The recent progress of pitch-based carbon anodes in sodium-ion batteries

Sodium-ion batteries (SIBs) have attracted significant attentions as promising alternatives to lithium-ion batteries for large-scale energy storage applications. Here carbon materials are considered as the most competitive anodes for SIBs based on their low-cost, abundant availability and excellent structural stability. Pitch, with high carbon content and low cost, is an ideal raw precursor to prepare carbon materials for large-scale applications. Nevertheless, the microstructures of pitch-based carbon are highly ordered with smaller interlayer distances, which are unfavorable for Na ion storage. Many efforts have been made to improve the sodium storage performance of pitch-based carbon materials. This review summarizes the recent progress about the application of pitch-based carbons for SIBs anodes in the context of carbon's morphology and structure regulation strategies, including morphology adjustment, heteroatoms doping, fabricating heterostructures, and the increase of the degree of disorder. Besides, the advantages, present challenges, and possible solutions to current issues in pitch-based carbon anode are discussed, with the highlight of future research directions. This review will provide a deep insight into the development of low-cost and high-performance pitch-based carbon anode for SIBs.