Graphite materials prepared by HTT of unburned carbon from coal combustion fly ashes: Performance as anodes in lithium-ion batteries

► The graphite-like materials prepared have provided reversible capacities of 310 mA hg−1 and a remarkable stable capacity along cycling. ► The high degree of crystallinity and the irregular particle shape with no flakes appear to be determinant factors for the anodic performance. ► The utilization of the materials prepared from coal fly ashes unburned carbon concentrates as anode in lithium-ion batteries appear feasible.