NOVELTY - Gel composition contains a solvent and a polymer obtained by addition reacting a compound (D) having at least3 ethylenic double bonds to a linear polymer having 2 terminal hydrosilyl groups obtained by addition reacting an ethylenic compound (A) and a silicon compound (B) optionally in the presence of a compound (A) and/or a compound (B).    USE - The composition is used in the production of batteries and electrochemical elements such as capacitors.    ADVANTAGE - The gel composition is stable.    DETAILED DESCRIPTION - (A) is of formula (CH2=CR1-R2-)2-Z1, (B) is of formula (H-Si(R3)2-R4-)2-Z2 or H-SiR3R5-H, and (D) is of formula (CH2=CR6-R7-)n1-Z3.    R1 = H, optionally substituted 1-18C alkyl or optionally substituted 6-20C aryl;    R2 = optionally substituted 1-18C alkylene, optionally substituted 6-20C arylene, optionally substituted 7-21C arylalkylene group, dialkyl(poly)silylene, diaryl(poly)silylene or a direct bond;    Z1 = polyoxyalkylene group, (poly)carbonate group, (poly)ester group, 1-36C alkylene group, 1-30C heteroatom-containing organic group with 1-6 heteroatoms, poly(meth)acrylate or a direct bond;    R3 = optionally substituted 1-18C alkyl, optionally substituted 6-20C aryl, or optionally substituted 7-21C arylalkyl group;    R4 = as R2;    Z2 = di-substituted divalent Si atom, optionally substituted 1-18C alkylene, optionally substituted 6-20C arylene, 1-30C heteroatom-containing organic group with 1-6 heteroatoms, benzene-polycarboxy group, phosphoric acid group, polyoxyalkylene group, (poly)carbonate group, (poly)ester group, poly(meth)acrylate or a direct bond;    R6 = as R1;    R7 = optionally substituted 1-18C alkylene, optionally substituted 6-20C arylene, optionally substituted 7-21C arylalkylene group, 1-30C heteroatom-containing alkylene group with 1-6 heteroatoms or a direct bond;    n1 = an integer of at least3;    Z3 = a C atom, 1-18C alkynyl group, 1-12C alkane-poly-yl group, Si atom, mono-substituted trivalent Si atom, 1-300C aliphatic group, 1-100C heteroatom-containing organic group with 1-50 heteroatoms, benzene-polycarboxy group, phosphate group, oxyphosphate group, (poly)carbonate group, (poly)ester group, poly(meth)acrylate or a direct bond.    INDEPENDENT CLAIMS are also included for (1) a gel-like ion conductive composition containing the composition above and an electrolyte; (2) a battery containing the gel-like ion conductive composition; (3) an electrochemical element containing the gel-like ion conductive composition; and (4) the manufacture of the battery or electrochemical element containing the ion conductive composition by forming the gel-like ion conductive composition, introducing into an outer shell and polymerizing or crosslinking.