▎ 摘　　要

NOVELTY - A composite electrode material has a porous honeycomb structure comprising cobalt-manganese phosphate and has aperture of 10-15 nm and nitrogen-doped graphene covered uniformly on the surface. USE - Composite electrode material for supercapacitor and asymmetric capacitor (all claimed). ADVANTAGE - The composite electrode material is prepared by a simple, convenient and fast one-step method. The porous structure of the electrode material provides enough channel for transfer of solution ions, specific capacity of up to 2033.4 F/g, power density of 602.1 W/kg, energy density of 141.2 Wh/kg, high retention rate, excellent circulation stability and initial capacitance of 86.7% even after 5000 cycles. DETAILED DESCRIPTION - A composite electrode material has a porous honeycomb structure comprising cobalt-manganese phosphate (Co0.55Mn0.45)2P2O7 and has aperture of 10-15 nm and nitrogen-doped graphene covered uniformly on the surface. An INDEPENDENT CLAIM is included for preparation of the composite electrode material, which involves dissolving cobalt chloride hexahydrate, manganese acetate tetrahydrate in ethylene glycol solution in the ratio of 0.490-0.981 g:0.238-0.714 g:20-50 mL to obtain cobalt-manganese precursor solution (A), adding phytic acid to the solution (A) to obtain precursor solution (B), adding urea and ultrasonically stirring to obtain solution (C), reacting the obtained mixture under microwave conditions, cooling obtained product to room temperature, and drying under vacuum.