Lithium Batteries for Medical Applications

This chapter on lithium batteries for medical applications is not meant to be an exhaustive review, but rather a broad overview of some of the different types of lithium batteries that power implantable medical devices. The battery systems described in this chapter fall into two major categories, primary or single use cells containing lithium metal anodes, and secondary or rechargeable systems utilizing lithium ion chemistry. Primary lithium batteries have been used for implantable devices such as cardiac pacemakers, drug pumps, neurostimulators and cardiac defibrillators. Secondary lithium ion batteries have been used with left ventricular assist devices, total artificial hearts, and implantable hearing assist devices.The first human implant of a lithium battery, a lithium/iodine cell that powered an implantable cardiac pacemaker, was conducted thirty years ago.1Since that time several different lithium anode batteries have been developed and used successfully in a diverse set of implantable medical devices. The cells used in these devices are typically developed for the application and have used various combinations of cathode, electrolyte and separator, to meet the specific requirements of a device. Despite the various approaches that have been used, there are several power source characteristics that are desirable across all applications.