Designing advanced electrode materials that can be reliably cycled at high temperatures and used for assembling advanced energy storage devices remain a major challenge. As a representative of novel wide bandgap semiconductors, silicon carbide (SiC) single crystals have broad prospects in high-temperature energy storage due to their excellent characteristics such as low thermal expansion coefficient, high temperature radiation resistance and stable chemical properties. In this work, an N-type SiC single-crystal material with a high-density porous structure was successfully designed and prepared by using an improved electrochemical anodic oxidation strategy. Besides, the N-type SiC single crystals were used in electrochemical energy storage as an integrated electrode material, exhibiting superior electrochemical performance. In addition, the high-temperature supercapacitor device assembled with ionic liquids has a wide operating temperature range and maintains a capacity of 88.24% after 5000 cycles at 150 °C. The reasons for its high energy storage performance are discussed through electrochemical tests and first-principles calculation methods. This study proves that the application of SiC single crystals in supercapacitor devices has great potential in the field of high-temperature energy storage, providing a reference for the further development of novel semiconductors in the field of energy storage and optoelectronic devices.