Pore Structure and Sodium Storage Performance of Sodium-Ion Battery Anodes

Pore structure affects ion transport and interfacial reactions in sodium-ion battery anodes and provides space to accommodate volume changes. This paper focuses on hard carbon, alloy anode and conversion composite materials, discusses the role of pore size, connectivity, pore opening and internal voids in the sodium storage process, and analyzes the advantages and limitations of different pore structures. The article also compares the synthesis strategies such as template method, activation method, carbonization control, dealloying and composite precursor derivatization, and explains how these methods shape the pore structure. Studies have shown that the sodium storage process and failure mechanism of different anode materials are very different, and the functional requirements of the pore structure are also different. The formation of pores is often accompanied by changes in phase composition. The contribution of pore structure cannot be evaluated only by capacity. The evaluation should also consider the sodium storage mechanism and failure process of the material under comparable electrode preparation and test conditions.