Some basic information about Battery Foil Pulling and Peeling Tests

In battery manufacturing, the adhesion strength of electrode layers to the foil surface is a critical factor in quality control and safety. Weak adhesion can lead to delamination, negatively impacting battery performance and durability. Therefore, peel and tensile tests are applied to assess the mechanical properties of electrode materials.

Among these, the most commonly used methods are the 90-degree peel test and the 180-degree peel test, which help quantify the bonding force between electrode materials and metal foils. These methods allow manufacturers to optimize material properties, improve production processes, and enhance battery reliability.

This article discusses the importance of battery foil testing, test procedures, relevant standards, and the equipment used.

Evaluation of Electrode Layer Strength

• Importance in battery performance: The adhesion strength of electrodes to the foil surface affects the mechanical and electrical stability of the battery during charge/discharge cycles.

• Impact on battery lifespan: Strong bonding prevents delamination over time, extending battery life.

• Potential issues and safety risks: Layer separation increases internal resistance, reducing efficiency and increasing the risk of overheating.

Battery Foil Peel Test Methods

90-Degree Peel Test

• Principle and process: The electrode layer is peeled from the surface at a 90-degree angle to measure adhesion strength.

• Measured parameters: Peel force (N/m), material integrity, and bonding quality.

• Applications and benefits: Used to evaluate interactions of electrode coatings with different foil types or surface treatments.

180-Degree Peel Test

• Principle and process: The layer is peeled at a 180-degree angle to assess the maximum bonding force.

• Variability by material and process: Surface treatments and adhesive formulations affect outcomes.

• Advantages: Measures flexibility and bonding effectiveness under production conditions.

Standards and Requirements

ASTM D3330 – Pressure-Sensitive Adhesive Peel Test

• Standard method for measuring peel adhesion of pressure-sensitive adhesives.

ISO 15184 – Mechanical Properties of Electrode Coatings

• Specifies hardness and durability metrics for coated electrode layers.

IEC 62660 – Mechanical Testing of Batteries

• International standard for assessing mechanical durability of battery cells and modules.

Conclusion and Recommendations

• Contribution to battery design: Enables development of safer and more durable battery structures.

• Material-specific test strategies: Peel method selection should align with the properties of electrode materials.

• Future research directions: Further testing of new binder systems and coating materials to improve adhesion and performance.