摘要
具有高锂离子迁移数和良好可加工性能的锂快离子导体对于全固态电池的发展非常重要。然而,现有的锂快离子导体主要限制于硬质陶瓷,目前尚无柔性聚合物类型的锂快离子导体被报道。在这个工作中,我们报告了一种通过三种不同有机单体的自由基聚合反应形成的三元无规共聚单离子快离子导体(SISC)。该SISC中包含丰富的锂离子传输位点和具有阴离子锚定功能的阴离子受体。此外,三种不同单体的共聚反应带来低结晶度和低玻璃化转变温度(T_(g)),有利于链段运动,从而获得小的锂离子传输的活化能(E_(a))。电化学测试结果表明,该SISC的室温离子电导率和锂离子迁移数分别达到1.29·mS·cm^(-1)和0.94。将SISC与锂金属负极和多种正极(包括LiFePO_(4)、LiCoO_(2)和硫化聚丙烯腈(SPAN))原位聚合,组装得到的全固态电池具有良好的电化学稳定性。其中,Li||LiFePO_(4)全固态电池表现出高达8C的倍率性能和良好的循环寿命(在0.5C倍率下稳定循环>700圈)。这项工作提供了一种新颖的聚合物基快离子导体设计理念,对于发展高性能全固态电池具有重要意义。
All-solid-state batteries(ASSBs)have been considered a promising candidate for the next-generation electrochemical energy storage because of their high theoretical energy density and inherent safety.Lithium superionic conductors with high lithium-ion transference number and good processability are imperative for the development of practical ASSBs.However,the lithium superionic conductors currently available are predominantly limited to hard ceramics.Practical lithium superionic conductors employing flexible polymers are yet to be realized.The rigid and brittle nature of inorganic ceramic electrolytes limits their application in high-performance ASSBs.In this study,we demonstrate a novel design of a ternary random copolymer single-ion superionic conductor(SISC)through the radical polymerization of three different organic monomers that uses an anion-trapping borate ester as a crosslinking agent to copolymerize with vinylene carbonate and methyl vinyl sulfone.The proposed SISC contains abundant solvation sites for lithium-ion transport and anion receptors to immobilize the corresponding anions.Furthermore,the copolymerization of the three different monomers results in a low crystallinity and low glass transition temperature,which facilitates superior chain segment motion and results in a small activation energy for lithium-ion transport.The ionic conductivity and lithium-ion transference number of the SISC are 1.29 mS·cm^(-1) and 0.94 at room temperature,respectively.The SISC exhibits versatile processability and favorable Young’s modulus(3.4±0.4 GPa).The proposed SISC can be integrated into ASSBs through in situ polymerization,which facilitates the formation of suitable electrode/electrolyte contacts.Solid-state symmetric Li||Li cells employing in situ polymerized SISCs show excellent lithium stripping/plating reversibility for more than 1000 h at a current density of 0.25 mA·cm^(-2).This indicates that the interface between the SISC and lithium metal anode is electrochemically stable.The ASSBs that employ in
作者
薛国勇
李静
陈俊超
陈代前
胡晨吉
唐凌飞
陈博文
易若玮
沈炎宾
陈立桅
Guoyong Xue;Jing Li;Junchao Chen;Daiqian Chen;Chenji Hu;Lingfei Tang;Bowen Chen;Ruowei Yi;Yanbin Shen;Liwei Chen(School of Nano-Tech and Nano-Bionics,University of Science and Technology of China,Hefei 230026,China;i-Lab,CAS Center for Excellence in Nanoscience,Suzhou Institute of Nano-Tech and Nano-Bionics,Chinese Academy of Science,Suzhou 215123,Jiangsu Province,China;School of Chemistry and Chemical Engineering,Shanghai Jiaotong University,Shanghai 200240,China)
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
2023年第8期115-124,共10页
Acta Physico-Chimica Sinica
基金
国家重点研究发展项目(2021YFB3800300)
国家自然科学基金(21733012,22179143)资助。
关键词
全固态锂金属电池
聚合物固态电解质
超离子导体
单离子导体
原位聚合
倍率性能
All-solid-state lithium metal battery
Solid polymer electrolyte
Superionic conductor
Single-ion conductor
In situ polymerization
Rate performance
