As an important instrument for the measurement of adiabatic thermal runaway of batteries, the core technical index of the battery adiabatic calorimeter is the self-exothermic detection sensitivity of the sample, that is, the ability to identify the weak exothermic heat of the sample. This index directly determines the measurement accuracy of the instrument for the characteristic temperature points such as the initial temperature of the battery self-exothermic heat. In order to achieve high detection sensitivity, the instrument is required to have ideal structural design, accurate temperature measurement technology and efficient temperature control algorithm, so as to achieve excellent adiabatic performance.
At present, there is a lack of measurement and calibration specifications for the whole battery adiabatic calorimeter in the industry, so there is no unified, scientific and reasonable method to verify the core indicators of the instrument, which is not conducive to objectively evaluating the performance of the instrument and regulating the instrument standards, and the data measured by the instrument with poor adiabatic performance will directly affect the relevant enterprises to carry out the safety design of the battery system, and have a negative impact on the development of the lithium battery related industries.
Some manufacturers and users use lithium batteries with empirical data as standard samples for instrument evaluation. There are some problems in this method: (1) The same batch of batteries may have slight differences in internal structure and materials, and the consistency of thermal runaway experimental data cannot be guaranteed, which will introduce additional uncertainty; (2) The thermal runaway process of some lithium batteries is severe, causing obvious pollution and even damage to instruments and equipment, and at the same time, high requirements for the test site.