The effect of manganese doping on the electrochemical properties of Prussian blue as the cathode for sodium-ion batteries

Abstract

Prussian blue analogs (PBAs) are considered as promising cathode materials for sodium-ion batteries due to their wide framework structures for the transportation of sodium ions. However, conventional Prussian blue analogs (PBAs) often suffer from structural instability and limited capacity due to inherent defects and lattice water in the structure. Herein, manganese-doped Prussian blue analogs (FeMn-PBAs) were synthesized via a modified co-precipitation method to address the issues of structural instability and low sodium storage capacity in PBAs, thereby exploring their potential as high-performance cathode materials for sodium-ion batteries (SIBs). The experimental results revealed that FeMn-PB exhibited a high initial capacity of 121.6 mAh g⁻¹ and outstanding cycling stability, retaining 96.6% of its capacity after 100 cycles of tests at a current density of 170 mA g⁻¹. The improved performance is attributed to reduced lattice water, and enhanced Na⁺ diffusion kinetics. This work provides new insights into the modification of PBAs and highlights the promising application of manganese ion doping in advancing energy storage technologies.