Mussel-Inspired Self-Healing Metallopolymers for Silicon Nanoparticle Anodes.

Abstract

Polymers with supramolecular functionality are receiving increasing attention for rechargeable battery binders, as strong supramolecular interactions can facilitate self-healing effect via bond-recovery of the cleaved cross-links. Such self-healing capability is useful for emerging high capacity battery materials that undergo large volume change. Benchmarking mussel s sticky byssus cuticle, herein, we report a copolymer binder with Fe3+-(tris)catechol coordination cross-links, which can induce self-healing effect for silicon anodes. The high strength of the Fe3+-(tris)catechol coordination bond can lead to recovery of the dissociated bond that occur from the large volume expansion of silicon. The given copolymer also contains monomer units with sufficient flexibility to increase the inter-chain motions for efficient Fe3+-(tris)catechol bond recovery. The superior electrochemical performance of the Si electrodes based on the proposed copolymer binder indicates that metallopolymers which utilize metal-organic ligand coordination for interchain cross-linking are promising binders with self-healing effect for sustainable cycling of high capacity battery electrodes.