Improved electrochemical performance for alkali and alkaline metal doped nanostructures as electrode material for energy storage applications

Abstract

Bismuth phosphate is one of the emerging electrode materials for various energy storage applications. Here we analyzed the electrochemical behavior of pure as well as alkali and alkaline metal (Na, K, and Mg) doped bismuth phosphate nanostructures synthesized using the microwave method. The phase and crystal structure of all the synthesized samples was confirmed through XRD. FESEM and High-resolution transmission electron spectroscopy (HRTEM) confirm the morphology and planes of prepared samples. Various oxidation states of the best-performed material were analyzed through X-ray photoelectron spectroscopy (XPS). Different doping elements play a significant role in tuning the electrochemical property of working electrodes for supercappetry/energy storage applications. All the pure and alkali doped working electrodes exhibited the high potential window of 1.4 V in an aqueous electrolyte which is an important parameter to enhance the energy density for the device applications. The specific capacity calculated from GCD is found to be maximum for Na-doped bismuth phosphate nanostructures, i.e., 1020 Cg−1 at the current density of 2 Ag−1. The cycle stability test was performed for the Na-doped bismuth phosphate sample for 3000 cycles with 86 % retention.