Lithium-ion battery anode material based on spherical natural graphite containing silicates

Abstract

Materials and novel methods for producing carbon anodes for Li-ion batteries are described. These materials use natural flake graphite that has been processed to improve physical properties but retains residual impurities including silicates and other silicon containing minerals that are difficult to eliminate economically. For the purposes of battery anode material production, further purification is required and traditionally uses hydrofluoric acid, adding significant cost and environmental management requirements. Alternate novel processes result in less costly and more environmentally friendly methods when compared against the standard acid purification with hydrofluoric acid. Methods for direct graphitization of unpurified spheroidized graphite material that includes a carbonaceous coating in production of a lithium ion battery anode are provided. Materials generated using these methods may be blended with artificial graphite and particulate Silicon or SiOmaterials for enhanced properties.