High energy density and superior charge/discharge efficiency polymer dielectrics enabled by rationally designed dipolar polarization  

作　　者：Zizhao Pan Yupeng Pan Li Li Xinwei Xu Jiufeng Dong Fei Jin Liang Sun Yujuan Niu Chen Xu Hong Wang 

机构地区：[1]Department of Materials Science and Engineering,Southern University of Science and Technology,Shenzhen,518055,Guangdong,China [2]Shenzhen Engineering Research Center for Novel Electronic Information Materials and Devices&Guangdong Provincial Key Laboratory of Functional Oxide Materials and Devices,Southern University of Science and Technology,Shenzhen,518055,Guangdong,China [3]Shenzhen Grubbs Institute and Department of Chemistry,Southern University of Science and Technology,Shenzhen,518055,Guangdong,China

出　　处：《Journal of Materiomics》2023年第3期601-608,共8页无机材料学学报（英文）

基　　金：supported by National Key Research&Development Program(No.2021YFB3800603);National Natural Science Foundation of China(No.92066208);Shenzhen Science and Technology Program(Nos.KQTD20180411143514543,JCYJ20180504165831308);Guangdong Natural Science Foundation(No.2020A1515011043).

摘　　要：Although many dielectric polymers exhibit high energy storage density(Ue)with enhanced dipolar polarization at room temperature,the substantially increased electric conduction loss at high applied electric fields and high temperatures remains a great challenge.Here,we report a strategy that high contents of medium-polar ester group and end-group(St)modification are introduced into a biode-gradable polymer polylactic acid(PLA)to synergistically reduce the loss and enhance Ue and charge-discharge efficiency(h).The resultant St-modified PLA polymer(PLA-St)exhibits an Ue of 6.5 J/cm^(3)with an ultra-high h(95.4%),far outperforming the best reported dielectric polymers.It is worth noting that the modified molecular structures can generate deep trap centers and restrict the local dipole motions in the polymer,which are responsible for the reduction of conduction loss and improvements in high-temperature capacitive performance.In addition,the PLA-St polymer shows intrinsically excellent self-healing ability and cyclic stability surviving over 500000 charge-discharge cycles.This work offers an efficient route to next-generation eco-friendly dielectric polymers with high energy density,low loss,and long-term stability.

关 键 词：Dielectric polymers Enhanced dipolar polarization End-group modification Self-healing ability Long-term stability 

分 类 号：O63[理学—高分子化学]