An elevated target amount of electrolyte is used to initially fill a molten carbonate fuel cell that is operated under carbon capture conditions. The increased target electrolyte fill level can be achieved in part by adding additional electrolyte to the cathode collector prior to start of operation. The increased target electrolyte fill level can provide improved fuel cell performance and lifetime when operating a molten carbonate fuel cell at high current density with a low-CO.sub.2 content cathode input stream and/or when operating a molten carbonate fuel cell at high CO.sub.2 utilization.

A method of making an electrolyte matrix includes: preparing a slurry comprising a support material, a coarsening inhibitor, an electrolyte material, and a solvent; and drying the slurry to form an electrolyte matrix. The support material comprises lithium aluminate, the coarsening inhibitor comprises a material selected from the group consisting of MnO.sub.2, Mn.sub.2O.sub.3, TiO.sub.2, ZrO.sub.2, Fe.sub.2O.sub.3, LiFe.sub.2O.sub.3, and mixtures thereof, and the coarsening inhibitor has a particle size of about 0.005 m to about 0.5 m.

A method of making an electrolyte matrix includes: preparing a slurry comprising a support material, a coarsening inhibitor, an electrolyte material, and a solvent; and drying the slurry to form an electrolyte matrix. The support material comprises lithium aluminate, the coarsening inhibitor comprises a material selected from the group consisting of MnO.sub.2, Mn.sub.2O.sub.3, TiO.sub.2, ZrO.sub.2, Fe.sub.2O.sub.3, LiFe.sub.2O.sub.3, and mixtures thereof, and the coarsening inhibitor has a particle size of about 0.005 m to about 0.5 m.

A method of making an electrolyte matrix includes: preparing a slurry comprising a support material, a coarsening inhibitor, an electrolyte material, and a solvent; and drying the slurry to form an electrolyte matrix. The support material comprises lithium aluminate, the coarsening inhibitor comprises a material selected from the group consisting of MnO.sub.2, Mn.sub.2O.sub.3, TiO.sub.2, ZrO.sub.2, Fe.sub.2O.sub.3, LiFe.sub.2O.sub.3, and mixtures thereof, and the coarsening inhibitor has a particle size of about 0.005 m to about 0.5 m.

A method of making an electrolyte matrix includes: preparing a slurry comprising a support material, a coarsening inhibitor, an electrolyte material, and a solvent; and drying the slurry to form an electrolyte matrix. The support material comprises lithium aluminate, the coarsening inhibitor comprises a material selected from the group consisting of MnO.sub.2, Mn.sub.2O.sub.3, TiO.sub.2, ZrO.sub.2, Fe.sub.2O.sub.3, LiFe.sub.2O.sub.3, and mixtures thereof, and the coarsening inhibitor has a particle size of about 0.005 m to about 0.5 m.

An electrolyte matrix for use with molten carbonate fuel cells having an enhanced stability and lifetime is provided. The electrolyte matrix includes lithium aluminate as a support material and a coarsening inhibitor. The coarsening inhibitor may be in the form of discrete particles or a dopant present in the support material. The coarsening inhibitor may include MnO.sub.2, Mn.sub.2O.sub.3, TiO.sub.2, ZrO.sub.2, Fe.sub.2O.sub.3, LiFe.sub.2O.sub.3, or mixtures thereof. The coarsening inhibitor prevents the formation of large pores in the electrolyte matrix during operation of the fuel cell, increasing the performance and the service lifetime of the electrolyte matrix.

An electrolyte matrix for use with molten carbonate fuel cells having an enhanced stability and lifetime is provided. The electrolyte matrix includes lithium aluminate as a support material and a coarsening inhibitor. The coarsening inhibitor may be in the form of discrete particles or a dopant present in the support material. The coarsening inhibitor may include MnO.sub.2, Mn.sub.2O.sub.3, TiO.sub.2, ZrO.sub.2, Fe.sub.2O.sub.3, LiFe.sub.2O.sub.3, or mixtures thereof. The coarsening inhibitor prevents the formation of large pores in the electrolyte matrix during operation of the fuel cell, increasing the performance and the service lifetime of the electrolyte matrix.

An elevated target amount of electrolyte is used to initially fill a molten carbonate fuel cell that is operated under carbon capture conditions. The increased target electrolyte fill level can be achieved in part by adding additional electrolyte to the cathode collector prior to start of operation. The increased target electrolyte fill level can provide improved fuel cell performance and lifetime when operating a molten carbonate fuel cell at high current density with a low-CO.sub.2 content cathode input stream and/or when operating a molten carbonate fuel cell at high CO.sub.2 utilization.

An elevated target amount of electrolyte is used to initially fill a molten carbonate fuel cell that is operated under carbon capture conditions. The increased target electrolyte fill level can be achieved in part by adding additional electrolyte to the cathode collector prior to start of operation. The increased target electrolyte fill level can provide improved fuel cell performance and lifetime when operating a molten carbonate fuel cell at high current density with a low-CO.sub.2 content cathode input stream and/or when operating a molten carbonate fuel cell at high CO.sub.2 utilization.

In one aspect of an inventive concept, a fuel cell system includes a cathode and an anode, a porous ceramic support positioned between the cathode and anode, and a molten electrolyte mixture in pores of the ceramic support. In another aspect of an inventive concept, a method for producing energy includes directing a gas stream through a cathode, where an inner side of the cathode is adjacent to a dual phase membrane including a ceramic support infiltrated with a molten electrolyte mixture, sweeping an outer side of the anode with water, where an inner side of the anode is adjacent to the dual phase membrane, and collecting energy from the anode. The dual phase membrane is sandwiched between the cathode and an anode.