, the Ministry of Industry and Information Technology issued the ''Safety Requirements for Power Batteries for Electric Vehicles ''(draft for comments) to replace the old GB38031-2020 standards. The new standards have made a series of modifications. The core logic is to improve the safety requirements for power batteries. The ultimate goal is to achieve that the battery will not catch fire or explode after thermal runaway, so that the occupants in the car have enough time to escape.
, with the rapid increase in the number of new energy vehicles, power battery safety accidents still occur from time to time. "Safety issues" have always been an invisible wall between car companies and consumers. "Requirements for the Safety of Power Batteries for Electric Vehicles" The revision of the standard can further improve the safety of power batteries and ease market anxiety.
The revision of "Safety Requirements for Power Batteries for Electric Vehicles" mainly includes: improving thermal diffusion requirements, improving thermal diffusion test methods, adding bottom impact test and fast charging cycle post-test.
in the process of formulating the new standard, after investigation and understanding by the research group, as of February 2024, 78% of the enterprises have the technical reserve of "no fire, no explosion". Based on the above situation, the research group agreed that it is technically feasible to raise the thermal diffusion requirement to "no fire, no explosion", so the new standard raises the thermal diffusion requirement to "no fire, no explosion".
In terms of specific test verification methods, the new standard proposes three tests to trigger the thermal runaway of the battery cell, namely, "acupuncture, external direct heating, and internal heating of the battery cell. During the test, the manufacturer can choose one of the triggering methods, or choose other methods to trigger thermal runaway. When the recommend three triggering methods do not trigger thermal runaway, it is considered that the battery product cannot be triggered thermal runaway and the test passes.
Thermal diffusion test judgment flow chart
In addition, the new standard also changed "this standard applies to rechargeable energy storage devices such as lithium-ion batteries and nickel-hydrogen batteries for electric vehicles" to "this document applies to power batteries for electric vehicles". This also means that the requirement of "no fire, no explosion" covers not only the commonly used lithium iron phosphate batteries and ternary lithium batteries, but also new power batteries such as sodium ion batteries and lithium metal batteries.
GB 38031-2020 "Safety Requirements for Power Batteries for Electric Vehicles", as one of the first mandatory national standards in the field of electric vehicles in China, has played an important role in regulating product production, guiding technological progress and supporting government management since its release in May 2020. GB 38031-2020 proposes that after the thermal runaway of the battery cell, the battery system should not catch fire or explode within 5 minutes after the warning signal is issued, so as to provide time for the safe escape of the occupants. Therefore, the battery factory and the main engine factory use fireproof and thermal insulation materials between the battery cells, the module and the upper cover of the PACK to delay or prevent the thermal spread of the battery pack and the spread of flame. Commonly used power battery thermal insulation materials areaerogel, foam ultra-fine glass wool, high silica cotton, epoxy resin board, mica board, etc., but can have both fire and non-combustible, high temperature resistant, efficient heat insulation and other characteristics of the requirements of only aerogel materials.
is the most suitable thermal insulation material for new energy vehicles and power batteries. When the cells in the battery are thermally out of control, aerogel materials can isolate the diffusion of heat to the surrounding cells, protect the normal operation of other cells, help the battery system to achieve far exceeding the national standard requirement of "no fire or explosion within 5 minutes", and greatly improve the safety of new energy vehicles. Since the aerogel materials have been gradually popularized and applied in the field of power batteries, high-performance aerogel materials continue to improve the safety and thermal protection standards of power batteries, the thermal runaway accidents of power batteries have been effectively reduced, and the lives and property safety of the people have been effectively guaranteed. With the characteristics of high thermal insulation performance and thin thickness, aerogel has become the most preferred thermal insulation material for new energy vehicles.
