operating as a negative electrode collector and was dried in situ to form a layer of an active material of the negative electrode which was then compression molded to form a negative electrode first 42 5 parts by weight of ethylene carbonate 42 5 parts by weight of propylene carbonate and 15 parts by weight of lipf 6 were mixed together to prepare a plasticizer to 30 parts by weight of the plasticizer were mixed 10 parts by weight of a copolymer of vinylidene fluoride and hexafluoropropylene and 60 parts by weight of tetrahydrofuran and dissolved to prepare a gelated electrolyte the gelated electrolyte was coated on a teflon sheet to give a film of a gelated electrolyte which was sandwiched between a layer of an active material of the positive electrode and a layer of an active material of the negative electrode and pressure bonded together to prepare a flat plate gelated electrolyte cell having an area of 2 5 cm by 4 0 cm and a thickness of 0 3 mm first lithium carbonate and cobalt carbonate were mixed at a ratio of 0 5 mol to 1 mol and the resulting mixture was fired in air at 900 u00b0 c for five hours to produce licoo 2 as an active material for the positive electrode 42 5 parts by weight of.