Hollow‐Structured Electrode Materials: Self‐Templated Synthesis and Their Potential in Secondary Batteries

Abstract Hollow‐structured electrode materials have found broad applications in secondary batteries. The built‐in cavity of the prepared materials shows favorable features such as structural stability against volumetric deformation, good reservoir for electrolyte, and fast charge transport kinetics, which are highly efficient to improve the electrochemical performance of the electrode materials, particularly their cycling stability and high rate capability. However, the full potential of hollow‐structured materials is restrained by their limited synthesis capability, which currently relies on template‐based protocols with well‐known challenges in both product yield and operational convenience. In this review, the recent progress on different synthetic methodologies for the creation of hollow structures without the use of extra templates is summarized. Starting from solid precursors, focus is laid on the formation mechanisms for the creation of a cavity inside the electrode materials, and subsequently different driving forces such as Ostwald ripening, Kirkendall effect, and selective etching of an inhomogeneous particle are discussed, highlighting the self‐templated processes as designable and scalable ones with good control on the key structural characters. Furthermore, the applications of hollow structures in different kinds of battery systems are discussed in terms of building up a clear structure‐performance relationship of the electrode materials. Finally, we provide a perspective on the development trends of self‐templated construction of hollow structures.