A novel cathode composition for use in a metal/fluorinated carbon battery is produced by mixing fluorinated carbons made from anisotropic and isotropic carbon, where the anisotropic carbon is carbon fiber and the isotropic carbon is graphite. This cathode composition has higher specific capacity and higher discharge rate capability than commonly used industrial products made using fluorinated petroleum cokes or similar materials. In addition this composition undergoes much less swelling (increase in volume) during discharge when compared with the commonly used fluorinated carbon.