A latent heat storage material is in the form of a composite material formed of a phase-change material to store latent heat and graphite flakes incorporated therein to improve thermal conductivity. The graphite flakes are distinguished by a high aspect ratio and a high anisotropy of thermal conductivity. The volume content of graphite flakes in the latent heat storage material is between 10 and 40%. The composite material can be obtained by mixing the components or infiltrating a bed containing graphite flakes with a liquid phase-change material. The graphite flakes are preferably aligned during mixing with the phase-change material by shaking or tamping, etc., so that the thermal conductivity in the direction that is advantageous for the individual application is maximized. A latent heat storage unit containing the material and processes for producing the material and the unit and processes for using the material, are also provided.