As the core part of lithium batteries, the performance of lithium battery cells directly affects the overall performance of the battery. Therefore, the baking process is crucial in the manufacturing of battery cells. This article will delve into the importance, principles, technical requirements, and practical applications of cell baking.

1、 The importance of cell baking

Cell baking is a crucial step in the manufacturing process of battery cells, with the main purpose of removing moisture and volatile substances inside the cell, improving the stability of the cell, and ensuring the safety and reliability of the battery. Unburned battery cells contain a large amount of moisture and volatile substances, which may cause short circuits, bloating, and even safety accidents during use. Therefore, cell baking is of great significance for ensuring the safety and reliability of batteries.

2、 The principle of cell baking

The principle of cell baking is mainly to evaporate and discharge the moisture and volatile substances inside the cell through a high-temperature environment. During the baking process, the battery cell is placed in a closed environment and heated to increase temperature. Moisture and volatile substances quickly expand upon heating and are discharged from the interior of the battery cell under pressure. At the same time, high temperature environments also help accelerate the process of volatile substances being discharged from the interior of the battery cell. After baking, the moisture and volatile substance content inside the battery cell are significantly reduced, thereby improving the stability of the battery cell and the safety of the battery.

3、 Technical requirements for cell baking

1. Temperature control: Baking temperature is an important factor affecting the baking effect of battery cells. If the temperature is too low, moisture and volatile substances cannot be completely discharged; If the temperature is too high, it may cause damage to the materials inside the battery cell. Therefore, it is necessary to set the baking temperature reasonably based on factors such as the material, structure, and performance of the battery cell.
2. Time control: Baking time is also an important factor affecting the baking effect. If the time is too short, moisture and volatile substances cannot be completely discharged; If the time is too long, it may cause unnecessary energy waste and equipment loss. Therefore, it is necessary to set the baking time reasonably based on the actual situation.
3. Humidity control: During the baking process, ensure that the humidity of the baking environment is controlled within a reasonable range. Excessive humidity can affect the baking effect; If the humidity is too low, it may cause excessive drying of the battery cells. Therefore, it is necessary to monitor and control the humidity of the baking environment in real time.
4. Gas control: During the baking process, it is necessary to reasonably control the composition of the discharged gas. For the emission of harmful gases, corresponding treatment measures need to be taken to avoid harm to the environment and personnel.
5. Equipment maintenance: Baking equipment is an important tool to ensure the baking effect of battery cells. In order to ensure the normal operation of the equipment and extend its service life, it is necessary to regularly maintain and upkeep the equipment.

4、 The baking process for lithium battery cells is as follows:**

1. Preparation: Clean the inside of the oven to remove dust and foreign objects from the box and the baking clip, and prevent dust from entering the battery cell during baking.
2. Trial operation: Turn on the main power switch for baking, as well as the vacuum valve and compressed air valve. After the baking is turned on, enter the main operation interface, press manual operation to enter the manual operation interface; Display layer number and corresponding selection buttons for each layer of oven: heating, vacuum, nitrogen filling; To choose vacuum pumping, first conduct a trial vacuum pumping on the oven. When the vacuum reaches -90KPA, fill it with nitrogen gas to check whether the equipment operates normally during vacuum pumping and nitrogen filling.
3. Start heating: After confirming that the baking is qualified, enter the manual operation interface; Start the heating button of the oven and heat it up.
4. Baking: Put the battery cells into the oven for baking.
5. Process inspection: During the baking process, the temperature and pressure inside the oven should be regularly checked to ensure they are within the specified range.
6. Nitrogen filling and discharging: As needed, perform nitrogen filling and discharging operations during the baking process.
7. Process recording: Detailed recording of the entire baking process, including temperature, pressure, time, and other data.

5、 Notes

1. Temperature control: The baking temperature of lithium batteries is usually between 50 ℃ -80 ℃, and it is required to maintain a stable temperature, which should not exceed 80 ℃.
2. Baking time: Baking time can be set according to different needs, usually between 5-10 hours.
3. Baking environment: The baking room should be dry, clean, and well ventilated to avoid secondary pollution to lithium batteries.
4. Anti static: During the baking process, static electricity should be prevented, especially when the air humidity is high.
5. Avoid rapid cooling: For the baking process of lithium batteries, it is important to avoid rapid cooling. Because there is a pressure difference inside the lithium battery during baking, if it is quickly cooled, it will cause uneven thermal expansion and contraction inside the lithium battery, leading to problems such as expansion and leakage.
6. Pay attention to instrument use and maintenance: During the baking process of lithium batteries, the baking temperature and time should be strictly controlled, and attention should be paid to the use and maintenance of the instrument.

6、 The practical application of battery cell baking

At present, cell baking technology has been widely applied in the manufacturing of various types of batteries. In the manufacturing of electric vehicle batteries, cell baking is one of the important links in the manufacturing process. Through effective cell baking technology, moisture and volatile substances inside the cell can be removed, improving the safety and reliability of the battery. Meanwhile, in the manufacturing of energy storage batteries, cell baking is also an important means to ensure battery performance. In addition, cell baking has also been widely used in the battery manufacturing of consumer electronics products. For example, lithium batteries in electronic products such as mobile phones and laptops need to undergo strict cell baking treatment to ensure the safety and reliability of the products.

7、 Conclusion

In summary, cell baking is one of the key processes in battery manufacturing, which is of great significance for ensuring the safety and reliability of batteries. In practical applications, it is necessary to strictly control parameters such as baking temperature, time, humidity, and gas emissions to ensure the effectiveness of cell baking. With the continuous development and progress of technology, we believe that cell baking technology will also be continuously improved and perfected, bringing more convenience and safety to people’s lives and work.

• 電芯