(Georgia Institute of Technology, 2020-01)
Sun, Zifei; Lu, Peilin; Fu, Wenbin; Wang, Baichuan; Magasinski, Alexandre; Zhang, Yawei; Yushin, Gleb
Iron fluoride (FeF3) is considered as a potential cathode for sodium-ion batteries due to its high capacity and low cost. However, the dissolution of active materials during cycling limits its further development. Herein, we design thin protective films at the surface of cathode materials by in-situ and ex-situ method. In in-situ method, an electrolyte of sodium-difluoro(oxalate)borate (NaDFOB) dissolved in a ternary solvent was utilized to develop the in-situ protective films. Ex-situ formed coatings are developed by atomic layer deposition technique. Both coatings minimize the active material dissolution and significantly improved the overall electrochemical performance of FeF3 cathodes in SIBs.