Challenge

Week 1 Understanding Different Battery Chemistry

1)Li-ion Batteries:

A lithium-ion (Li-ion) battery is an advanced battery technology that uses lithium ions as a key component of its electrochemistry.
It is a type of a rechargeble battery which uses the reversible reduction of lithium ions to store energy.
While discharging negative electrode gives up electron and gets oxidised.
While charging negative electrode accept electron and gets reduced.

Li-ion uses Cathode(+ve electrode) , Anode(-ve electrode) and electrolyte as conductor.
The cathode and anode is separated by a layer called separator.
Cathode is a "metal oxide", Anode consist of porous "carbon" and electrolyte is a mixture of sulphuric acid and distlled water.
When discharging the ions flow from the anode to the cathode through the electrolyte and separator,during charging reverses the direction and the ions flow from the cathode to the anode.

The materials & chemical reactions occurring at the anode, cathode and overall reactions of all the types of Li-ion cells :

I've attached an Excel sheet for the above tabular column for the reference.

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

I) LCO - Lithium cobalt Oxide(LiCoO2) :

A lithium cobalt oxide battery has a graphite carbon anode and a cobalt oxide cathode with a layered structure for ion movement.
The Li-cobalt battery’s high specific energy makes it a popular choice for consumer electronics, such as digital cameras, mobile phones and laptop.
The drawback of this type of cell is low saftey, short lifespan and overheating while applying high loads.

II) LMO - Lithium manganese oxide(LiMn2O4):

Li-ion with manganese spinel was first published in the Materials Research Bulletin in 1983.
In 1996, Moli Energy commercialized a Li-ion cell with lithium manganese oxide as cathode material.
The architecture forms a three-dimensional spinel structure that improves ion flow on the electrode, which results in lower internal resistance and improved current handling.
A further advantage of spinel is high thermal stability and enhanced safety, but the cycle and calendar life are limited.
These tyoes of cells are used in medical devices, portable power tools,hybrid and electric vehicle and powertrains.

Lithium nickel cobalt aluminum oxide battery, or NCA, has been around since 1999 for special applications.
It shares similarities with NMC by offering high specific energy, reasonably good specific power and a long life span.
Less flattering are safety and cost, NCA is a further development of lithium nickel oxide; adding aluminum gives the chemistry greater stability.
Applications are EVs,powertrain,medical devices.

IV) NMC - Lithium Nickel Manganese Cobalt Oxide (LiNiMnCoO2) :

One of the most successful Li-ion systems is a cathode combination of nickel-manganese-cobalt (NMC).
Similar to Li-manganese, these systems can be tailored to serve as Energy Cells or Power Cells. For example, NMC in an 18650 cell for moderate load condition has a capacity of about 2,800mAh and can deliver 4A to 5A.
NMC in the same cell optimized for specific power has a capacity of only about 2,000mAh but delivers a continuous discharge current of 20A.
Applications are E-bikes,EVs,powertrain,medical devices.

V)LFP - Lithium Iron Phosphate(LiFePO4) :

Li-phosphate offers good electrochemical performance with low resistance.
This is made possible with nano-scale phosphate cathode material.
The key benefits are high current rating and long cycle life, besides good thermal stability, enhanced safety and tolerance if abused.
Li-phosphate is more tolerant to full charge conditions and is less stressed than other lithium-ion systems if kept at high voltage for a prolonged time.
As a trade-off, its lower nominal voltage of 3.2V/cell reduces the specific energy below that of cobalt-blended lithium-ion.

VI) LTO - Lithium Titanate (Li2TiO3) :

Batteries with lithium titanate anodes have been known since the 1980s.
Li-titanate replaces the graphite in the anode of a typical lithium-ion battery and the material forms into a spinel structure.
The cathode can be lithium manganese oxide or NMC. Li-titanate has a nominal cell voltage of 2.40V, can be fast charged and delivers a high discharge current of 10C, or 10 times the rated capacity.
The cycle count is said to be higher than that of a regular Li-ion. Li-titanate is safe, has excellent low-temperature discharge characteristics and obtains a capacity of 80 percent at –30°C.
Applications like aerospace and military equipment, EVs, electric powertrains, solar-powered street lighting, telecommunications systems, and UPS.

Ship work like this
in your own course.