1, lithium ion safety

How is the feature implemented?

a, the diaphragm 135 ° C automatic shutdown protection, using the international advanced Celgars2300PE-PP-PE three-layer composite film. When the temperature rise of the battery reaches 120 ° C, the membrane pores on both sides of the PE composite membrane are closed, the internal resistance of the battery is increased, and the internal temperature rise of the battery is slowed down. When the temperature rises to 135 °C, the PP film hole is closed, the battery is internally broken, and the battery is no longer heated to ensure the battery is safe and reliable.

b. Adding an additive to the electrolyte When the battery is overcharged and the battery voltage is higher than 4.2V, the electrolyte additive and other substances in the electrolyte are polymerized, the internal resistance of the battery is greatly increased, and a large area of the battery is broken inside, and the battery is not Warm up again.

c. Battery cover composite structure The battery cover adopts the scoring explosion-proof ball structure. When the battery is warmed up, part of the gas generated during the activation process of the battery expands, the internal pressure of the battery increases, and the pressure reaches a certain degree of cracking and deflation.

d. Various environmental abuse tests conduct various abuse experiments, such as external short circuit, overcharge, acupuncture, impact, incineration, etc., to examine the battery safety performance. At the same time, the battery was subjected to temperature shock test and mechanical properties such as vibration, drop and impact, and the performance of the battery in the actual use environment was investigated.

2. Why is constant pressure?

Is the charging current gradually decreasing?

Because the constant current process is terminated, the electrochemical polarization inside the battery is maintained at the same level in the entire constant current. Under the constant voltage process, the concentration polarization of the internal Li+ is gradually eliminated and the number of ions migrated. And the speed is expressed as the current is gradually reduced.

3. What is the capacity of the battery?

The capacity of the battery is divided into rated capacity and actual capacity. The rated capacity of the battery refers to the design or manufacture of the battery to specify or ensure that the battery should emit a minimum amount of electricity under certain discharge conditions. Li-ion stipulates that the battery is charged for 3 hours under normal temperature, constant current (1C) constant voltage (4.2V) controlled charging conditions. The actual capacity of the battery refers to the actual amount of electricity discharged by the battery under certain discharge conditions, mainly by the discharge rate. And the effect of temperature (so strictly speaking, the battery capacity should indicate the charge and discharge conditions). Common units of capacity are: mAh, Ah = 1000mAh).

4. What is the internal resistance of the battery?

It refers to the resistance that current flows through the inside of the battery while the battery is working. It has two parts: ohmic internal resistance and polarization internal resistance. The large internal resistance of the battery will cause the battery discharge operating voltage to decrease and the discharge time to be shortened. The internal resistance is mainly affected by factors such as the material of the battery, the manufacturing process, and the structure of the battery. It is an important parameter to measure battery performance.

Note: Generally, the internal resistance of the charge state is the standard. Measuring the internal resistance of the battery requires a special internal resistance meter and cannot be measured with a multimeter ohmmeter.

5. What is the open circuit voltage?

After the battery is fully charged, the open circuit voltage is about 4.1-4.2V, and after the discharge, the open voltage is about 3.0V. The open circuit voltage of the battery can be used to judge the state of charge of the battery. What is the working voltage? The discharge working voltage is around 3.6V.

6. What is the internal pressure of the battery?

Refers to the internal air pressure of the battery, which is caused by the gas generated during the charging and discharging process of the sealed battery, and is mainly affected by factors such as battery material, manufacturing process, and battery structure. The reason for this is mainly due to the accumulation of gas inside the battery and the gas generated by the decomposition of the organic solution in the battery. High-rate continuous over-charging will cause the battery temperature to rise and the internal pressure to increase. In severe cases, it will have destructive effects on the performance and appearance of the battery, such as liquid leakage, drum bottom, increased internal resistance of the battery, discharge time and cycle life. Shorten and so on. Any form of Li-ion can cause serious damage to battery performance and even explosion. Help Li-ion to use constant current and constant voltage charging during charging to avoid overcharging the battery.

7, why the battery should be stored

Can it be packaged for shipping after a while?

The storage performance of the battery is an important parameter to measure the stability of the overall performance of the battery. After the battery has been stored for a certain period of time, the capacity and internal resistance of the battery are allowed to change to some extent. After a period of storage, the electrochemical performance of the internal components can be stabilized, and the self-discharge performance of the battery can be understood to ensure the quality of the battery.

8. Why do you want to turn it into?

After the battery is manufactured, the internal positive and negative materials are activated by a certain charge and discharge method, and the process of improving the charge and discharge performance of the battery and the comprehensive performance of self-discharge and storage is called formation, and the battery powder can be converted into a real performance.

9. What is the capacity?

In the manufacturing process of the battery, the actual capacity of the battery may not be completely consistent due to the process, and the process of classifying the battery by capacity according to a certain charging and discharging system is called distributing.

10. What is the pressure drop?

The battery is qualitatively charged to more than 80%, and its battery no-load voltage is measured. The 5W/2W battery is used as a load to connect the positive and negative terminals of the battery as an open circuit of the battery, and the devices of the path are connected in series. The voltage drop of 5 seconds after the switch is turned on is not more than 0.4V, which is mainly for testing the battery load performance.

11. What is a static resistor?

What is dynamic resistance?

a, static resistance is the internal resistance of the battery when discharging.

b. Dynamic resistance is the internal resistance of the battery during charging.

12. What welding methods are used for the positive and negative electrodes?

a. The positive electrode uses an ultrasonic welder.

b, the spot welder for the negative electrode.

13. What is the purpose and location of the battery core adhesive tape?

a. The position of the battery core sticker is not deformed after the battery core is wound and formed. The bottom adhesive tape prevents the bottom of the positive electrode in the cell from contacting the battery case and causing a short circuit.

b. The side sticker makes the battery core not deformed after being wound. The bottom adhesive tape prevents the bottom of the positive electrode sheet in the battery cell from coming into contact with the battery case to cause a short circuit of the battery.

14. What is the humidity requirement for the drying room?

Why is the battery weighed before filling?

a, the relative humidity is below 6%.

b. Weighing to accurately calculate the amount of liquid injection.