How to ensure the intrinsic safety of lithium-ion batteries,
Lithium Ion Batteries,

▍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.

At present, most of the safety accidents of lithium-ion batteries occur due to the failure of the protection circuit, which causes the battery thermal runaway and results in fire and explosion. Therefore, in order to realize the safe usage of lithium battery, the design of protection circuit is particularly important, and all kinds of factors causing the failure of lithium battery should be taken into account. In addition to production process, failures are basically caused by changes in the external extreme conditions, such as over-charge, over-discharge and high temperature. If these parameters are monitored in real time and corresponding protective measures will be taken when they change, the occurrence of thermal runaway can be avoided. The safety design of lithium battery includes several aspects: cell selection, structural design and functional safety design of BMS.There are many factors affecting cell safety in which the choice of cell material is the foundation. Due to different chemical properties, the safety varies in different cathode materials of lithium battery. For example, lithium iron phosphate is olivine-shaped, which is relatively stable and not easy to collapse. Lithium cobaltate and lithium ternary, however, are layered structure that is easy to collapse. Separator selection is also very important, as its performance is directly related to the safety of the cell. Therefore in the selection of cell, not only detection reports but also manufacturer’s production process, materials and their parameters shall be considered.Heat dissipation is mainly for some large energy storage or traction batteries. Due to the high energy of these batteries, the heat generated when charging and discharging is huge. If the heat cannot be dissipated in time, the heat will accumulate and results in accidents. Therefore, the selection and design of enclosure materials (It should have certain mechanical strength and dustproof and waterproof requirements), the selection of cooling system and other internal thermal insulation, heat dissipation and fire extinguishing system should all be taken into account.