Week 1 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.

Solution:

Battery:

1. A Battery is a device consisting of one or more electrochemical cells with external connections for powering electrical devices such as Flashlights, mobile phones and electric cars.
2. When a battery is supplying electric power, its positive terminal is the cathode and its negative terminal is the anode.
3. The terminal marked negative is the source of electrons that will flow through an external electric circuit to the positive terminal.
4. When a battery is connected to an external electric load, a Redox reaction converts high-energy reactants to lower energy products, and the free energy difference is delivered to the external circuit as electrical energy.
5. There are two types of batteries,
6. Primary cell - These batteries are one time use batteries and they cannot be recharged for further usage.
7. Secondary cell - These batteries can be recharged and can be used for multiple times.

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,

(I) Cathode

(ii) Anode

(iii) Electrolyte

(iv) Separator

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

Working of Lithium-ion:

• The battery is made up of an anode, cathode, separator, electrolyte, and two current collectors (positive and negative), the anode and cathode store the lithium.
• The electrolyte carries positively charged lithium ions from the anode to the cathode and vice versa through the separator.
• The movement of the lithium ions creates free electrons in the anode which creates a charge at the positive current collector.

The electrical current then flows from the current collector through a device being powered (cell phone, computer, Electric motor etc.) to the negative current collector. The separator blocks the flow of electrons inside the battery

• While the battery is discharging and providing an electric current, the anode releases lithium ions to the cathode, generating a flow of electrons from one side to the other.
• When charging, the opposite happens, where Lithium ions are released by the cathode and received by the anode.
• This is the working principle of a lithium-ion battery.

Types of Lithium-ion battery:

There are some types of lithium-ion cells based on their composition and they are:

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.

Comparison of different types of Li-ion batteries based on characteristics:

Detailed Comparison Table :

Li- ion cell Type	Cathode	Anode	Electrolyte	Seperator	Overall Reaction at Cathode & Anode	Applications:
LCO	Graphite	Lithium Cobalt Oxide	Ethylene Carbonate+Li salt	Polyolefin	Li1-xCoO2(s)xLi+xe- -->LiCoO2(s)	Mobile phones, laptops and digital cameras
LMO	lithium manganese oxide	Graphite carbon	Methyl carbonate+Li salt	Polyolefin	Mn2+ . 2LIC6 - Mn-2Li++ graphite	Power tools medical devices electric powertrains
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)
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
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 edurances
LTO	Comprised of Nickel	Lithium-	Propylene	Polyolefin		UPS electric power train, solar powered street lighting

Basic comparison table Based on performance :

Lithium-ion battery Types	Specific Power	Specific Energy	Safety	Life Span	Cost	Performance
Lithium Cobalt Oxide	Low	High	Low	Low	Low	Medium
Lithium Manganese Oxide	Medium	Medium	Medium	Low	Low	Low
Lithium Nickel Manganese Cobalt Oxide	Medium	High	Medium	Medium	Low	Medium
Lithium Iron Phosphate	High	Low	High	High	Low	Medium
Lithium Nickel Cobalt Aluminum Oxide	Medium	High	Low	Medium	Medium	Medium
Lithium Titanate	Medium	Low	High	High	High	High

Summary of the Table

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. 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 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 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 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.

Below image is downloaded from google images for easy understanding purpose

Lithium-ion batteries are used in most aspects of our everyday lives. Most devices like smartphones and laptops cannot operate without these batteries. Lithium-ion batteries have also become very important in the field of electromobility as it is now the battery of choice in most electric vehicles. Its high specific energy gives it an advantage over other batteries.

There are different types of lithium-ion batteries and the main difference between them lies in their cathode materials. Different kinds of lithium-ion batteries offer different features, with trade-offs between specific power, specific energy, safety, lifespan, cost, and performance.

The six lithium-ion battery types that we will be comparing are Lithium Cobalt Oxide, Lithium Manganese Oxide, Lithium Nickel Manganese Cobalt Oxide, Lithium Iron Phosphate, Lithium Nickel Cobalt Aluminum Oxide, and Lithium Titanate. Firstly, an understanding of the key terms below will allow for a simpler and easier comparison.

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 a high current and indicates loading capability. Batteries for power tools are made for high specific power and come with a reduced specific energy.

A high specific power usually comes with reduced specific energy and vice versa. The pouring of bottled water in a glass is a perfect analogy of the relationship between specific power and specific energy. The water in the bottle can be thought of as specific energy. Pouring the water at a slow rate doesn’t provide enough force (low specific power) but the water lasts longer in the bottle (high specific energy). On the other hand, if we pour the water out at a faster rate it provides a greater impact (high specific power). However, the water wouldn’t last very long in the bottle ( low specific energy).

Performance: This measures how well the battery works over a wide range of temperatures. Most batteries are sensitive to heat and cold and require climate control. Heat reduces life, and cold lowers 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 batteries 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 cost is a huge factor when selecting the type of lithium-ion battery.

Now that we have an understanding of the major battery characteristics, we will use them as the basis for the comparison of our six types of lithium-ion batteries. The characteristics are rated as either high, moderate, or low. The table below provides a simple comparison of the six lithium-ion battery types.

Links and References :

Gdrive Link :

https://drive.google.com/drive/folders/1i2ff4u_aT8SP6ni-NVWrb7bgxMPViZCs

References :

1. wikipedia : https://en.wikipedia.org/wiki/Electric_battery

2. https://afdc.energy.gov/vehicles/electric_batteries.html

3. https://www.energizer.com/about-batteries/battery-chemistry

4. Google Images