The biggest advantage of ternary lithium-ion batteries is their relatively high energy density compared to lithium iron phosphate batteries. However, a significant drawback of ternary lithium-ion batteries is their lower ignition point when subjected to impact or high temperatures. Therefore, ternary lithium-ion batteries require stringent protection measures to prevent accidents.
Ternary lithium-ion batteries offer a good balance between capacity and safety, making them a battery with excellent overall performance.
I. Advantages of ternary lithium-ion batteries
Co3+: Reduces cation mixing and occupancy, stabilizes the layered structure of materials, lowers impedance, increases conductivity, and improves cycle performance and efficiency.
Ni2+ can improve the capacity of materials (increase the volumetric energy density of materials). However, due to the similar radii of Li and Ni, excessive Ni can also cause lithium-nickel mixing due to dislocation phenomena with Li. The higher the concentration of nickel ions in the lithium layer, the more difficult it is for lithium to be inserted and extracted in the layered structure, resulting in poorer electrochemical performance.
Mn4+ can not only reduce material costs but also improve the safety and stability of materials. However, excessively high Mn content can easily lead to the formation of spinel phases, which can disrupt the layered structure, reduce capacity, and cause cycle degradation.
High energy density and good cycle performance are the biggest advantages of ternary lithium-ion batteries. 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. Therefore, for batteries of the same size, weight, and even the same ampere-hour, ternary lithium-ion batteries with higher voltage platforms have a longer driving time.
The discharge voltage platform of a single ternary lithium-ion battery is as high as 3.7V, while that of lithium iron phosphate is 3.2V, and that of lithium titanate is only 2.3V. Therefore, from the perspective of energy density, ternary lithium-ion batteries have an absolute advantage.
In winter, when temperatures drop to 5 degrees Celsius, the performance of ternary lithium-ion batteries is about 90% of that in summer; there is a decrease, but it is not very significant. In more northern regions, the decrease will be more pronounced.
II. Disadvantages of ternary lithium-ion batteries:
Ternary lithium-ion batteries mainly include nickel-cobalt-aluminum lithium-ion batteries and nickel-cobalt-manganese lithium-ion batteries. Due to the high-temperature structural instability of nickel-cobalt-aluminum, high-temperature safety is poor, and excessively high pH value can easily cause the cells to swell and lead to danger. Currently, they are relatively expensive.
