Week 1 Understanding Different Battery Chemistry
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
Aim:
To make a study and understand about the electrochemistry of different types of lithium ion cells
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. Battery:
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 When a battery is supplying electric power, its positive terminal is the cathode and its negative terminal is the anode.
The terminal marked negative is the source of electrons that will flow through an extemal electric circuit to the positive terminal. 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.
There are two types of batteries,
1. Primary cell-These batteries are one time use batteries and they cannot be recharged for further usage.
2. Secondart 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,
(1) Cathode
(ii) Anode
(iii) Electrolyte
(iv) Seperator
(1) Cathode:
They are the positive elctrodes of the cell. The cathode elctrode is usually made up ot
1. Layered Transition metal oxides - Has high Capacity but high in cost and poor in safety
2. Spinels-High power Density but poor in conductivity and stability.
3. Olivines-Lees capacity but has long life and are high in safety.
(ii) Anode:
They are the negative eictrodes of the cell.
The anode elctrode 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 dis Skill Bot You may now pick from the options De or type in your query through the solvent.
Generally Lithium ion cells have electrolyes of Organic solvents such a carbonate, dimethyl carbonate, propylene carbonate and lithium salt as solut
(iv) Seperator
A battery separator is a type of polymeric membrane that is positioned between the positively charged anode and the negatively charged cathode. This positioning helps prevent electrical short circuiting
The primary function of the separator is to prevent physical contact between the anode and cathode, while facilitating ion transport in the cell. The challenge with designing safe battery separators is the trade-off between mechanical robustness and porosity/transport properties.
The battery separator is a porous polymer membrane used to create a physical barrier between electrodes in a battery cell. The separator must be mechanically robust to ensure safe operation over the cell's service life: mechanical failure leading to electrode contact can result in catastrophic failure of the cell.
- Working of Lithium ion Battery
Fig-Working Principle
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 Sows 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 chemical compositions and they
1. Lithium cobalt exide-LiCoO2 (LCO)
Also known as lithium cobaltate or lithium-ion cobalt batteries, ithium cobalt onde batteries are made from lithium carbonate and cobalt.
*They have a cobalt oude cathode and use graphite carbon as their anode material during discharge, lithium ions move from anode to cathode, with the now 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-LiMn204 (LMO)
The first commercial lithium-ion cells made with lithium manganese oxide as a cathode
material were produced in 1996 by Moll Energy. Lithium manganese oxide batteries are notable for their high temperature stability and are also sater 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-LINICOAIO2 (NCA)
*Lithium nickel cobalt aluminum code 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 at 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 -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 ifecycle- fully charged batteries can be stored with little change to the total lifespan of the battery's charge LF-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 -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 -titanate batteries, and there is potential for this type of battery to be used in electric buses for public transportation However, these battenes have lower inherent voltage or lower energy density, than other lithium ion battery varieties, which can present issues with powering vehicles efficientlyn Even so, the density of lithium titanate batteries is still higher than other non-lithium-ionnbatteries, which is a plus
2.Compare the differences between each type of Li+ion batteries based on their characteristics
| 1 | Lithium ion cell type | Cathode | Anode | Electrolyte | Reaction |
| 2 | LCO | Graphite | Lithium cobalt oxide | Ethylene carbonate+Plyolefine li salt | Lil-xC002(s)+xli +xe → liCo02(s) |
| 3 | LMO | Lithium Mangnese oxide | Graphite carbon |
Methyl carbonate + Polyolefin lithium salt |
Mn2++ 2 LiC6 → Mn + 2 Li++ graphite |
| 4 | NCA | Compromised of nickel cobalt and aluminium | Graphite carbon | Polyolefin corbonate + Polyfilene li salt | Li(1-x)Nio2 → (2-x)Li(1-x)/(2-x)O +x/202 |
| 5 | NMC | Compromised of nickel cobalt and Manganese | Lithium metal graphite | Methyl carbonate + Polyolefin lithium salt | Li(x) MO2(s) → Li(org) + Li (x-1)MO2(s) + e- |
| 6 | LFP | compromised of lithium iron and phosphate | Graphite carbon | Polyolefin corbonate + Polyfilene li salt | LiFeII PO4 ⇌Fe III PO4 +Li+ e- |
| 7 | LTO | compromised of lithium-titanium-oxide | lithium-titanium-oxide | Propelyne corbonate + Polyfilene li salt | Li4Ti5O12 + 3Li + + 3e → 4 Li7Ti5O12 |