HERMETIC FEEDTHROUGH ASSEMBLY AND ASSOCIATED METHODS

An implantable medical device, battery and method include memory configured to store program instructions. At least one of circuitry or a processor are configured to execute the program instructions in connection with at least one of monitoring a biological signal or administering a therapy. The device includes a battery comprising a cell stack that includes an anode, a cathode, and one or more separator layers electrically insulating the anode from the cathode. The device includes a case having a feedthrough port and a feedthrough assembly disposed in the feedthrough port. The feedthrough assembly includes a ferrule having a lumen. An inner conductor is disposed within the lumen of the ferrule. The inner conductor is formed from a material having a first composition and a first coefficient of thermal expansion (CTE). An insulating core is disposed within the lumen of the ferrule and separates the inner conductor from the ferrule. The insulating core is formed from a material having a second composition and a second CTE. The first CTE of the inner conductor is equal to or greater than the second CTE of the insulating core and the first and second compositions are molecularly bonded with one another to form a hermetic seal between the inner conductor and the insulating core.