E-beam irradiation of poly(vinylidene fluoride-trifluoroethylene)induces high dielectric constant and all-trans conformation for highly ionic conductive solid-state electrolytes  

作　　者：Chen Dai Florian JStadler Zhong-Ming Li Yan-Fei Huang 

机构地区：[1]College of Materials Science and Engineering,Shenzhen University,Shenzhen 518055,China [2]College of Polymer Science and Engineering and State Key Laboratory of Polymer Materials Engineering,Sichuan Univer-sity,Chengdu 610065,China

出　　处：《Energy Materials and Devices》2023年第2期95-105,共11页能源材料与器件（英文）

基　　金：support provided by the Shenzhen Science and Tech-nology Research and Development Fund(JCYJ20220531102013031);the National Natural Science and Foundation of China(52373040,52103037,and U21A2090);the Shenzhen University 2035 Program for Excellent Research(2023C005);the Natural Science Foundation of Guangdong Province(2023A1515030247).

摘　　要：Polymer matrices have limited abilities to dissociate lithium salts and transport ions,thus making most solid-state polymer electrolytes(SPEs)have extremely low ionic conductivities(10−7-10−5 S/cm)at 25℃.In this work,a high-energy electron-beam(e-beam)irradiation is applied to a poly(vinylidene fluoride-trifluoroethy-lene)[P(VDF-TrFE)]SPE to improve the ionic conductivity.P(VDF-TrFE)easily shows pure all-trans(TTTT)conformation with all fluorine atoms located on one side of the carbon chain to provide an ion transport high-way.E-beam irradiation keeps large amounts of TTTT conformation of P(VDF-TrFE)and produces-CF3 side groups,where the latter expands the interchain distance to split the large ferroelectric domains into nanosize to induce a unique relaxor ferroelectric behavior.This enhances the dielectric constant of the irradiated P(VDF-TrFE)from 15 to 20 and thus facilitates lithium salt dissociation.As a consequence,the ionic conduc-tivity of the irradiated P(VDF-TrFE)SPE is increased from 5.8×10^(−5)to 1.6×10^(−4)S cm^(−1)at 25℃.The solid-state Li//Li symmetrical cell cycles for more than 3000 h at 25℃without a short circuit.Furthermore,the solid-state LFP//Li cell cycles stably for more than 350 cycles with a capacity retention of around 91.3%at 1 C and 25℃.This study paves a new way to prepare high-performance SPEs by inducing high dielectric constants and abundant TTTT conformations through e-beam irradiation.

关 键 词：solid-state polymer electrolytes PVDF dielectric constant electron-beam irradiation all-trans conformation 

分 类 号：TN2[电子电信—物理电子学]