What is the safety of customized lithium-ion batteries?portable power station with solar panel

　　In order to avoid over discharge or overcharging of customized lithium-ion batteries caused by improper use, a triple protection mechanism is installed inside the single lithium-ion battery. One is the use of switching elements. When the temperature inside the battery rises, its resistance increases accordingly. When the temperature is too high, the power supply will automatically stop; The second is to choose appropriate partition materials. When the temperature rises to a certain value, the micron sized micropores on the partition will automatically dissolve, preventing lithium ions from passing through and stopping internal reactions in the battery; The third is to set a safety valve (which is the vent hole on the top of the battery). When the internal pressure of the battery rises to a certain value, the safety valve automatically opens to ensure the safety of the battery's use.

　　Sometimes, although the battery itself has safety control measures, due to certain reasons, the control fails, and there is a lack of safety valve or gas cannot be released through the safety valve in time, causing the internal pressure of the battery to rise sharply and cause an explosion.

　　In general, the total energy stored in lithium-ion batteries is inversely proportional to their safety. As the battery capacity increases, the battery volume also increases, leading to poor heat dissipation performance and a significant increase in the likelihood of accidents. For lithium-ion batteries used in mobile phones, the basic requirement is that the probability of safety accidents should be less than one in a million, which is also the minimum standard acceptable to the public. For large capacity lithium-ion batteries, especially those used in automobiles, it is particularly important to use forced cooling.

　　Choosing a safer electrode material and lithium manganese oxide material ensures a fully charged state in terms of molecular structure. The lithium ions in the positive electrode are fully embedded in the negative electrode carbon pores, fundamentally avoiding the generation of dendrites. At the same time, the stable structure of lithium manganese oxide makes its oxidation performance much lower than that of lithium cobalt oxide, and the decomposition temperature exceeds 100 ℃ of lithium cobalt oxide. Even if internal short circuits (punctures), external short circuits, and overcharging occur due to external forces, the danger of combustion and explosion caused by the precipitation of lithium metal can be completely avoided.

　　In addition, the use of lithium manganese oxide material can significantly reduce costs.

　　To improve the performance of existing safety control technologies, the first step is to improve the safety performance of lithium-ion battery cells, which is particularly important for large capacity batteries. Choose a diaphragm with good thermal shutdown performance. The function of the diaphragm is to isolate the positive and negative poles of the battery while allowing the passage of lithium ions. When the temperature rises, it is closed before the diaphragm melts, causing the internal resistance to rise to 2000 ohms and stopping the internal reaction.

　　When the internal pressure or temperature reaches the preset standard, the explosion-proof valve will open and begin to relieve pressure to prevent excessive accumulation of internal gas and deformation, ultimately causing the shell to burst.

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