ADVANCED IMPLANTABLE RECHARGEABLE BATTERIES FOR VAS

STATE-OF-THE-ART, IMPLANTABLE, NICKEL-CADMIUM (NI-CD) RECHARGEABLE BATTERIES USED IN VENTRICULAR ASSIST SYSTEMS OFFER BARELY ADEQUATE ENERGY DENSITY AND CYCLE LIFE. ADVANCES IN RECHARGEABLE BATTERY TECHNOLOGY WOULD GREATLY IMPROVE THE DAY-TO-DAY COMFORT OF PATIENTS WHILE SIMULTANEOUSLY REDUCING THE NEED FOR SURGERY TO REPLACE WORN-OUT CELLS. WHILE RECHARGEABLE LITHIUM (LI) BATTERIES EXCEL WITH RESPECT TO ENERGY DENSITY, THE BEST LI SYSTEMS CURRENTLY AVAILABLE AFFORD ONLY 50 PERCENT OF THE CYCLE LIFEOF MODERN NI-CD BATTERIES. IN PHASE I, A NEW STRATEGY FOR DRAMATICALLY INCREASING THE CYCLE LIFE OF LI BATTERIES BASED ON A NEW CLASS OF HIGH-PERFORMANCE SOLVENTS WILL BE INVESTIGATED. THESE SOLVENTS WILL BE EVALUATED AGAINST LI FOR CHEMICAL AND ELECTROCHEMICAL STABILITY. FINALLY, ELECTROLYTES COMPRISINGTHESE NEW SOLVENTS AND A SALT WILL BE CYCLED IN FULL LI/TIS2 TEST VEHICLES. THESE ADVANCED LI BATTERIES ARE EXPECTED TO HAVE 3 TO 5 TIMES THE CYCLE LIFE OF CURRENT RECHARGEABLE LI SYSTEMS.