If the protection circuit or the detection cabinet is out of control, the charging voltage will be greater than 5V, causing the electrolyte decomposition, violent reaction inside the battery, rapid rise of internal pressure of the battery. Solution: Manufacturers should check electrolyte suitability and assembly problems, while controlling the dust-free workshop environment. Partly, the loss is due to the large self-discharge of the battery itself. Solution: Using spot-welded nickel strips of good quality is what manufacturers should do. Some spot-welded nickel strips are poorly made, so it requires a large current to spot weld, which comes with high temperature, which then causes a short circuit inside the battery. Root cause 2: Too large spot welding current. Unmarked sides and large surface can’t be spot welded. Solution: The correct spot welding position should be at the bottom or marked “A” or “-” side. Root cause 1: Incorrect spot welding location. Symptom 4: Battery loss after spot welding Increasing the thickness of the casing or reducing the internal material can reduce the expansion. Solution: This is a normal battery reaction. Generally, the normal increase is 0.3 to 0.6 mm. However, after more than 50 weeks, it will not increase any more. Solution: Manufacturers should strictly control the battery processing process and the workshop environment to avoid short circuit and overheating.Ĭase 3: Lithium battery expands during circulation.Īs the battery circulates, the thickness increases as the number of cycles increases.
Generally, there is processing abnormalities (such as short circuit, overheating, etc.), resulting internal overheating, electrolyte decomposition and battery expansion. Solution: Don’t overcharge, especially don’t charge for more than 12 hours at a time.Ĭase 2: Lithium battery expands when processing. However, overcharging will cause electrolyte decomposition, increase internal pressure, and finally lithium batteries expansion. When charging lithium battery, it will naturally expand, but generally not more than 0.1 mm. Symptom 3: Lithium battery expansionĬase 1: Lithium battery expands when charging. The battery should be carefully tested to control product quality. Solution: Manufacturers should pay special attention to welding procedure.
When the battery is processed (spot welding, ultrasonic, etc.), the battery is abnormally heated, causing the thermal closure of the diaphragm and sharply increased internal resistance. Solution: It can be solved by charging and discharging activation. Lithium batteries are stored for too long, resulting in excessive capacity loss, internal passivation, and increased internal resistance. Solution: The internal resistance should be tested by the principle of AC (Alternating Current) bridge method. If the detection accuracy is not enough or the contact resistance cannot be eliminated, it will show that the internal resistance is too large. Root cause 1: Detecting equipment differences. Solution: This low voltage has nothing to do with quality issues and can be solved by charging.
In the short-term storage (12 hours), the voltage difference is very small, but the voltage difference is large when stored for a long time. Due to contact resistance or detection of charge, the current is inconsistent caused by the uneven charge of the cell. Solution: Charge the bare lithium battery directly using the charger with over-voltage protection, but do not use universal charge. Root cause 1: High self-discharge, which causes low voltage. If the voltage is below 2V, the internal structure of lithium battery will be damaged, and the battery life will be affected. Hope our post help you with what you need. So in here in this post, we share with you some of the most commonly seen root causes to lithium-ion battery accident and their solutions. As widely used as lithium-ion battery, it’s not uncommon that similar incidents happen every now and then. “…lithium battery caught fire, and exploded…” No, not another one! This is what we say or hear someone else say when there’s news about yet another battery accident.
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