Sodium iron pyrophosphate: A novel 3.0 V iron-based cathode for sodium-ion batteries

• DOI: 10.1016/j.elecom.2012.08.028
• Publication Date: 2012-09-10T15:05:28Z
• Authors: Prabeer Barpanda; Tian Ye; Shin-ichi Nishimura; Sai-Cheong Chung; Yuki Yamada; Masashi Okubo; Haoshen Zhou; Atsuo Yamada
• Keywords: Triclinic crystal system

Extending the pyrophosphate chemistry for rechargeable Na-ion batteries, here we report synthesis and electrochemical characterization of Na2FeP2O7, a novel Fe-based cathode material sodium batteries. Prepared by conventional solid-state as well solution-combustion (at 600 °C), Na2FeP2O7 adopts triclinic structure (space group: P-1) with three-dimensional channels running along [100], [− 110] [01-1] directions. With no further optimization, as-synthesized was found to be electrochemically active, delivering reversible capacity 82 mAh·g− 1 Fe3 +/Fe2 + redox potential centered around 3 V (vs. Na/Na+). its theoretical ~ 100 high rate-capability, forms promising material, distinction being first ever pyrophosphate-class sodium-ion