Hollow structured cathode materials for rechargeable batteries

Hollow structuring has been intensively studied as an effective strategy to improve the electrochemical performance of the electrode materials for rechargeable batteries in terms of specific capacity, rate capability, and cycling performance. To date, hollow structured anode materials have been extensively investigated, while hollow structured cathode materials (HSCMs) are relatively less explored because of the difficulties in morphological control as well as the concern of reduced volumetric capacities. In this paper, we provide an overview of the research advances in the synthesis and evolution of HSCMs for metal (Li, Na, etc.) ion batteries. Attributing to the advantages of hollow structures including high surface area, excellent accessibility to active sites, and enhanced mass transport and diffusion, hollow structuring can significantly improve the performance of high-capacity cathode materials with low kinetics, such as lithium rich layered oxides, silicates, and V₂O₅. It is anticipated that the precise and facile control of the spatial configuration can balance the electrochemical performance of HSCMs and the volumetric capacities of HSCMs, leading to practical high-performance batteries.