Simple controllable foam structure NiCo₂S₄ for high-performance hybrid supercapacitors

In this work, to reduce the “dead volume” due to the accumulation of synthesized products, the foam-structured NiCo₂S₄ (FSNCS) with a specific surface area of 25.4 m² g ⁻¹ was successfully synthesized by using well-dispersed SiO₂ nanospheres as the framework. The FSNCS exhibited 559.3 C g ⁻¹ at a current density of 1 A g ⁻¹, which was 173.3 C g ⁻¹ higher than the performance of the NCS synthesized without the addition of SiO₂. Additionally, a hybrid supercapacitor is successfully assembled with FSNCS as the positive electrode and active carbon (AC) as the negative electrode. The FSNCS//AC displays maximum specific energy of 28.8 Wh kg⁻¹ at a specific power of 375.0 W kg⁻¹, together with good cyclic life with 88.9% capacity retention over 5000 cycles at 8 A g ⁻¹. It is worth noting that the hybrid supercapacitor can provide strong power for the operation of the motor fan. The simple structure design provides an innovative and effective way to develop high-performance energy storage devices.