Quantitative lithium substitution of carboxyl hydrogens in polyacrylic acid binder enables robust SiO electrodes with durable lithium storage stability  

作　　者：Weihua Wang Wenyi Li Siyi Jing Huiping Yang Huiqun Wang Ling Huang Yuxiang Mao Xikun Pang Yudai Huang Li Zhang 

机构地区：[1]State Key Laboratory of Physical Chemistry of Solid Surfaces,Department of Chemical and Biochemical Engineering,College of Chemistry and Chemical Engineering,Collaborative Innovation Centre of Chemistry for Energy Materials(iChEM),Xiamen University,Xiamen 361005,Fujian,China [2]State Key Laboratory of Chemistry and Utilization of Carbon-Based Energy Resources,College of Chemistry,Xinjiang University,Urumqi 830017,Xinjiang,China

出　　处：《Journal of Energy Chemistry》2024年第10期352-360,I0007,共10页能源化学（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant Nos.92372101,52162036 and 21875155);the Fundamental Research Funds for the Central Universities (Grant Nos.20720220010);the National Key Research and Development Program of China (Grant Nos.2021YFA1201502)。

摘　　要：The design of advanced binders plays a critical role in stabilizing the cycling performance of large-volume-effect silicon monoxide(SiO)anodes.For the classic polyacrylic acid(PAA)binder,the self-association of-COOH groups in PAA leads to the formation of intramolecular and intermolecular hydrogen bonds,greatly weakening the bonding force of the binder to SiO surface.However,strengthening the binder-material interaction from the perspective of binder molecular regulation poses a significant challenge.Herein,a modified PAA-Li_(x)(0.25≤x≤1)binder with prominent mechanical properties and adhesion strength is specifically synthesized for SiO anodes by quantitatively substituting the carboxylic hydrogen with lithium.The appropriate lithium substitution(x=0.25)not only effectively increases the number of hydrogen bonds between the PAA binder and SiO surface owing to charge repulsion effect between ions,but also guarantees moderate entanglement between PAA-Li_x molecular chains through the ion-dipole interaction.As such,the PAA-Li_(0.25)/SiO electrode exhibits exceptional mechanical properties and the lowest volume change,as well as the optimum cycling(1237.3 mA h g^(-1)after 100cycles at 0.1 C)and rate performance(1000.6 mA h g^(-1)at 1 C),significantly outperforming the electrode using pristine PAA binder.This work paves the way for quantitative regulation of binders at the molecular level.

关 键 词：Polyacrylic acid binder SiO anode Quantitative lithium substitution Charge repulsion effect Adhesion strength 

分 类 号：TM912[电气工程—电力电子与电力传动] TQ430.7[化学工程]