An inner layer of the high-heat-
conductivity aluminum-plastic
composite film is composed of a modified material prepared from charged
polythiophene derivatives and high-heat-
conductivity filler and a
polyethylene heat-sealing material, a middle layer of the high-heat-
conductivity aluminum-plastic
composite film is an
aluminum foil subjected to
plasma treatment, and an outer layer of the high-heat-conductivity aluminum-plastic
composite film is a PET film subjected to
corona treatment. The preparation method of the composite film comprises the following steps: 1, preparing a modified material from charged
polythiophene and a high-thermal-conductivity filler, and carrying out mixed melting,
extrusion and
casting on the modified material and a heat-sealing material to obtain an inner-layer material; 2, performing
plasma treatment on the
aluminum foil to serve as an intermediate layer material; 3, carrying out
corona treatment on PET, and taking the treated PET as an outer layer material; 4, performing composite molding on the inner layer material, the middle layer material and the outer layer material; the
composite membrane is used for packaging the
lithium ion battery. The modified material added with the high-thermal-conductivity filler is introduced into the inner layer of the composite film, so that the
thermal conductivity of the composite film is improved, good
chemical stability is kept, the packaging reliability of the composite film is ensured, and the requirements of the
lithium ion battery in high-power, high-energy-density and high-safety scenes are met.