Cubic silicon carbide anode material for low-temperature solid oxide fuel cell

Abstract

Cubic silicon carbide (3C-SiC) synthesized with different methods was investigated as the anode material of low-temperature solid ceramic fuel cells because of high electron mobility, excellent thermal and mechanical stability, and high electrochemical reactivity towards redox-based reactions as well as low leakage current. The sample prepared via the carbothermal reduction method has multiple phases of cubic SiC (JCPDS 01–075-0254), SiO₂ (01–076-0933), and quartz (00–008-0415), respectively. Further samples developed using hydrothermal and solid-state methods show the cubic structure of SiC with JCPDS No. 01–073-1708. Fourier transform spectroscopy confirms the presence of Si–C, Si–C and Si–O bonds in the synthesized material. Raman analysis shows the transverse optical line of Si–C stretching mode in all three samples at 801 cm⁻¹. Thermal analysis reveals that the sample prepared using the solid-state method is more stable due to negligible weight loss and less decomposition during thermal heat treatment. The microstructure of materials synthesized using the solid-state method has more porosity, and therefore, better electrical conductivity of 1.1 Scm⁻¹ is obtained compared to other samples synthesized by the hydrothermal method and carbothermal reduction method, respectively. The cell reached the maximum power density of 100 mW cm⁻² with an open circuit voltage of 1.1 V at 550 °C. This work demonstrates an innovative synthesis method for 3C-SiC and novel material for developing highly efficient anode materials of solid ceramic fuel cells.

Graphical Abstract