TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Salt: The lithium salt is chosen from lithium hexafluorophosphate (LiPF6), lithium-chlorine complex (LiClO4), lithium hexafluoro arsenate (LiAsF6), lithium tetrafluoro borate (LiBF4) and lithium-sulfonate salts such as LiCF3SO3, LiC2F5SO3, LiC4F9SO3, LiN(CF3SO2)2, LiN(C2F5SO2)2 and LiC(CF3SO2)3.    TECHNOLOGY FOCUS - POLYMERS - Preferred Polymer: The polymer is obtained by polymerizing spiro ring system monomer (A) having polymerizable functional group in a molecule, salt monomer (B) having at least one polymerizable functional group in a molecule, a monomer (C) having 2 or more polymerizable functional group in a molecule, and monomer (D) having a polymerizable functional group in a molecule. The spiro ring system has at least one oxygen atom. The polymerization is carried out by actinic-ray irradiation and/or heating. Preferred Monomer: The monomer (B) has organic anion with polymerizable functional group and onium cation with polymerizable functional group. The onium cation and the organic anion has an ion interaction between the lithium salt. The monomer (B) is of formula (1). The monomer (C) contains onium salt, and is of formula (2). The monomers (B,C) have substituent of formula (3). The monomer (D) is N-alkylated (meth)acrylamide and/or (meta)acrylester, preferably N-isopropyl (meth)acrylamide. The monomer (A) has structure of formula (4), and is of formula (5). The monomers (A-D) are solid at room temperature.P1-P4=substituent having polymerizable functional group;Y-=ionic functional group concerned with ion interaction, chosen from sulfoxyl, carboxyl, phosphoxyl and sulfonimide;R1-R20=group optionally having ring system, chosen from (un)substituted alkyl or alkenyl, aryl, aralkyl, aralkenyl, alkoxyalkyl or acyloxy alkyl, and optionally couples to form cyclic structure, and contains hetero atom;X-=anion chosen from F-, Cl-, Br-, I-, ClO4-, BF4-, AsF6-, PF6-, RSO3-, RCO2-, (RO2S)2N- and (RO2S)3C-;andR=same as R1 and is free from polymerizable functional group.Preferred Group: The polymerizable functional group has carbon-carbon double bond, and is preferably chosen from (meth)acryloyl, (meth)acrylamide, (meth)acryloyloxy, allyl, vinyl, styryl, and functional group of unsaturated ring system.