High-performance supercapacitor electrodes: Hierarchical integration of bimetallic structures incorporating silver and copper phosphates with a 3D fernlike stellar dendritic architecture

Abstract

Batteries and supercapacitors remain at the front of research within the field of energy storage technologies. Over the years, the continues evolution of battery and supercapacitor device components has demonstrated remarkable advancement, evolving from simple metal blocks to complex, porous, and engineered structures composed of metal-based active materials. Towards this goal, transition metal phosphates (TM-POs) offer significant role enhancing the properties and architecture of the resulting metal-based active materials. This study introduces a unique electrode material with a dendritic structure of silver copper phosphates, derived from AgPO3 integrated with hexagonal Cu2P2O7. The improved electrochemical performance of silver copper phosphates compared to pristine AgPO3 and Cu2P2O7 is demonstrated by its increased specific capacity, reduced resistivity, higher redox activity, and a more advantageous diffusion-dominated storage mechanism. An assembled solid-state symmetric (SSCs) device, using silver copper phosphate electrodes exhibits a capacitance of 298.5 F g−1 at 15 mA cm−2, and high energy density of 20.3 Wh kg−1 with superior power density, also retains 91.7 % of its capacitance after 7000 cycles. When assembled a solid-state asymmetric supercapacitor (SSACs), as an integrated device using activated carbon and silver copper phosphate electrodes exhibits a high energy density of 30.62 Wh kg−1 at a power density of 1334 W kg−1 with retaining its capacity retention of 87.9 % even after 10,000 cycles. The enhanced capacity performance is further evaluated through first-principle investigations, elucidating that the distinct and intact heterostructure of silver copper phosphate exhibits improved metallic characteristics. This research of innovative electrodes holding superior properties holds potential for advancing next-generation electrodes for supercapacitor devices.