Cathode Materials ofSIBs

Cathode material is one of the key components of a sodium-ion battery (SIB) that significantly determines the working voltage, energy density, cycle life, and material cost. In this case, the exploration of suitable cathode materials is crucial and urgent for the development of SIBs. Similar to lithium-ion batteries (LIBs), an ideal cathode material for a SIB is expectantly composed of a stable host structure, unblocked ion pathways, and sufficient redox centers that support highly reversible intercalation reactions. After decades of investigation, various cathode materials for SIBs, mainly including oxides, polyanions, Prussian blues and analogues, organic and other types of compounds, have been discovered, exhibiting distinct features. In this chapter, detailed introductions of the cathode materials for SIBs are presented, focusing on the developing history, working principle, merits and drawbacks, and the state-of-the-art progress for each type of material.