Effect of particle size and graphitic degree of silicon-derived carbons on electrochemical performance in aqueous electrolyte

摘要

Electrochemical double-layer capacitors (EDLCs) known as supercapacitors, typical of high power density, have received a significant level of interest for use in the electric utility industries for a variety of potential applications including hybrid electric vehicles. However, their energy density needs to be improved to meet the higher requirements in energy demand for future applications. Commercial supercapacitors are based on high surface area porous carbons [1]. Carbon materials with high surface area combining micropores and mesopores have been proven suitable for enhancing capacitance properties [2,3]. Therefore, the combination of optimal porosity and the properties of carbon materials are essential to increase the energy densities of supercapacitors. It is thus detrimental to understand the role of the carbon structure on the energy storage mechanism. Because of their high surface area and tunable pore size, carbide-derived carbons (CDC) have attracted special attention lately as electrode materials for energy storage devices[4,5]. This work presents a qualitative study on how particle size, pore size distribution and graphitization of CDC materials can affect the electrochemical performance such as the specific capacitance, the capacitance retention and the stability. SiC carbide-derived carbons (SiC-DCs) were used as electrode materials to clarify the role of the porosity along with the particle size and graphitization in aqueous electrolyte.