The biggest impact on lithium battery materials is the moisture in the air, floating dust particles, of which the greatest impact and harm is moisture. In the manufacturing process of lithium batteries, once the raw materials are entered by moisture in the air, it will affect the safety of lithium batteries, and serious generally cause lithium batteries to bulge or even explode; and floating soil and dust in the atmospheric environment will cause short circuits in lithium batteries. Therefore, lithium battery production will be carried out in the dust-free workshop.
Lithium battery dust-free workshop from the technical process level, the most important thing is environmental control, the most important of which is "relative humidity" and "cleanliness control".
Lithium battery dust-free workshop is generally a Class C plant. Depending on the production process, CEIDI designers set up different functional areas and match them with different cleanliness spaces. Of course, the partition should also fully consider the explosive characteristics of lithium battery production, taking into account the future fire acceptance. How to arrange the thousand-level, 100,000-level, 100,000-level interval to meet functional needs and save energy is a profound science, and here CEIDI Xidi has a small point that can be revealed: the cleanliness level of the two connected workshops should not exceed two orders of magnitude.
The same is the dust-free workshop, the clean room of the lithium battery dust-free workshop and the clean room of other industries The biggest difference is the high humidity control requirements in the production environment (the temperature requires low dew point), so when ceidi Xidian air conditioner selection configuration, not only consider the sending, return air system configuration of the initial, medium and high efficiency filter, so that the indoor ambient air is continuously circulated and filtered, to ensure that the air suspended particles are controlled to a certain concentration, the air conditioning unit also has to have a dehumidification section, and the wet air conditioning unit is the key equipment to reduce the environmental dew point. At present, in the production and manufacturing process of lithium batteries, the dew point temperature required by the internal air in the clean room between lithium battery production plants is difficult to control and stabilize. Moreover, there will definitely be production personnel to produce, and the battery industry production line will lead to a large number of staff has been physically operating on the battery production line, at this time the production personnel must also emit more moisture than usual, the part of the moisture will more or less certainly leak out of the clean clothes, so the part of the moisture must be purged in time, so it will have higher requirements for the performance of the dehumidification unit: the general battery industry must choose a unit with good stability (can run continuously) and a large amount of dehumidification. It is best to produce gases in the range of -50 °C ~ -60 °C dew point (precise control) to continuously purge the clean room so that humidity, temperature and cleanliness can meet production requirements.
According to the safety and economy of raw materials and production, CEIDI is generally recommended for the humidity control ladder of the lithium battery production workshop: 30% of the relative humidity ≦ workshop (such as mixing, coating machine head, tail, etc.); relative humidity ≦ 20% workshop (such as roll pressing, filmmaking, baking, etc.); relative humidity ≦ 10% workshop (such as lamination, winding, assembly, etc.), dew point temperature ≦-45 °C workshop (such as battery baking, liquid injection, sealing, etc.). The specific humidity control will have a little difference, should be operated according to the actual situation of each battery enterprise, and the dehumidification cycle operation also needs to control the residence time of the process.
To maintain a standard production environment in a dust-free workshop for lithium batteries, there are other in-house technical systems that need to be implemented as appropriate.
Decoration system
Ground: clean area and non-clean area 3mm epoxy resin self-leveling ground, positive and negative mixing workshop, positive and negative pole load-bearing room can be used 3mm stainless steel floor. The wall surface adopts handmade rock wool color steel plate (A class fireproof material, color steel plate thickness 0.476mm * 50mm), ceiling color steel plate adopts handmade glass magnesium hollow color steel plate (A class fireproof material, color steel plate thickness 0.476mm * 50mm, load bearing 100Kg / square), the door body is made of formed steel purification door, and the glass window is made of tempered glass.
Electrical lighting system
The purification workshop lighting adopts LED lights, the illumination requirements are 250-300Lx, and the relevant power outage emergency lighting plate is configured. Wires and conduits are made of fire-retardant materials.
Process piping systems
Vacuum pipes and pure water pipelines can be used U-PVC pipelines, nitrogen pipelines using aluminum alloy pipes, air pressure pipelines using galvanized steel pipes and stainless steel pipes.
Air conditioning ventilation system
The refrigeration host and dehumidification unit can be provided by Party A, and the general air conditioning terminal equipment adopts air conditioning box and fan coil. The duct can be made of angle iron flange, and the insulation adopts B1 fire retardant insulation cotton.
Differential pressure control
To prevent external sources of contamination from entering the lithium battery workshop? The air pressure in the workshop must be controlled within a reasonable range. CEIDI Generally controls the pressure difference in the connected workshops at 0.03 - 0.05.
At present, the overall manufacturing cost of China's lithium battery industry is in a state of high energy consumption. In this particular industry, pre-construction environment control is quite important. Dehumidification + purification is the fundamental place to improve the quality of lithium battery production. Helping owners develop energy-efficient one-stop clean engineering solutions and controlling quality throughout the process is the responsibility and mission of clean engineering integrated service providers such as CEIDI Xidi.
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