To realize constituent elements for realizing a nonaqueous secondary battery having
high energy density and high repeating stability, and a nonaqueous secondary battery using the same. To present also a
lithium ion secondary battery of light weight and
high energy density to be used in various electronic appliances and power source of
electric vehicle or the like. By using
vanadium oxide expressed as M2+xV4O11, where x is 0 or more to 1 or less, and M is a monovalent
metal ion such as Cu and Li, as positive
electrode, a nonaqueous secondary battery having
high energy density and high repeating stability is obtained. Moreover, by using the carbon obtained by heating a cured resin by adding an aromatic compound of 2 to 10 rings to a
high polymer before curing, as negative
electrode, a nonaqueous secondary battery of high
energy density is obtained. By composing an electrochemical element by using a gel or
solid ion conductor having an iron containing an organic cationic structure including
quaternary nitrogen or its derivative and different cations at least as coexistent ions, a nonaqueous secondary battery of high
energy density is obtained. As the
current collector of the battery, by using a
graphite sheet obtained by baking a
high polymer film, a
lithium ion secondary battery of light weight, excellent cycle characteristics and high
energy density is presented.