SBIR-STTR Award

This project will determine whether the Li/CuCl2 inorganic electrolyte rechargeable battery can replace the 40 Ahr , 31 V AgO/Zn battery in the Delta, EELV, or Atlas launch vehicles. Calculations from extensive experimental data show that a Li/CuCl2 battery of the same size as the present AgO/Zn battery would required 9 instead of 19 cells and would deliver 101 Ahr while meeting the continuous and pulse load discharge requirements. One advantage of the Li/CuCl2 battery is that it has a self-discharge rate of only 0.8%/month compared to a much higher rate for AgO/Zn. The approach in Phase I will involve construction of Li/CuCl2 cells with first 8 cm2 and later up to 61 cm2 electrodes in hermetically welded metal cases. The cells will be discharged at continuous and pulse loads to simulate the Delta load profile. The electrode thickness and other design features will be semi-optimized. Innovative technology will be developed to improve the performance of the positive electrode. From the results 40 and 100 Ahr launch vehicle Li/CuCl2 cells in hermetic cases will be designed and the specific energy and other performance characteristics calculated.

During this project, 5 to 40 Ahr size Li/CuCl2 cells will be constructed, first in demountable metal cell cases, then in practical hermetic welded metal cell cases with glass-to-metal seals terminals and vents. The cells will be discharged at simulated Delta III and IV launch vehicle (LV) discharge regimes and a variety of abuse, 60 and 70 C activated storage tests will be carried out. Calculations from extensive experimental data show that 40 Ahr Li/CuCl2 cells in a lightweight case could deliver 202 Whr/kg at a full 40 Amp discharge and 2 second 250 A pulses above 2.10 V. Nine Li/CuCl2 cells would replace 19 AgO/Zn cells in a 30.5 V LV battery with 52% less space. About 40% of the Phase II effort will involve a technology development task that will include work to (i) semi-optimize an oxidation resistant shutdown separator that contains a fuse material that will melt at 100 C shutting down a 40 Ahr cell, (ii) devise new technology to totally contain SO2 inside a sealed battery box in case a cell vents and (iii) to discover and develop new transition metal halide positive electrodes capable of over 350 Whr/kg. Electronic circuits and software to charge nine cell Li/CuCl2 batteries will also be developed.

Benefits:
The proposed project could result in rechargeable lithium-copper chloride cells for use in commercial launch vehicles, aircraft, implantable medical devices, pipeline inspection crawlers and communications equipment. Other applications could include power for outdoor tools, lighting and communications equipment for farmers, police, construction workers and sportsmen.