Week 1 Understanding Different Battery Chemistry

Question:1

Aim: To 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

Answer:

• The lithium ion batteries can be designed for the optimal capacity and with the draw back of limted loading slow charging and reduced long duration
• In industrial battery may have the moderate amper hour rating but they mainly focus on durability
• The specific energy which only provides the part of battery permance
• Here before starting into the materials and chemical reactions of different type of lithium ion batteries The battery is mainly made up of anode and cathode separator electrolyte and two currents collectors
• The anode and cathode store the ;ithium
• Here the electrolyte carries postive charged lithium ions from anode to the cathode and aslo through the seperator
• Movement of the lithium ions creates a charge at the postive current collector
• So the electric current then floes from the current collector through a device powered to the negtive current collector
• Here the seperator blocks the flow of electrons inside the battery

Main parts of Lithium ion battery:

• If when the battery is dicharging and giving an electric current the anode releases lithium ions to the cathode and it genrates a flow of electrons from one side to other side
• If we plugging in the device the opposite will happen that the lithium ions are realsed by the cathide and recived by the anode

Charging process and Discharging :

Here mainly there are 6 commonly used Lithium ion batteries they are:

1) Lithium cobalt oxide (LiCoO2)-LCO

2) Lithium manganese oxide (LiMn2O4)-LMO

3) Lithium nickel manganese cobalt oxide (liNiMnCoO2)- NMC

4) Lithium iron phosphate (LiFePO4)-LFP

5) Lithium Nickel cobalt aluminium oxide (LiNiCoAlO2) -NCA

6)Lithium titanate (Li2TiO3)-LTO

This each lithium batteries are provides with the different characteristics and are used in the different applications

• Lithium cobalt oxide LCo battery was first invented in the year 1991
• It is anode material is LiaC6 the cathode material is LibCoO2 and the carrier is Li+
• This is used in various applications ranging from electronic devices to all the phones and laptops batteries
• Here the higher of lithium batteries for portable device are cobalt based
• The system which contains a cobalt oxide cathode and graphite carbon anode

C6 + LiCoO2 <-----------> LixC6 + Li1-xCoO2

• The lithium ion manganese oxide battery LMO is a lithium ion cell which uses the manganese dioxide MnO2 as the cathode material
• Here the function through the same intercalation are de -inter calation mechanism as the other seconadry battery techonlogy such as the LiCoO2
• The cathode based on the manganese oxide components are earth abundant inexpensive and non toxic and provide the better thermal stability
• MnO2 +Li+ +e -------->LiMnO4

• Lithium nickel cobalt aluminium oxides NCA battery has been used around since 1999 for the special applications
• It mainly shares the similarities with the NMC by offering high specific energy reasonably good power and long life time span

Li1-xMO2 +LixCn---------------> LiMO2+nC

• Lithium nickel manganese cobalt oxide NMC battery offer the combination of a nickel manganese and the cobalt
• This are sometime aslo know as lithium manganese cobalt oxide batteries
• The NMC batteries have the high specific energy or the power

Li0.5CoO2-->1/2LiCoO2+1/6Co3O4 + 1/6O2

• lithium iron phosphate battery LiFeO4 batteries which is aslo know as lithium phosphate batteries as well
• This are mainly uses phosphate as cathode material
• It aslo benfit in addation from the low resistance properties which enchance their thermal stability and saftey

LiFePO4 + 6C --------->LiC6 + FePO4

• Lithium titanate oxide LTO batteries is a type of rechargable battery which has the advantage of being faster to charge other then lithium ion batteries
• But iy also as disadvantage of having a much lower energy density

Li4Ti5O12 + 3Li+ + 3e- <---------> Li7Ti5O12

Li7Ti5O12 + 2Li+ + 2e- <---------> Li9Ti5O12

Question:2

Aim: To Compare the differences between each type of Li+ion batteries based on their characteristics

Answer:

The main 6 types of lithium ion batteries are discussed above now we see the difference in there charcteristics which can be found while chossing a battery

• Nominal voltage : It is the system voltage at which the device is mainly designed to operate
• Here the rated voltage is basically higher than the nominal voltage to ensure the safe operation of a device
• Cycle: It took place when charing and discharging for a single time makes a cycle
• If the higher the cycles can take place the higher the cycles can takes place then life sapn is aslo higher
• Thermal run way: It mainly begins when the heat is generated within the vattery excceds the amount of heat which is dissipated to its sourroundings
• The internal battery temperature will continue to rise which casuing a domino effect
• The rise in temperature in a single battery will start to affect other batteries nearby the pattern will continue
• Specific energy: The amount of energy stored per unit mass (wh/kg)
• It is very important deciding factor which dcides how much energy or power from the differnt batteries with the same amount of weight

Different types of Lithium ion based batteries:

• Nominal voltage: Here the most of the batteries are very close when it comes to the characteristics
• LMO 3.7 has the highest range and LTO 2.4 has the lowest range volts
• Cycle: This are different by the siginificant amount from each other The LTO battery has the longest life cycle so that it can have last long period of time and it is exactly opposite for the LMO type batteries
• charging current rate: If the higher the charging current the less time the battery will take to get fully charged
• LTO and LTP are highest NCA comes very close to its values
• Discharging current rate : If in case we need higher amount of discharge rates and faster charging times we should chosse a high rated battery
• The LTO has higher discharge rate 10 times higher then the other and it time is one the safest batteries
• Thermal runaway: This mainly occurs in the situations where if there is an increase in temperature chnages the conditions in a way that causes increase in temperature often leading a destructive results
• The LTO has the highest temp rating in this and NCA and LCP has its lowest
• Specific energy : It is calculated by integrating from 0 to t cutoff
• We can aslo get the sepcific energy desity in wh
• Lithium ion cobalt cathodes offer the highest energy density
• This tyoe of applications are mainly laptops cell phones digital camers
• The power density indicates how much the power a battery can deliver on required

So for easy way of choosing the battery the 6 key features are given value within the range 0-5 for all of the given with the same parameter

This are considerd in case of 5 point hexagonal analysis of the battery

i) specific energy

ii) power

iii) safety

iv) life span

v) performance

vi) cost

LCO:

Here Li cobalt excels the higher specific energy but it offers only a moderate performance specific power safety and life span

LMO :

It is although moderate in overall performance newer design of Li manganese offer the imporved in specific power safety and life span

LFP:

The Li phosphate has the excellent saftey and long life span but moderate specific energy and elevated self discharging

NMC:

Here NMC has the good overall perferomance and excels on the specific energy

this battery is mainly preferred candidate for the electric vehicle and has the lowest self heating

NCA:

It has the higher energy and power density as well as good life span make NCA a candidate for EV powertrains

But high cost and marginal safety are negative

LTO:

The Li titanate excels the safety low temperature performance and life span

The efforts are being made to imporve the specific energy and lower the cost

So this type of lithium ion batteries are some of the most popular in the market

Because the technology is continously seeing more change and developement new lithium methodes are always beging developed and those which exist are being devloped

Conculsion:

We have succesfully complted the above given task

In case 1 we have Prepared 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.Given a detailed explanation on it

In case 2 we have Compared the differences between each type of Li+ion batteries based on their characteristics