Asymmetric fireproof gel polymer electrolyte constructed by boron-contained covalent organic framework for dendrite-free sodium metal battery  

作　　者：Zhanming Liu Rui Wang Jiayi Yu Zhengrui Miao Zijian Xu Jianguo Ren Suli Chen Tianxi Liu 

机构地区：[1]Key Laboratory of Synthetic and Biological Colloids Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi, 214122, China [2]BTR New Material Group Co., Ltd., Shenzhen, 518000, China

出　　处：《Nano Research》2024年第11期9679-9687,共9页纳米研究（英文版）

基　　金：financially supported by the Natural Science Foundation of Jiangsu Province(No.BK20210474);the National Natural Science Foundation of China(NSFC,No.52203261);the project of research on the industrial application of “controllable synthesis of nanocarbon-based polymer composites and their application in new energy”(No.CJGJZD20210408092400002)。

摘　　要：Gel polymer electrolytes (GPEs) with flexibility, easy processability, and low cost have been regarded as promising alternatives for conventional liquid electrolytes in next-generation sodium metal batteries (SMBs). However, GPEs often suffer from combustion risk and inferior interfacial compatibility toward Na metal anode, which severely limit their wide commercial applications. Here, a rational design of asymmetric fireproof GPE (AFGPE) modified with a boron-contained covalent organic framework (BCOF) on one side is developed through in-situ crosslinking polymerization process. Benefiting from the unique structure and composition, the resulting AFGPE exhibits high Na+ transference number, wide electrochemical window, excellent mechanical properties and high safety. Especially, the nanoscale BCOF layer with uniform nanochannels works as ion sieve that homogenizes Na+ flux during Na plating process, while the abundant Lewis-acid B sites can strongly capture counter anions and decrease space charge layer at anode side, thus promoting the uniform Na deposition to effectively suppress dendrite growth. Consequently, the Na/AFGPE/Na symmetric cells demonstrate remarkable cycling stability for over 1200 h at 0.1 mA·cm^(-2), and the solid-state SMBs exhibit outstanding cycling properties and rate capability, delivering a high capacity retention of 96.4% under current density of 1 C for over 1000 cycles.

关 键 词：gel polymer electrolyte sodium metal battery covalent organic framework FLAME-RETARDANT interfacial stability 

分 类 号：TQ317[化学工程—高聚物工业] TM912[电气工程—电力电子与电力传动]