Innovators at NASA Johnson Space Center have developed a calorimeter that is able to measure the total heat generated when specific types of Lithium-ion (Li-ion) cells are driven into a thermal runaway condition. By understanding the behavior of a thermal runaway Li-ion battery, designers can improve the cell cases to contain or reduce damages experienced during thermal runaway. For this reason, this technology can benefit many different industries that depend on Li-ion batteries.
Li-ion batteries are an integral part of energy storage systems used in NASA's Exploration program, as well as many modern terrestrial industries. Innovators at NASA Johnson wanted a better way to measure total and fractional heat response of specific types of Li-ion cells when driven into a thermal runaway condition.
The calorimeter consists of at least two chambers, one for the battery cell under test and at least one other chamber for receiving the thermal runaway ejecta debris. Both are designed to be structurally strong and thermally insulated. When the test cell is intentionally driven into thermal runaway, ejecta explodes into the ejecta chamber and is decelerated and collected. Thermal sensors are strategically placed throughout the chambers to collect thermal data during the test. Customized software analyzes the thermal data and determines key calorimeter parameters with a high degree of accuracy.