NOVELTY - A composite electrical power collector has a current-collection substrate, and an electroconductive conclusion layer containing highly branched polymer having nitrogen-containing repeating unit (I) or (II) and carbon nanotube formed on substrate.    USE - Composite electrical power collector is used for electrode of secondary battery and capacitor (claimed) for electrical automotive applications.    ADVANTAGE - The hyper-branched polymer of composite electrical power collector has high adhesiveness with respect to current collector substrate. The electroconductive conclusion layer of composite electrical power collector has high carbon nanotube concentration. The energy storage device comprising the composite electrical power collector has suppressed decrease in voltage, large electrical current characteristics and durability.    DETAILED DESCRIPTION - A composite electrical power collector has a current-collection substrate, and an electroconductive conclusion layer containing highly branched polymer having nitrogen-containing repeating unit of formula (I) or (II) and carbon nanotube formed on substrate.    Ar1-Ar3=bivalent organic group of formula (iii)-(vii);    Z1,Z2=H, alkyl optionally having 1-5C branched structure or monovalent organic group of formula (viii)-(xi), where Z1 and Z2 are not alkyl simultaneously;    R1-R4=H, halo, alkyl optionally having 1-5C branched structure, alkoxy optionally having 1-5C branched structure, carboxy, sulfo, phosphoric acid group, phosphonic acid group or their salts;    R5-R38=H, halo, alkyl optionally having 1-5C branched structure, alkoxy optionally having 1-5C branched structure, carboxy, sulfo, phosphoric acid group, phosphonic acid group or their salts;    R39-R62=H, halo, alkyl optionally having 1-5C branched structure, haloalkyl optionally having 1-5C branched structure, phenyl, OR63, COR63, NR63R64, COOR65, carboxy, sulfo, phosphoric acid group, phosphonic acid group or their salts;    R63,R64=H, alkyl optionally having 1-5C branched structure, haloalkyl optionally having 1-5C branched structure or phenyl;and    R65=alkyl optionally having 1-5C branched structure, haloalkyl optionally having 1-5C branched structure or phenyl.    INDEPENDENT CLAIMS are included for the following:    (1) electrode for energy storage device, which has composite electrical power collector and active material layer formed on electroconductive conclusion layer of composite electrical power collector; and    (2) composition for forming electroconductive conclusion layer, which includes highly branched polymer having nitrogen-containing repeating unit (I) or (II) and carbon nanotube.