Analyzing synthesis routes for BaCuPO₄: implications for hydrogen evolution and supercapattery performance

In recent years, energy storage and conversion tools have evolved significantly in response to rising energy demands. Owing to their large surface area, superior electric and chemical stabilities, and thermal conductivities, barium copper phosphate (BaCuPO₄) materials are promising electrode materials for electrochemical energy storage systems. In this study, the synthesis of nanostructures (NSs) using hydrothermal and chemical precipitation methods and exploring the electrochemical characteristics of BaCuPO₄ in asymmetric supercapacitors provides a comparative investigation. Systematic characterization shows that nanomaterials prepared by applying the hydrothermal method have a more crystalline and large surface area than chemical precipitation. In the three cell arrangements, the hydrothermally prepared BaCuPO₄ NSs delivered a high specific capacity (764.4 C g^-1) compared to the chemical precipitation route (660 C g^-1). Additionally, the supercapattery associated with the two electrode assemblages delivers an optimum specific capacity of 77 C g^-1. The energy and power density of BaCuPO₄//AC NSs were 52.13 W h kg^-1 and 950 W kg^-1, respectively. A durability test was also performed with BaCuPO₄//AC NSs for 5000 consecutive cycles. Further, the coulombic efficiency and capacity retention of BaCuPO₄//AC after 5000 cycles were 81% and 92%, respectively. Bimetallic phosphate is comparatively suggested for future perspectives towards HER to overcome the performance of single metal phosphate materials. This is the first approach, we are aware of, for investigating the electrochemical behavior of BaCuPO₄, and our results suggest that it may be useful as an electrode material in electrochemical systems requiring high energy and rate capabilities.