You might have seen enigmatic letters and numbers such as NCM 711, NCM 811 or NCA when you were reading articles about batteries. What do the code-like battery terms mean?
What is a Ternary Battery?
Lithium-ion batteries produce electricity through the chemical reactions created when lithium ions shuttle between the cathode and anode. Lithium, a cathode material, is unstable in its elemental form and exists in the form of lithium metal oxides (LiMO₂), combining with other metal elements. If lithium cobalt oxide (LCO), a common cathode material in lithium-ion batteries, adds nickel and another element to have 3 elements in the cathode, a “ternary battery” is produced.
Understanding Ternary Batteries
To learn about ternary batteries, you should first know the characteristics of metal elements in the cathode. Nickel is the key to energy density; cobalt and manganese reliability; and aluminum output of batteries. As each of these elements has different characteristics, the performance of a battery varies on the element and proportion used for making the battery.
Types of Ternary Batteries
The most common ternary batteries are nickel-cobalt-manganese (NCM) and nickel-cobalt-aluminum (NCA) batteries. First of all, the correct notation for NCM is LNCMO. It is called NCM for convenience’s sake, and is created when nickel (Ni) and manganese (Mn) are mixed into lithium cobalt oxide (LCO). NCM has nickel, cobalt and manganese at a 1:1:1 ratio. It is currently the most used type for batteries mainly because it is a good option for the cathode of EV batteries. In response to the skyrocketing raw material prices, other types such as NCM 712 and NCM 811 are developed by raising the proportion of nickel that improves energy density while reducing the proportion of costly cobalt.
NCA is also a cathode material that contains lithium cobalt oxide, but it is combined with nickel (Ni), cobalt (Co) and aluminum (Al). In this cathode material, nickel, cobalt and aluminum are combined at an 8:1:1 ratio. The high nickel content and inclusion of aluminum make for high energy density and output compared to other materials. For this reason, NCA is mainly used for small batteries such as cylindrical batteries.
Battery makers put a high priority on developing cathode materials, because they are critical for battery performance and capacity. Now, next time you see the terms like NCM, NCM811 or NCA, you will know what elements are included at what ratio in the cathode material.