TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Electrode: In the electrode, each of the composite carbon particles consist of particles of the second electrically conductive carbon material, and optionally third electrically conductive material, coated on the surface of a particle of the first capacitor carbon material, and where the surface coverage on the particles of the first capacitor carbon material by the second electrically conductive carbon material, and optionally third electrically conductive material, is at least 20%. The surface coverage on the particles of the first capacitor carbon material by the second electrically conductive carbon material, and optionally third electrically conductive material, is at least 50%. The particle size of the second electrically conductive carbon material is one-fifth or less of that of the first capacitor carbon material; or the particle size of the second electrically conductive carbon material is one-tenth or less of that of the first capacitor carbon material. The first capacitor carbon material is a high specific surface area carbonaceous material. It has a specific surface area of at least 500 m2/g measured by adsorption using Brunauer-Emmett-Teller (BET) isotherm. The specific surface area is at least 1000 m2/g. The first capacitor carbon material is selected from activated carbon. The second electrically conductive carbon material is a high electrically conductive carbonaceous material. Second electrically conductive carbon material has a conductivity of at least 0.6 S/cm at 500 KPa measured at 20 degrees C. It is selected from at least one of carbon black, graphite, glassy carbon, and a nanocarbon fiber. The carbon mixture comprises a third electrically conductive carbon material. Third electrically conductive carbon material is selected from at least one of carbon black, graphite, glassy carbon, and a nanocarbon fiber. Nanocarbon fiber is selected from at least one of a carbon nanowire, a carbon nanotube, and a carbon whisker. The coating layer of the carbon mixture comprises 4 to 100 parts by weight of the second electrically conductive carbon material relative to 100 parts by weight of the first capacitor carbon material. The coating layer of the carbon mixture further comprises 50 parts by weight or less of the third electrically conductive carbon material relative to 100 parts by weight of the first capacitor carbon material. Coating layer of the carbon mixture further comprises 2 to 30 parts by weight of a binder relative to 100 parts by weight of the first capacitor carbon material. The coating layer of the carbon mixture comprises 4 to 100 parts by weight of the second electrically conductive carbon material relative to 100 parts by weight of the first capacitor carbon material, 50 parts by weight or less of the third electrically conductive carbon material, 2 to 30 parts by weight of a binder, 20 parts by weight or less of a thickener, and 20 parts by weight or less of a short fiber relative to 100 parts by weight of the first capacitor carbon material. An amount of the carbon mixture for the coating layer of the electrode is 1 to 15% by weight relative to the weight of the active battery material on the electrode. The electrode is a negative electrode comprising negative active battery material for a lead-acid storage battery. The electrode is a positive electrode comprising positive active battery material for a lead-acid storage battery. Carbon mixture containing composite carbon particles is produced by at least one of grinding, granulating and unifying, the particles of the first capacitor carbon material with the particles of the second electrically conductive carbon material, and optionally third electrically conductive carbon material. Grinding is bead or ball milling. Preferred Device: The device is a lead-acid storage battery. EXAMPLE - No suitable example given.