Especially preferred are graphite microbeads such as those produced by Osaka Gas in Japan (MCMB 25-28, 10-28, or 6-28).Suitable conductive additives for the anode composition include carbons such as coke, carbon black, carbon fibers, and natural graphite, metallic flake or particles of copper, stainless steel, nickel or other relatively inert metals, conductivemetal oxides such as titanium oxides