Week 1 Understanding Different Battery Chemistry

Aim:

To make a study and understand about the electrochemistry of different types of lithium ion cells.

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,

-cathode

-anode

-electrolyte

-seperator

WORKING OF LITHIUM ION CELL:

*The battery is made up of an anode cathode separator electrolite and two current collectros the anode and cathode store the lithum

*The electrolite carrries positively charges lithium ions from the anode to cathode and vice versa through the separator

*The movement of the lithium ions creates free electrons in the anode which create a charge at the positive current collector

*The electrical current then flows from the current collector through a device being powerd 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 recevied by the cathoe

*This is the working priciple of a lithium ion battery

1.Lithium cobalt oxide-LiCoO2(LCO)

*Also known as lithium cobaltate or lithium-ion cobalt batteries, lithium cobalt oxide bateries are made from

lithium carbonate and cobalt

*They have a cobalt oxide cathode and use graphite carbon as their anode material during discharging lithium ions move from anode to cathode with the flow reversing when the battery is charging

This type battery has some drawbacks inlcuding a relatively short battery life abd limited specific power additionaly these batteries are not as safe as other types

2.Lithum ion manganese oxide(LMO)

*Lithium ion manganese oxide battery is a lithium ion cell that uses manganese dioxide MnO2 as a cathode material they function through the same intercalation/de-intercalation mechanism as other commercialized secondary battery technologies such as LiCoO2.cathode based on manganese oxide components are earth abundant,intexpensive non toxic and provide better thermalstability

3.Lithium Nickel cobalt aluminium oxides(NCA)

*This battery has been around since 1999 for spacial applications .it shares similarites with NMC by offering high specific energy reasonably good specific power and a long life span

4.Lithium Nickel manganese cobalt Oxide(NMC)

*This battery offer a combinaton a nickel manganese and cobalt they are sometimes known as lithium manganese cobalt oxide batterys. NMC batteries have a high specific energy or power

5.Lithium iorn phosphate battery(LiFeO4)

This batteries which is known as Li-phospate batteries as well they use phosphate as cathode meterial.in addition they benifit from the low resistance properties that enchance their thermal stabilityand safety

6.Lithium Titanate oxide(LTO)

This is a type of rechargable battery which has the advantage of being faster to charge than other lithium ion batteries but its disadvantage of having a much lower energy density

2)Compare thr differences between each type of Li+ion batteries based on their characteristics

The major 6 types of lithium ion batteries was discussed early now the major differences in the characteristics can be found when choosing a battery the major things that can be differenciated from one another

Nominal vloltage:it is the system voltage at which the device is desinged 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 when took place for a single time makes a cycle the higher the cycles can take place the higher the cycles can take place then the lifespan

Thermal runway:The thermal runway begins when the heat generated wuthin a battery exceeds the amount of heat that is disspated to its surroundings internal battery temperature will continue to rise causing the battery current to rise creating a domino effect the rise in temperature in a single batterty will being to effect the rise in temperature in a single battery will begin to effect other batteries nearby and the pattern will continue

specific heat:it is the amount of energy stored per unit mass . this is a very important deciding factor that decides how much energy or power from different batteries with the same amount of weight

Specific energy of different types of lithium based batteries:

The main differences between the lithium ion batteries can be differentiate on the charactristics

Nominal Voltage:Most of the batteries are very close when it comes to characteristics.LMO has the highest range and LTO has the lowest range in volts

cycle life: They differ by a significant amount from each other.LTO battery has the longest life cycle so that it can last longer period of time and it is exactly opposite for the LMO type batteries

Charge current rate:Higher the charge current, the less time the battery will take to get fully charged.LTO and LTP are highest NCA comes close to its condensers

Discharge current rate;if we need higher discharge rates and faster charging times we should choose a high rated batttery instead.LTO has a discharge rate 10 times higher than the other and it t=is one of the safest batteris

Thermal runaway:A thermal runaway occurs in situations where an increase in temperature changes the conditions in a way that causes increase in temperature often leading a destructive result.LTO has the highest temperature rating in this and NCA and LCP has its lowest

Specific energy:The specific energy density can be calculated by integrating from 0 to t_cutoff. we can obtain the specific energy density in WH kg^-1. lithium ion with cobalt cathodes offer the highest energy densities. this type of applications are cell phones,laptop and digitall cameras.power desity indicates how much power a battery can deliver on demand

for ease of choosing a battery from laymans prespective, the 6key features are given a value within 0-5 range for all of the given with the same parameters which are considerd in case of 5 point hexagonal analysis of the batteries. they are

1.specific energy

2.specific power

3.safty

4.performance

5.life span

6.cost

LCO:

Li-cobalt excels on high specific energy but offers only moderate performance specific power,safty and life span

LMO:

Although moderate in overall performance,newer designs of Li-manganese offer improvements in specific power,saty and life span.

NMC:

NMC has good overall performance and excel on specific energy. this battery is the preferred candidate for the electric vehicle and has candidate for the electric vehicle and has the lowest self heating rate

LFP:

Li-phospate has excellent safty and long life span but moderate specific energy and elevated self discharge

NCA:

High energy and power densities as well as a good life span make NCA a candidate for EV powertrains. HIGH cost and marginal safty are negative

LTO:

Li-titanate excels in safty, low temperature performance and life span. effort are being made to improve the specific energy and lower the cost

These types of lithium ion batteries are same of the most popular.As technology is continousely seeing more development,new lithium technologies are always being developed and those which exists are being developed