Key tips:
Lithium batteries are prone to fire and explosion, which is one of the concerns of consumers buying electric vehicles. In order to solve this pain point, a Chongqing enterprise made the battery into a "sandwich" with new materials, which effectively cracked this problem.
In recent years, the problem of lithium battery fire and explosion has emerged endlessly, becoming one of the important reasons why many people are unwilling to buy electric vehicles.
Why is it easy to catch fire? When subjected to a violent collision, the pure metal collector fluid inside the battery breaks, forming burrs of dozens or even hundreds of microns, piercing the diaphragm, leading to short circuit and causing thermal runaway.
Could this problem be solved by replacing the pure metal fluid collector with a material that does not break easily?
Chongqing Jinmei New Material Technology Co., LTD. (hereinafter referred to as Jinmei), which has lasted nearly 10 years of research and development, has turned this idea into a reality, and made the battery into a "sandwich" with new materials to crack the problem of lithium battery fire and explosion of new energy vehicles.

Chongqing Jinmei new material technology Co., Ltd. production line. The interviewed unit provided a direct attack on the pain point of lithium battery explosion and the development of "sandwich" materials
Why is Kimi developing this new material? It all started in 2015.
That year was recognized by the industry as the "first year" of the development of new energy vehicles, and the lithium battery industry was on the rise. In March, a Samsung mobile phone exploded while charging news, affecting the nerves of the entire industry.
"New materials must be developed to solve the safety problem of lithium batteries, otherwise it will face a bottleneck in the future." At that time, Henan Zang Shiwei had close cooperation with an industry head enterprise in equipment, and learned that the other side had such a demand, and the idea of cross-border entrepreneurship was born.
The idea proposed by the customer is to replace the traditional aluminum foil and copper foil fluid collection in the lithium battery with a "metal-polymer material - metal" three-layer composite structure, with the polymer material as a "sandwich" layer, and the upper and lower sides of the deposit metal aluminum or metal copper, like a "sandwich".
In this way, when the battery is subjected to a violent collision, the elastic polymer material film can act as a buffer. Internal heating to a certain extent, the melting point of the polymer material is lower than the metal will become soft and melt, which adds a polymer "fuse" to the battery cell. Moreover, the composite fluid collector can not produce large-scale metal burrs, avoid thermal runaway, and thus avoid explosion.
Zang Shiwei with the core members, all over the country to find equipment, find materials, find talent, make samples, engage in research and development, 2 years later in Anhui founded a company, the formation of pilot production capacity.
"I didn't think it would be so hard to do original innovation." Zang Shiwei lamented. At the beginning of 2018, the composite copper collector sample based on polyethylene terephthalate was offline and sent to the customer's laboratory for packaging and testing, but it was "hit in the head".
Under normal circumstances, at least 2000 charge and discharge cycles, the performance of the sample decreased significantly after 500 cycles, and it was found after disassembly that the middle layer of substrate was melted and directly collapsed.
At that time, more than 300 million yuan had been "burned" in research and development, and Zang Shiwei felt "black in the eyes".
After overcoming technical difficulties, industrialization has become a "roadblock"
Since PET is not suitable as a "sandwich" base material, then change the material.
Paper film, PI, etc., almost all of the polymer materials that meet the requirements, the team found to try again, and during that time, everyone spent day and night, taking the production workshop as their home.
After nearly half a year and thousands of experiments, the team finally found that polypropylene as a base material has high impact resistance, but also resistant to a variety of organic solvents and acid and alkali corrosion. The problem is solved, but also bring unexpected gains - to the 6-micron composite copper collector, for example, in addition to the upper and lower 1 micron of copper, the middle 4 microns are polymer materials, compared with the traditional fluid collector weight reduction of 60%, material cost savings of nearly 50%, energy density increased by 5-10%.
At the end of 2018, Jinmei's first generation of products - 6-micron copper composite fluid collector and 10-micron aluminum composite fluid collector officially rolled off the assembly line, and achieved the first installation of 30,000 electric vehicles and put them into the European market.
"Hurry up." The customer was satisfied with the installation results and requested higher specifications.
Anhui factory production capacity is limited, Jin Mei everywhere to seek to expand production and research and development base. At that time, Chongqing, Sichuan, Xiamen three places at the same time to the company offered an olive branch. As a traditional industrial base, Chongqing's deep industrial heritage attracted Zang Shiwei. In September 2019, Jinmei landed in Chongqing, and the factory was renovated and put into use in the second half of the following year.
Since landing in Chongqing, Jinmei has invested more than 1 billion yuan in equipment and research and development. "From small batches to large batches, it is not as simple as 1 to 2. The difficulty of mass production is more than 90 percent of the development." Zang Shiwei said.

Chongqing Jinmei New Material Technology Co., LTD., staff in the operation of equipment. The surveyed units are aiming at the 100 billion market and building the Chongqing factory as a production capacity output base
This innovative product, production equipment research and development and assembly and process development, all rely on their own to feel the stones across the river, setbacks are common. The first production after the assembly of the equipment, let everyone be dumbfounded - the product is either deformed, or perforated, all waste.
What went wrong? We removed the equipment and found that the key problem may be in the coating process of the deposition system.
Jin Mei is the use of physical vapor deposition coating, the vaporization point of copper is 2567 ° C, the vaporization point of aluminum is 3550 ° C, the melting point of polymer materials is about 120 ° C, which leads to the metal has not vaporized, polymer materials often have melted away.
There are many technical difficulties like this. The team re-developed the process, adjusted the equipment structure, architecture and deposition mode, coupled with thermal management and cold management process improvements, and completed the entire equipment after nearly a year.
By the end of 2021, the production line will be in steady trial production. Starting from 2022, it will be mass-produced and installed successively, and applied to brand models such as polar Krypton. Also in this year, Jin Mei has more than 10 million yuan of revenue. In 2023, the copper and aluminum composite fluid collection production process is fully opened, the aluminum production line optimization rate is more than 80%, the copper production line is rapidly climbing, and the annual capacity reaches 10 gigawatt-hour battery consumption.
"No matter how much capacity you have, 95% of your production line will belong to us!" The head customer put out the word. The remaining 5% of the products are used by Jinmei to expand other customers, including consumer batteries, energy storage, military and so on.
According to the prediction of authoritative institutions, by 2030, the global fluid collection material application will form more than 200 billion yuan market scale. The prospect is considerable, the product is in short supply, and has a leading advantage, but Jin Mei is not satisfied with the status quo.
"Starting this year, we will shift our research and development to equipment standardization and optimization." Zang Shiwei introduced that Jinmei plans to build Chongqing into a lighthouse factory, as a production capacity output base, to achieve mass production climb and production capacity release at the same time, to further promote the product extremely thin, extremely lightweight development, the future goal is the annual production capacity of 100Gwh battery consumption, output value of 10 billion yuan.