▎ 摘　　要

NOVELTY - Mesoporous polydopamine/graphene nanosheet composite comprises graphene substrate and mesoporous polydopamine nanosheet, where mesoporous polydopamine nanosheet is attached to the graphene substrate. The mesoporous polydopamine/graphene nanosheet composite material is provided with spherical or spheroidal mesopores. USE - Mesoporous polydopamine/graphene nanosheet composite used in porous electrode material, supercapacitor, membrane and battery (all claimed). ADVANTAGE - The mesoporous polydopamine/graphene nanosheet composite material has excellent electrochemical performance, and shows high mass specific capacity and excellent cycling stability when used as an active electrode material of a supercapacitor. The battery diaphragm is modified to construct a functional diaphragm, so that the metal cathode is endowed with high coulombic efficiency and ultra-long cycle performance. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) Method for the preparation of mesoporous polydopamine/graphene nanosheet composite, which involves: (1) reacting a mixture containing graphene oxide, a mesoporous template, a dopamine monomer and an initiator to obtain an intermediate product; (2) sequentially carrying out reduction treatment and template agent removal on the intermediate product to obtain the mesoporous polydopamine/graphene nanosheet composite material. (2) Porous electrode material, which comprises polydopamine/graphene nanoplatelet composites and mesoporous polydopamine/graphene nanoplatelet composites. (3) Membrane, which comprises mesoporous polydopamine/graphene nanoplatelet composite and mesoporous polydopamine/graphene nanoplatelet composite.