A medical device includes a rechargeable lithium-ion battery for providing
power to the medical device. The lithium-ion battery includes a positive
electrode including a current collector and a first active material, a
negative electrode including a current collector and a second active
material, and an auxiliary electrode including a current collector and a
third active material. The auxiliary electrode is configured for
selective electrical connection to one of the positive electrode and the
negative electrode. The first active material, second active material,
and third active material are configured to allow doping and undoping of
lithium ions. The third active material exhibits charging and discharging
capacity below a corrosion potential of the current collector of the
negative electrode and above a decomposition potential of the first
active material.