Week 1 Understanding Different Battery Chemistry

1.Lithium Cobalt Oxide, LCO

The battery consists of a cobalt oxide cathode with a layered structure.
The anode is graphite (carbon). During the discharge cycle, lithium ions move from the anode to the cathode,and in the reverse direction during charge.The graphite anode limits the battery life as the solid electrolyte interface changes and also as a result of anode thickening.One of the drawbacks of the LCO battery is that its current capability in both charge and discharge is limited

at anode,LiC6→xLi++xe−+C6
at cathode,Li1−xCoO2+xLi++xe−→LiCoO2
overall reaction,C6+LiCoO2⟷LixC6+Li1−xCoO2

2.Lithium Iron Phosphate Battery, LFP
The Lithium Iron Phosphate, LFP type of lithium ion battery provides a low internal resistance and high current capability.In order to provide its high of current capability, this type of li-ion battery uses a nano-scale phosphate cathode material.In terms of performance this type of lithium ion battery provides a slightly lower terminal voltage and it has a slightly higher self-discharge rate than other forms. However against this it provides a high current rating, and good thermal stability combined
with a good level of, and good thermal stability.
A lithium iron phosphate battery cell is similar to the lithium cobalt oxide cell. The anode is still graphite and the electrolyte is also much the same. The difference is that the lithium cobalt dioxide cathode has been replaced with the more stable lithium iron phosphate.In fact, no lithium or iron ions remain in the iron phosphate (FePO4) cathode of a fully charged cell.

at anode,LiC6→Li++e−+C6
at cathode,LiFe(III)PO4+xLi++xe−→LiFe(II)PO4;FePO4+Li++e−→LiFePO4
overall reaction,LiFePO4+6C→LiC6+FePO4

3.Lithium Manganese Oxide, LMO

This type of lithium battery uses a cathode made from lithium-manganese spinel (Li+Mn3+Mn4+O4). Spinel is a type of mineral with a distinctive AB2O4 structure.The spinel structure has very good thermal stability, improving the battery’s safety. It also promotes ion flow within the electrolyte and lessens the internal resistance that contributes to the loss of a battery’s power over time.

Anode: LinC6 <->nLi+ + ne−
Cathode: Lim − nMn2O4 + nLi+ + ne− <->LimMn2O4
Overall: LinC6 + Lim − nMn2O4 <->Li0C6 + LimMn2O4

4.Lithium Nickel Cobalt Aluminium Oxide, NCA
The Lithium Nickel Cobalt Aluminium Oxide battery, or NCA, is a li-ion battery type that is rarely seen in consumer applications but is being investigated for the automotive industry. Its main advantage is that it has a good life span and high energy and power density figures NCA is a further development of lithium nickel oxide; adding aluminum gives the chemistry greater stability. It shares similarities with NMC by offering high specific energy, reasonably good specific power and a long life span. Less flattering are safety and cost.

Anode LinC6 <-> Li0C6 + nLi+ + ne−
Cathode Lim − n(NixCoyAlz)O2 + nLi+ + ne− <-> Lim(NixCoyAlz)O2
Overall LinC6 + Lim − n(NixCoyAlz)O2 <-> Li0C6 + Lim(NixCoyAlz)O2

5.Lithium Nickel Manganese Cobalt Oxide, NMC

These batteries are generally made with a cathode with one-third nickel, one-third manganese and one-third cobalt.The key to this lithium ion battery type is the combination of nickel and manganese. Nickel is known for its high specific energy, but poor stability whereas manganese provides low internal resistance but at the cost of low specific energy. Combining both in a cell in the correct
manner is able to provide the required balance of the properties of both metals.There is a move towards NMC-blended Li-ion as the system can be built economically and it achieves a good performance. The three active materials of nickel, manganese and cobalt can easily be blended to suit a wide range of applications for automotive and energy storage systems (EES) that need frequent cycling.

Anode LinC6 <->Li0C6 + nLi+ + ne−
Cathode Lim − n(NixMnyCoz)O2 + nLi+ + ne− <->Lim(NixMnyCoz)O2
Overall LinC6 + Lim − n(NixMnyCoz)O2 <->Li0C6 + Lim(NixMnyCoz)O2

6.LTO
Lithium titanate (LTO) batteries replace the graphite in the anode with lithium titanate and use LMO or NMC as the cathode chemistry.The result is an extremely safe battery with a long lifespan that charges faster than any other lithium battery type.Li-titanate replaces the graphite in the anode of a typical lithium-ion battery and the material forms into a spinel structure. The cathode can be
lithium manganese oxide or NMC. Li-titanate has a nominal cell voltage of 2.40V, can be fast charged and delivers a high discharge current of 10C, or 10 times the rated capacity. The cycle count is said to be higher than that of a regular Li-ion. Li-titanate is safe, has excellent low-temperature discharge characteristics and obtains a capacity of 80 percent at –30°C (–22°F).

anode -Li4Ti5O12+4Li++4e- <-> 4LiMn2O4
cathode-4Mn2PO4+4Li++4e-<->4LiMn2O4
overall-4Mn2O4+Li4Ti5O12<->4LiMn2O4+Ti4O12

2.

The differences between each type of Li+ ion batteries are given below-

Lithium Cobalt Oxide has high specific energy compared to the other batteries, making it the preferred choice for laptops and mobile phones. It also has a low cost and a moderate performance. However, it is highly unfavorable in all the other aspects when compared to the other lithium-ion batteries. It has low specific power, low safety,and a low lifespan.

Lithium Manganese Oxide has moderate specific power, moderate specific energy, and a moderate level of safety when compared to the other types of lithium-ion batteries.It has the added advantage of a low cost. The downsides are its low performance and low lifespan. It is usually used in medical devices and power tools.

Lithium Nickel Manganese Cobalt Oxide has two major advantages as compared to the other batteries. The first one is its high specific energy, which makes it desirable in electric powertrains, electric vehicles, and electric bikes. The other is its low cost. It is moderate in terms of specific power, safety, lifespan, and performance when compared to the other lithium-ion batteries. It can be optimized to either have high specific power or high specific energy.

Lithium Iron Phosphate only has one major disadvantage when compared to other types of lithium-ion batteries, and that is its low specific energy. Other than that, it has moderate to high ratings in all the other characteristics. It has high specific power, offers a high level of safety, has a high lifespan, and comes at a low cost.The performance of this battery is also moderate. It is often employed in electric motorcycles and other applications that require a long lifespan and a high level of safety.

Lithium Nickel Cobalt Aluminum Oxide offers one strong advantage compared to the five other batteries: high specific energy. It is pretty moderate in the rest of the characteristics like performance, cost, specific power, and lifespan. The only downside to this battery type is its low level of safety. Its high specific energy and moderate lifespan make it a good candidate for electric powertrains.

Lithium Titanate offers high safety, high performance, and a high lifespan which are very important features every battery should have. Its specific energy is low compared to the five other lithium-ion batteries, but it compensates for this with moderate specific power. The only major disadvantage of lithium titanate as comparedto the other lithium-ion batteries is its extremely high cost. Another important feature of this battery worthy of mention is its remarkably fast recharge time. It can be
used for storing solar energy and creating smart grids.