The six types of lithium batteries specifically include:
llithium cobalt oxide (LiCoO2)
llithium manganese oxide (LiMn2O4)
llithium nickel cobalt manganese oxide (LiNiMnCoO2 or NMC)
llithium nickel cobalt aluminate (LiNiCoAlO2 or NCA)
llithium iron phosphate (LiFePO4)
lLithium titanate (Li4Ti5O12)
1. Lithium Cobalt Oxide (LiCoO 2)
Its high specific energy makes lithium cobalt oxide a popular choice for mobile phones, notebook computers and digital cameras. The battery consists of a cobalt oxide cathode and a graphite carbon anode. The cathode has a layered structure. During discharge, lithium ions move from the anode to the cathode, while the direction of flow is opposite during the charging process.
Lithium cobalt oxide is excellent in terms of high specific energy, but it can only provide general performance in terms of power characteristics, safety and cycle life.
The disadvantages of lithium cobalt oxide are relatively short life, low thermal stability and limited load capacity (specific power). Like other cobalt hybrid lithium-ion batteries, lithium cobalt oxide uses graphite anodes, and its cycle life is mainly limited by the solid electrolyte interface (SEI). Newer material systems have added nickel, manganese and/or aluminum to increase life, load capacity and reduce costs.
2. Lithium Manganese Oxide (LiMn2O4)
Lithium manganate battery, the structure forms a three-dimensional spinel structure, which can improve the flow of ions on the electrode, thereby reducing internal resistance and improving current carrying capacity. Another advantage of spinel is that it has high thermal stability and improved safety, but its cycle and life are limited.
Low battery internal resistance can achieve fast charging and large current discharge. The lithium manganese oxide battery of the 18650 battery cell can be discharged at a current of 20-30A and has a moderate heat accumulation. Load pulses up to 50A/1S can also be applied. Continuous high load at this current will cause heat to accumulate, and the battery temperature must not exceed 80°C (176°F). Lithium manganate is used in power tools, medical equipment, and hybrid and pure electric vehicles.
The capacity of lithium manganese oxide is about one third lower than that of lithium cobalt oxide. Design flexibility allows engineers to choose to maximize battery life or increase maximum load current (specific power) or capacity (specific energy).Although the overall performance is mediocre, the new lithium manganese oxide design can improve power, safety and life.
3. Lithium nickel cobalt manganese oxide (LiNiMnCoO 2 or NMC)
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 to be used as an energy battery or power battery.
The focus of NMC is on the combination of nickel and manganese. Similar to this is table salt, in which the main ingredients sodium and chloride are toxic in themselves, but they are mixed together as a seasoning salt and 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.
NMC is the battery of choice for electric tools, electric bicycles and other electric power systems. The cathode combination is usually 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 the reduced cobalt content. Another successful combination is NCM, which contains 5 parts nickel, 3 parts cobalt and 2 parts manganese (5-3-2). Other combinations of cathode materials in different amounts can also be used.
NMC has good overall performance and outstanding performance in terms of specific energy. This battery is the first choice for electric vehicles and has the lowest self-heating rate. Due to the relatively good performance of the system's economy and overall performance, NMC hybrid lithium-ion batteries have attracted more and more attention. The three active materials of nickel, manganese and cobalt can be easily mixed to suit a wide range of applications in automobiles and energy storage systems (EES) that require frequent cycles. The diversity of the NMC family is growing.
4. Lithium Iron Phosphate (LiFePO 4)
Lithium phosphate has good electrochemical properties and low resistance. This is achieved through nano-scale phosphate cathode materials. The main advantages are high rated current and long cycle life; good thermal stability, enhanced safety and tolerance to abuse.
If kept at a high voltage for a long time, lithium phosphate is more resistant to all charging conditions and has less stress than other lithium-ion systems. The disadvantage is that the lower nominal voltage of the 3.2V battery makes the specific energy lower than the cobalt-doped lithium-ion battery.
For most batteries, low temperatures will reduce performance, and elevated storage temperatures will shorten their service life, and lithium phosphate is no exception. Lithium phosphate has a higher self-discharge than other lithium-ion batteries, which may cause aging and then bring balance problems. Although it can be compensated by selecting high-quality batteries or using advanced battery management systems, both methods increase the cost of the battery pack.
5. Lithium nickel cobalt aluminate (LiNiCoAlO2 or NCA)
Nickel-cobalt lithium-aluminate batteries or NCA have been used since 1999. It has a high specific energy, a fairly good specific power and a long service life, which are similar to NMC. The less likable is safety and cost. NCA is a further development of lithium nickel oxide; the addition of aluminum gives the battery better chemical stability.
High energy and power density and good service life make NCA a candidate for EV power system.
6. Lithium titanate (Li4Ti5O12)
Lithium titanate replaces graphite in the anode of a typical lithium-ion battery, and the material forms a spinel structure. The cathode can be lithium manganate or NMC. The nominal battery voltage of lithium titanate is 2.40V, which can be quickly charged and provides a high discharge current of 10C. It is said that the number of cycles is higher than that of conventional lithium-ion batteries. Lithium titanate is safe, has excellent low-temperature discharge characteristics, and can obtain 80% of the capacity at -30°C (-22°F).
LTO (usually Li4Ti5 O12) has zero strain, no SEI film formation and no lithium electroplating phenomenon during fast charging and low temperature charging, so it has better charge and discharge performance than traditional cobalt-blended Li-ion and graphite anodes. The thermal stability at high temperatures is also better than other lithium-ion systems; however, batteries are expensive. The specific energy is low, only 65Wh/kg, which is equivalent to NiCd. The lithium titanate is charged to 2.80V, and it is 1.80V at the end of the discharge. Typical applications are electric power transmission systems, UPS and solar street lights.