If the lithium battery is overcharged, continuing to charge when the battery is full will cause the positive electrode material structure to change, resulting in loss of capacity and its decomposition to release oxygen. and the electrolyte will be produced. Of violent chemical reactions, the worst result is naturally an explosion.
After the lithium battery discharges the internally stored energy and the voltage reaches a certain value, continued discharge will lead to over-discharge. The discharge cut-off voltage is generally determined based on the discharge current.
Working principle of lithium batteriesLithium metal batteries: lithium metal batteries generally use manganese dioxide as the positive electrode material, lithium metal or its metal alloy as the negative electrode material and use an electrolytic solutione non-aqueous. Discharge reaction: Li+MnO2=LiMnO2.
Lithium ion battery: Lithium ion battery generally uses lithium alloy metal oxide as the positive electrode material, graphite as the negative electrode material, and non-aqueous electrolyte.
Lithium batteries are rechargeable batteries. Typically, lithium batteries are fully charged at 4.2 V. There are also batteries with other voltages. Lithium battery charging methods include fast charging, slow charging, trickle charging, constant current charging, etc. But be careful to avoid overcharging, overdischarging, short circuit protection and other problems with lithium batteries.
How much damage will overcharging and overdischarging lithium batteries cause to the battery?
If the lithium battery is overcharged, continue charging when the batteryttery is full will cause the positive electrode material structure to change, resulting in loss of capacity, and its decomposition of oxygen and electrolyte will cause a violent chemical reaction, and finally The bad result is of course a blast.
After the lithium battery discharges the internally stored energy and the voltage reaches a certain value, continued discharge will lead to over-discharge. The discharge cut-off voltage is generally determined based on the discharge current. The general setting for 0.2 C to 2 C discharge is 1.0 V/piece, and the setting for discharge above 3 C, such as 5 C or 10 C, is 0.8 V/piece. Excessive battery discharge can have catastrophic consequences on the battery, especially large current. excessive discharge or repeated overdischarge has a greater impact on the battery.
In a general wayeral, excessive discharge will increase the internal pressure of the lithium battery and destroy the reversibility of positive and negative active materials. Even if it is charged, it can only be partially restored, along with its capacity. will also be significantly reduced. If the lithium battery is deeply charged and deeply discharged, the battery loss will be greater. The ideal working state of the lithium battery is shallow charging and discharging, in which case the battery life will be longer.
Why does gas appear when a lithium battery is overcharged or overdischarged?
Ordinary lithium-ion batteries will produce a small amount of gas inside the battery during the charging process, which is usually absorbed during discharging. Too large charging current and frequent overcharging will aggravate gas production, increase pressuren internal part of the lithium battery and will cause swelling. A slight bulge of the battery is allowed. Avoiding overloading is the key to reducing the bulge.
In addition, the chemical properties of lithium are very active and easy to burn. When the lithium battery is charged and discharged, the temperature inside the battery continues to rise. The gas generated during the activation process expands. and the internal pressure of the battery increases until the pressure reaches a certain level. It will rupture to a certain extent, causing leakage, fire or even explosion, so it is absolutely important to ensure its safety performance.