Superficially activating strategies to elevate the supercapacitor performance of nano-cube nickel cobalt-Prussian blue

Abstract

Prussian Blue Analogs (PBA) has good application potential in supercapacitors due to their unique microstructure characteristics. Nevertheless, the limited conductivity of these materials poses a significant obstacle to their widespread application as electrodes in supercapacitors. Herein, the conductivity of NiCo-PBA is enhanced through the implementation of three surface treatment methods, namely sulfidizing, selenizing and phosphating, and then the explicit electrochemical performance of NiCo-PBA was elevated. In addition, the P-NiCo-PBA//AC ASC occupies the best energy density (48.90 Wh kg−1/42.16 Wh kg−1) at a certain power density (1947.38 W kg−1/9545.10 W kg−1) compared to the NiCo-PBA//AC ASC, S-NiCo-PBA//AC ASC and Se-NiCo-PBA//AC ASC, and the specific capacitance retention rate of P-NiCo-PBA//AC ASC after 10,000 cycles is 88.25%. The phosphating strategy outperforms sulfidizing and selenizing strategies in enhancing the performance of nanocube-like NiCo-PBA supercapacitors. The accomplishment significantly broadens the potential applications of PBA-based materials as electrodes for supercapacitors.