Recent years have seen an alarming surge in fire incidents caused by lithium-ion batteries in smartphones, raising awareness of their risks. Yet these batteries continue to be valued due to their high voltage, large capacity, energy density, and longevity—essential features in smartphones, electric vehicles, and home storage systems, as well as integral parts of IoT applications.

Why Are Lithium-Ion Batteries Expanding?

Lithium-ion batteries used in smartphones typically use lithium cobalt oxide as their cathode material, graphite for the anode, and gel polymer electrolyte, which are enclosed within an aluminium laminate pouch. Their swelling may be attributable to several factors, including:

1. Electrolyte Oxidation: Over time, battery electrolytes will oxidize, producing gases which cause swelling. This gas formation causes the battery to expand further than anticipated.

2. Manufacturing Defects: If metal particles or other foreign materials enter during manufacturing, they can puncture a separator and lead to internal shorts that cause internal short-circuiting. This could potentially lead to explosions (ruptures or fires) and heat production that decomposes electrolytes and produces gas, contributing to swelling.

3. External Forces: Even without inherent flaws, external impacts or pressure can deform the battery, leading to internal shorts.

How Can I Remedy a Swollen Lithium-Ion Battery?

If a battery becomes swollen, immediate steps must be taken to mitigate its condition rather than simply disposing of it directly. Any attempts at puncturing or disassembling it yourself could prove highly hazardous and should, therefore, be avoided at all costs.

Safe Disposal Steps

1. Containment: For safe disposal of your battery, place it in an inert metal drum to reduce any risk of explosions or fires that might arise suddenly.

2. Professional Handling: Once the battery has been secured, contact a professional according to manufacturer specifications for disposal or recycling.

Even when the battery shows no signs of swelling without immediate issues, it can quickly heat up, potentially leading to thermal runaway and an explosion. Therefore, professional assistance in disposing of smartphone batteries should be sought.

Precautions for Handling Batteries Yourself: Before handling the battery yourself, ensure it has been fully discharged. Make a small hole in its casing in a well-ventilated area and immerse it in water to deactivate it. However, some sources recommend saltwater immersion, plain water will do just as effectively.