High-Frequency AC Heating of Batteries in Extreme Cold Environments

The low temperature environment of the lunar surface and the long duration of the lunar nights (~14 days) require batteries to integrate ancillary thermal management systems to maintain an optimum operational temperature range. Current battery heating methods are heavy, bulky, and thermally inefficient. Here we present an innovative technology that uses high-frequency AC current to heat-up the battery’s liquid electrolyte directly and uniformly with the least amount of electrical energy, as compared to the currently available technologies (e.g. external convection heating, internal resistive elements, battery self-heating, etc). The implementation of the system does not require modification or replacement of any internal components of the existing batteries since the external high AC frequency circuitry can be integrated into the battery management system (BMS) electronics. Our technology has been experimentally demonstrated by enabling commercial off-the-shelf Li-ion batteries operate at their optimum operating range in extremely cold environments (< -60C), delivering 100% of their nominal storage capacity and cycling life expectancy. The objective of the proposed project is to develop a robust electrical energy storage technology that can be readily integrated into the battery systems powering NASA’s space missions for operation in extreme cold environments. The main goal of the Phase I work is to further develop and experimentally validate Omnitek’s proprietary high-frequency AC heating technology to enable the use of lithium-ion battery cells in ultra-low temperature environments. Omnitek’s thermal management technology is applicable to any existing electrochemical energy storage device containing an electrolyte. These include primary or rechargeable batteries and supercapacitors. This innovation can quickly and safely condition batteries to their optimum temperature operating range enabling top charge/discharge performance and long cycling life.