Composite current collector and lithium ion battery

The invention provides a composite current collector and a lithium ion battery, the composite current collector comprises a base material, a first heat conduction layer and a first conductive layer, and the first heat conduction layer is arranged between the base material and the first conductive layer; the heat conductivity coefficient of the first heat conduction layer is larger than that of the base material, and the heat conductivity coefficient of the first heat conduction layer is larger than that of the first conductive layer. According to the composite current collector provided by the invention, the first heat conduction layer with a higher heat conduction coefficient is arranged, so that the heat of the lithium ion battery in the charging and discharging process is uniformly conducted, the lithium precipitation phenomenon caused by heat focusing is avoided, and the safety of the lithium ion battery in application is ensured. 本申请提供一种复合集流体和锂离子电池，其中，所述复合集流体包括：基材、第一导热层和第一导电层，所述第一导热层设置于所述基材和所述第一导电层之间；所述第