Interpretation of the attenuation of ternary lithium-ion battery packs

Lithium-ion battery manufacturers interpret the attenuation of ternary lithium-ion battery packs. As far as the attenuation of ternary lithium-ion battery packs is concerned, there is no way to deal with it at the current level of technology. At present, we can only judge whether it is normal attenuation or abnormal attenuation through the feedback from the battery. At present, the state stipulates that during the warranty period, the performance of the battery shall not be degraded by more than 20%, otherwise, the lithium-ion battery manufacturer will replace it free of charge. Lithium-ion battery manufacturers interpret the attenuation of ternary lithium-ion battery packs. The voltage platform of ternary lithium-ion battery packs is very high. Under the same volume or weight, the specific energy and specific power of ternary lithium-ion batteries are greater. In addition, ternary lithium-ion batteries have great advantages in terms of high-rate charging and low-temperature resistance. Due to the smaller size, higher capacity density, and low temperature resistance of ternary lithium-ion battery packs, they are currently being widely used in new energy vehicles. For example, we are familiar with Tesla, which uses ternary lithium-ion batteries in all its models. The life of a ternary lithium-ion battery is 2000 charge-discharge cycles. We count it as one charge per day, and it can last for more than 5 years. However, there is still a difference between actual use and theory. If 1,000 charge-discharge cycles are performed, the ternary lithium-ion battery has actually attenuated by 50%, which means that the overflow battery can only run half of the original mileage. In addition, an excellent lithium-ion battery management system can also slow down the degradation of ternary lithium-ion batteries. The life of a ternary lithium-ion battery means that the capacity of the battery decays to 70% of the nominal capacity after a period of use, and the life is considered to be terminated. The attenuation of electric vehicles in the first year is relatively large, usually around 8%; in the following 2-3 years, it will attenuate by 4%; during the 5-6 years of continuous use, the attenuation gradually slows down, usually only 1%. The essence that affects the capacity decay of ternary lithium-ion battery packs is the reduction of the content of lithium ions that can be extracted. The main factors are the structural damage or deactivation of the positive and negative materials, the analysis of the electrolyte, the abuse of lithium-ion batteries, and so on. The charging and discharging process of the battery is a complex electrochemical process, and the factors that cause the battery capacity attenuation are not single, and the deterioration of one aspect may cause other factors to jointly affect the battery's capacity, cycle performance, energy density, etc. Regarding the attenuation of lithium-ion batteries, lithium-ion battery manufacturers have also given a 20% limit value. If the attenuation exceeds this value during the warranty period, there will be corresponding replacement services. As we all know, the attenuation of the battery is directly related to the car owner's daily experience with the car. Next, let's talk about the attenuation value. One is the ternary lithium-ion battery pack represented by Tesla. It has higher energy density, small size and light weight, but because heat dissipation is a big problem, it needs extra space and quality to install a water-cooled heat dissipation system, and Safety is not as good as iron batteries. In addition, its battery decays relatively quickly, about 800-1200 full charge cycles, it decays by 20%. It should be noted that once the ternary lithium-ion battery is found to have a distinct attenuation, you can immediately confirm whether it is within the warranty period and whether the measured attenuation value is within the normal range. If the attenuation exceeds 20% within the scope of the warranty, you can apply to the lithium-ion battery manufacturer to replace the battery for free. If it does not exceed 20% during the warranty period, it is normal.