Abstract: An electrochemical method was used to deposit aluminum on a graphite plate in a molten NaCl-KCl-AlCl₃ mixture with a weight ratio of 1:1:8 to form a coatings with different thicknesses. The thickness and morphology of the coating were controlled by the current density and electrochemical deposition time. Results indicated that the thickness of the coating increased with deposition time up to 240 min at a current density of 1.06 A/dm² and a dendritic structure coating was formed by increasing the deposition time beyond 300 min. The greater the current density, the faster the deposition rate. When the current density was increased to 3.28 A/dm², the thickness of the coating reached a maximum of 148 μm for an electrochemical deposition time of 120 min. Excellent adhesion strength between the aluminum coating and graphite substrate was proved by thermal shock resistance and scratch hardness tests. The thermal conductivity of the samples was increased significantly from an initial value of 115.7 to 199.0 W/(m·K).