Characteristics and parameters of lithium nickel cobalt manganese oxide (LiNiMnCoO 2 or NMC) battery
We often talk about ternary lithium batteries or iron-lithium batteries, which are named after the positive active material. Six common lithium battery types and their main performance parameters, the same technical route of the battery, the specific parameters are not exactly the same, this article shows the general level of the current parameters. The six lithium batteries specifically include: lithium cobalt oxide (LiCoO2), lithium manganate (LiMn2O4), lithium nickel cobalt manganese oxide (LiNiMnCoO2 or NMC), lithium cobalt aluminum aluminate (LiNiCoAlO2 or NCA), lithium iron phosphate (LiFePO4) , lithium titanate (Li4Ti5O12).
Let us first look at the performance and parameters of Lithium nickel cobalt manganese oxide (LiNiMnCoO 2 or NMC) batteries.
One of the most successful lithium ion systems is the cathode combination of nickel manganese cobalt (NMC). Similar to lithium manganate, this system can be customized for use as an energy battery or a power battery. For example, an NMC in an 18650 battery under medium load conditions has a capacity of approximately 2,800 mAh and can provide a 4A to 5A discharge current; the same type of NMC is optimized for a specific power with a capacity of only 2,000mAh, but can provide 20A Continuous discharge current. The silicon-based anode will reach 4000 mAh or more, but the load capacity is reduced and the cycle life is shortened. The silicon added to the graphite has a defect that the anode expands and contracts with charging and discharging, so that the mechanical stress of the battery is largely unstable.
The secret of NMC lies in the combination of nickel and manganese. Similar to this is the salt, in which the main components sodium and chloride are themselves toxic, but they are mixed as a seasoning salt and a food preservative. Nickel is known for its high specific energy, but its stability is poor; the manganese spinel structure can achieve low internal resistance but low specific energy. The two active metals have complementary advantages.
The NMC is the battery of choice for power tools, electric bikes and other electric power systems. The cathode combination is typically one-third nickel, one-third manganese and one-third cobalt, also known as 1-1-1. This provides a unique blend that also reduces raw material costs due to reduced cobalt content. Another successful combination is NCM, which contains 5 parts nickel, 3 parts cobalt and 2 parts manganese (5-3-2). Other different amounts of cathode material combinations can also be used.
Due to the high cost of cobalt, battery manufacturers have switched from cobalt to nickel cathodes. Nickel-based systems have higher energy density, lower cost, and longer cycle life than cobalt-based batteries, but their voltages are slightly lower.
New electrolytes and additives can charge a single battery to more than 4.4V, increasing power. Figure 7 shows the characteristics of the NMC.
NMC's spider map
NMC has good overall performance and excels in terms of specific energy. This battery is the first choice for electric vehicles with the lowest self-heating rate.
Due to the economical and comprehensive performance of the system, NMC hybrid lithium-ion batteries are receiving more and more attention. The three active materials of nickel, manganese and cobalt can be easily mixed to suit the wide range of applications for automotive and energy storage systems (EES) that require frequent cycles. The diversity of the NMC family is growing.
|Lithium nickel manganese cobalt oxide: LiNiMnCoO2 cathode, graphite anode|
Abbreviation: NMC (NCM, CMN, CNM, MNC, MCN similar to different metal combinations) started in 2008
|Voltage||3.60V, nominal 3.70V; battery typical working range 3.0-4.2V or higher|
|Charging (C rate)||0.7-1C, charging to 4.20V, some to 4.30V; 3 hours typical charging. Charging current above 1C will shorten battery life|
|Discharge (C rate)||1C; 2C may be feasible on some batteries; 2.50V cutoff|
|Cycle life||1000-2000 (related to depth of discharge, temperature)|
|Thermal runaway||Typical value is 210 ° C, high charge promotes thermal runaway|
|application||Electric bicycle, medical equipment, electric vehicle, industrial|
|Comment||Provide high capacity and high power, hybrid batteries, welcomed by many uses, increasing market share|