Patent ID: 7794869

Claim:
A battery comprising: a positive electrode comprising a current collector and a first active material; a negative electrode comprising a current collector and a second active material; and an auxiliary electrode comprising a current collector and a third active material; wherein the auxiliary electrode is configured for a selective electrical connection to the negative electrode; and at least one of a switch and a diode configured to implement the selective electrical connection as a function of at least one of the voltage difference between the positive and negative electrodes, the voltage difference between the positive and auxiliary electrodes, and the voltage difference between the negative and auxiliary electrodes; wherein the first active material, the second active material, and the third active material are configured to allow doping and undoping of lithium ions; and wherein 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.