Bonding layer for an electrode in solid oxide fuel cells and method of manufacture thereof

A method of forming a bonding layer on a substrate, the method comprising forming a first mixture comprising a precursor, an organic fuel, and a first solvent, wherein the precursor comprises one or more metal nitrates comprising manganese nitrate, cobalt nitrate, iron nitrate, copper nitrate, nickel nitrate, zinc nitrate, and a combination thereof;

• stirring the first mixture to form a homogeneous first mixture;
• heating the homogeneous first mixture at a first temperature to evaporate the first solvent and form a gel-like first mixture;
• heating the gel-like first mixture at a second temperature to initiate a combustion reaction between the organic fuel and the one or more metal nitrates and thereby form an oxide intermediate precursor;
• calcining the oxide intermediate precursor at a third temperature in an oxidizing atmosphere to form a calcined intermediate comprising a manganese-cobalt spinel oxide having a nominal composition of MnxCo3-xO4, where x ranges from 0 to 3, excluding x=2;
• exposing the calcined intermediate to a reducing gas mixture at a fourth temperature to at least partially reduce the calcined intermediate and form a reduced calcined intermediate;
• forming a contact paste comprising the reduced calcined intermediate and an organic constituent and
• applying the contact paste to a surface of the substrate and sintering the contact paste at a fifth temperature to remove the organic constituent and form the bonding layer on the substrate, wherein the bonding layer comprises a single-phase spinel-type metal oxide formed by reoxidation of the reduced calcined intermediate during the sintering.

A solid oxide fuel cell, comprising:

• an anode, a cathode, an electrolyte disposed between the anode and the cathode, and an interconnect electrically coupled to at least one of the anode or the cathode;
• and
• a bonding layer disposed on at least one of the anode, the cathode, or the interconnect, wherein the bonding layer comprises a single-phase spinel-type metal oxide having a nominal composition MnxCo3-xO4, where x ranges from 0 to 3, excluding x=2,
• wherein the bonding layer is formed by sintering a reduced calcined intermediate such that the reduced calcined intermediate is reoxidized during the sintering to form the single-phase spinel-type metal oxide, and
• wherein the reduced calcined intermediate is derived from a calcined intermediate produced by calcining an oxide intermediate precursor formed by a combustion reaction between an organic fuel and a precursor comprising one or more metal nitrates comprising manganese nitrate, cobalt nitrate, iron nitrate, copper nitrate, nickel nitrate, zinc nitrate, or a combination thereof.