What types of new energy vehicle power batteries do you know?
Most traditional vehicles use fossil fuels, but the important energy source for electric vehicles is electric energy. The core of electric vehicles is the development of batteries for electric vehicles. New energy vehicle batteries are an important key breakthrough point in the modern industry. At present, the mainstream types of new energy vehicle power batteries on the market are roughly classified into lead-acid batteries, nickel-hydrogen batteries, lithium cobalt oxide batteries, lithium manganate batteries, lithium iron phosphate batteries and ternary lithium ion batteries (nickel cobalt manganese acid Lithium-ion batteries) and several other categories.
Lead-acid batteries
Lead-acid batteries have low cost, good low temperature performance, and high cost performance; low energy density, short life, large volume, and poor safety. Due to the low energy density and service life, electric vehicles as power cannot have a good speed and a high cruising range, and are generally used for low-speed vehicles.
NiMH batteries
Nickel-metal hydride batteries have low cost, mature technology, long life and durability; low energy density, large volume, low voltage, and battery memory effect. Due to its super durability, it has been used for a long time by Toyota's hybrid model Prius. Compared with the lithium-ion battery, the battery cell voltage is only 1.2v, which is 1/3 of the lithium-ion battery. Therefore, the volume of the nickel-hydrogen battery is much larger than that of the lithium-ion battery when the required voltage is constant. Although its performance is better than that of lead-acid batteries, it contains heavy metals, which will pollute the environment when abandoned.
Lithium Ion Battery
Lithium-ion batteries are among the most technologically advanced batteries available today. This kind of battery has high energy density, and can store more electricity; long cycle life, can be charged and discharged more times, and lasts for a long time. There are mainly two types of lithium-ion batteries used in electric vehicles: lithium iron phosphate batteries and ternary lithium-ion batteries. In simple terms, "lithium iron phosphate" and "ternary lithium" are both positive electrode materials for power lithium batteries, which have a decisive role in battery energy density. Therefore, in the naming rules of batteries, they are mostly named after positive electrode materials, and ternary lithium ion The same is true for the origin of both batteries and lithium iron phosphate batteries.
Lithium Iron Phosphate Battery
The lithium iron phosphate battery has good thermal stability, safety, low cost, long life, low energy density and low temperature. Thermal stability is the best among power lithium-ion batteries. When the battery temperature is 500-600℃, its internal chemical composition begins to decompose, and puncture, short circuit, high temperature will not burn or explode, so it is safer than Panasonic's lithium cobalt oxide battery and has a longer service life .
However, the low energy density results in a heavier battery, a larger volume, and a mediocre vehicle mileage. The biggest pain point is the low-temperature charging problem. When the temperature is lower than -5°C, the charging efficiency is low, which is not suitable for the needs of charging in the north in winter.
Ternary lithium-ion battery
Ternary lithium-ion batteries have high energy density, long cycle life, and are not afraid of low temperatures; they are not stable enough at high temperatures. The energy density can reach the highest, but the high temperature performance is relatively poor. For pure electric vehicles with requirements for cruising range, it is the mainstream direction, and it is suitable for northern weather, and the battery is more stable at low temperature. The Model 3 announced by Tesla uses Panasonic's 21700 ternary cylindrical battery.
The disadvantage is that the deoxidation temperature of the ternary material is 200 ℃, and the acupuncture experiment cannot be passed, indicating that the ternary battery is prone to fire, explosion and other safety accidents when the internal short circuit and the battery shell are damaged.
Lithium iron phosphate battery and ternary lithium ion battery, can not simply say which is better, can only say that each is good at winning the game. Lithium iron phosphate batteries are superior in long life, good safety, and low cost, but their energy density and low-temperature performance are inferior; ternary lithium-ion batteries are superior in terms of high energy density and more power storage, but their safety and lifespan are inferior.
In a few years, it will be time to look at solid-state lithium-ion batteries. Solid-state lithium-ion batteries, the electrolyte is changed from liquid to solid, with large capacity, fast charging speed, and no risk of electrolyte leakage and fire. It can be described as an ideal power lithium battery. Several companies around the world have launched prototype batteries for solid-state batteries, and perhaps within three or five years, such batteries will emerge.