Week 1 Understanding Different Battery Chemistry

Aim : To solve the Following Question:

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.

Solution 1. As per question Table for the Types of Lithium-ion cells.

Below Shown is a image of the table:

Based on the Parameters

Lithium-ion Cell:

• The Lithium-ion batteries are secondary type of batteries which can be recharged for further usage.
• The Lithium-ion cells have four main Components in it and they are,

1. Cathode
2. Anode
3. Electrolyte
4. Separator

(i) Cathode:

• They are the positive electrodes of the cell.
• The cathode electrode is usually made up of,

1. Layered Transition metal oxides - Has high Capacity but high in cost and poor in safety.
2. Spinel’s - High power Density but poor in conductivity and stability.
3. Olivine’s - Less capacity but has long life and are high in safety.

(ii) Anode:

• They are the negative electrodes of the cell.
• The anode electrode is usually made up of,

1. Graphite
2. Hard Carbon, these anodes are less in cost and high in stability and specific capacity.

(iii) Electrolyte:

* An electrolyte is a substance that produces an electrically conducting solution when dissolved in a polar solvent.

* The dissolved electrolyte separates into cations and anions, which disperse uniformly through the solvent.

* Generally Lithium ion cells have electrolyte of Organic solvents such as, Ethylene carbonate, dimethyl carbonate, propylene carbonate and lithium salt as solute.

(iv) Separator:

• Battery separators provide a barrier between the anode (negative) and the cathode (positive) while enabling the exchange of lithium ions from one side to the other.
• There are metals that conduct ions but they do not conduct the electrons through them

Sr No	Li- ion cell Type	Cathode	Anode	Electrolyte	Separator	Overall Reaction at Cathode & Anode	Applications:
1	LCO	Graphite	Lithium Cobalt Oxide	Ethylene Carbonate +Li salt	Polyolefin	Li1-xCoO2(s)x Li+xe--->LiCoO2(s)	Mobile phones, laptops and digital cameras
2	LMO	lithium manganese oxide	Graphite carbon	Methyl carbonate +Li salt	Polyolefin	Mn2+ . 2LIC6 - Mn-2Li++ graphite	Power tools medical devices electric powertrains
3	NCA	Comprised of Nickel cobalt & Aluminium	Graphite carbon	Propylene carbonate+Li salt	Polyolefin	Li(1-x)NiO2 - (2- x)Li(1-x)/(2-x)Ni1/(2-x) O+x/202	medical devices electric Power trains (Tesla)
4	NMC	Comprised of Nickel cobalt & Manganese	Lithium metal Graphite	Methyl carbonate +Li salt	Polyolefin	Li(x)MO2(s) - Li+(org) . Li(x-1)MO2(s) e-.	E-bikes medical devices Evs
5	LFP	Comprised of Lithium, Iron & Phosphate	Graphite Carbon	Propylene carbonate+ Li salt	Polyolefin	LiFePO4⟶FePO4+Li++e−Li++C6+e−⟶LiC6	Industrial portable and stationary needling, high load currents and endurances
6	LTO	Comprised of Nickel	Lithium-	Propylene	Polyolefin	Li4Ti5012+3Li+ +3e⟶4Li7Ti5012	UPS electric power train, solar powered street lighting

• The types of lithium-ion cells based on their composition and they are shown in the above table:

1. Lithium cobalt oxide - LiCoO2 (LCO)

• Also known as lithium cobaltite or lithium-ion cobalt batteries, lithium cobalt oxide batteries are made from lithium carbonate and cobalt.
• They have a cobalt oxide cathode and use graphite carbon as their anode material; during discharge, lithium ions move from anode to cathode, with the flow reversing when the battery is charging.

This type of battery has some drawbacks, including a relatively short battery life and limited specific power. additionally, these batteries are not as safe as other types.

2. Lithium Manganese Oxide - LiMn2O4 (LMO)

• The first commercial lithium-ion cells made with lithium manganese oxide as a cathode material were produced in 1996 by Moil Energy.
• Lithium manganese oxide batteries are notable for their high temperature stability and are also safer than other lithium-ion battery types.
• For this reason, they are often used in medical equipment and devices, but they may also be used in power tools, electric bikes and more.
• It is also possible to use lithium manganese oxide batteries to power laptops and electric powertrain cars.

3. Lithium Nickel Cobalt Aluminium Oxide - LiNiCoAlO2 (NCA)

• Lithium nickel cobalt aluminium oxide batteries are also called NCA batteries, and are becoming increasingly important in electric powertrains and in grid storage.
• NCA batteries are not common in the consumer industry, but are promising for the automotive industry.
• NCA batteries provide a high-energy option with a good lifespan, but they are not as safe as they could be compared to other lithium-ion battery types and are quite costly.

4. Lithium Nickel Manganese Cobalt Oxide - LiMnCoO2 (NMC)

• Also known as lithium manganese cobalt oxide or NMC batteries, include a cathode made of a combination of nickel, manganese and cobalt.
• Like other lithium-ion battery varieties, NMC batteries can have either a high specific energy density or a high specific power. They cannot, however, have both properties.
• This battery type is most common in power tools and in powertrains for vehicles.
• The cathode combination ratio is usually 60 percent nickel, 20 percent manganese and 20 percent cobalt. This means that the raw material cost is lower than it is for other lithium-ion battery options, as cobalt can be quite expensive.
• These batteries may come down in price further in the future, as some battery makers are planning to switch their battery chemistry to a higher $\%$ of Nickel, so that they can use less cobalt.
• This battery type is commonly preferred for electric vehicles due to its very low self-heating rate.

5. Lithium Iron Phosphate - LiFePo4 (LFP)

• Lithium iron phosphate batteries, also known as li-phosphate batteries, use phosphate as a cathode. They benefit from low resistance properties, which enhance their safety and thermal stability.
• Other benefits include durability and a long lifecycle - fully charged batteries can be stored with little change to the total lifespan of the battery's charge.
• Li-phosphate batteries are often the most cost-effective option as well when their long battery life is taken into consideration. However, the lower voltage of the li-phosphate battery means that it has less energy than other types of lithium batteries.
• Accordingly, these batteries are often used in electric motorcycles as well as other applications that need a long lifecycle and significant safety.

6. Lithium Titanium Oxide - LiTiO2 (LTO)

• Finally, lithium titanate, also known as li-titanate, is a class of battery that allows for ever-increasing applications. the main advantage of the li-titanate battery is its remarkably fast recharge time.
• Currently, manufacturers of electric vehicles and bikes use li-titanate batteries, and there is potential for this type of battery to be used in electric buses for public transportation.
• However, these batteries have lower inherent voltage, or lower energy density, than other lithium-ion battery varieties, which can present issues with powering vehicles efficiently. Even so, the density of lithium titanate batteries is still higher than other non-lithium-ion batteries, which is a plus.

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

We have made a Table based on the Characteristics:

• Specific energy: This defines the battery capacity in weight (Wh/kg). The capacity relates to the runtime. Products requiring long runtimes at moderate load are optimized for high specific energy.
• Specific power: It's the ability to deliver high current and indicates loading capability. Batteries for power tools are made for high specific power and come with reduced specific energy
• Nominal Voltage: It is the system voltage at which the device is designed to operate. The rated voltage is usually higher than the nominal voltage to ensure the safe operation of the device.
• Cycle: The charge and discharge make a Cycle
• The current rate (C): This is used to determine the fast charging capability of a battery.
• Thermal Runaway: It is a condition where an increase in temperature changes the conditions which increase the temperature further, often leading to disaster.
• Performance: This measures how well the battery works over a wide range of temperature. Most batteries are sensitive to heat and cold and require climate control. Heat reduces the life, and cold lowers the performance temporarily.
• Lifespan: This reflects cycle life and longevity and is related to factors such as temperature, depth of discharge and load. Hot climates accelerate capacity loss. Cobalt blended lithium ion also usually have a graphite anode that limits the cycle life.
• Safety: This relates to factors such as the thermal stability of the materials used in the batteries. The materials should have the ability to sustain high temperatures before becoming unstable instability can lead to thermal runaway in which flaming gases are vented. Fully charging the battery and keeping it beyond the designated age reduces safety.
• Cost: Demand for electric vehicles has generally been lower than anticipated and this is mainly due to the cost of lithium-ion batteries. Hence cast is a huge factor when selecting the type of lithium-ion battery.

Sr No	Lithium-ion battery Types	Specific Power	Specific Energy	Safety	Life Span	Cost	Performance
1	Lithium Cobalt Oxide	Low	High	Low	Low	Low	Medium
2	Lithium Manganese Oxide	Medium	Medium	Medium	Low	Low	Low
3	Lithium Nickel Manganese Cobalt Oxide	Medium	High	Medium	Medium	Low	Medium
4	Lithium Iron Phosphate	High	Low	High	High	Low	Medium
5	Lithium Nickel Cobalt Aluminum Oxide	Medium	High	Low	Medium	Medium	Medium
6	Lithium Titanate	Medium	Low	High	High	High	High

Above image can be studied as:

• NMC type battery covers all the characteristics as a better selection to the choice as it covers larger area under the curve have a popular chemistry for the Industry.
• LMO as a choice but has a low life span.
• While LTO and LFP type of batteries covers better even better characteristics as of the best performance and the high life cycle but has a low specific Energy.
• As of LTO type battery is a high Cost battery and the mostly costed batteries.

Conclusion:

1. In the Question 1. we have made 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 and given detailed explanations on it.
2. In the Question 2. we have made a comparison between the differences between each type of Li+ ion batteries based on their characteristics.