Cobalt phosphide and cobalt nanoparticles (CoP-CoNC/CC) produced by the precipitation technique were implanted into N-doped nonporous carbon by Vijayakumar Elayappan et al. The material performed better electrochemically as it was being made, having a specific capacitance of 975 F g -1 at 1 mA cm 2 in a 2 M KOH electrolyte . For the electrode material of SCs, Chang Soo Lee et al. produced u-hl-MOF@Co1xS@ C (u-hl-MSC) with a core-shell structure.