Multilayer composite positive electrode of lithium-sodium double-ion system, hybrid capacitor and preparation method of hybrid capacitor

The invention relates to the field of capacitors, and provides a multi-layer composite positive electrode of a lithium-sodium dual-ion system, a hybrid capacitor and a preparation method of the hybrid capacitor in order to solve the problem of poor low-temperature performance of the lithium-ion hybrid capacitor. A current collector is arranged in the middle of the multi-layer composite positive electrode, the two sides of the current collector are coated with inner layers, the outer sides of the inner layers are coated with outer layers, the inner layers adopt lithium ion/capacitance carbon mixed electrodes, the outer layers adopt sodium ion/capacitance carbon mixed electrodes, and the coating surface density ratio of the inner layers to the outer layers is 1: (0.25-4); the sodium ion system improves the low-temperature performance of the capacitor, the lithium ion system ensures the energy density, so that the low-temperature performance of the device is improved under the condition that the energy density o