Preparation and Performance of Manganese-Based Prussian Blue Analogues Cathode Materials

Manganese-based Prussian blue analogues (MnHCF) are synthesized as cathode materials for sodium-ion batteries via a co-precipitation method, utilizing sodium citrate as a chelating agent to modulate nucleation and crystal growth. The materials are characterized by XRD, SEM, FTIR, and XPS, confirming the successful synthesis of MnHCF with varying chelating agent concentrations. As the concentration increased, the crystal size decreases from 1–3 μm to 100 nm, demonstrating effective inhibition of crystal growth. Electrochemical evaluations reveal that the C2 sample, synthesized with 0.1 mol l−1 sodium citrate, delivers the optimal performance. It retains 59.3% of its capacity after 200 cycles at 1 C and exhibited a specific capacity of 56.2 mAh g−1 even at a high rate of 5 C. This study underscores the critical role of chelating agent concentration in enhancing the structural stability and electrochemical kinetics of MnHCF, presenting a viable strategy for developing high-performance Prussian blue analogue cathodes.