Enhancing Mechanical Resilience in Li-Ion Battery Cathodes with Nanoscale Elastic Framework Coatings

Abstract

Lattice volume changes in Li-ion batteries active materials are unavoidable during electrochemical cycling, posing significant engineering challenges from the particle to the electrode level. In this study, we present an elastic framework coating designed to absorb and reversibly release strain energy associated with particle volume changes, thereby enhancing mechanical resilience at both the particle and electrode levels. This framework, composed of multiwalled carbon nanotubes (MWCNTs), is applied to nickel-rich LiNi_0.9Co_0.05Mn_0.05O₂ (NCM9055) cathodes at a low loading of 0.5 wt %, effectively mitigating critical issues such as particle cracking, volume changes, and electrode thickness variations during cycling. Leveraging these advantages, an energy-dense electrode is achieved with a high active material loading of 20 mg cm^–2, without the need for additional carbon additives. Demonstrated in a pouch cell format, this electrode achieves an exceptional capacity retention of 77.7% after 1000 cycles. This approach provides a comprehensive solution for designing Li-ion batteries capable of withstanding lattice volume variations, offering valuable insights for next-generation batteries technologies.