(DE19652174-A1)      A method for the preparation of polymer electrolytes used in rechargeable lithium intercalation cells that contain a lithium salt capable of dissociation dispersed in a polymer matrix comprising a self-supporting vinylidene fluoride/hexafluoropropylene copolymer film, comprises exchanging plasticiser in the film with a solution of the lithium salt in an organic solvent so that the polymer contains 20-70 wt.% of the lithium salt solution.    The plasticiser used is stable under electrochemical conditions in the cell and is chosen from hexylene carbonate, octylene carbonate or tributyl phosphate.    ADVANTAGE -   The stability of these plasticisers compared with eg. propylene carbonate, ethylene carbonate or dimethyl carbonate ensures that they give the required diaphragm conductivity and do not lead to a rapid loss in cell capacitance, therefore they do not have to be completely extracted from polymer electrolytes.    (JP10188667-A)      A method for the preparation of polymer electrolytes used in rechargeable lithium intercalation cells that contain a lithium salt capable of dissociation dispersed in a polymer matrix comprising a self-supporting vinylidene fluoride/hexafluoropropylene copolymer film, comprises exchanging plasticiser in the film with a solution of the lithium salt in an organic solvent so that the polymer contains 20-70 wt.% of the lithium salt solution.    The plasticiser used is stable under electrochemical conditions in the cell and is chosen from hexylene carbonate, octylene carbonate or tributyl phosphate.    ADVANTAGE -   The stability of these plasticisers compared with eg. propylene carbonate, ethylene carbonate or dimethyl carbonate ensures that they give the required diaphragm conductivity and do not lead to a rapid loss in cell capacitance, therefore they do not have to be completely extracted from polymer electrolytes.    (US6077627-A)      A method for the preparation of polymer electrolytes used in rechargeable lithium intercalation cells that contain a lithium salt capable of dissociation dispersed in a polymer matrix comprising a self-supporting vinylidene fluoride/hexafluoropropylene copolymer film, comprises exchanging plasticiser in the film with a solution of the lithium salt in an organic solvent so that the polymer contains 20-70 wt.% of the lithium salt solution.    The plasticiser used is stable under electrochemical conditions in the cell and is chosen from hexylene carbonate, octylene carbonate or tributyl phosphate.    ADVANTAGE -   The stability of these plasticisers compared with eg. propylene carbonate, ethylene carbonate or dimethyl carbonate ensures that they give the required diaphragm conductivity and do not lead to a rapid loss in cell capacitance, therefore they do not have to be completely extracted from polymer electrolytes.