1. Choose safe cathode materials. Currently, there are two mass-produced materials products of lithium cobalt oxide and lithium manganate. Lithium cobalt oxide is a very mature system in terms of small batteries, because of the characteristic of lithium cobalt oxide (LiCo) in terms of molecular structure: after overflowing, there are still a lot of lithium ions left in the positive electrode, and when overcharged, it remains in the positive electrode. Lithium ions will rush to the negative electrode. The formation of dendrites on the negative electrode is an inevitable result of overcharging batteries using lithium cobalt oxide materials. Even in the normal charging and discharging process, there may be excess lithium ions that dissociate to the negative electrode. Dendrite. Therefore, cell phone batteries have repeatedly exploded because of failure of the maintenance circuit on the one hand, but more importantly, there is no fundamental solution to the problem in terms of data. At the same time, lithium cobalt oxide is highly oxidizing, and it will differentiate at 175 degrees. The shell leaks and touches the air, causing incineration and blasting.
2. Selecting lithium manganate materials, in terms of molecular structure, ensure that in the fully charged state, the lithium ions of the positive electrode have been completely embedded in the carbon pores of the negative electrode, fundamentally preventing the occurrence of dendrites. The stable structure of lithium manganese oxide makes its oxidation function far lower than that of lithium cobalt oxide, and its differentiation temperature exceeds 100 degrees of lithium cobalt oxide. Beware of the risk of incineration and blasting due to the precipitation of metallic lithium.
3. Choose a barrier with a good thermal shutdown function. The purpose of the barrier is to block the positive and negative electrodes of the battery and allow the passage of lithium ions. When the temperature rises, it is closed before the barrier melts, so that the internal resistance rises to 2000 ohms and the internal reaction stops.
4. Explosion-proof valve: When the internal pressure or temperature reaches the preset specification, the explosion-proof valve will be opened and pressure will be relieved to guard against excessive accumulation of internal gas and deformation, which will eventually cause the shell to burst.
5. Maintenance circuit: Usually, the maintenance circuit needs to be used to guard against overcharge, overdischarge, and super current. The important principle is that after measuring the voltage and total current of each cell, controlling the switching circuit to turn off the entire loop, there is no too high difficulty in circuit planning. But whether the planning of the maintenance circuit is reasonable and whether the reliability is high enough is the talent of the test and manufacturer. The maintenance circuit is based on a PCb circuit composed of about dozens of resistors, capacitors, switch MOS tubes and other electronic components, and each component has the possibility of failure. A failed maintenance circuit will show two conditions: open circuit or conduction. When open circuit, the user cannot use the battery pack, and the conduction state will test the battery's ability to resist overcharge.
JUNLEE Group is an integrated full power energy factory that specializes in Uninterruptible Power Supply (UPS), Lead-Acid Battery, Battery pack, EV battery, Energy Storage Battery, Energy storage power station, Power pack Gel battery, PV Inverter and Solar system.
Production capacity reach 200000 KVaH per month. Products apply to Electric vehicles,electric mobility, solar & wind energy storage system, UPS, backup power, telecommunication, medical equipment and lighting.
JUNLEE sets up "Power research center" with more High-tech products.More than 100 engineers provided in-time and efficient one-stop solutions.
They mission strives to bring green power to the world.
To learn more about Li-ion batteries, please refer to https://www.junleepower.com/