Advantages and disadvantages of power ternary battery
Ternary lithium power battery is one of the lithium batteries, which uses lithium nickel cobalt manganate as positive material. It is cheaper than lithium cobalt, has a slightly higher voltage resistance, a slightly lower average voltage, a slightly higher capacity, and a slightly lower capacity than lithium cobalt acid batteries of the same type.
Power battery performance indicators mainly include five dimensions: energy storage density, cycle life, charging speed, resistance to high and low temperatures and safety. Among them, energy storage density and safety are two new requirements. Lithium titanate batteries and lithium manganate batteries are discarded because of low energy storage density, while lithium cobalt acid is put on the shelf because of poor safety. Only lithium iron phosphate batteries and lithium-ion power batteries remained in the mainstream market for electric bus and passenger car markets, respectively.
The standard operating voltage of Ternary Lithium Power Battery is between 3.6 and 3.8V, and the energy density of Ternary Lithium Power Battery is between 140 and 160wh/kg. Of course, this is not the highest density at this stage but the density of some power batteries that have been loaded at present. Ternary lithium power batteries involve the decomposition of positive materials in the process of use. The decomposition temperature of Ternary lithium power batteries is 200 C. Therefore if the thermal management system of the power batteries is not properly handled, the auto-ignition of the vehicle will easily occur. At 20 C below zero, Ternary lithium power batteries can release 70%. So in winter in the north, electric vehicles equipped with three-lithium-ion power batteries will have a reduced range of mileage. Now some electric vehicles are equipped with power battery temperature control systems to keep the power batteries within the most appropriate operating temperature range.
The main feature of ternary lithium power batteries is that the unit power is larger, which is the result compared with lithium iron phosphate batteries. A major disadvantage of Ternary Lithium Power Batteries, however, is that they have a lower ignition point when subjected to impact and high temperatures. Therefore, the protection of lithium ternary power batteries is very demanding to prevent accidents. Ternary lithium power battery is a battery with excellent comprehensive performance because of its balanced capacity and safety. Ternary lithium power batteries are characterized by:
1) Co3+: reduces the occupancy of cationic mixing, stabilizes the layered structure of materials, reduces impedance values, improves conductivity, and improves cycling and efficiency performance.
2) Ni2+: Increases the capacity of the material (increases the bulk energy density of the material). However, due to the radius similar to that of Li and Ni, excessive Ni2 also results in lithium-nickel mixing due to dislocation with Li. The higher the concentration of nickel ions in the lithium layer, the harder the detachment of lithium in the layered structure, resulting in poor electrochemical performance.
3) Mn4+: This not only can reduce the cost of materials, but also can improve the safety and stability of materials. However, excessive Mn content is prone to occur spinel phase, which destroys the layered structure, decreases the capacity and decreases the cyclic decay.
High energy density and good cycling performance are the greatest advantages of ternary lithium power batteries. The voltage platform is an important indicator of the energy density of power batteries, which determines the basic performance and cost of power batteries. The higher the voltage platform, the larger the specific capacity, so the same volume, weight and even the same safe-time power batteries. Ternary lithium batteries with higher voltage platforms last longer.
The discharge voltage platform of a single lithium-ion power battery is up to 3.7V, lithium iron phosphate is 3.2V, and lithium titanate is only 2.3V. Therefore, lithium-ion power battery has an absolute advantage in terms of energy density. Ternary lithium-powered batteries decrease about 90% in summer at temperatures ranging from 0 to 5 in winter, but not significantly. More to the north, it will fall a little more.
The disadvantage of ternary lithium power batteries: Lithium nickel cobalt aluminate batteries and lithium nickel cobalt manganese acid batteries are the main power lithium batteries of ternary materials. Due to the unstable high-temperature structure of nickel cobalt aluminum, the safety at high temperatures is poor, and the excessive pH value of nickel cobalt aluminum can easily inflate the monomer.