Self-healing chemistry enables the stable operation of silicon microparticle anodes for high-energy lithium-ion batteries

Abstract

The ability to repair damage spontaneously, which is termed self-healing, is an important survival feature in nature because it increases the lifetime of most living creatures. This feature is highly desirable for rechargeable batteries because the lifetime of high-capacity electrodes, such as silicon anodes, is shortened by mechanical fractures generated during the cycling process. Here, inspired by nature, we apply self-healing chemistry to silicon microparticle (SiMP) anodes to overcome their short cycle-life. We show that anodes made from low-cost SiMPs (~3-8 µm), for which stable deep galvanostatic cycling was previously impossible, can now have an excellent cycle life when coated with a self-healing polymer. We attain a cycle life ten times longer than state-of-art anodes made from SiMPs and still retain a high capacity (up to ~3,000 mA h g(-1)). Cracks and damage in the coating during cycling can be healed spontaneously by the randomly branched hydrogen-bonding polymer used.

Recent Progress on Polymeric Binders for Silicon Anodes in Lithium-Ion Batteries

“…23(a), it was predicted that the self-healing polymer would be stretchable and repair spontaneously the mechanical fracturing of Si-based anodes via hydrogen bonding. The cycling stability and rate capability of Si microparticle anodes were greatly improved [49]. The self-healing Si anodes retained a high Li extraction capacity of ~2,500 mAh g -1 during 20 cycles.…”

“…The Bao group proposed self-healing chemistry to repair mechanically damaged Si-based electrodes spontaneously [49]. They noted that the crosslinked network of self-healing polymers could be stretched to three times its initial length without breaking, whereas PVDF and alginate binders could be stretched only by 10% and 2%, respectively.…”

Supramolecular Interfacial Polymerization: A Controllable Method of Fabricating Supramolecular Polymeric Materials

“…Over the past decades, significant advances have been made in developing methods of supramolecular polymerization, from spontaneous to controllable and living supramolecular polymerization 31, 32, 33, 34, 35, 36, 37, 38. Furthermore, supramolecular polymers have displayed potential applications in many interdisciplinary fields, such as molecular muscles,39, 40, 41 self‐healing materials,42, 43, 44 self‐healing organic electronics,45, 46 heterogeneous catalysis,47 degradable drug nanocarriers,48 and stimuli‐responsive supramolecular gels 49, 50, 51…”

Graphene Oxide Wrapped Amorphous Copper Vanadium Oxide with Enhanced Capacitive Behavior for High‐Rate and Long‐Life Lithium‐Ion Battery Anodes

“…To build a better battery, several factors should be taken into account, including energy density, rate capability, cost, safety, and sustainability 5, 6, 7, 8, 9, 10. To achieve this goal, there has been an intensive search interest on new cathode and anode materials with promising electrochemical performance 11, 12, 13, 14, 15. In the case of anode materials, concerns about the long‐term availability of a few elements have naturally driven researchers toward iron, copper, vanadium, and titanium 16, 17, 18, 19, 20, 21.…”