Advances in metal phosphides for sodium-ion batteries

Sodium-ion batteries(SIBs)have been extensively studied as the potential alter-native to lithium-ion batteries(LIBs)due to the abundant natural reserves and low price of sodium resources.Nevertheless,Na+ions possess a larger radius than Li+,resulting in slow diffusion dynamics in electrode materials,and thus seeking appropriate anode materials to meet high performance standards has become a trend in the field of SIBs.In this context,owing to the advantages of high theoretical capacity and proper redox potential,metal phosphides(MPs)are considered to be the promising materials to make up for the gap of SIBs anode materials.In this review,the recent development of MPs anode materials for SIBs is reviewed and analyzed comprehensively and deeply,including the synthesis method,advanced modification strategy,electrochemical performance,and Na storage mechanism.In addition,to promote the wide application of the emerg-ing MPs anodes for SIBs,several research emphases in the future are pointed out to overcome challenges toward the commercial application.