Hydrogen storing method and unit

Abstract

The invention relates to a method for storing hydrogen and for producing hydrogen in which, for storing hydrogen, a unit ( 2 ) having: a cation donor, particularly of H − ions, an anode ( 20 ), a cathode capable of storing atomic and/or molecular ( 22 ) hydrogen, a wall ( 21 ) permeable to ions, having an electrical non conducting but ionic conducting material, between the cathode and the cation donor, is subjected to an electric field allowing the formation, at least at the cathode and electrical non conducting material interface, of atomic and/or molecular hydrogen and storing said hydrogen at least in the cathode, and in which, to restitute hydrogen gas, the cathode is heated and/or depressed.

1 .- 29 . (canceled) 
   
   
       30 . A method for storing and producing hydrogen comprising:
 subjecting to an electric field a unit comprising:
 a cation donor; 
 an anode; 
 a cathode configured for storing atomic and/or molecular hydrogen; and 
 a wall that is permeable to ions, comprising an electrically non-conducting but ion-conducting material, between the cathode and the cation donor, 
 wherein the electric field causes the formation, at least at the interface of the cathode and of the electrically non-conducting material, of atomic and/or molecular hydrogen; 
   storing the hydrogen at least within the cathode; and   restoring gaseous hydrogen by heating the cathode and/or putting the cathode under vacuum.   
   
   
       31 . The method of  claim 30 , wherein the cation donor is a donor of H +  ions. 
   
   
       32 . The method as claimed in  claim 30 , wherein the wall that is permeable to ions has a water permeability of less than 5% of the mass of hydrogen produced. 
   
   
       33 . The method as claimed in  claim 32 , wherein the cathode contains less than 5 wt % of water. 
   
   
       34 . The method as claimed in  claim 30 , wherein the wall that is permeable to ions has zero water permeability. 
   
   
       35 . The method as claimed in  claim 30 , wherein the cathode comprises an intermetallic compound chosen from the following list: of AB 5  type (A and B being metals), LaNi 5 , phases of lavas (Zr, Ti), (Mn, V, Cr, Ni) 2 , ZrMn 2  or TiMn 2 , Mg, TiFe, Mg 2 Ni, the vanadium-based centered cubic solid solutions, BaReH 9  (the formula corresponding to the hydrided state), Mg 2 FeH 6  (the formula corresponding to the hydrided state), NaAlH 4  (the formula corresponding to the hydrided state), LiBH 4  (the formula corresponding to the hydrided state), and all the compounds and derivatives thereof or alloys thereof. 
   
   
       36 . The method as claimed in  claim 30 , wherein the electrically non-conducting material comprises a ceramic. 
   
   
       37 . The method of  claim 36 , wherein the ceramic comprises hexagonal boron nitride. 
   
   
       38 . The method of  claim 37 , wherein the boron nitride is activated boron nitride, the activated boron nitride being activated by an acid solution under an electric field. 
   
   
       39 . The method as claimed in  claim 30 , wherein the wall that is permeable to ions comprises one or more layers of different materials, at least one of these layers exercising a cation-conducting function. 
   
   
       40 . The method as claimed in  claim 30 , wherein the wall comprises a porous layer having a support role between the layer that has the cation-conducting function and the electrolyte. 
   
   
       41 . The method as claimed in  claim 30 , wherein the cation donor is an acidic aqueous solution. 
   
   
       42 . The method as claimed in  claim 30 , wherein the cation donor is circulated in the unit. 
   
   
       43 . The method as claimed in  claim 30 , wherein the voltage applied between the anode and the cathode during the production of hydrogen is between 1 and 300 V. 
   
   
       44 . The method as claimed in  claim 30 , wherein the cathode is heated at a temperature greater than 30° C. in order to produce gaseous hydrogen. 
   
   
       45 . The method as claimed in  claim 44 , wherein the cathode is heated by a Joule effect during the circulation of an electric current. 
   
   
       46 . The method as claimed in  claim 44 , wherein the cathode is heated after draining the electrolyte. 
   
   
       47 . The method as claimed in  claim 44 , wherein the unit is heated at a temperature below that which yields the discharging of hydrogen, during a phase of hydrogen production and storage. 
   
   
       48 . The method as claimed in  claim 30 , wherein the atomic and/or molecular hydrogen is also stored in the electrically non-conducting but ion-conducting material. 
   
   
       49 . A unit for the storage and restitution of hydrogen comprising:
 an anode;   a cathode capable of storing atomic and/or molecular hydrogen;   a cation donor;   a wall that is permeable to ions, comprising an electrically non-conducting but ion-conducting material between the cathode and the cation donor;   an electrical connector to electrically power the anode and the cathode in order to create an electric field between them that enables the formation of atomic and/or molecular hydrogen at least within the cathode and the storage thereof at least in the cathode, the unit being configured to collect the gaseous hydrogen released by the cathode at least during the heating of the latter; and   a fluid connector to channel the gaseous hydrogen thus released to the outside of the unit.   
   
   
       50 . The unit as claimed in  claim 49 , further comprising an electrical resistance element for heating the cathode. 
   
   
       51 . The unit as claimed in  claim 50 , further comprising a device for regulating the temperature of the cathode. 
   
   
       52 . The unit as claimed in  claim 49 , wherein the cathode comprises an intermetallic compound. 
   
   
       53 . The unit as claimed in  claim 49 , wherein the electrically non-conducting material comprises a ceramic. 
   
   
       54 . The unit as claimed in  claim 49 , wherein the cation donor is an aqueous acid solution. 
   
   
       55 . The unit as claimed in  claim 49 , further comprising an elastic return member configured to make the cathode bear against the electrically non-conducting but ion-conducting material. 
   
   
       56 . The unit as claimed in  claim 49 , further comprising a connector for filling and/or purging of the cation donor. 
   
   
       57 . The unit as claimed in  claim 49 , further comprising a coupling that enables the extraction of the gaseous hydrogen stored. 
   
   
       58 . The unit as claimed in  claim 49 , wherein the anode is supported by the wall that is permeable to ions.