Embedding MnO₂ Ultrafine Nanoparticles within Graphene‐Based Hybrid Elastomer as an Anode for Enhanced Lithium Storage

Abstract

Abstract Despite its high theoretical capacity, the practical application of MnO 2 anodes for lithium‐ion batteries is still hindered by poor rate capability, owing to its low electronic conductivity and large volume variation during Li + insertion/extraction. Herein, these tough issues are tackled by embedding MnO 2 ultrafine nanoparticles within polydopamine‐modified reduced graphene oxide. This smart design skillfully utilizes the reduction and self‐polymerization properties of dopamine to reduce graphene oxide while MnO 2 ultrafine nanoparticles are embedded in the polydopamine and form a stable interface. The polydopamine, acting as an elastomer, can cushion the stress associated with the expansion of MnO 2 ultrafine nanoparticles, and the reduced graphene oxide, as the highly conductive matrix, can greatly improve the rate performance. The resultant composites exhibit a high reversible capacity, excellent cycling stability, and good rate performance, owing to the synergistic effects among conductive graphene, elastic polydopamine, and ultrafine MnO 2 .