Hard–Soft Segment Synergism Binder Facilitates the Implementation of Practical SiC600 Electrodes

Abstract

AbstractAs an emerging anode material for commercialization, the silicon (or SiOx)/graphite composite (SiC) anode faces bottlenecks such as large volume expansion and short cycle lifespan, which hinder its commercial implementation process. To remove these limitations, a mussel byssal thread‐inspired hard–soft segment synergism binder (denoted as PCH‐CR) is presented based on an in situ ester cross‐linking reaction between a hydrophilic copolymer of sodium 2‐carboxyethylacrylate and N‐(2‐hydroxyethyl)acrylamide as the hard segment with an oleophilic elastomer carboxylic styrene butadiene rubber as the soft segment. This synergetic hard–soft segment binder design can evidently improve the polymer topological structure entropy, thus obtaining enhanced mechanical and adhesive properties. By virtue of these strengths, the as‐prepared SiC600 (600 mAh g−1 at 0.1 C) electrodes can apparently suppress electrode volume expansion, and subsequently maintain high structural integrity and interfacial stability during cycling. As a result, the as‐prepared SiC600 electrode at a limited PCH‐CR binder dosage achieves unprecedented cycling and rate performance in coin and home‐made soft package cells. These results promise great potential for the as‐developed binder for practical SiC600 electrode applications. This work marks a new milestone in developing state‐of‐the‐art binders toward high‐specific‐capacity Si‐based anode applications.