1. An implantable medical device, comprising: a rechargeable battery; a coil for wirelessly receiving radiation from an external charger for recharging the rechargeable battery; a rectifier coupled to the coil for producing a DC voltage; circuitry for receiving the DC voltage and for protecting and controlling the recharging of the rechargeable battery; wherein the rechargeable battery comprises: a first substrate comprising titanium; an anode on the first substrate; a second substrate; a cathode on the second substrate consisting of lithium-nickel-cobalt oxide; and an electrolyte and separator layer between the anode and the cathode.