The invention report discloses nanostructured composites intended for energy storage applications, e.g. Li-ion batteries, and the method of producing the composites. The materials concept and approach have been successfully reduced recently into practice. The nano-composites are made from a semi-conductive, electrochemically active phase and a highly electron conductive minor phase, in particular graphene that electrically interconnects the active phase in three dimensions, only with a very small amount (~1%). One step, scalable approach was conceived and successfully used to fabricate the nanocomposites. The synthesized composites as electrodes of Li-ion batteries demonstrated significantly improved electrochemical performance, in particular in the power and energy. Thus the nanocomposites are promising electrode materials in high energy/power batteries for applications, such as plug in hybrid electrical vehicles.