Citation

Meng Tian, Xiao Chen, Shengtong Sun*, Dong Yang*, and Peiyi Wu*. A Bioinspired High-Modulus Mineral Hydrogel Binder for Improving the Cycling Stability of Microsized Silicon Particle-Based Lithium-Ion Battery. Nano Res. 2019, 12, 1121-1127.

Abstract

Silicon with high specific capacity is deemed an ideal anode material for lithium ion batteries, which, however suffers from low cycling life due to its dramatic volume changes. Water-soluble polymer binders recently gain increasing attention by providing an eco-friendly and low-cost way in improving the cycling stability of Si-based anodes. Herein, a novel bioinspired supramolecular mineral hydrogel binder consisting of polyacrylic acid (PAA) physically crosslinked with amorphous calcium carbonate (ACC) nanoparticles is designed for high-performance anodes made from low-cost microsized Si particles. Owing to its organic-inorganic hydrophilic nature, ACC-PAA hybrid binder exhibits the reported highest modulus (~ 22 GPa) for polymer binders in electrolyte, even higher than lithiated Si species (Li15Si4, ~ 12 GPa). Together with its excellent adhesion and electrochemical stability, ACC-PAA binder can effectively suppress the pulverization of Si particles and maintain the mechanical integrity of electrodes during cycling. Therefore, even with a low binder content, the anode still shows an initial discharge capacity of 2,973 mAh·g−1 and Coulombic efficiency of 81.5%, and retains 75% at a current density of 600 mA·g−1 after 100 cycles. The present organic-inorganic hybrid mineral binder may open a new approach for designing more effective polymer binders for Si-based lithium-ion batteries.