Tried as early as in the 60s with pacemakers: https://en.wikipedia.org/wiki/Artificial_cardiac_pacemaker#Lithium_battery https://en.wikipedia.org/wiki/Artifici

Tried as early as in the 60s with pacemakers: https://en.wikipedia.org/wiki/Artificial_cardiac_pacemaker#Lithium_battery https://en.wikipedia.org/wiki/Artificial_cardiac_pacemaker#L...