▎ 摘　　要

NOVELTY - Composite material comprises carbon matrix arranged in layers, and graphite particles filled between the carbon matrix sheets, heat conduction film waste material, and doping element. The ratio of the D90 of the carbon matrix to the D90 of the graphite particles is ≥ 10. The heat conduction film waste material comprises graphene heat conduction film, natural graphite heat conduction film and/or artificial graphite heat conduction film. The carbon matrix includes graphene and/or graphite. The doping element includes iron, cobalt, copper, nickel, chromium, zinc and/or manganese. USE - The composite material is useful for secondary battery (claimed). ADVANTAGE - In the composite material, the stacked carbon matrix has ultra-high electrical conductivity, which can form a conductive path and improve the electrical conductivity of the composite material, the graphite particles filled between the carbon matrix sheets can increase the conductive contact point, enhances the connectivity of the conductive path, can ensure the full contact between the carbon matrix sheet and the graphite particles, ensures the integrity of the conductive network, and improves the conductive performance and capacity of the composite material. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: a method for preparing composite material; and a secondary battery.