Ternary lithium batteries are lithium-ion rechargeable batteries that use nickel, cobalt, and manganese transition metal oxides as cathode materials. They combine the excellent cycle performance of lithium cobalt oxide, the high specific capacity of lithium nickel oxide, and the high safety and low cost of lithium manganese oxide. They utilize molecular-level mixing, doping, coating, and surface modification methods to synthesize composite lithium-intercalated oxides with synergistic effects of nickel, cobalt, and manganese. They are currently a widely researched and applied type of lithium-ion rechargeable battery.
Lifespan of ternary lithium batteries
The lifespan of a lithium battery refers to the period after which its capacity decreases to 70% of its nominal capacity (at room temperature of 25°C, standard atmospheric pressure, and discharged at 0.2C). The industry generally calculates cycle life based on the number of full charge-discharge cycles.
The theoretical lifespan of ternary lithium batteries is approximately 800 cycles, which is moderate among commercially available rechargeable lithium batteries. Lithium iron phosphate batteries have a lifespan of around 2000 cycles, while lithium titanate batteries are said to reach 10,000 cycles. Currently, mainstream battery manufacturers promise more than 500 cycles (under standard charge and discharge conditions) in their ternary cell specifications. However, after cells are assembled into battery packs, due to consistency issues—primarily voltage and internal resistance—their cycle life is approximately 400 cycles. Furthermore, if lithium batteries are frequently discharged at high rates and high temperatures, their lifespan will drastically decrease to less than 200 cycles.
Advantages and disadvantages of ternary lithium batteries
Ternary lithium batteries offer a good balance between capacity and safety, making them a battery with excellent overall performance.
High energy density is the biggest advantage of ternary lithium batteries, and voltage plateau is a crucial indicator of battery energy density, determining the battery's basic performance and cost. A higher voltage plateau means a larger specific capacity. Therefore, for batteries of the same size, weight, and even ampere-hour, ternary lithium batteries with a higher voltage plateau have a longer driving range. The discharge voltage plateau of a single ternary lithium battery is as high as 3.7V, compared to 3.2V for lithium iron phosphate and only 2.3V for lithium titanate. Therefore, from an energy density perspective, ternary lithium batteries have an absolute advantage over lithium iron phosphate, lithium manganese oxide, or lithium titanate.
Poor safety and short cycle life are the main shortcomings of ternary lithium batteries, especially safety performance, which has been a major factor limiting their large-scale packing and integrated applications. Extensive field tests show that large-capacity ternary batteries struggle to pass safety tests such as nail penetration and overcharge tests. This is why large-capacity batteries generally incorporate more manganese, or even use them in combination with lithium manganese oxide. A cycle life of 500 cycles is below average for lithium batteries; therefore, the primary application area for ternary lithium batteries is currently consumer electronics such as 3C digital products.
