Gas Sensor Device Containing Lithium Garnet

A method of sensing a SOx gas using an electrochemical sensor comprising:

• exposing the SOx gas to a sensing electrode comprising Li2SO4 and at least one of a metal oxide or a second metal sulfate, wherein a first surface of the sensing electrode is disposed on at least a portion of a first surface of a lithium garnet electrolyte;
• heating the sensing electrode and the lithium garnet electrolyte to a temperature sufficient to achieve a reaction between the SOx gas, Li+ and O2 to form Li2SO4, thereby changing a potential of the electrochemical sensor;
• and
• detecting a change in the potential of the electrochemical sensor.

A method of making an SOx sensing electrode comprising:

• creating a mixture of Li2SO4 and at least one of a metal oxide or a second metal sulfate;
• applying the mixture to at least a portion of a first surface of a lithium garnet electrolyte;
• and
• annealing the lithium garnet electrolyte and the mixture to form the SOx sensing electrode on the at least a portion of the first surface of the lithium garnet electrolyte.