Composite current collector and preparation method and application thereof

The invention provides a composite current collector and a preparation method and application thereof. The composite current collector comprises a polymer supporting layer; the transition layer is arranged on the surface of at least one side of the polymer supporting layer, the material of the transition layer comprises a nano-metal material modified by a silane coupling agent, and the nano-metal material comprises a nano-metal simple substance and/or a nano-metal oxide; and the conductive layer is arranged on the surface of the transition layer along the direction far away from the polymer supporting layer. The nano-metal material modified by the silane coupling agent is introduced as the transition layer, organic and inorganic interfaces can be tightly combined, the bonding force between the polymer supporting layer and the transition layer is improved, meanwhile, the particle aggregation degree can be reduced through modification of the silane coupling agent, the particles are evenly distributed in the tra