The disadvantage is that the deoxygenation temperature of ternary materials is 200℃, and they cannot pass the needle penetration test, indicating that ternary batteries are prone to safety accidents such as combustion and explosion when there is an internal short circuit or damage to the battery casing.
What exactly are the three elements in a ternary lithium-ion battery? The "ternary" in ternary lithium-ion batteries refers to a polymer containing three metallic elements: nickel (Ni), cobalt (Co), and manganese (Mn) or aluminum (Al). These elements serve as the positive electrode in ternary lithium-ion batteries. All three are indispensable and play a crucial role within the battery.
Nickel: Its main use is to increase the volumetric energy density of batteries, which is a key breakthrough in improving driving range. However, excessive nickel content can cause nickel ions to occupy lithium ion positions (nickel-metal hydride mixing), resulting in a decrease in capacity.
Cobalt: It suppresses the mixing of cations to improve stability and extend battery life. In addition, it also determines the charging and discharging speed and efficiency (rate performance) of the battery. However, excessive cobalt content will lead to a reduction in actual capacity.
Aluminum or manganese: Cobalt is a very expensive rare metal with high cost. The purpose of manganese or aluminum is to reduce the cost of cathode materials while improving the safety and stability of the battery.
To increase the capacity of ternary lithium-ion batteries, the proportion of nickel in the cathode must be increased. Therefore, the proportion of nickel has been continuously increasing, from the early NCM111 to the NCM523 and NCM611 in the last two years, and then to the NCM811 that has been launched this year. As battery energy density increases, the use of nickel is becoming more and more extensive.
Using more nickel inevitably reduces the proportion of cobalt and manganese. Will this affect battery life and stability? Theoretically, yes, but currently, the mainstay of ternary lithium-ion batteries is undoubtedly the "high-nickel" ternary lithium-ion battery. This is partly due to policy reasons; electric vehicles with longer driving ranges and higher battery energy densities receive more government subsidies. On the other hand, automakers are vying for attention, engaging in a range race, as if whoever has the longest range has the most advanced technology.
With the phasing out and eventual withdrawal of subsidies, the "high-nickel" impulse in ternary lithium-ion batteries may cool down. Meanwhile, with advancements in lithium iron phosphate (LFP) technology, competition with ternary lithium batteries is to be expected. BYD revealed in August that its upcoming new generation of LFP batteries will boast a 50% increase in volumetric energy density, a lifespan of up to 8 years/1.2 million kilometers, and cost savings of 30%. Some analysts suggest that LFP's energy density could rival that of 622 ternary lithium-ion batteries. If this is true, coupled with its superior safety, long lifespan, and low cost, LFP batteries may very well return to the forefront.
It's not accurate to say which is better, lithium iron phosphate (LFP) batteries or ternary lithium-ion batteries; rather, each has its strengths. LFP batteries excel in long lifespan, safety, and low cost, but their energy density and low-temperature performance are slightly inferior. Ternary lithium-ion batteries, on the other hand, boast high energy density and large capacity, but their safety and lifespan are slightly less desirable.
