Scalable and general synthesis of spinel manganese-based cathodes with hierarchical yolk–shell structure and superior lithium storage properties

Hierarchical yolk–shell structured cathodes with controllable composition are potentially attractive materials for the fabrication of lithium-ion batteries, but they are difficult to synthesize. In this work, we present a simple, scalable, and general morphology-inheritance strategy to synthesize spinel manganese cathodes with a hierarchical yolk–shell structure. Starting from uniform Mn carbonate spheres prepared by an ultrafast and scalable microwave-assisted method, we show that the subsequent sintering results in the formation of Mn₂O₃ precursors with a yolk–shell structure, which can be effectively transferred to spinel manganese cathodes via simple impregnation and solid-state reaction. Owing to the simple and scalable nature of the present strategy, materials prepared through this approach have great potential as cathodes of lithium-ion batteries, where they can lead to high specific capacity, outstanding cyclability, and superior rate capability. In particular, both LiMn₂O₄ and LiNi_0.5Mn_1.5O₄ with hierarchical yolk–shell structure achieved nearly theoretical capacity, without any apparent decay after 100 cycles at 1 C. Moreover, 80% of the initial discharge capacities of both samples can be maintained for up to 500 cycles at a high rate of 10 C.