Electrochemical Device Comprising a Proton-Conducting Ceramic Electrolyte

Abstract

The invention relates to the use of a ceramic of formula Ba 2(1−x) M 2x In 2(1−y) M′ 2y O 4+δ (OH) δ′ where M represents at least one metal cation with an oxidation number II or III or a combination thereof, M′ represents at least one metal cation with an oxidation number III, IV, V or VI or a combination thereof, 0<x<1, 0<y<1, δ<2 and 0<δ′<2, as solid proton-conducting electrolyte in an electrochemical device, in particular a fuel cell, an electrolytic cell, a membrane separating hydrogen from a gas mixture, or also a hydrogen detector, at an operating temperature of said electrochemical device preferably comprised between 200° C. and 600° C.

1 - 11 . (canceled) 
   
   
       12 . A fuel cell comprising an anode compartment, with an anode, fed continuously with hydrogen or with a gas mixture containing hydrogen, and a cathode compartment with a cathode, fed with oxygen or air, the two compartments being separated by the proton-conducting electrolyte of formula
   Ba 2(1−x)M   2x In 2(1−y) M′ 2y O 4+δ (OH) δ′     
     where
 M represents at least one metal cation with an oxidation number II or III or a combination thereof, M′ represents at least one metal cation with an oxidation number III, IV, V or VI or a combination thereof, 0≦x≦1, 0≦y≦1, δ≦2 and 0<δ′≦2, 
 and an electrical circuit connecting the anode to the cathode. 
 
   
   
       13 - 16 . (canceled) 
   
   
       17 . The fuel cell as claimed in claim  1 , wherein said ceramic has a proton conductivity, measured at 400° C., greater than 10 −3  S/cm. 
   
   
       18 . The fuel cell as claimed in claim  1 , wherein M represents a cation of a metal selected from the group consisting of Sr, Ca and the elements of the lanthanide series. 
   
   
       19 . The fuel cell as claimed in claim  1 , wherein M′ represents a cation of a metal selected from the group consisting of Ga, Sc, Y, Ti, Zr, Hf, Nb, Ta, W, Mo and the elements of the lanthanide series. 
   
   
       20 . The fuel cell as claimed in claim  4 , wherein M′ represents Ti(IV). 
   
   
       21 . The fuel cell as claimed in claim  1 , wherein 0≦y≦0.7. 
   
   
       22 . The fuel cell as claimed in claim  6 , wherein 0≦y≦0.3. 
   
   
       23 . The fuel cell as claimed in claim  1 , wherein the ceramic is impermeable to gases. 
   
   
       24 . The fuel cell as claimed in claim  1 , wherein the ceramic is a fritted ceramic material. 
   
   
       25 . The fuel cell as claimed in claim  9 , wherein the fritted ceramic material has a closed porosity and a level of compactness greater than 95%. 
   
   
       26 . The fuel cell as claimed in claim  10 , wherein the closed porosity and the level of compactness greater than 95% can be obtained by fritting at a temperature lower than or equal to 1400° C.