Phase separation strategy achieves printable corrosion-resistant ternary SiOC supercapacitors with sustained capacitance increase

Carbon-ceramic material with well-designed components and architectures is an effective strategy to fulfill the chemical-stability requirements of long-life supercapacitors. Herein, we proposed a direct cation-induced component recombination strategy to convert the intrinsically insulated SiOC ceramic to an electrochemically active ternary state for stable and long-life capacitive energy storage. Meanwhile, the cation-induced component recombination process can be directly coupled to advanced photocurable 3D printing technology to create the integral ternary SiOC electrode with various 3D structures for a complex-shaped supercapacitor. As a result, the ternary SiOC electrodes with four-type triply periodic minimal surface structures have been successfully printed and used in an alkaline supercapacitor with high corrosivity. The integral ternary SiOC electrode with Diamond structure demonstrates high capacity (756 mF·g⁻¹ at 1.7 mA·g⁻¹). The symmetrical supercapacitor based on ternary SiOC electrodes with a Diamond structure exhibits outstanding long-term durability (181.5 % capacity retention after 10,000 cycles) in highly corrosive environments. In addition, the ternary SiOC electrode also shows extremely high cycling stability in highly corrosive seawater, with a capacity retention rate of over 95 % after 20,000 cycles. Therefore, this novel 3D-printed ternary SiOC electrodes provides an efficient approach for developing long-term stable and reliable supercapacitors for applications in highly corrosive environments.