News detail
Several factors affecting the performance of lithium battery
Release time：
2022-11-17 15:11
1: Discharge current
The size of the discharge current affects the lithium battery. Different lithium batteries support different discharge rates. Usually, there are batteries with discharge rates of 0.2C, 0.5C 1C 3C 5C 10C 20C, and the same type of battery. Under different discharge rates, the capacity retention rate is different. The larger the discharge rate, the less capacity will be released. Therefore, when choosing a lithium battery, pay attention to choosing a battery suitable for the load working current. Of course, a battery with a larger discharge rate will have a smaller nominal capacity and a relatively lower energy density. The better the current flow through the internal tabs and welding positions, the smaller the internal resistance of the battery. For the same type of battery, long-term high-rate discharge will also affect the cycle life, and the cycle life will decay faster.
2: Charging current
What effect does the charging current have on lithium batteries? Generally, the charging rate recommended for lithium batteries is 0.2C. For example, a 10Ah lithium battery generally uses 2A charging current, and 0.5C charging is also used in many applications. Of course, there are many fast charging solutions on the market, such as 1C-2C solutions. It takes 30 minutes to fully charge, and 40 minutes to fully charge these. The charging current has a great influence on the capacity retention rate, cycle life and safety of the battery. The larger the charging current, the smaller the actual charged capacity, and the greater the cycle life decay. Safety will also decrease. We all know that most of the lithium battery combustion accidents happen during the charging process of the battery.
However, the length of charging time directly affects the customer experience, so what should I do? For our specific projects and specific application scenarios, we have to choose the most suitable one for the project itself.
3: Working temperature
Generally, for conventional lithium batteries, the charging temperature is 0~45 degrees, and the discharge temperature is -20~60 degrees. At low temperature, lithium ions are not active enough, and the temperature is too high, and lithium ions are too active, so lithium batteries generally have a clear Lithium batteries have a high energy density and store a lot of energy, but they are also very fragile, so how to use them in strict accordance with the manufacturer's instructions. Charging at low temperature will cause lithium precipitation. Lithium metal precipitates on the surface of the battery anode, forming dendrites, piercing the diaphragm between the anode and cathode, causing internal short circuit of the battery cell, causing heat generation, combustion, and even explosion. With the innovation of technology and the improvement of electrolyte, special lithium batteries can be charged at -20°C~45°C and discharged at -50°C~60°C. Of course, the cost will be higher.
The effect of temperature on battery discharge performance, the lower the operating temperature, the less the capacity will be released when tested with the same current. Lithium batteries of different materials have different capacity retention rates at the same temperature, about -20 degrees , The general capacity retention rate of ternary lithium batteries is about 80%, and that of lithium iron phosphate is generally about 60%.
At present, the low-temperature lithium battery has a capacity retention rate of 0.5C at -40 degrees, which is about 80%, and low-temperature high-rate batteries can reach 1C 3C low-temperature discharge. How does it perform at high temperatures? Within the maximum temperature specified by the manufacturer, it has little effect on the capacity, but long-term high-temperature operation also has an impact on the cycle life of the battery. Many high-temperature batteries on the market have basically been tested by Yunsheng Electronic Technology. It is so-called, and the concept is secretly changed. You must know that lithium batteries can work at high temperature in a short period of time, and there is no abnormality on the surface. Long-term tests are prone to bulges, liquid leakage, and fires.
4:
Different working conditions actually have a greater impact on lithium batteries. Like our daily digital products, they are charged once a day, fully charged at night, and lighted during the day. This is deep charging and deep discharging, like our solar energy. Photovoltaic energy storage, when a little electricity is released, it will be recharged immediately. This situation is called latent charge and latent discharge. The first situation has a greater impact on the life of the lithium battery, and the cycle life is attenuated more severely.
Copyright: Jiangxi Haiyou Lithium New Energy Technology Co., Ltd Business license seo
Technical support:300.cn