Spiderweb-like Three-Dimensional Cross-Linked AGE Binder for High Performance Silicon-Based Lithium Battery

Abstract

In the research of anode materials for lithium-ion batteries, silicon materials have become a research hotspot in the field of new energy batteries by virtue of their theoretical specific capacity of up to 4200 mA h g^–1. However, the volume change of the silicon anode during lithiation/delithiation is as high as 300%, which leads to the collapse of the electrode structure and thus affects its cycling stability. Here, we propose a spiderweb-like 3D network binder named AGE to resist the volume expansion of the silicon anode and maintain its integrity during long cycling time. Epichlorohydrin as a crosslinker to form a spiderweb-like network (AGE) with gum Arabic (GA) and guar gum (GG) under the open loop condition of epichlorohydrin. During the lithiation/lithiation process, the three-dimensional network structure of the AGE binder can dissipate the stresses generated in the silicon material, and the abundant polar functional groups of AGE can effectively interact with the hydrogen on the surface of the silicon material by hydrogen bonds. In this way, the structure of the silicon cell remains intact, and the cycling stability is significantly improved (93.4% of the initial capacity) compared to that with PAA as the binder (23.2% of the initial capacity).