How to solve the safety problem of large-capacity lithium-ion batteries

　　Author ：Iflowpower – Portable Power Station Supplier

1. Choose a safe positive material, currently positive for lithium cobaltate and lithium manganganate, two mass production materials. Lithium cobaltate is a mature system in small battery, as lithium cobaltate in the molecular structure (LiCo) characteristics: After the overflow, there are still a lot of lithium ions to remain in the positive electrode, when it is over, remain in the positive electrode The lithium ion will flour to the negative electrode, constituting the dendride in the negative electrode is an inevitable result of the battery over-charge using the lithium cobalt-based data, and even in the normal charge and discharge process, there may be excess lithium ion free to the negative constitutes Dendritic crystal.

Therefore, the mobile phone battery has repeatedly blasting events, on the one hand, because the maintenance circuit is invalid, but more important is that there is no fundamental solution in the information. A strong oxidative property of lithium cobaltate, differentiates at 175 degrees, housing leak, touch with air, incineration, blasting. 2.

Choose lithium manganate data, guaranteed in the molecular structure, and the lithium ion of the positive electrode is completely embedded in the negative electrode carbon hole in the molecular structure. A stable structure of lithium manganate, so that its oxidation is much lower than lithium cobaltate, and the differentiated temperature exceeds 100 degrees of lithium cobaltate, even if the internal short circuit (acupuncture), external short circuit, when the external force occurs, it can be thoroughly Alert because of the risk of incineration, blasting. 3.

Select the hot shutdown function, the separation of the separation is to block the positive and negative electrode of the battery, promise the lithium ion. When the temperature rises, the closure is performed before the melting is melted, thereby rising the internal resistance to 2000 ohms, so that the internal reaction is stopped. 4, explosion-proof valve: When the internal pressure or temperature reaches the preset specification, the explosion-proof valve will open, start the pressure of the pressure, and the internal gas stack is too much, and there is a deformation, eventually cause the housing burst.

5, maintenance circuit: usually maintenance circuitry needs to be alert over charge, over-discharge, large current use. The principle is to measure the voltage and total current of each cell, the control of the switching circuit is turned off throughout the circuit, and there is no difficulty in the planning of the circuit. However, the planning of maintenance circuit is not reasonable, the reliability is not enough, it is the talents of the test plus manufacturers.

The maintenance circuit is based on the PCB circuit composed of an electronic component such as a resistor, a capacitor, a switch MOS tube, and various components have a possibility of failure. The failure maintenance circuit will present two orientations, which will cause the user to use the battery pack when it is open, and the status of the conduction will test the talents of the electrical cell resistance.