductivity(7.39×10^(-4) S cm^(-1),25℃)and ultra-low activation energy(0.112 eV).The LiNi0.8Co0.1Mn0.1O2/NPC/Li solid-state batteries exhibit quite stable cycling performance at 25℃.
作者
刘晓潼
温博华
钟贵明
程醒
简翠英
郭勇
黄妍斐
马家宾
史沛然
陈立坤
张丹丰
吴士超
柳明
吕伟
贺艳兵
康飞宇
Xiaotong Liu;Bohua Wen;Guiming Zhong;Xing Cheng;Cuiying Jian;Yong Guo;Yanfei Huang;Jiabin Ma;Peiran Shi;Likun Chen;Danfeng Zhang;Shichao Wu;Ming Liu;Wei Lv;Yan-Bing He;Feiyu Kang(Shenzhen All-Solid-State Lithium Battery Electrolyte Engineering Research Center,Institute of Materials Research(IMR),Tsinghua Shenzhen International Graduate School,Tsinghua University,Shenzhen 518055,China;School of Materials Science and Engineering,Tsinghua University,Beijing 100084,China;Laboratory of Advanced Spectro-electrochemistry and Li-ion Batteries,Dalian Institute of Chemical Physics Chinese Academy of Sciences,Dalian 116023,China;Department of Mechanical Engineering,York University,Toronto,ON M3J 1P3,Canada;Nanoyang Group,State Key Laboratory of Chemical Engineering,School of Chemical Engineering and Technology,Tianjin University,Tianjin 300072,China;College of Materials Science and Engineering,Shenzhen University,Shenzhen 518055,China)
基金
supported by the National Key Research and Development Program of China (2021YFF0500600)
National Natural Science Foundation of China (No.U2001220)
Shenzhen All-Solid-State Lithium Battery Electrolyte Engineering Research Center (XMHT20200203006)
Shenzhen Technical Plan Project (RCJC20200714114436091,JCYJ20220818101003007,and JCYJ20220818101003008)。
