Constructing high-toughness polyimide binder with robust polarity and ion-conductive mechanisms ensuring long-term operational stability of silicon-based anodes  

作　　者：Yongjun Kang Nanxi Dong Fangzhou Liu Daolei Lin Bingxue Liu Guofeng Tian Shengli Qi Dezhen Wu 

机构地区：[1]State Key Laboratory of Chemical Resource Engineering,Beijing University of Chemical Technology,Beijing 100029,China [2]ENFI R&D Institute,China ENFI Engineering Corporation,Beijing 100038,China [3]China Automotive Battery Research Institute Co.,Ltd.,Beijing 101407,China [4]Changzhou Institute of Advanced Materials,Beijing University of Chemical Technology,Changzhou 213164,Jiangsu,China

出　　处：《Journal of Energy Chemistry》2024年第6期580-591,I0014,共13页能源化学（英文版）

基　　金：supported by the National Natural Science Foundation of China (51673017);the National Natural Science Foundation of China (21404005);the Fundamental Research Funds for the Central Universities (XK1802-2);the Natural Science Foundation of Jiangsu Province (BK20150273)。

摘　　要：Silicon-based materials have demonstrated remarkable potential in high-energy-density batteries owing to their high theoretical capacity.However,the significant volume expansion of silicon seriously hinders its utilization as a lithium-ion anode.Herein,a functionalized high-toughness polyimide(PDMI) is synthesized by copolymerizing the 4,4'-Oxydiphthalic anhydride(ODPA) with 4,4'-oxydianiline(ODA),2,3-diaminobenzoic acid(DABA),and 1,3-bis(3-aminopropyl)-tetramethyl disiloxane(DMS).The combination of rigid benzene rings and flexible oxygen groups(-O-) in the PDMI molecular chain via a rigidness/softness coupling mechanism contributes to high toughness.The plentiful polar carboxyl(-COOH) groups establish robust bonding strength.Rapid ionic transport is achieved by incorporating the flexible siloxane segment(Si-O-Si),which imparts high molecular chain motility and augments free volume holes to facilitate lithium-ion transport(9.8 × 10^(-10) cm^(2) s^(-1) vs.16 × 10^(-10) cm^(2) s~(-1)).As expected,the SiO_x@PDMI-1.5 electrode delivers brilliant long-term cycle performance with a remarkable capacity retention of 85% over 500 cycles at 1.3 A g^(-1).The well-designed functionalized polyimide also significantly enhances the electrochemical properties of Si nanoparticles electrode.Meanwhile,the assembled SiO_x@PDMI-1.5/NCM811 full cell delivers a high retention of 80% after 100 cycles.The perspective of the binder design strategy based on polyimide modification delivers a novel path toward high-capacity electrodes for high-energy-density batteries.

关 键 词：Polyimide binder High toughness Robust ionic transport Silicon-based anodes Lithium-ion batteries 

分 类 号：TQ433.4[化学工程] TM912[电气工程—电力电子与电力传动]