TECHNOLOGY FOCUS - METALLURGY - Preferred Material: 50 vol.% or less of the space of three-dimensional continuous-form carbon fiber is filled with metal microparticles of tin, silicon, lead, aluminum, gold, platinum, indium, magnesium, zinc, cadmium and/or silver, which can occlude-discharge lithium, by reduction method of metal ion, preferably electroplating.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Compounds: The compound having aromatic ring is aniline, pyrrole, thiophene, and/or their derivatives. The phosphazene compound is of formula: R1Y1-P(-Y1R1)2=N-X or (NPR22)n.R1,R2=monovalent substituent or monovalent halogen element;Y1=bivalent coupling group, bivalent element, or single bond;X=substituent containing carbon, silicon, germanium, tin, nitrogen, phosphorus, arsenic, antimony, bismuth, oxygen, sulfur, selenium, tellurium and/or polonium;andn=3-15.Preferred Composition: The non-aqueous electrolyte further contains an aprotic organic solvent.    TECHNOLOGY FOCUS - POLYMERS - Preferred Process: The 3D continuous-form carbon fiber contains fibril-like polymer obtained by oxidize-polymerizing a compound having an aromatic ring, and baking in a non-oxidizing atmosphere. The oxidation polymerization is electrolytic oxidizing polymerization. EXAMPLE - A copper electrode was immersed into aqueous acid containing aniline monomer and hydrogen tetrafluoroborate, and a platinum board was used as a counter electrode. Electrolytic polymerization was carried out at room temperature for 10 minutes to obtain polyaniline. The polyaniline was washed with ion-exchange water and vacuum dried for 24 hours, to obtain fibril-like polyaniline. The obtained polyaniline was heated to 950degreesC in argon atmosphere, maintained for 1 hour, and baked to obtained three-dimensional continuous-form carbon fiber having fibril diameter of 40-100 nm and surface resistance of 1 Omega. The carbon fiber was immersed in a solution containing tin ion dissolved in sulfuric acid, electroplated, water-washed, and dried to obtain tin-supporting carbon fiber. An organic solvent containing ethyl acetate (50 mass%) and ethanol (50 mass%) was added and kneaded to tin-supporting carbon fiber. The kneaded material was coated on a copper foil and dried at 100-120degreesC, to obtain a cathode sheet of 60 microns thickness. Acetylene black (in mass parts) (3), polyvinylidene fluoride (3), and lithium cobaltate (94) were added and mixed with the organic solvent. The resulting material was coated on an aluminum foil and dried at 100-120degreesC, to produce an anode having thickness of 80 microns. Lithium hexafluorophosphate was dissolved in a mixed solution of ethylene carbonate (in vol.%) (30), ethyl methyl carbonate (60), and phosphazene compound (10) of formula: (NPR22)n (n is 3, 1 R2 group is ethoxy and other 5 R2 groups are fluorine) to obtain a non-aqueous electrolyte. The anode and cathode were separated by TF 4030 (RTM: cellulose separator) and non-aqueous electrolyte was introduced to produce a coin-shaped lithium ion battery. The obtained battery had favorable cycle characteristics.