Graphene electrode assisted additive-free synthesis of crystalline silver dendrites: An efficient material for supercapacitor applications

Abstract

In this work, highly crystalline silver dendrites are synthesized by a simple and low-cost process using graphene as anode and cathode electrodes in the two-electrode electrochemical system. The silver dendrites dewet to form a beehive-like shape on the graphene electrode substrate (cathode), which is easily detached further. This preparation method of substrate-isolated silver dendrites without using any additive is unique and different from other conventional methods of synthesizing silver dendrites. The prepared silver dendrites were utilized in an activated carbon (AC)-based supercapacitor electrode. The charge-discharge analysis shows that the hybrid material composed of activated carbon and silver dendrites (AC/AgD) shows an improved specific capacitance of 367 F/g compared to that (188 F/g) of activated carbon at 1 A/g and excellent cyclic stability of 98.7 % capacitance retention after 10,000 cycles. Cyclic voltammetry analysis shows that AC/AgD has a maximum specific capacitance of 363 F/g at 1 mV/s. Moreover, a solid-state symmetric supercapacitor with AC/AgD electrode materials has a wide working potential of 1.7 V and shows an excellent energy density of 77.47 Wh/kg at a power density of 4250 W/kg and a good cycle life. The unique architecture and high electric conductivity of dendritic silver facilitate efficient electron transport and effective charge storage. The study underscores a novel route of synthesis of silver dendrites and their application in next-generation energy storage devices.