Deciphering the reaction mechanism and rapid Na+ diffusion in CdPS3 for efficient sodium-ion storage

Metal phosphorus trichalcogenides (MPTCs) have demonstrated remarkable advantages as anode materials for alkali metal ion batteries because of their unique electronic structure and layered characteristics. In this study, layered CdPS 3 was successfully prepared by chemical vapor transport, and its Na + storage performance and reaction mechanisms were systematically investigated. Electrochemical tests revealed that CdPS 3 maintains a reversible capacity of 195.7 mA h g −1 after 340 cycles at a high current density of 5 A g −1 , revealing exceptional cyclic stability. Comprehensive characterization confirmed that the sodium storage process follows a typical multi-stage mechanism encompassing intercalation, conversion, and alloying (mainly during the first 40 cycles) processes, wherein partial conversion of CdPS 3 generates electrochemically active CdS nanoparticles that participate in subsequent electrochemical processes. Kinetic analysis indicated high Na + diffusion coefficients in CdPS 3 , while theoretical calculations revealed preferential Na + adsorption within the CdPS 3 interlayers. These findings provide important theoretical and experimental foundations for developing high-performance metal phosphorus trichalcogenides anode materials.