Keyword search: battery plant , lithium battery factory , power bank works , lifepo4 battery mill , lithium forklift battery manufacturer

Reasons and treatment measures for the detachment of the shell of the lithium-ion battery drum

Characteristics of lithium-ion battery housing

Lithium is the lightest basic metal, with an atomic number of 3 and an atomic weight of 6.941. In order to improve safety and voltage, scientists have developed materials such as graphite and lithium cobalt oxide to store lithium atoms. The molecular structure of these materials forms tiny nanoscale storage cells that can be used to store lithium atoms. In this way, even if the battery casing ruptures and oxygen enters, the oxygen molecules are too large to fit into the tiny battery, thus preventing lithium atoms from coming into contact with oxygen and exploding.

Battery protection measures

When the charging voltage exceeds 4.2V, lithium-ion batteries will begin to have side effects. The greater the pressure, the greater the risk. When the voltage of a lithium-ion battery exceeds 4.2V, less than half of the lithium atoms remain in the positive electrode material, and the battery often crashes, resulting in a permanent decrease in battery capacity. If the battery is charged, the subsequent lithium metal will accumulate on the surface of the material because the negative electrode battery is already filled with lithium atoms. These lithium atoms grow dendritic crystals from the cathode surface towards lithium ions. These lithium crystals will pass through diaphragm paper, short-circuit anode and cathode. Sometimes the battery explodes before a short circuit occurs. This is because during overcharging, electrolytes and other substances will decompose into gas, causing the battery casing or pressure valve to expand and burst, allowing oxygen to enter and react with lithium atoms accumulated on the negative electrode surface, leading to negative electrode explosion.

Therefore, when charging lithium-ion batteries, a voltage limit must be set in order to balance the battery's lifespan, capacity, and safety. The optimal upper limit of charging voltage is 4.2v. The discharge of lithium-ion batteries must also have a lower voltage limit. When the battery voltage is below 2.4V, some materials begin to be damaged. Moreover, as the battery will self discharge and the voltage will decrease as it grows, it is best not to stop discharging at 2.4V. During the discharge period from 3.0V to 2.4V, lithium-ion batteries can only release about 3% of their capacity. Therefore, 3.0V is the ideal discharge cutoff voltage. During charging and discharging, in addition to voltage limitation, current limitation is also necessary. When the current is too high, lithium ions do not have time to enter the storage battery and will accumulate on the surface of the material.

When these ions acquire electrons, they crystallize lithium atoms on the surface of the material, which is as dangerous as overcharging. If the battery box is broken, it will explode. Therefore, the protection of lithium-ion batteries should at least include three parts: upper limit of charging voltage, lower limit of discharge voltage, and upper limit of current. In addition to lithium-ion batteries, a general lithium-ion battery pack also has a protective plate, which is important for providing these three protections. However, the three protective panels are clearly insufficient, and lithium-ion battery explosions continue to occur frequently around the world. To ensure the safety of the battery system, it is necessary to analyze the causes of battery explosions more carefully.

Lithium ion battery explosion

1. Large internal polarization;

2. The electrode absorbs water and reacts with the electrolyte, resulting in gas bubbles;

3. The quality and performance of the electrolyte;

4. The injection volume does not meet the technical requirements;

5. Laser welding has poor sealing performance during installation and preparation, resulting in air leakage during measurement;

6. Dust and electrode dust are prone to causing micro short circuits;

7. The thickness of the anode and cathode plates is greater than the process range, making it difficult to enter the shell;

8. Sealing issues with liquid injection; Poor sealing performance of steel balls leads to air bubbles;

9. The shell wall thickness is too large, and the shell material cannot enter, causing deformation of the shell and affecting the thickness;

High ambient temperature is also an important cause of explosions.

Lithium ForkLift Batteries ,Ensure Quality

Our lithium battery production line has a complete and scientific quality management system

Ensure the product quality of lithium batteries

Years of experience in producing lithium forklift batteries

Focus on the production of lithium batteries

WE PROMISE TO MAKE EVERY LITHIUM BATTERY WELL

We have a comprehensive explanation of lithium batteries

QUALIFICATION CERTIFICATE

THE QUALITY OF COMPLIANCE PROVIDES GUARANTEE FOR CUSTOMERS

MULTIPLE QUALIFICATION CERTIFICATES TO ENSURE STABLE PRODUCT QUALITY

Providing customers with professional and assured products is the guarantee of our continuous progress.

Applicable brands of our products