Electrolyte separator and method of making the electrolyte separator

A method comprising;

• selecting an ion-conducting first ceramic and an electrically insulating second ceramic;
• wherein the difference in the coefficient of thermal expansion of the ion-conducting first ceramic and the electrically insulating second ceramic is less than or equal to about 5 parts per million per degrees Centigrade, and wherein at least one of the first ceramic or the second ceramic comprises a strengthening agent;
• partially filling a mold with a first material comprising the ion-conducting first ceramic and filling the remaining portion of the mold with a second material comprising the electrically insulating second ceramic;
• applying a pressure to the mold to form a green body;
• sintering the green body at a temperature to form a graded integral structure comprising the ion-conducting first ceramic at a first end and the electrically insulating second ceramic at a second end.

An electrochemical cell, comprising:

• an electrolyte separator structure comprising a graded integral structure, wherein the graded integral structure comprises an ion-conducting first ceramic at a first end and an electrically insulating second ceramic at a second end;
• wherein the difference in the coefficient of thermal expansion of the ion-conducting first ceramic and the electrically insulating second ceramic is less than or equal to about 5 parts per million per degrees Centigrade;
• and
• wherein at least one of the first ceramic or the second ceramic comprises a strengthening agent.

An electrochemical cell comprising;

• an electrolyte separator structure comprising a graded integral structure comprising a closed first end and an open second end, wherein the graded integral structure comprises an ion-conducting first ceramic at the closed first end and an electrically insulating second ceramic at the open second end;
• wherein the open second end of the graded integral structure is fitted with a collar, the collar comprising a cermet layer, and a layer of an electrically insulating ceramic;
• wherein the electrically insulating ceramic in the collar is disposed at the open second end of the graded integral structure;
• wherein the difference in the coefficient of thermal expansion of the ion-conducting first ceramic and the electrically insulating second ceramic is less than or equal to about 5 parts per million per degrees Centigrade;
• and
• wherein at least one of the first ceramic or the second ceramic comprises a strengthening agent.

A method comprising;

• forming a graded integral structure comprising an ion-conducting first ceramic and an electrically insulating second ceramic;
• wherein the difference in the coefficient of thermal expansion of the ion-conducting first ceramic and the electrically insulating second ceramic is less than or equal to about 5 parts per million per degrees Centigrade, wherein at least one of the first ceramic or the second ceramic comprises a strengthening agent;
• wherein the graded integral structure comprises a closed first end and an open second end, wherein the structure comprises an ion-conducting first ceramic at the first end and an electrically insulating second ceramic at the second end;
• wherein the second end of the graded integral structure is fitted with a collar, the collar comprising a cermet layer, and a layer of an electrically insulating ceramic;
• sintering the graded integral structure and the collar at a temperature to form a joint between the layer of the electrically insulating ceramic in the collar and the electrically insulating second ceramic at the second end.