Causes and effects of tab folding during lithium battery manufacturing process
Dec 18, 2023
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Lithium-ion batteries are commonly used rechargeable batteries that find extensive applications in mobile devices, electric vehicles, and other fields. During the manufacturing process of lithium-ion batteries, tab folding is a common issue that can have adverse effects on battery performance and safety. Let’s explore the causes and impacts of tab folding.
1. Reasons for tab folding
Tab folding refers to the phenomenon that the metal foils at the edges of the positive and negative electrode sheets of lithium batteries are bent or folded during the manufacturing process. The main reasons for the folding of tab are as follows:
1.1 Design issues: Inadequate sizing or shape of the positive and negative electrode foils in the battery design can make it challenging to maintain their flatness during the manufacturing process, leading to folding.
1.2 Material issues: Poor quality of the metal foils used for the positive and negative electrode foils, or improper processing techniques, can result in insufficient strength, making them prone to folding.
1.3 Manufacturing process issues: Improper handling, unstable equipment, or inappropriate process parameter settings during the manufacturing process can all contribute to tab folding.
1.4 Temperature issues: Improper temperature control during the manufacturing process, such as excessively high or low temperatures, can cause deformation and folding of the metal foils.
2.The influence of tab folding
Tab folding in lithium-ion batteries can have adverse effects on battery performance and safety. The specific impacts are as follows:
2.1 Decreased battery performance: Tab folding can result in poor contact between the positive and negative electrode foils, hindering the flow of current and affecting the discharge performance and capacity of the battery.
2.2 Increased internal resistance: Tab folding causes deformation and poor contact of the metal foils, leading to an increase in the internal resistance of the battery. This results in higher energy losses during battery discharge.
2.3 Reduced battery lifespan: Tab folding can lead to unstable contact between the positive and negative electrode foils, which can cause localized heating at the folded tabs and thermal instability within the battery, thereby shortening its lifespan.
2.4 Decreased safety: Tab folding can lead to internal short circuits and thermal instability, posing risks of overheating, explosions, and even fire incidents. This compromises the safety of the battery.
3.Methods to prevent and solve pole tab folding
To prevent and address tab folding issues, the following measures can be taken:
3.1 Design optimization: During the battery design phase, optimize the dimensions and shapes of the positive and negative electrode foils to avoid large edges that increase the risk of tab folding.
3.2 Material optimization: Choose high-quality metal foil materials and optimize the processing techniques to enhance the strength and ductility of the foils, reducing the likelihood of tab folding.
3.3 Process control: Implement strict control over process parameters, ensuring equipment stability and accurate operations to minimize the occurrence of tab folding due to process issues.
3.4 Temperature control: Properly control the temperature during the manufacturing process to avoid adverse effects on the deformation and folding of the metal foils caused by excessively high or low temperatures.
3.5 Inspection and screening: Establish a robust quality control system to conduct rigorous inspection and screening of the positive and negative electrode foils, ensuring their quality and flatness.
3.6 Safety testing: Perform thorough safety testing during the production process, including short-circuit and thermal runaway tests, to ensure that tab folding does not compromise the safety of the battery.
In summary, tab folding is a common issue in the manufacturing process of lithium-ion batteries that can have adverse effects on battery performance and safety. To prevent and address tab folding, optimization and control are required in various aspects such as design, materials, and processes to ensure battery quality and stability. Only by effectively preventing tab folding can high-quality and safe lithium-ion battery products be produced.
By implementing these preventive measures and quality control processes, the occurrence of tab folding can be minimized, ensuring the performance and safety of lithium-ion batteries.
