Na-Rich Prussian White Cathodes for Long-Life Sodium-Ion Batteries

Prussian blue analogues (PBA) recently have received great interest for promising applications in low-cost sodium-ion batteries (SIBs). However, controlled synthesis of high-performance PBA is still challenging. In this work, a facile precipitation route was used to synthesize Na-rich PBAs with superior electrochemical performance. It was found that two shapes of the products, namely, small irregular particles and large cuboid particles, coexist by adding sodium citrate in the sodium hexacyanoferrate side during the synthesis. The product shows large capacity (144 mAh g–1 under a 0.1 C rate), good rate performance (115.6 mAh g–1 under a 1 C rate, 86.6 mAh g–1 under a 10 C rate), and long-term cycling stability (73.4% retention after 780 cycles under a 0.5 C rate, 72.7% retention after 2100 cycles under a 1 C rate). This work offers a promising route to prepare PBA-based cathode materials for high-performance SIBs.