Just when some domestic brands that originally manufactured cars gradually entered the manufacturing field of Laotoule.
Nishikawa Province, Kyushu Automobile Factory.
After more than two months, the Jiuzhou Automobile Factory has undergone tremendous changes.
Next to the old factory of Jiuzhou Automobile Factory, two newly built factories have been completed.
The scale is even greater than that of the previous Jiuzhou Automobile Factory.
One of the factories is Kyushu Electric Vehicle Factory, which produces two-wheeled electric vehicles.
Another factory is the Hengxin Battery Factory, which specializes in providing batteries for Kyushu Mini and, subsequently, Kyushu two-wheeled electric vehicles.
At this time, inside the Hengxin Battery Factory.
A group of senior managers from Kyushu Automobile, led by Xu Yifan, are inspecting this battery production line, which has just begun official production today.
It is different from the Jiuzhou Automobile production workshop where you can easily see pieces of materials being processed and turned into auto parts.
There are more devices here, but you can no longer witness the process of turning a piece of material into a battery.
Lithium-ion battery is a complex system, including positive electrode, negative electrode, separator, electrolyte, current collector, binder, conductive agent, etc.
Reactions involved include electrochemical reactions of positive and negative electrodes, lithium ion conduction and electronic conduction, as well as heat diffusion, etc.
The production process of lithium batteries is long and involves more than 50 processes.
Overall, the lithium battery manufacturing process can be divided into the front-end process (pole piece manufacturing), the middle-end process (battery core synthesis), and the back-end process (formation packaging).
The production goal of the front-end process is to complete the manufacturing of positive and negative electrode sheets. The main processes are: stirring, coating, rolling, slitting, film making, and die-cutting.
The equipment involved mainly includes: mixers, coating machines, roller presses, slitting machines, tableting machines, die-cutting machines, etc.
In the first process of the battery production workshop, after the incoming materials are inspected by the staff, they are transported to the next process according to the positive and negative electrode materials.
After the crushed phosphate ore and iron ore are inspected, they are transported by the conveyor belt to the next stage of batching process.
At the same time, Lu Jingping, who was following Xu Yifan and others, introduced information related to these devices to everyone.
"The molecular formula of lithium iron phosphate, LiFePO4, also known as lithium iron phosphate, lithium iron phosphorus, or LFP for short, is a cathode material for lithium-ion batteries.
There are many methods for preparing LiFePO4 cathode materials, which can be roughly divided into liquid phase method and solid phase method.
The liquid phase method includes low-temperature synthesis methods such as co-precipitation method, hydrothermal method, sol-gel method, etc.
Solid phase methods include high temperature solid phase sintering method, carbothermal reduction method, microwave sintering method, etc.
Our Hengxin Battery Factory uses a high-temperature solid-phase method.
This method of preparing cathode materials has the advantages of simple process, easy industrialization, easy removal of decomposition products to reduce impurities, and easy control of preparation conditions.
The disadvantages are that the crystal size of the cathode material produced is larger, the phase is uneven, and the calcination time is long, etc. "
Under the leadership of Cui Wuyuan, who is responsible for managing battery production tasks, and Lu Jingping, who is responsible for technical support and built this battery factory, everyone wearing dustproof clothing walked slowly in the battery production workshop.
Choi Moo-won, a Samsung talent, also has considerable management capabilities. He was able to stand out among hundreds of workers in just about a month, which shows his outstanding learning ability. After he was promoted from skilled workers by Xu Yifan, he was temporarily responsible for managing the battery production workshop Deputy manager of the production department for production tasks.
Ingredients, positive electrode coating, negative electrode coating, positive electrode production, negative electrode production, positive electrode welding sheet, negative electrode welding sheet, cutting diaphragm, inspection and dust removal, core pressing, short circuit detection, bottom and top packaging, shell insertion, short circuit detection again, Cover welding, baking, electrolyte injection, formation, volume separation, internal resistance and thickness measurement, packaging, full inspection, and delivery.
The group walked through the long production line and saw many employees who were busy producing.
From time to time someone shouted for support.
"Qiu Gong, save me, save me!"
"Master Jiang, come quickly!"
For some steps that are not particularly proficient, if you occasionally encounter situations that you do not understand, you have to ask the original R&D team member responsible for the technology to provide guidance!
Of course, there are still relatively few calls for support. It’s just that we have just gone from training to practical operation, and we are still not sure about some small details that we have not noticed before. It will take another two days to get used to it.
Cui Wuyuan reported on the current working conditions of employees in the battery production workshop.
“Nowadays, these employees are not particularly skilled in their work, and their production capacity has not reached its peak at all.
But because the battery factory is large enough, it is expected that this production workshop can already supply Kyushu Motor's Kyushu Mini.
At the same time, when the employees are skilled and operating at full power, the battery factory will be enough to meet the needs of Kyushu Mini and two-wheeled electric vehicles.
Apart from this, this is just the first production workshop, and five battery production workshops of the same size are under construction in the future. "
Although when it comes to craftsmanship, managers are confused.
As for how many batteries it can produce, it is much clearer.
After leading everyone to look around, everyone finally saw the final finished battery.
In the last process of the product production line, the qualified cells are packaged into battery packs of different capacities after capacity measurement.
The casing of the battery pack is uniformly made of high-strength plastic.
Depending on the capacity, the number of cells packaged inside is different.
Some pack the batteries completely, and some put some materials in the middle to make up the number.
A battery pack with unified specifications. The encapsulated battery pack is similar to a large battery. It is common on all new Kyushu minis, but the capacity is different. According to different configurations, it can be installed on different models and can be used directly. .
Looking at the battery packs being produced piece by piece, Lu Jingping said with a little regret.
“Unfortunately, due to factors such as cost and production process, this battery cannot fully achieve the performance of lithium iron phosphate batteries manufactured under laboratory conditions.
The performance of the final product is only about 80% of the samples prepared in the laboratory.
The energy density is 130Wh/kg, and the low-temperature environment capacity is only 60%. After more than 4,200 cycles, the remaining battery capacity is 80%. "
Xu Yifan said consolingly: "Even if it's about 80%, the performance is enough nowadays.
I believe that you will develop better and more powerful batteries in the future. At the same time, our manufacturing process will also be improved in the future, and we will have more money to buy better equipment. "
After finishing speaking, he then asked: "By the way, how is the specific safety of this battery?"
Safety is Xu Yifan’s top priority!
Although theoretically speaking, lithium iron phosphate batteries have basically no risk of catching fire, this new lithium iron phosphate battery is naturally safer than ternary lithium batteries.
But Xu Yifan still needs to ask about the actual product.
Lu Jingping answered without even thinking: "In terms of the safety of our battery, we have made key optimizations according to your requirements, boss!
The finished product has passed thermal shock, overcharge, short circuit, heavy object impact, overcharge protection, overdischarge protection, short circuit protection, constant humidity and heat performance, and battery external stress.
Vibration, collision, free fall, external short circuit, forced discharge, abnormal charging, incorrect installation, over-discharge, low air pressure, extrusion, high-rate charging.
Various tests include acupuncture, puncture, external electric shock, knife and ax chop, etc.
And all test results are excellent! "
