Carbon wrapped CoP hollow spheres for high performance hybrid supercapacitor

Carbon coated CoP hollow spheres (CoP/C) were prepared from cobalt-based MOFs via simple calcining and subsequent phosphorization process. Meanwhile, N-doped carbon shells were also synthesized by a low-cost hard-templating method. Both of the obtained CoP/C and N-doped carbon shells deliver remarkable specific capacitances and excellent capacitance retentions when used as electrodes for supercapacitor. Remarkably, the asymmetric supercapacitor device based on the CoP/C and N-doped carbon shells delivers a high energy density of 16.14 Wh kg⁻¹ at a power density of 700 W kg⁻¹ and outstanding cycling stability (99.5% capacitance retention after 5000 cycles at a current density of 7 A g⁻¹). CoP/C should be a promising electrode material for next-generation supercapacitor application.