SOLUTION 1 :

Li-ion batteries

Lithium ion is a dry rechargeable type of battery which comes usually in small size as compared to other batteries. It is usually used mostly in electronic devices like laptops, cellphones etc. They have also gained popularity in electric vehicles and military and aerospace applications.

Similar to the lead- and nickel-based architecture, lithium ion uses a cathode(positive electrode), an anode(negative electrode) and electrolyte as a conductor. The cathode is a metal oxide and the anode consist of porous carbon.During discharge, the ions flow from anode to cathode through the electrolyte and separator; charge reverses and ions flow from cathode to anode.The Figure below illustrates the process,

When the cell charges and discharges, ion shuttle between cathode (positive electrode) and anode (negative electrode).On discharge, the anode undergoes oxidation, or loss of electrons, and the cathode sees a reduction, or a gain of electrons. Charge reverses the motion

CHARGING:-

During discharge, the lithium ions are de-intercalated from the anode travel back through the electrolyte to the cathode. This also releases the electrons that were tying them to the anode, and these flow through an external wire, providing the electric current that we used to do work. It's the connection of external wires that allows the reaction to proceed - when the electrons are free to travel, so are the positively charged lithium ions that will balance the movement of their negative charge.

When the cathode becomes full of lithium ions, the reaction stops, and the battery is flat. Then when we recharge the Lithium ion batteries again, the external electric charge that we apply pushes the lithium ions back into the anode from the cathode.

DISCHARGING:-

Types of Li-ion Cells

• Lithium Cobalt Oxide - (LCO):-
  
  Also known as lithium cobaltate or lithium-ion cobalt batteries, lithium cobalt oxide batteries are made from lithium carbonate and cobalt. Due to their very high specific energy, these batteries are used for cell phones, laptops and electronic cameras. 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,Battery University notes that these batteries are not as safe as other types. Even so, their characteristics make them the popular choice for cell phones and other portable electronic devices.
• Lithium Manganese Oxide - (LMO):-
  
  Lithium manganese oxide batteries are also commonly called lithium manganate or lithium-ion manganese batteries and are sometimes referred to as li-manganese or manganese spinel.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.
  
  
• Lithium Iron Phosphate - (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. Electric vehicles often use these batteries as well.
  
  
• Lithium Nickel Manganese Cobalt Oxide - (NMC):-
  

  Also known as lithium manganese cobalt oxide or NMC batteries, lithium nickel manganese cobalt oxide batteries are made of several materials common in lithium-ion battery types. They 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 battery type is commonly preferred for electric vehicles due to its very low self-heating rate.
  
  

• Lithium Nickel Cobalt Aluminium Oxide - (NCA):-
  

  Lithium nickel cobalt aluminum 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. NCA batteries must be accompanied by monitoring devices to ensure driver safety.

  Given the consistent use of NCA batteries in electric vehicles, it is possible that demand for these batteries will rise as electric vehicles become more common.
  
  

• Lithium Titanate - (LTO):-
  
  Finally, lithium titanate, also known as li-titanate, is a`C6+LiCoO2 leftrightarrow LiC6+CoO2` class of battery that allows for ever-increasing applications. The main advantage of the li-titanate battery is its remarkably fast recharge time due to its nanotechnology.
  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.
  Applications for these batteries can include military and aerospace uses, and they may also be used for storing wind and solar energy and creating smart grids. Furthermore, Battery Space suggests these batteries could also be used in system-critical backups for power systems.

The materials & chemical reactions occurring at the anode and cathode and the overall chemical reactions of all types of Li-ion cells have been mentioned in the table given below:

SOLUTION 2:-

On the basis of characteristics, the Li+ ion batteries can be compared in the following ways :

Lithium Cobalt Oxide(LiCoO2):-