Growth of mesoporous carbon supported (bimetallic) phosphides derived from Prussian blue for supercapacitors

In the context of supercapacitor energy storage, maintaining high cycle stability while enhancing energy density and coulomb efficiency is crucial. In this investigation, NiCo Prussian blue analogue (PBA) electrode materials were synthesized using the coprecipitation method, and subsequently modified via sulfurization and phosphating to obtain oxides (PBAO), sulfides (PBAS) and phosphides (PBAP) derived from Prussian blue cubes. The microphysical structure of PBA was engineered to enhance conductivity and electrochemical performance, with an in-depth exploration of the effects of sulfurization and phosphating. Additionally, mesoporous carbon (SAC) was doped into the previously prepared PBA, leading to the successful preparation of SAC@PBA-P electrode material with exceptional electrochemical performance. By utilizing electrochemical testing and various characterization techniques, the underlying sources of the observed performance differences were analyzed both experimentally and through electrochemical mechanisms. Furthermore, the addition of 0.01 M potassium ferricyanide to the 3 M KOH electrolyte significantly improved the coulomb efficiency of the material under the condition of high current density and long cycle time. Finally, an asymmetric supercapacitor (ASC) was constructed using industrial activated carbon as the negative electrode with the prepared SAC@PBA-P electrode material, and its electrochemical performance was evaluated to explore the practical application potential and prospects of this material.