In the lithium ion/lithium polymer battery industry – the severe battery failures and battery fires are very well characterized. There are a lot of companies that make a living from failure analysis of batteries. I pick their brains on a regular basis and I get to plagiarize what they have taught me. All severe lithium ion/polymer cell failures can be attributed to one of the follow root causes:

1. External Thermal Damage
2. Overcharge
3. Overdischarge
4. External Short Circuit
5. Internal Short Circuit
6. External Mechanical Damage