Composite Ceramic Material and Method for Manufacturing the Same

Abstract

Provided is a composite ceramic material for a fuel cell and a method for manufacturing the same. The composite ceramic material for the fuel cell forms a cored structure where perovskite ceramic particles having a small particle diameter surround lanthanum cobaltite particles having a large particle diameter, and lanthanum cobaltite is added as a starting material in a process of synthesizing the perovskite ceramic particles to be synthesized. The composite ceramic material for the fuel cell described herein improves an electric connection characteristic between a separation plate and a polar plate of the fuel cell, and is chemically and mechanically stable.

1 . A composite ceramic material comprising:
 fine ABO 3  type perovskite ceramic particles compositely synthesized with lanthanum cobaltite (LaCoO 3 ) particles having a particle diameter that is larger than a particle diameter of the perovskite ceramic particle.   
     
     
         2 . The composite ceramic material of  claim 1 , wherein:
 a ratio of the lanthanum cobaltite is greater than 10 wt % and less than 90 wt %.   
     
     
         3 . The composite ceramic material of  claim 1 , wherein:
 the perovskite ceramic particle is   any one of (La,Sr)MnO 3 , (La,Sr)CoO 3 , (La,Sr) (Co,Fe)O 3 , and (La,Ca) (Cr,Co,Cu)O 3 .   
     
     
         4 . The composite ceramic material of  claim 1 , wherein:
 a particle diameter of the lanthanum cobaltite particle is 0.5 to 5.0 μm.   
     
     
         5 . The composite ceramic material of  claim 1 , wherein:
 the lanthanum cobaltite particle has a sphere shape.   
     
     
         6 . The composite ceramic material of  claim 1 , wherein:
 a particle diameter of the perovskite ceramic particle is 100 nm or less.   
     
     
         7 . The composite ceramic material of  claim 1 , wherein:
 a cored structure where the perovskite ceramic particles surround the lanthanum cobaltite particles is formed.   
     
     
         8 . The composite ceramic material of  claim 1 , wherein:
 the lanthanum cobaltite is synthesized by being added with a starting material in a process of synthesizing the perovskite ceramic particles.   
     
     
         9 . The composite ceramic material of  claim 1 , wherein:
 a composition of the perovskite ceramic is (La 0.8 Ca 0.2 )(Cr 0.1 Co 0.6 Cu 0.3 )O 3 .   
     
     
         10 . A method of manufacturing a composite ceramic material, comprising:
 adding a mixture where citric acid and lanthanum cobaltite powder are mixed with each other to a nitrate aqueous solution where a plurality of nitrates are dissolved;   heating and agitating the aqueous solution to convert a reactant from a sol state to a gel state;   heating the reactant produced in the heating and agitating to a temperature of a self-ignition or more of the citric acid to combust the citric acid; and   pulverizing chars produced in the combusting the citric acid and then calcining the chars at 700° C. or more.   
     
     
         11 . The method of manufacturing a composite ceramic material of  claim 10 , wherein:
 a particle diameter of the lanthanum cobaltite powder is 0.5 to 5.0 μm.   
     
     
         12 . The method of manufacturing a composite ceramic material of  claim 10 , wherein:
 the nitrate aqueous solution is obtained by dissolving at least one metal nitrate selected from lanthanum nitrate, calcium nitrate, chrome nitrate, cobalt nitrate, copper nitrate, iron nitrate, bismuth nitrate, yttrium nitrate, manganese nitrate, strontium nitrate and nickel nitrate in distilled water to correspond to a composition of a ABO 3  perovskite ceramic.   
     
     
         13 . The method of manufacturing a composite ceramic material of  claim 10 , wherein:
 a ratio of the lanthanum cobaltite added to the nitrate aqueous solution is greater than 10 wt % and less than 90 wt %.   
     
     
         14 . The method of manufacturing a composite ceramic material of  claim 13 , wherein:
 the ABO 3  perovskite ceramic is any one of (La,Sr)MnO 3 , (La,Sr)CoO 3 , (La,Sr) (Co,Fe)O 3 , and (La,Ca) (Cr,Co,Cu)O 3 .   
     
     
         15 . The method of manufacturing a composite ceramic material of  claim 14 , wherein:
 a composition of the (La,Ca) (Cr,Co,Cu)O 3  is (La 0.8 Ca 0.2 )(Cr 0.1 Co 0.6 Cu 0.3 )O 3 .   
     
     
         16 . The method of manufacturing a composite ceramic material of  claim 10 , wherein:
 the citric acid is a combustible organic material contributing to forming a metal complex and forming ceramic powder by combustion at high temperatures.   
     
     
         17 . The method of manufacturing a composite ceramic material of  claim 16 , wherein:
 the combustible organic material is any one of glycine nitrate, polyethylene glycol, urea and ethylenediamine tetraacetate.   
     
     
         18 . The method of manufacturing a composite ceramic material of  claim 10 , further comprising:
 uniformly mixing powder calcined in the calcining, a combining material, a dispersion material and a solvent to manufacture a viscous fluid (slurry).   
     
     
         19 . The method of manufacturing a composite ceramic material of  claim 18 , further comprising:
 applying the viscous fluid on a polar plate or a separation plate of a fuel cell and then sintering the viscous fluid.   
     
     
         20 . The method of manufacturing a composite ceramic material of  claim 19 , wherein:
 the sintering is performed at 600° C. or more for 1 hour or more.