Week 1 Understanding Different Battery Chemistry

AIM :

Understanding Different Battery Chemistry

OBJECTIVE :

1.Prepare a table which includes materials & chemical reactions occurring at the anode and cathode of LCO, LMO, NCA, NMC, LFP and LTO type of lithium ion cells.Give your detailed explanation on it

2.Compare the differences between each type of Li+ion batteries based on their characteristics

1. Prepare a table which includes materials & chemical reactions occurring at the anode and cathode of LCO, LMO, NCA, NMC, LFP and LTO type of lithium ion cells.Give your detailed explanation on it.

• LITHIUM ION BATTERY -

A lithium-ion (Li-ion) battery is an advanced battery technology that uses lithium ions as a key component of its electrochemistry. During a discharge cycle, lithium atoms in the anode are ionized and separated from their electrons. The lithium ions move from the anode and pass through the electrolyte until they reach the cathode, where they recombine with their electrons and electrically neutralize. The lithium ions are small enough to be able to move through a micro-permeable separator between the anode and cathode. In part because of lithium’s small size (third only to hydrogen and helium), Li-ion batteries are capable of having a very high voltage and charge storage per unit mass and unit volume.

Li-ion batteries can use a number of different materials as electrodes. The most common combination is that of lithium cobalt oxide (cathode) and graphite (anode), which is most commonly found in portable electronic devices such as cellphones and laptops. Other cathode materials include lithium manganese oxide (used in hybrid electric and electric automobiles) and lithium iron phosphate. Li-ion batteries typically use ether (a class of organic compounds) as an electrolyte.

• Charging & discharging of li-ion battery :

1. During charging, lithium ions (yellow circles) flow from the positive electrode (red) to the negative electrode (blue) through the electrolyte (gray). Electrons also flow from the positive electrode to the negative electrode, but take the longer path around the outer circuit. The electrons and ions combine at the negative electrode and deposit lithium there.
2. When no more ions will flow, the battery is fully charged and ready to use.

3. During discharging, the ions flow back through the electrolyte from the negative electrode to the positive electrode. Electrons flow from the negative electrode to the positive electrode through the outer circuit, powering your laptop. When the ions and electrons combine at the positive electrode, lithium is deposited there.

4. When all the ions have moved back, the battery is fully discharged and needs charging up again.

• Types of Lithium ion batteries -

1. LCO (Lithium cobalt oxide) :

LCO (Lithium cobalt oxide) was invented in the year 1991. Its anode material is LiaC6, the cathode material is LibCoO2 and the carrier is Li+.It is used in various applications ranging from electronic devices to all laptops and phone batteries.The majority of lithium-ion batteries for the portable devices are cobalt based. The system contains a cobalt oxide cathode (positive electrode) and graphite carbon anode (negative electrode).

2. LMO (Lithium magnesium oxide) :

LMO (Lithium magnesium oxide) was invented in the year 1996. Its anode material is LiaC6, the cathode material is LibMn2O4 and the carrier is Li+. It is used in different applications like power tools and electric cars.LMO batteries have the ability to deliver a lot of energy in a short period of time, which makes them extremely useful for use in power tools like drills.In 1996, lithium manganese oxide was first used as a cathode material. A three dimensional spinel structure was formed by this structure, this improves the flow of ions between the electrodes. The high flow decreases the internal resistance and increases loading capability.LMO batteries are usually used in medical devices and equipment, power tools, electric bikes and more. Because of their thermal resistance and higher safety. LMO batteries can also be used for laptops and electrical cars.

3. NCA (Lithium nickel cobalt aluminum oxide) :

NCA (Lithium nickel cobalt aluminium oxide) battery was invented in the year 1999. Its anode material is LiaC6, the cathode material is LiNiCoAlO2 and the carrier is Li+. It is used in different applications like power grid applications, medical devices and electric cars. Most notably Tesla deploys NCA batteries in their electric vehicles system.

NCA batteries can store the same amount of energy as NMC. NCA batteries are not widely common in the consumer industry, but are quite promising in the electric car industry.

4.NMC (Nickel Manganese Cobalt Oxide):

NMC (Nickel Manganese Cobalt Oxide) battery was invented in the year 2008. Its anode material is LiaC6, the cathode material is LiNiMnCoO2 and the carrier is Li+. They commonly use it in different applications like Energy Systems and electric cars.NMC combines the best of nickel and manganese. Nickel has high specific energy but poor stability; manganese can form a spinel structure so as to achieve low internal resistance yet provides a low specific energy. Joining the metals increases the strengths from both parts.NMC batteries are widely used for power tools, energy storage systems (EES) which need frequent cycling and electrical power-trains like automotives. The cathode combination typically used is 1-1-1 which means one third nickel, one third manganese and one third cobalt. This reduces the raw material cost due to lowered content of cobalt. Another known combination for NCM is 5-3-2 (5 parts nickel, 3 parts cobalt and 2 parts manganese). Other combinations are also possible

5. LFP (Lithium iron phosphate) :

LFP (Lithium iron phosphate) was invented in the year 1996. Its anode material is LiaC6, the cathode material is LibFePO4 and the carrier is Li+. They use LFP batteries in different applications like electric cars, electric buses and electric trucks. The LFP is ideal for use in electric trucks or buses – as volume or weight isn’t really a restriction as is in cars- because the battery is less energy dense yet cheaper to manufacture than other Li-ion batteries types.

In addition, they use LFP batteries in other applications like electric motorcycles which need a longer life cycle and increased safety. LFP provides good electrochemical performance with lower resistance. This is enabled by the nano scale phosphate cathode material. The main benefits are long cycle life, higher current rating and thermal stability which means extra safety.

6. LTO (Lithium Tinatate) :

LTO (Lithium Tinatate) was invented in the year 2008. Its anode material is Li7Ti5O12, the cathode material is LibFePO4 and the carrier is Li+. They use it in different applications like UPS, electrical power trains, solar powered street lights, fast charge stations and forklifts. Other applications for LTO batteries include aerospace and military uses, and more importantly wind and solar energy storage and smart grids creation.Li-titanate is used instead of the graphite in the anode of a common lithium-ion battery and the material is formed into a spinel structure. The cathode material is either LMO or NMC.As mentioned, they use li-titanate batteries in electric vehicles, yet LTO batteries have lower energy density than other Li-ion battery types, which can be a disadvantage in efficiently powering vehicles. Still, the density of LTO batteries is higher than other non-Li-ion batteries.

• Material and chemical reactions occur at the anode & Cathode :

2.Compare the differences between each type of Li+ion batteries based on their characteristics .

• Comparison between six types of Lithium ion batteries -

Lithium-ion battery Types	SP	SE	SF	LS	CS	PF
Lithium Cobalt Oxide	L	H	L	L	L	M
Lithium Manganese Oxide	M	M	M	L	L	L
Lithium Nickel Manganese Cobalt Oxide	M	H	M	M	L	M
Lithium Iron Phosphate	H	L	H	H	L	M
Lithium Nickel Cobalt Aluminum Oxide	M	H	L	M	M	M
Lithium Titanate	M	L	H	H	H	H

Where,

SP - specific power

SE - specific energy

SF - safety

LS - lifespan

CS - cost

PF - performance

L - low

M - moderate

H - high

Explanation :

1. Lithium Nickel Manganese Cobalt Oxide(NMC):-

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.

2. Lithium Nickel Cobalt Aluminum Oxide(NCA):-

In this battery type has one strong advantage as compared to the five other batteries and that is 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.

3. Lithium Manganese Oxide(LMO):-

It 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.

4. Lithium Titanium Oxide (LTO):-

This battery has 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 compared to 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.

5. Lithium Iron phosphate (LFP):-

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.

6. Lithium cobalt oxide (LCO):-

Lithium Cobalt Oxide has high specific energy as compared to the other batteries which make it the preferred choice for laptops and mobile phones. It also has a low cost and a moderate performance. It has low specific power, low safety, and a low lifespan.

Conclusion :

Here we understood about lithium ion battery and its types, also li-ion battery charging & discharging process.We understood difference between all li-ion batteries.