SBIR 95-1 SOLICITATION

PROJECT SUMMARY

Proposal Number:

10.02-6744

Project Title:

CHEMICALLY MODIFIED ELECTRODES FOR IMPROVED CAPACITY AND LIFE IN RECHARGEABLE LITHIUM BATTERIES

Technical Abstract:

Oxides such as LiCoO2 have been used as the cathode in recently commercialized rechargeable lithium batteries. However, these highly oxidizing materials attack and decompose liquid electrolytes when fully charged, causing severely shortened cell life and safety hazards. Current designs avoid this problem using voltage limitation, which reduces the achievable energy density by a factor of two. Another solution would be to use an oxidation-resistant polymer electrolyte; however, polymer electrolytes have low conductivities, which limits the discharge rate unacceptably. State-of-the-art oxide cathode materials for rechargeable lithium batteries will be chemically modified to improve their energy density and cycle life. The innovation will combine the oxidation resistance of polymer electrolytes with the high conductivity of liquid electrolytes, by chemically attaching an ultrathin layer of polymer electrolyte to the oxide surface by silanization. This will protect the electrolyte from degradation while adding minimally to cell impedance, and enable a two-fold improvement in energy density. New modified electrodes will be tested in lithium cells and compared to the performance of conventional electrodes. The program will demonstrate that chemically modified electrodes can be incorporated in lithium batteries which are safe, have long cycle and shelf life, and energy density > 150 Whr/kg.

Potential Commercial Applications:

Reliable, high energy, high power rechargeable batteries would find a large market in portable consumer products such as telephones, televisions, video cameras, computers and hand-held tools.

Name and Address of Offeror:

TPL, Inc.
3768 Hawkins Street, NE
Albuquerque, NM 87109-4511