Thermal insitu analyses of multicomponent pyrophosphate cathodes materials

Abstract

Development of secondary batteries based on abundant and inexpensive elements are vital. Amongvarious alternative choices, sodium-ion batteries (NIBs) are promising because of plentiful resourcesand low costs of sodium metal. Different types of cathode materials for NIBs have been designed andstudied to meet the challenging requirements. Among them pyrophosphate cathodes have shownpromising electrochemical performance and thermal stability in sodium ion batteries (SIBs). In thepresent study, we report synthesis and thermal behavior of a novel Na2Fe0.33Mn0.33Co0.33P2O7 cathodematerial developed for sodium rechargeable batteries. The material was developed through solid stateprocess. The structural analysis of Na2Fe0.33Mn0.33Co0.33P2O7 revealed that the substitution ofmulticomponent transition metals have achieved triclinic crystal structure (P1 space group). TGA/DTAand thermal in-situ XRD analyses (25~550oC) confirm decent thermal stability of this material up to550oC even in the desodiated state with negligible weight loss (5%). Owing to its promising thermalstability, Na2Fe0.33Mn0.33Co0.33P2O7, would be an attractive cathode for sodium ion batteries.