Long Life Thermal Battery for Sonobuoy

The prospects of significantly enhancing antisubmarine warfare (ASW) sonobuoys require exponential improvements in thermal battery capability. The fused-salt primary battery LiSi/CoS2 has shown tremendous progress in meeting the advanced requirements. Adaptation of recent advances in high-rate rechargeable thermal batteries provides a cost-effective approach for fully meeting size 'A' sonobuoy performance objectives. Specifically, an innovative super insulated container (vacuum/multifoil, which is 10-100 times as effective as Microtherm) promises to extend operating times beyond 4 hours to 12 hours. Reduced thickness of insulation would allow increased battery stack diameter and capacity (by 25%) to exceed 200 ping-seconds or power at greater than 13 kW. Rechargeable thermal battery peripheral seals, thinner (by 50%) fiber-separator; FeS2-CuFeS2 cathodes with 25% higher capacity density and lower-melting electrolyte are options for further increasing 'A' size sonobuoy battery performance and life. Battery life and performance could be doubled concurrently. Phase II would demonstrate the improved sonobuoy battery and aid in commercialization of the rechargeable thermal battery. A t of the long life thermal battery for the 'A' size sonobuoy.