Electrolyte separation wall for the selective transfer of cations through the wall, manufacturing process and transfer process

Abstract

An electrolyte separation wall includes an active layer of a material capable of developing intercalation and deintercalation reactions for the selective transfer of cations through the wall and a support layer made of a porous material acting as support for the active layer. A cation selective transfer process uses such a transfer wall. According to a manufacturing process of such a transfer wall, a solution including an active material in powder form, a binder and a solvent are prepared, then the surface of a support layer made of porous material is coated with the solution and the solvent is evaporated.

1 - 19 . (canceled) 
     
     
         20 . Electrolyte separation wall including a sealed active layer of a material capable of developing intercalation and deintercalation reactions for selective transfer of cations through the wall, and a support layer consisting of a porous material acting as support for the active layer. 
     
     
         21 . The wall according to  claim 20 , wherein the porous material is selected from the group consisting of mullite, silica, glass fibre, quartz and a ceramic. 
     
     
         22 . The wall according to  claim 20 , wherein porosity of the porous material is between 0.4 and 0.6. 
     
     
         23 . The wall according to  claim 20 , wherein the material of the active layer is a binary or ternary material behaving as host network and with cation reversible accommodation properties according to an oxidation-reduction reaction. 
     
     
         24 . The wall according to  claim 23 , wherein the material of the active layer is a metallic chalcogenide. 
     
     
         25 . The wall according to  claim 24 , wherein the metallic chalcogenide is a chalcogenide with molybdenum clusters (Mo n X n+2  or M x MO n X n+2 ) . 
     
     
         26 . The wall according to  claim 23 , wherein the material of the active layer is a compound of lithium and a metal in oxide, phosphate or fluoride form or a combination of these forms, and the metal being selected from the group consisting of nickel, cobalt, iron, manganese, vanadium, titanium and chrome. 
     
     
         27 . A manufacturing process for an electrolyte separation wall comprising: preparing a solution including an active material in the form of a powder, a binder and a solvent, coating a surface with a support layer of porous material with said solution, and evaporating the solvent to form a sealed active layer on the support layer. 
     
     
         28 . The process according to  claim 27 , comprising using poly(vinylidene fluoride) as said binder. 
     
     
         29 . The process according to  claim 27 , comprising using 1-methyl-2-pyrrolidone as the solvent. 
     
     
         30 . The process according to  claim 27 , comprising providing the material in powder form in a proportion of 80% in weight excluding the solvent. 
     
     
         31 . The process according to  claim 27 , comprising providing the material in powder form with a grain size between 30 and 100 μm. 
     
     
         32 . A process according to  claim 27 , wherein the solution includes graphite in powder form. 
     
     
         33 . The process according to  claim 27 , comprising polishing the active layer until the support layer appears through the active layer. 
     
     
         34 . A cation selective extraction process by electrochemical transfer wherein a transfer wall is used as an electrolyte separation wall and a transfer of cations is ensured through said transfer wall by generating a potential difference (ΔE) between a first electrolyte and a second electrolyte or said transfer wall to induce an intercalation of cations in the transfer wall on a side of the first electrolyte, and a scattering of the cations in said transfer wall then deintercalation of the cations in the second electrolyte. 
     
     
         35 . The process according to  claim 34 , comprising using a non-aqueous electrolyte for at least one of the electrolytes. 
     
     
         36 . The process according to  claim 34 , comprising electrically connecting the transfer wall to a device measuring a potential between said wall and reference electrodes located respectively in each of said electrolytes and adjusting potential applied to said electrolytes. 
     
     
         37 . The process according to  claim 34 , comprising generating wherein the potential difference (ΔE) between the first electrolyte and the transfer wall and the step of deintercalation of the cations on the side of the second electrolyte comprising performing a chemical deintercalation by a chemical oxidising agent in the second electrolyte. 
     
     
         38 . The process according to  claim 34 , comprising ensuring a succession of cation transfers through transfer walls arranged successively between said electrolytes and at least one intermediary electrolyte between the transfer walls.