Talking about the advantages and disadvantages of lithium battery power batteries
Advantages and disadvantages of lithium battery power battery
Lithium iron phosphate battery is a kind of lithium-ion battery. Its characteristic is that it does not contain noble metal elements such as cobalt. The raw materials used are phosphorus and iron. These elements are not only rich in resources, but also relatively inexpensive. The safety of lithium iron phosphate batteries is second to none in lithium batteries. It decomposes at 700℃~800℃, but it will not be as violent as the chemical reaction of ternary lithium materials, nor will it release oxygen molecules. safety. Because of this, it has also become one of the main categories of electric vehicle batteries. In addition, high charging and discharging efficiency and no pollution to the environment are also its advantages. However, it also has its own shortcomings. Due to the low energy density of the battery, its volume is relatively large; the battery capacity is small, which makes its continued driving ability relatively low; after it is scrapped, its recyclable value is very low; Moreover, due to its poor low-temperature performance, studies have shown that a battery with a capacity of 3500mAh, if it is operated at -10°C, after less than 100 charge and discharge cycles, the power will rapidly decay to 500mAh, which is basically scrapped.
The energy density of the ternary lithium battery used in the Tesla MODEL S is greater than that of the lithium iron phosphate battery, which means that the ternary lithium battery of the same weight has a longer range than the lithium iron phosphate battery. However, when the temperature of the ternary lithium battery itself is 250-350°C, its internal chemical components begin to decompose, so higher requirements are placed on the battery management system, and the cost of the battery is also relatively high. To put it simply, ternary lithium materials are more likely to catch fire than lithium iron phosphate materials. However, due to the increasing requirements of consumers for driving mileage, car companies have attracted more and more attention in recent years. They adopt certain technical and design measures to avoid its defects as much as possible.
Japanese manufacturers choose lithium manganese oxide batteries because their overall performance is relatively balanced, and the technology is not as radical as ternary lithium batteries. Because no precious metal cobalt is required, the cost is much lower and there is no patent restriction. This sounds like Japanese The electrification of affordable strategies continues. Lithium manganate is a positive electrode material with low cost, safety and low temperature performance, but its material itself is not very stable and easily decomposes to produce gas, so it is mostly used in combination with other materials to reduce the cost of battery cells, but its cycle life Faster attenuation, prone to swelling, poor high-temperature performance, and relatively short life. It is mainly used for large and medium-sized batteries and power batteries. Its nominal voltage is 3.7V. Although its energy density is not as good as that of ternary lithium batteries, other comprehensive performance is quite outstanding.
The high cost and safety of lithium batteries are the main reasons why Toyota mainly uses nickel-metal hydride batteries in vehicles. Ni-MH batteries gradually developed after the 1990s. For example, many hybrid vehicles represented by Toyota Prius use such batteries as energy storage components. Its main advantage is that it can adapt to high current discharge, which is more suitable for occasions that require greater power output. Its energy density is larger, which increases the mileage. Ni-MH battery discharges electricity relatively smoothly and generates less heat. Its main disadvantage is the "memory effect", that is, the capacity of the battery will attenuate during the cycle of charging and discharging, and overcharging or discharging may aggravate the capacity loss of the battery. Therefore, for manufacturers, the Ni-MH battery control system will actively avoid excessive charging and discharging in settings, such as artificially controlling the battery charging and discharging interval within a certain percentage of the total capacity to reduce the rate of capacity decay.