Random Copolymer Hydrogel as Elastic Binder for the SiO x Microparticle Anode in Lithium-Ion Batteries

Zheng Weng; Shenghan Di; Long Chen; Gang Wu; Ying Zhang; Chuankun Jia; Ning Zhang; Xiaohe Liu; Gen Chen

doi:10.1021/acsami.2c12128

Random Copolymer Hydrogel as Elastic Binder for the SiO _x Microparticle Anode in Lithium-Ion Batteries

ACS Appl Mater Interfaces. 2022 Sep 21;14(37):42494-42503. doi: 10.1021/acsami.2c12128. Epub 2022 Sep 8.

Authors

Zheng Weng¹, Shenghan Di¹, Long Chen¹, Gang Wu¹, Ying Zhang², Chuankun Jia³, Ning Zhang¹, Xiaohe Liu², Gen Chen¹

Affiliations

¹ School of Materials Science and Engineering, Key Laboratory of Electronic Packaging and Advanced Functional Materials of Hunan Province, Central South University, Changsha 410083, China.
² Zhongyuan Critical Metals Laboratory and School of Chemical Engineering, Zhengzhou University, Zhengzhou 450001, Henan, P. R. China.
³ College of Materials Science and Engineering, Changsha University of Science & Technology, Changsha 410114, China.

PMID: 36073747
DOI: 10.1021/acsami.2c12128

Abstract

Silicon suboxides (SiO_x) have been widely concerned as a practical anode material for the next-generation lithium-ion batteries due to their relatively high theoretical capacity and lower volume change compared to silicon (Si). Nevertheless, traditional binder poly(vinylidene difluoride) (PVDF) still cannot hold the integrity of the SiO_x particle due to its weak van der Waals force. Herein, a copolymer binder for SiO_x microparticles is synthesized through a facile method of free radical polymerization between acrylamide (AM) and acrylic acid (AA). By adjusting the mass ratio of the AM/AA monomer, the copolymer binder can generate a covalent-noncovalent network with superior elastic properties from the synergistic effect. During electrochemical testing, the SiO_x anode with the optimal copolymer binder (AM/AA = 3:1) delivered a reversible capacity of 734 mAh g^-1 (two times that of commercial graphite) at 0.5C after 300 cycles. Thus, this work developed a green and effective strategy for synthesizing a water-soluble binder for Si-based anodes.

Keywords: SiOx; copolymer hydrogel; covalent−noncovalent network; elastic binder; microparticle.