Portal de Periódicos da CAPES

Na 2 FeP 2 O 7 : A Safe Cathode for Rechargeable Sodium-ion Batteries

2013; American Chemical Society; Volume: 25; Issue: 17 Linguagem: Inglês

10.1021/cm401657c

1520-5002

Prabeer Barpanda, Guandong Liu, Chris D. Ling, Mao Tamaru, Maxim Avdeev, Sai‐Cheong Chung, Yuki Yamada, Atsuo Yamada,

Chemical Synthesis and Characterization

Vying for newer sodium-ion chemistry for rechargeable batteries, Na2FeP2O7 pyrophosphate has been recently unveiled as a 3 V high-rate cathode. In addition to its low cost and promising electrochemical performance, here we demonstrate Na2FeP2O7 as a safe cathode with high thermal stability. Chemical/electrochemical desodiation of this insertion compound has led to the discovery of a new polymorph of NaFeP2O7. High-temperature analyses of the desodiated state NaFeP2O7 show an irreversible phase transition from triclinic (P1̅) to the ground state monoclinic (P21/c) polymorph above 560 °C. It demonstrates high thermal stability, with no thermal decomposition and/or oxygen evolution until 600 °C, the upper limit of the present investigation. This high operational stability is rooted in the stable pyrophosphate (P2O7)4– anion, which offers better safety than other phosphate-based cathodes. It establishes Na2FeP2O7 as a safe cathode candidate for large-scale economic sodium-ion battery applications.