High Capacity Negative Electrodes for Rechargeable Lithium-Ion Batteries

Period of Performance: 11/24/1999 - 02/03/2002


Phase 2 SBIR

Recipient Firm

Maxpower, Inc.
141 Christopher Lane
Harleysville, PA 19438
Principal Investigator

Research Topics


Phase I successfully identified Sn-alloys exhibiting first cycle irreversible Capacity losses less than 16% and specific capacities greater than 400 mAh/g. Based on these results, an expanded Phase II program is proposed to fully develop the Phase I results. The Phase II program consists of three tasks with objectives of minimizing initial capacity losses to less than 16 %, increasing practical gravimetric and volumetric capacities greater than 400 mAhig and 1000 mAh/cc, and extending cycle life to deliver at least 80 % of initial capacity after 250 cycles. Three tasks are proposed for this program. Task I involves expanded studies to synthesize new binary Sn and Sb alloys with metals such as Ni, Cu, Zn and Fe. Composite graphite-Sn and Sb anodes are included. Synthetic methods include ballmilling, electrodeposition, electroless deposition, and atomic atomization. Task 2 involves complete electrochemical evaluation of new and optimized anode materials in half-cells and prototype 100 mAh Li-ion pouch cells. In Task 3, the technology developed in Tasks I and 2 will be transferred to develop technology for construction of prototype 18650 Li-ion cells. These prototype 18650 Li-ion cells will be tested at MaxPower and delivered to the Army for independent testing and evaluation. BENEFITS: An expanded Li-ion cell technology base with respect to enhanced energy and rate capabilities, in general , and operability over the entire military range, in particular, will help push the Li-ion rechargeable batteries toward wide dual ( military and commercial) market acceptance. All types of portable devices and equipment's, wireless communication devices, are key commercial applications. Both spirally wound and soft packaging (pouch) cell technology will provide significant market dimension, commercially and militarily.