What does the PTC CID of 18650 lithium battery mean?

PTC is a thermistor with a positive temperature coefficient! It is used in batteries to protect against overcharging, overdischarging and overcurrent!

CID

current interrupting device

The working principle is:

When the battery core fails (such as overheating, short circuit, overload, etc.), a lot of gas will be generated inside, and when the pressure increases, the solder joints welded to the aluminum plate and the pressure plate fall off and the pressure plate turns over, causing an internal short circuit in the core of the battery, which plays a protective role.

What are the dangers of not adding PTC to the 18650 lithium battery?

The three wires of the lithium battery lithium 7.4V2200mAh are: the red wire is the positive electrode of 7.4 volts, the black wire is the negative electrode of the terre and the white wire is 3.7 volts for the balance voltage at the middle of the battery.

If the battery does not have a protective plate, the three wires are: the red wire is the positive pole, the black wire is the negative pole, and the other colored wires are the center pole of the battery. battery. These three wires are connected to the motherboard of your product. The center pole allows your product's motherboard to monitor the voltage of the lithium battery.

If the battery has a protection board, the three wires are: the red wire is the positive terminal of the battery, the black wire is the negative terminal of the battery and the other colored wires are the NTC . (thermistor) of the protection board. The thermistor is for the motherboard. Detects the temperature of lithium batteries or distinguishes the battery type.

Detailed information

Working principle

Lithium metal battery:

1. Battery that usesmanganese dioxide as a positive electrode material, lithium metal or its metal alloy as a negative electrode material, and which uses a non-aqueous electrolyte solution.

2. Discharge reaction: Li+MnO2=LiMnO2

Lithium-ion battery:

1. Lithium-ion batteries generally use lithium alloy metal oxide as the element. Positive electrode material, graphite as negative electrode material, battery using non-aqueous electrolyte.

2. The reaction that occurs on the positive charge electrode is

LiCoO2==Li(1-x)CoO2+XLi++Xe-(electron)

6C+XLi++Xe-?=LixC6

4 The total reaction of the rechargeable battery: LiCoO2. +6C=Li(1-x)CoO2 +LixC6

Remarks

1. Storage requirements: In an environment with a temperature of 20 ± 5 ℃ and humidity not exceeding 50%, air and water vapor mustwind be avoided during transport. Erosion of aluminum foil;

2. This product is divided into two models, A and B. The main features of each are: Model A has a black appearance, the thickness of the conventional coating is 4-8 μm on both sides, and its conductive performance is better. To underline ; the appearance of model B is light gray, the thickness of conventional coating is 2-3μm on both sides, the coating area can. be welded with fewer layers and the coating machine can identify skip gaps;

3. Type B (gray) painted. The carbon aluminum sheet can be directly ultrasonic welded in the coating area. It is only suitable for welding laminated battery tabs (maximum 2-3 layers of pole pieces), but the ultrasonic power and time require precise adjustment;

4. The heat dissipation of carbon layer is worse than that of fireille of aluminum, so the belt speed and baking temperature should be adjusted appropriately when coating

5. comprehensive improvement in the performance of lithium batteries and capacitors, but it cannot be used as the main factor to change some aspects of battery performance, such as battery energy density, high and low temperature performance, high voltage, etc.

Reference materials:

18650 lithium battery does not need to add PTC. The PTC only detects the surface temperature of the lithium battery to avoid safety risks caused by excessive temperature of the lithium battery.

PTC is the abbreviation of Positive Temperature Coefficient, which means positive temperature coefficient, and is generallynt refers to semiconductor materials or components with a high positive temperature coefficient. Usually, the PTC we are referring to refers to the positive temperature coefficient thermistor, or PTC thermistor for short. PTC thermistor is a typical temperature sensitive semiconductor resistor when it exceeds a certain temperature (Curie temperature), its resistance value increases gradually as the temperature increases.

A type of thermistor, the resistance value of the positive temperature coefficient thermistor gradually increases as the temperature of the PTC thermistor body increases.