Lithium-Ion (Li-ion) and Lithium-ion Polymer (Li-polymer) Battery Safety

Physical Sciences, Inc. (PSI) has demonstrated that electroactive polymer coatings (EAP) may be applied to the surface of the cathode materials for lithium-ion batteries to protect against catastrophic cell failure. These EAP coatings form an electrochemical"switch"that can prevent catastrophic failure in lithium-ion batteries by reversibly changing from a conductor to an insulator on overdischarge or short-circuit of a cell. During a Phase II program PSI proposes to optimize and demonstrate on a prototype scale the EAP coatings. Laboratory scale batteries will be used to evaluate the cycling and rate performance of the coatings and select the optimal combination for scale-up. Pouch cells will then be constructed to demonstrate the safety benefits offered by the EAP coatings. Upon demonstration in a pouch cell, material will be delivered to SAFT America for the construction of cylindrical cells. The performance of these cells will be fully characterized and utilized to further optimize the coating before construction of additional cylindrical cells for delivery to the Air Force. Successful construction of the cylindrical cells and demonstration of improved battery safety will demonstrate the readiness of the EAP coatings for transition to a commercial or military application.