Thanks to the active actions of technology-leading power battery companies and car companies, multi-level safety protection technology has been comprehensively constructed from intrinsic safety, active safety, and passive safety, and the non-thermal diffusion technology of battery systems has been gradually realized since 2020.
An obvious phenomenon is that heat-free diffusion technology has become the mainstream of the current development of the new energy vehicle industry.
Wu Kai, chief scientist of CATL, publicly stated that according to the statistics of CATL customers’ requirements for thermal diffusion, half of the customers in 2019 had no requirements for thermal diffusion; in 2020, more than 80% of the customers’ requirements were consistent with the national standard, that is, the thermal diffusion time was not Less than 5 minutes is enough, and 14% of customers require that the system does not have thermal diffusion; in 2021, the safety requirements of customers have been completely changed, and 86% of customers have required no thermal diffusion of battery packs.
Wu Kai believes that the current national standard requires ≥5 minutes of thermal diffusion, which is the lowest threshold level requirement, and enterprises should take no thermal diffusion as the design standard.
In March 2020, BYD released a blade battery that can pass the acupuncture test.
In the same month, JAC New Energy launched the "cellular battery", becoming the first domestic car company to pass the new national standard thermal runaway safety test.
In September 2020, CATL took the lead in realizing heat-free diffusion on 811 products.
In December 2020, Honeycomb Energy released the "jelly battery", which can achieve "no fire and no smoke" in the fully charged acupuncture test of the sample battery.
In the same month, Sunwoda "can't fire" batteries mass-produced.
In March 2021, based on the MIR platform products of China Innovation Aviation, the safety technology of GAC's magazine battery system can realize that the whole package of ternary lithium batteries cannot be ignited by acupuncture.
Immediately after that, Dongfeng Lantu showed its self-developed battery system technologies - "amber" and "mica", to achieve "no fire in 5 minutes", and further to achieve "no fire for 50 days, no fire for 50 days" and even stand for 30 minutes. explode".
In June, Great Wall Motors disclosed the related concepts and innovative technologies of Dayu battery technology to ensure that the "large-capacity high-nickel battery" battery pack can achieve no fire, no fire, and "high-nickel" battery pack "heating two cells and triggering thermal runaway continuously" at any position. Do not explode.
In July, the acupuncture of the pole core of the extreme krypton car only produced smoke, and the highest temperature of the stabbed battery core reached 801.4 ℃, which did not catch fire or explode.
Zhang Yao, vice president of Xinwangda Electric Vehicle Battery Co., Ltd., said that in November 2020, the company has mass-produced batteries that do not catch fire. At present, all products of the company are integrated with "no fire" safety solutions and technologies.
It is worth noting that, based on the iteration of technology and the evolution of market demand, power battery companies are expanding non-thermal diffusion technology to higher-performance battery solutions.
Wu Kai said that CATL has been committed to the safe design of high specific energy systems, and the heat-free diffusion technology with a higher specific energy of 1000km will also be mass-produced in 2023.
Zhang Yao said that it is expected to mass-produce BEV super fast charging "non-firing" batteries by the end of the year, which can meet the requirements of 700 kilometers of battery life on a single charge, 400 kilometers of battery life after 10 minutes of charging, and meet the requirements of a 10-year 200,000-km warranty.
From the perspective of achieving no thermal diffusion technology, the company mainly starts from the cell body, module and system level:
First, at the cell body level, through the improvement of the physical properties of the material body and the addition of flame retardants, the intermediate body of the cell is changed in extreme cases, such as heat absorption, surface passivation, blocking expansion, The effect of mechanical effect, etc., so as to realize that the battery does not catch fire.
Second, at the module and system levels, heat-resistant, heat-insulating materials and thermal conductivity designs are added, so that even if one cell experiences thermal runaway, it will not affect other cells.
