A hydrophilic poly(methyl vinyl ether-alt-maleic acid) polymer as a green, universal, and dual-functional binder for high-performance silicon anode and sulfur cathode

Binders could play crucial or even decisive roles in the fabrication of low-cost, stable and high-capacity electrodes. This is especially the case for the silicon (Si) anodes and sulfur (S) cathodes that undergo large volume change and active material loss in lithium-ion batteries during prolonged cycles. Herein, a hydrophilic polymer poly(methyl vinyl ether-alt-maleic acid) (PMVEMA) was explored as a dual-functional aqueous binder for the preparation of high-performance silicon anode and sulfur cathode. Benefiting from the dual functions of PMVEMA, i.e., the excellent dispersion ability and strong binding forces, the as-prepared electrodes exhibit improved capacity, rate capability and long-term cycling performance. In particular, the as-prepared Si electrode delivers a high initial discharge capacity of 1346.5 mAh g1 at a high rate of 8.4 A/g and maintains 834.5 mAh g1 after 300 cycles at 4.2 A/g, while the as-prepared S cathode exhibits enhanced cycling performance with high remaining discharge capacities of 663.4 mAh g1 after 100 cycles at 0.2 C and 487.07 mAh g1 after 300 cycles at 1 C, respectively. These encouraging results suggest that PMVEMA could be a universal binder to facilitate the green manufacture of both anode and cathode for high-capacity energy storage systems. Crown Copyright (c) 2021 Published by ELSEVIER B.V. and Science Press on behalf of Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. All rights reserved.