Batteries power much of today’s technology, from everyday electronics to electric vehicles and energy storage systems. While attention is often placed on chemistry and cell design, one critical component is frequently overlooked: the tab.
At Avocet Battery Materials, we recognise that tabs are not just electrical connectors. They are a key part of battery safety and reliability.
Why Tabs Matter for Battery Safety
In a pouch cell, the tab forms the connection between the internal electrode stack and the external circuit. It also plays a structural role at the seal point of the pouch, where mechanical stress and internal pressure are most likely to concentrate.
During abnormal conditions, such as overcharging or overheating, batteries can generate excess heat and gas. This can lead to swelling within the pouch, increasing pressure at the tab interface. If the tab and its seal are not strong enough to withstand these forces, there is a risk of electrolyte leakage. In extreme cases, this can lead to ignition.
For this reason, the integrity of the tab seal is essential in containing the internal environment of the cell.
Designed to Withstand Real-World Conditions
Battery swelling can occur for several reasons, including:
- Overcharging
- Elevated temperatures
- Ageing over time
- Exposure to moisture
In each of these cases, pressure builds within the cell and is transferred to the tab area, often the most mechanically vulnerable point.
At Avocet Battery Materials, our tab designs are developed to withstand these conditions. A key focus is ensuring strong adhesion between the tab material and the polymer seal, so that the pouch remains sealed even under increased internal pressure.
Testing Beyond Minimum Requirements
To validate tab performance, peel strength testing is used to measure how well the tab remains bonded within the pouch seal. While many manufacturers work to meet minimum thresholds, our approach is to go further.
At Avocet Battery Materials, we also carry out advanced ageing tests that simulate harsh or “bad battery” conditions, such as elevated temperatures and long-term stress. These tests show that our tabs and polymer seals continue to perform reliably, even in more demanding scenarios.
This gives our customers added confidence that their cells will remain stable not just in normal operation, but over time and under less favourable conditions.
Managing Heat and Preventing Thermal Runaway
Overheating is another major risk in lithium-based batteries. Excess heat can lead to capacity loss, swelling, and in severe cases, thermal runaway, where the cell releases large amounts of energy in a short period of time.
Tabs play a role here as well. By using materials with high thermal conductivity, heat can be more effectively dissipated away from the cell. This helps to stabilise the system and reduce the likelihood of uncontrolled temperature rise.
A Critical Component, Not an Afterthought
Battery safety depends on the performance of every component, not just the chemistry inside the cell. Tabs are a critical interface where electrical, thermal, and mechanical factors all meet.
At Avocet Battery Materials, we focus on delivering tab solutions that support not only performance, but also safety and reliability. By designing beyond minimum requirements and validating through testing, we help our customers build batteries that perform as expected, even in challenging conditions.
