The impact of the internal resistance of lithium batteries on battery performance is very great. The lithium batteries produced by the manufacturer will also be different. Our common ternary lithium batteries and lithium iron phosphate cells have small internal resistance. This means that during the charging process, metal ions will be relocated from the battery pole, and will not affect the ion diffusion speed in the electrolyte. However, when the packaging of some products says "safe", "7 times can be filled", "low temperature 20 degrees" and other similar propaganda words, the actual test results may not be the case. There are three main reasons for the impact on the performance of lithium batteries through internal resistance:

　　1. Affects the charge and discharge efficiency of lithium batteries

　　During the charging process of the battery, when the internal resistance increases, the contact area of the electrolyte and the electrode surface will increase and increase the response activity of the battery. At the same time, after increasing the battery resistance, lithium ions will be easier to embed in the electrode material. During the discharge process, because lithium ion is not easy to embed in the electrode material, the capacity attenuation is faster. The smaller the internal resistance, the smaller the resistance to the lithium ion, the smaller the lithium ion can spread quickly to the negative surface. And small internal resistance can also lead to poor battery cycle performance. In some application scenarios, the internal resistance is even small and even affects the battery life. During the work process, if abnormal conditions such as the decay of battery capacity and the number of cycles decreases rapidly, you can first consider whether it is caused by the internal resistance. Note: All data in this article comes from the author's experiment and theoretical calculation.

　　2. The battery capacity attenuation is accelerated

　　The size of the internal resistance has a great impact on the attenuation of the battery capacity. For example, we charged the phone with a battery 5 battery. When we charged it about 80%, we could not fully charge. Because the mobile phone is not without electricity after use. This is caused by internal resistance. In order to maintain normal work, it must continue to discharge to about 80%. So many people say why the battery has a decline in capacity after a period of time? This is because the internal resistance of the battery is increased. During the charging process, due to the increase in the resistance between the electrode and the electrolyte, the power loss has increased, reducing the cycle life of the battery. So the smaller the internal resistance, the better? Internal resistance is not good, because it will cause the battery to accelerate attenuation. It is generally recommended that you control the internal resistance of the lithium battery to below 1000MΩ.

　　3. Caused the electrolyte decomposition, resulting in heat loss of heat

　　The chemical active substance contained in the electrolyte reacts with the lithium negative pole. In the process of migrating lithium ions to the positive pole, reactions will also occur, such as side reactions and decomposition, which will cause electrolyte decomposition. The greater the internal resistance, the greater the pressure of the lithium battery. When the internal pressure is greater than the external environment, the active substances in the electrolyte will release more gases, producing a large amount of heat and causing the battery to fire and explode.

　　4. Reduce the diffusion capacity of lithium ions, leading to a decline in battery safety performance

　　Under normal circumstances, the battery safety with less internal resistance is better, and the safety performance of the battery is mainly determined by the electrochemical reactions inside the battery. The smaller the internal resistance of the battery, the faster the internal response speed, and the faster the voltage rises; otherwise, the voltage rising speed is slow. Therefore, when the voltage is low, the internal response rate of the battery slows down. If the response rate is too slow, it will cause a large amount of heat during the electrochemical reaction process to cause dangerous conditions such as short circuit or explosion.

　　5. The smaller the internal resistance, the more prone to heat out of control

　　The internal resistance of the lithium battery has a close relationship with the capacity. During the use, due to charging and discharge, a large amount of calories will be generated inside. If the temperature inside the lithium battery exceeds its operating temperature range, it will cause abnormal phenomena such as lithium branches crystal, which will cause internal short circuits. The higher the lithium battery capacity, the greater the possibility of heat out of control. Therefore, the internal resistance of lithium batteries should not be too small.

Read recommendations:

AA

Lithium battery SOC.402030 lipo battery

3.2v 60ah lifepo4 battery.What is the concept of 18650 batteries?

18650 battery pack 3.7v

Nickel Metal Hydride No. 5 battery