Lithium Ion Battery Leak Detection App.Note

Introduction : As demand for lithium ion batteries continues to surge across electric vehicles (EVs), consumer electronics and energy storage systems, ensuring their safety and reliability has never been more critical. One of the most important steps in quality control is lithium ion battery leak detection, which helps manufacturers identify even the smallest leaks in battery cells, modules or packs.

Undetected leaks can lead to performance loss, electrolyte contamination, safety hazards and even thermal runaway, making advanced leak detection systems a key part of modern battery production. In this app. note, we will cover how lithium ion battery leak detection works, the benefits it offers to manufacturers and end users and the top vendors supplying cutting edge solutions in this space.

Li-Ion Battery Leak Detection Procedure

Following steps are followed in leak detection for the battery cell.

1. First battery cell is inspected visually for any damage. After this, the battery is sealed to ensure leak detection system can assess its integrity without any external interference.
2. Following are some of the methods used to detect leaks in lithium-ion batteries.

• Helium Leak Testing : The battery is placed in vacuum chamber and helium is injected into it. The chamber is evacuated and mass spectrometer is used to detect presence of any helium escaped from the battery, indicating leak.
• Electrolyte Tracing : This method uses specialized sensors to detect presence of electrolyte solvents escaped from the Li-Ion battery.
• Pressure Decay Testing : The battery is pressurized and rate of pressure drop is monitored. A rapid decrease in the pressure suggests presence of leak.

3. During testing, data is collected and analyzed to assess integrity of the battery. This delps in identification of location and size of any leaks.
4. The detected leak rate is compared against predefined thresholds. If it exceeds acceptable limits, battery is deemed to be defective.
5. Batteries that fail the leak test are either reworked to address the leaks or disposed of according to safety protocols.
6. From above results, only batteries meeting safety and performance standards proceed to the next stages of production.

One such test system with model number ELT3000 PLUS from Inficon is shown in the figure. It is electrolyte leak detector. As per datasheet it can detect smallest leak rate of 5 x 10^-7 mbar l/s. Refer datasheet or visit https://www.inficon.com/ website for more details.

Advantages of Battery Leak detection

Following are some of the benefits of Li-Ion battery leak detection system.

1. Detection of leaks minimizes risks of fires, explosions or chemical reactions by identifying issues early. This is crucial for prevention of hazardous situations by timely intervention.
2. Leaks can lead to loss of electrolyte which is essential for electrochemical reactions of the battery. By detecting and addressing leaks promptly, manufacturers can maintain optimal performance and extends battery life.
3. Preventing leaks is not only about safeguarding human health and safety but also about protecting the environment. Leak detection systems help in identifying and mitigating such risks, contributing to environmental stewardship and compliance with regulatory standards.
4. Leak detection systems provide a means to verify that batteries meet safety and quality standards.
5. Early detection of leaks can prevent more extensive damage to battery cells and associated components, reducing the need for costly repairs or replacements.

Lithium Ion Battery Leak Detection Solution Providers

Conclusion: In summary, integrating lithium ion battery leak detection systems is a proactive approach to ensuring safety, performance and environmental responsibility. These systems play a critical role in the sustainable development and operation of battery technologies across various applications.