(EP842216-A1)      A solid polymer electrolyte comprises a salt incorporated into a crosslinked terpolymer network which is formed by polymerisation of: (a) a 1st monomer having 2 acryloyl gps.; (b) a 2nd monomer having one acryloyl gp. or one allyl gp., and also having a high polarity due to the incorporation of a carbonate or cyano gp.; and (c) a 3rd monomer having an acryloyl or oligo(oxyethylene) gp..    Also claimed is a solid polymer electrolyte comprising a lithium salt and a plasticiser in a crosslinked polymer network of formula (I) in which R1 = H or (fluorinated) 1-10C alkyl; R2 = -C(O)-O(CH2CH2O)y1-R4; R3 = -CN or -C(O)-(OCH2CH2O)z1-OC(O)O-R4; R4 = 1-10C (fluorinated) alkyl or (fluorinated) aryl; x1, y1 and z1 = integers of 1-20; and m, n and i = the mol. reactions of monomers = 0-1.    USE -   Used in high energy rechargeable solid state batteries, super-capacitors, fuel cells, sensors, electrochromic devices, etc..    ADVANTAGE -   Thin films of the electrolyte have good mechanical properties and useful ambient temp. ionic conductivity without phase sepn..    (JP11510308-W)      A solid polymer electrolyte comprises a salt incorporated into a crosslinked terpolymer network which is formed by polymerisation of: (a) a 1st monomer having 2 acryloyl gps.; (b) a 2nd monomer having one acryloyl gp. or one allyl gp., and also having a high polarity due to the incorporation of a carbonate or cyano gp.; and (c) a 3rd monomer having an acryloyl or oligo(oxyethylene) gp..    Also claimed is a solid polymer electrolyte comprising a lithium salt and a plasticiser in a crosslinked polymer network of formula (I) in which R1 = H or (fluorinated) 1-10C alkyl; R2 = -C(O)-O(CH2CH2O)y1-R4; R3 = -CN or -C(O)-(OCH2CH2O)z1-OC(O)O-R4; R4 = 1-10C (fluorinated) alkyl or (fluorinated) aryl; x1, y1 and z1 = integers of 1-20; and m, n and i = the mol. reactions of monomers = 0-1.    USE -   Used in high energy rechargeable solid state batteries, super-capacitors, fuel cells, sensors, electrochromic devices, etc..    ADVANTAGE -   Thin films of the electrolyte have good mechanical properties and useful ambient temp. ionic conductivity without phase sepn..    (CN1192762-A)      A solid polymer electrolyte comprises a salt incorporated into a crosslinked terpolymer network which is formed by polymerisation of: (a) a 1st monomer having 2 acryloyl gps.; (b) a 2nd monomer having one acryloyl gp. or one allyl gp., and also having a high polarity due to the incorporation of a carbonate or cyano gp.; and (c) a 3rd monomer having an acryloyl or oligo(oxyethylene) gp..    Also claimed is a solid polymer electrolyte comprising a lithium salt and a plasticiser in a crosslinked polymer network of formula (I) in which R1 = H or (fluorinated) 1-10C alkyl; R2 = -C(O)-O(CH2CH2O)y1-R4; R3 = -CN or -C(O)-(OCH2CH2O)z1-OC(O)O-R4; R4 = 1-10C (fluorinated) alkyl or (fluorinated) aryl; x1, y1 and z1 = integers of 1-20; and m, n and i = the mol. reactions of monomers = 0-1.    USE -   Used in high energy rechargeable solid state batteries, super-capacitors, fuel cells, sensors, electrochromic devices, etc..    ADVANTAGE -   Thin films of the electrolyte have good mechanical properties and useful ambient temp. ionic conductivity without phase sepn..