Rechargeable electrochemical accumulator

Abstract

A metallic lithium rechargeable electrochemical accumulator, including at least one lithium metal electrode and at least one polymeric electrolyte gel. The accumulator is capable of operating at temperatures from −20 to 60° C., essentially without formation of lithium dendrites on the whole surface of the metallic lithium electrode. The above is also wherein a particularly long life, even with intensive use at low temperature. The rechargeable accumulator can be produced by use of a production method with particular application of temperature control during the specific production stages. As a result of the extremely high electrochemical performance of said accumulator, in particular the remarkable stability thereof, the accumulator can be used in new application fields such as hybrid vehicles, electric vehicles and emergency supply systems such as those of the UPS type.

1 . (canceled) 
     
     
         2 . Metallic lithium rechargeable electrochemical accumulator comprising at least one anode made of metallic lithium or a lithium rich intermetallic alloy and at least one cathode separated by an separator, each of the anode, cathode and separator being in the form of a film, said separator being impregnated by a crosslinked polymeric gel electrolyte,
 the surface of the anode which faces the electrolyte having a passivation film formed of the crosslinked polymeric gel electrolyte which occupies the space between the electrodes and the separator and the cavities of the materials which form the electrodes and the separator.   
     
     
         3 . An accumulator according to  claim 2 , wherein the film forming the cathode is made of a material selected from LiFePO 4 , LiCoO 2 , LiNiO 2 , Li4Ti 5 O 12  and mixtures thereof. 
     
     
         4 . An accumulator according to  claim 2 , wherein the anode is made of a film of metallic lithium film or of an intermetallic lithium rich alloy film. 
     
     
         5 . An accumulator according to  claim 4 , wherein the intermetallic alloy is an Li—Al, Li-steel, Li—Sn or Li—Pb alloy. 
     
     
         6 . An accumulator according to  claim 2 , wherein the separator is made of polyethylene, polypropylene, polyether or a polyethylene/polypropylene mixture. 
     
     
         7 . An accumulator according to  claim 2 , wherein the polymer electrolyte gel further comprises at least one organic or inorganic additive. 
     
     
         8 . An accumulator according to  claim 7 , wherein the additive is glass or ceramic. 
     
     
         9 . An accumulator according to  claim 7 , wherein the additive is selected from titanium oxides, aluminum oxides and mixtures thereof, and the additive content is less than 10% w/w. 
     
     
         10 . An accumulator according to  claim 2 , wherein the polymeric gel electrolyte contains a lithium salt selected from LiBF 4 , LiPF 6 , LiTFSI, LiBETI, LIFSI and mixtures thereof. 
     
     
         11 . An accumulator according to  claim 2 , wherein:
 the cathode is made of a material selected from LiFePO 4 , LiCoO 2 , LiNiO 2 , Li 4 TiO 12  and mixtures thereof;   the anode is made of metallic lithium or an intermetallic alloy film selected from Li—Al, Li-steel, Li—Sn or Li—Pb alloy;   the polymer gel electrolyte contains a lithium salt and an additive selected from titanium oxides, aluminum oxides and mixtures thereof, and the additive content is less than 10% w/w.