TECHNOLOGY FOCUS - POLYMERS - Preferred Fluoropolymer Content: The content of fluorinated polymers is 0.1-10 wt.% and more preferably 0.5-5 wt.%.Preferred Fluoropolymers: The preferred fluorinated polymers are PVDF, PHFP, PCTFE, PTFE, PVF2 and PVF.Preferred Positive Electrode: The positive electrode is a composite material comprising a compound inert to electron conduction and favorizing the transfer of electric charges to a collector such as graphite, acetylene black and the polymeric electrolyte. It is constituted by a mixed or intercalated compound comprising compounds or salts of an alkali transition metal possessing a strong electronic activity with respect to alkali metals and capable of imposing on them when they are in an ionized state a weak chemical potential as compared with that which they exhibit in the metallic state. It comprises carbon, transition metal based active matter and a polymeric electrolyte matrix. The active matter is vanadium, manganese, nickel or cobalt oxide or a mixture of these oxides. Its thickness is 10-150 mum (more preferably 10-100 mum) and it contains 20-80 wt.% (more preferably 25-65 wt.%) of active matter.Preferred Negative Electrode: The negative electrode is of lithium.Preferred Polymeric Electrolyte: The macromaterial is a poly(ethylene or butylene oxide) or polyoxyalkylene based polyether. It contains 5-30 wt.%, but most preferably 8-25 wt.% of magnesium oxide and may also contain 0.5-3 wt.% of an antioxidant, which is preferably a quinone derivative, hydroquinone or a phenolic antioxidant. It is prepared by extrusion or by coextrusion with the electrode films. EXAMPLE - A comparison was made between two batteries. The first, inventive, battery had a positive electrode comprising a mixture of vanadium oxide, electrolyte and acetylene black (12 vol.%). The negative electrolyte was lithium. The electrolyte was composed of 69.7 wt.% of mol.wt. 300000 poly(ethylene oxide) in which was placed in solution sufficient lithium trifluorosulfonylimidide to give an atomic oxygen/lithium ratio of 20 (17.6%), 9.8 wt.% magnesium oxide, 0.7 wt.% antioxidant and 2.2 wt.% PVDF/HFP copolymer. The positive electrode was 60 mum thick with a capacity about 1 mAh/cm2, the negative electrode of uniform surface and the electrolyte were 50mum thick. The second battery had identical positive and negative electrodes, but the electrolyte consisted of 71.3 wt.% poly(ethylene oxide), sufficient lithium trifluorosulfonylimide to give a ratio of 20 (18%), 10% magnesium oxide and 0.7 wt.% antioxidant. The two batteries were cycled at a controlled current density. The charging time was 10 hours and the discharge time 5 hours. The charging current was progressively increased until the maximum capacity of the battery was attained or a short circuit resulting from the formation of a dendrite occurred. The second battery short circuited when the charging current density exceeded 0.1 mA/cm2. The first battery could be charged up to 0.2 mA/cm2 without causing a short circuit.