TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Composition: The electroconductive particles (1) are carbon-type electroconductive particles containing metallic element. The metallic element is chosen from platinum, gold, silver, copper, nickel, chromium, zirconium, and titanium. The content of metallic element on at least one surface of the layer (1) is 0.5 atomic% or more. The layer (1) has the region (A) and region (B). The region (A) is located on one surface of layer (1), and contains carbon-type electroconductive particles or electroconductive particles containing metallic element. The concentration of region (A) is increased with respect to the region (B). The region (B) contains electroconductive particles containing metallic element. The metallic element of metal thin-film layer is chosen from copper, nickel, chromium, titanium, platinum, iron, aluminum, zirconium, gold, and silver or its alloy, oxide, carbide, nitride, silicide, boride and phosphide. The content rate of carbon-type electroconductive particles (2) in layer (2) is more than the content rate of carbon-type electroconductive particles in layer (3). The content of carbon-type electroconductive particles (2) is 20 pts. wt. or more with respect to 100 pts. wt. polymeric material (2). Preferred Process: The metal thin-film layer of layer (2) is formed by physical forming-into-a-film method and/or chemical forming-into-a-film method. Preferred Properties: The thickness of metal thin-film layer of layer (2) is less than 1 mu m. The battery electrical power collector has thickness of 1-100 mu m, electrical resistance per unit area along thickness direction of less than 10 Omega .cm2, and surface resistivity of 100 Omega /square or less.    TECHNOLOGY FOCUS - POLYMERS - Preferred Composition: The electroconductive material further contains saturated hydrocarbon-based polymeric compound (b) having hydroxyl group. The content of carbon-type electroconductive particles (2) in the layer (2) is more than the content of carbon-type electroconductive particles in the layer (3). The polymeric material (2) is chosen from elastomer, denatured polyolefin, ethylene-vinyl acetate copolymer, polyamide, polyimide and polyamidoimide. The high molecular compound (a) has structural unit derived from cyclic olefin in a principal chain. The high molecular compound (a) having alicyclic structure is norbornene-type polymer and/or its hydrogenated substance. The component (b) has structural unit of vinyl alcohol as main component. The weight ratio of electroconductive particle (1) and polymeric material (1) is 1:99-99:1. The polymeric material (3) is chosen from polyvinyl acetate, polyamide, polyamidoimide, polyimide, polycarbonate, polyethylene terephthalate, polybutylene terephthalate, cyclic polyolefin, polyphenylene sulfide, polytetrafluoroethylene, polyetheretherketone, silicone, nylon, vinylon, polyethylene, polypropylene and polyphenylene ether. The weight ratio of polymeric-material (3) and electroconductive particles is 1:99-99:1. Preferred Property: The epoxy equivalent of the epoxy resin (c) is 500 g/equivalent or less.