What are the advantages and disadvantages of ternary lithium batteries?
Release time：
2023-04-21 10:31
Source：
The main functions and advantages and disadvantages of the three metal elements are as follows:
Co3+: reduce the mixed occupation of cations, stabilize the layered structure of the material, reduce the impedance value, increase the conductivity, and improve the cycle and rate performance.
Ni2+: It can increase the capacity of the material (increase the volumetric energy density of the material), and due to the similar radius of Li and Ni, too much Ni will also cause lithium-nickel mixed arrangement due to dislocation with Li, and the concentration of nickel ions in the lithium layer The larger is, the more difficult it is for Li to deintercalate in the layered structure, resulting in poor electrochemical performance.
Mn4+: Not only can reduce the material cost, but also can improve the safety and stability of the material. However, if the Mn content is too high, the spinel phase will easily appear and the layered structure will be destroyed, resulting in reduced capacity and cycle attenuation.
High energy density is the biggest advantage of ternary lithium batteries, and the voltage platform is an important indicator of battery energy density, which determines the basic performance and cost of the battery. The higher the voltage platform, the greater the specific capacity, so the same volume, weight, or even the same Anshi's battery, the ternary material lithium battery with a higher voltage platform has a longer battery life.
The discharge voltage platform of a single ternary lithium battery is as high as 3.7V, lithium iron phosphate is 3.2V, and lithium titanate is only 2.3V. Therefore, from the perspective of energy density, the ternary lithium battery is higher than lithium iron phosphate, lithium manganate or Lithium titanate has an absolute advantage.
Poor safety and short cycle life are the main shortcomings of ternary lithium batteries, especially safety performance, which has been a major factor that has always limited its large-scale matching and large-scale integration applications.
A large number of actual tests show that it is difficult for a ternary battery with a large capacity to pass safety tests such as acupuncture and overcharge, which is why more manganese is generally introduced into large-capacity batteries, and even mixed with lithium manganese oxide.
