Process for stabilizing primary electrochemical generators with reactive anodes made from zinc, aluminum or magnesium and an anode for such a generator stabilized by this process

Abstract

A process is provided for stabilizing a primary electrochemical generator comprising at least one reactive anode made from a metal chosen from the group comprising zinc, aluminum and magnesium, characterized in that to said electrode is added a percentage of 0.01% to 1% by weight with respect to the metal, of at least one .[.perfluorated.]. .Iadd.polyfluorated .Iaddend.organic compound of the ethoxylated fluoroalcohol type. It also relates to an anode obtained by the above mentioned process and a primary electrochemical generator, with alkaline or saline electrolyte, comprising an anode of this type.

I claim: 
     
       1. Process for stabilizing a primary electrochemical generator comprising at least one reactive anode made from a metal taken from the group consisting of zinc, aluminium and magnesium, characterized in that there is added to said electrode a percentage of 0.01% to 1% by weight with respect to the metal of at least one .[.perfluorated.]. .Iadd.polyfluorated .Iaddend.organic compound of the ethoxylated fluoroalcohol type. 
     
     
       2. The stabilization process according to claim 1, characterized in that the anode, being made from zinc, comprises mercury in an amount less than 2% by weight with respect to the zinc, .[.more especially when it is intended for an alkaline electrolyte generator.].. 
     
     
       3. The stabilization process according to claim 1 or 2, characterized in that the .[.perfluorated.]. .Iadd.polyfluorated .Iaddend.compound corresponds to the formula:   C.sub.n F.sub.2n+1 --(CH.sub.2).sub.p --(CH.sub.2 CH.sub.2 O).sub.q --OH (1)     in which:   n is between 4 and 20.[., preferably between 6 and 8.].;   p is between 1 and 10 g .[.and is preferably close to 2,.]..Iadd.; .Iaddend. and   q is between 3 and 40.[., preferably between 10 and 12.]..   
     
     
       4. The stabilization process according to claim 3, characterized in that the .[.perfluorated.]. .Iadd.polyfluorated .Iaddend.organic compound has the formula:   C.sub.6 F.sub.13 C.sub.2 H.sub.4 (C.sub.2 H.sub.4 O).sub.q OH (3)     in which q is close to 12.   
     
     
       5. The stabilization process according to claim 3, characterized in that a mixture of two or more compounds according to the formula (1) of claim 3, are used. 
     
     
       6. The stabilization process according to claim 5, characterized in that polyfluorated organic .Iadd.compound .Iaddend.is formed by the mixture of the two following compounds:   C.sub.6 F.sub.13 C.sub.2 H.sub.4 (C.sub.2 H.sub.4 O).sub.14 OH (4)     and     C.sub.10 F.sub.21 C.sub.2 H.sub.4 (C.sub.2 H.sub.4 O).sub.14 OH     with a mean molecular mass corresponding to the compound:     C.sub.6 F.sub.15 C.sub.2 H.sub.4 (C.sub.2 H.sub.4 O).sub.14 OH.     
     
     
       7. The stabilization process according to claim 1 or 2, characterized in that the .[.perfluorated.]. .Iadd.polyfluorated .Iaddend.organic compound corresponds to the formula:   C.sub.n F.sub.2n-1 --(CH.sub.2).Iadd..sub.p .Iaddend.--(CH.sub.2 CH.sub.2 O).sub.q --OH                                             (2)     in which:   n is between 4 and 20 .[., preferably 6 and 8.].;   p is between 1 and 10 .[.and is close to 2.].; .Iadd.and .Iaddend.   is between .[.and.]. 3 and 40 , preferably between .Badd.10 and 12.]..Baddend..   
     
     
       8. The stabilization process according to claim 7, characterized in that the .[.perfluorated.]. .Iadd.polyfluorated .Iaddend.compound corresponds to the formula: ##STR3## .[. 
     
     
       9.  An anode for a primary electrochemical generator obtained by the process according to any one of the preceding claims..]. .[.10. A primary electrochemical generator with alkaline electrolyte, characterized in that it comprises an anode according to claim 9, particularly with the limitation according to claim 2..]. .[.11. A primary electrochemical generator with saline electrolyte, characterized in that it comprises an 
     
     
        anode according to claim 9. .]. .Iadd.12.  The stabilization process according to claim 3, wherein n is between 6 and 8, p is close to 2 and q is between 10 and 12. .Iaddend. .Iadd.13. The stabilization process according to claim 3, wherein n is between 6 and 8 and q is between 10 and 
     
     
        12. .Iaddend. .Iadd.14.  An anode for a primary electrochemical generator comprising a metal taken from the group consisting of zinc, aluminum and magnesium and a percentage from 0.01% to 1.0% of at least one polyfluorated organic compound of the ethoxylated fluoroalcohol type. .Iaddend. .Iadd.15. An anode for a primary electrochemical generator according to claim 14, wherein the metal is zinc and further comprising mercury in an amount less than 2% by weight with respect to zinc. .Iaddend. .Iadd.16. An anode for a primary electrochemical generator according to claim 14, wherein the polyfluorated compound has the formula:   C.sub.n F.sub.2n+1 --(CH.sub.2).sub.p --(CH.sub.2 CH.sub.2 O).sub.q --OH     in which:   n is between 4 and 20,   p is between 1 and 10, and   
     
     
       q is between 3 and 40. .Iadd.17.  An anode for a primary electrochemical generator according to claim 16, wherein the polyfluorated organic compound has the formula:   C.sub.6 F.sub.13 C.sub.2 H.sub.4 (C.sub.2 H.sub.4 O).sub.q OH     in which q is close to 12. .Iaddend. .Iadd.18. An anode for a primary electrochemical generator according to claim 16, comprising two or more of the polyfluorated compounds. .Iaddend. .Iadd.19. An anode for a primary electrochemical generator according to claim 18, comprising     C.sub.6 F.sub.13 C.sub.2 H.sub.4 (C.sub.2 H.sub.4 O).sub.14 OH     and   C 10  F 21  C 2  H 4  (C 2  H 4  O) 14  OH   in amounts such that the polyfluorated component has a mean molecular mass corresponding to the compound:     C.sub.7 F.sub.15 C.sub.2 H.sub.4 (C.sub.2 H.sub.4 O).sub.14 OH. .Iaddend.     
     
     
        .Iadd.20.  An anode for a primary electrochemical generator according to claim 14 wherein the polyfluorated organic compound has the formula:   C.sub.n F.sub.2n-1 --(CH.sub.2).sub.p --(CH.sub.2 CH.sub.2 O).sub.q --OH     in which:   n is between 4 and 20,   p is between 1 and 10, and   
     
     
       q is between 3 and 40. .Iaddend. .Iadd.21.  An anode for a primary electrochemical generator according to claim 20, wherein the polyfluorated compound has the formula: ##STR4## 
     
     
        .Iaddend. .Iadd.22.  A primary electrochemical generator with alkaline electrolyte, characterized in that it comprises an anode according to claims 14 to 21. .Iaddend. .Iadd.23. A primary electrochemical generator with saline electrolyte, characterized in that it comprises an anode according to claims 14 to 21. .Iaddend.