Testing Data of Cell Thermal Runaway and Analysis of Gas Production,
Analysis of Gas Production,

▍What is PSE Certification?

PSE (Product Safety of Electrical Appliance & Material) is a mandatory certification system in Japan. It is also called ‘Compliance Inspection’ which it is a mandatory market access system for electrical appliance. PSE certification is composed of two parts: EMC and product safety and it is also an important regulation of Japan safety law for electrical appliance.

▍Certification Standard for lithium batteries

Interpretation for METI Ordinance for Technical Requirements(H25.07.01)， Appendix 9，Lithium ion secondary batteries

▍Why MCM?

● Qualified facilities: MCM is equipped with qualified facilities which can be up to the whole PSE testing standards and conduct tests including forced internal short circuit etc. It enables us to provide different customized testing reports in the format of JET, TUVRH, and MCM etc.

● Technical support: MCM has a professional team of 11 technical engineers specialized in PSE testing standards and regulations, and is able to offer the latest PSE regulations and news to clients in a precise, comprehensive and prompt way.

● Diversified service: MCM can issue reports in English or Japanese to meet clients’ need. So far, MCM has completed over 5000 PSE projects for clients in total.

The safety of energy storage system is a common concern. As one of the critical components of energy storage system, the safety of lithium-ion battery is particularly important. As thermal runaway test can directly evaluate the risk of fire occurring in energy storage system, many countries have developed corresponding test methods in their standards to assess the risk of thermal runaway. For example, IEC 62619 issued by the International Electrotechnical Commission (IEC) stipulates the propagation method to evaluate the influence of thermal runaway of the cell; Chinese national standard GB/T 36276 requires thermal runaway evaluation of the cell and thermal runaway test of the battery module; The U.S. Underwriters Laboratories (UL) publishes two standards, UL 1973 and UL 9540A, both of which assess thermal runaway effects. UL 9540A is specially designed to evaluate from four levels: cell, module, cabinet, and heat propagation at installation level. The results of thermal runaway test can not only evaluate the overall safety of the battery, but also allow us to quickly understand the thermal runaway of cells, and provide comparable parameters for the safety design of cells with similar chemistry. The following group of testing data for thermal runaway is for you to understand the characteristics of thermal runaway on each stage and the materials in the cell.
Stage 3 is the electrolyte decomposition stage (T1~ T2). When temperature reaches 110℃, the electrolyte and the negative electrode, as well as the electrolyte itself will occur a series of decomposition reaction, producing a large amount of gas. The continuously generating gas makes the pressure inside the cell increase sharply, reaching the pressure relief value, and the gas exhausting mechanism opens (T2). At this time, much gas, electrolytes and other substances release, taking away part of the heat, and the temperature increasing rate becomes negative.