Design and construction of Prussian blue analogue combined by Na2WO4 toward high-performance cathode materials for Li-ion battery

Abstract

Prussian blue analogues have been considered as one of hopeful cathode materials of Li-ion batteries (LIBs) because of their tunable composition, low cost and simple synthesis method, but the high volume variation and electrical resistance during cycling limit the wide application. In this work, Na1.06Fe[Fe(CN)6]·2.8H2O/Na2WO4 (PBA/NW) composites with high performance are successfully synthesized by a hydrothermal route following through a simple solution dispersion approach. The Na2WO4 coating will not alter the structure and morphology of PBA sample. Na2WO4 coating improves the structure stability and Li+ insertion/extraction reversibility, and decreases the charge transfer resistance, then promotes the transfer of Li+. The PBA-NW2 indicates an outstanding reversible discharge capacity of 134.9 mAh g−1 at 1C after 1000 cycles, but the pure PBA only performs a discharge capacity of 108 mAh g−1. In addition, PBA-NW2 also indicates superior rate property with discharge capacity of 150.3, 145.1, 140.0, 132.5, 132.32, 105.3, 91.9 mAh g−1 at 0.1, 0.3, 0.5, 1, 2, 5 and 10C, respectively. This work offers a facile and easy synthesis method to construct high-performance Prussian blue analogues cathode material for low-cost LIBs.