Spidroin‐Inspired Hierarchical Structure Binder Achieves Highly Integrated Silicon‐Based Electrodes

Abstract

AbstractAs a promising component for next‐generation high energy lithium‐ion batteries, silicon‐based electrode has attracted increasing attention by virtue of ultrahigh theoretical specific capacities. Nevertheless, fast capacity fade posed by tremendous silicon‐based electrode volume changes during cycling remains a huge challenge before large‐scale applications. Herein we develop an aqueous‐oil binary solution based blend (AOB) binder characterized by a spidroin‐like hierarchical structure for tolerating huge volume change of silicon‐based electrodes. In AOB binder, the hydrophobic tetrazole groups‐containing polymer (donate as PPB) and water‐soluble amorphous poly(acrylic acid) mimicks the β‐sheet and α‐helix structure of spidroin, respectively. Benefitted by such biomimetic design, AOB binder enables both high tensile strength and elasticity, and strong electrode adhesion, therefore apparently stabilizing silicon‐based electrode structure and rendering prolonged electrode cycle life. Such a strategy endows a 3.3 Ah soft package cells assembled with Si/C composite anode and NCM811 cathode with a discharge specific capacity of 2.92 Ah after 700 cycles. This work marks a milestone in developing state‐of‐the‐art silicon‐based electrodes towards high energy density lithium battery applications.This article is protected by copyright. All rights reserved