Week 1 Understanding Different Battery Chemistry
TASK 1:
a) 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:
Introduction:
Lithium-ion Cells are a secondary type of battery cell that is they are rechargeable and also they are reusable which makes them ideally suited for automotive applications and certain consumer electronics When two or more cells connected they are referred to as batteries Like other batteries Lithium-ion batteries also rely on the chemical energy stored in the bonds and atoms of elements and compounds and utilize this energy in a chemical reaction occurring inside the cell. The chemical energy from this reaction is converted to electrical energy and it is used. Since the Lithium-ion cells are rechargeable, they can perform the reverse reaction using electricity as well
Electrolyte
- The electrolyte is an ionic conductor that provides the medium for internal ionic charge transfer between the electrodes
- The electrolyte must often comprise a liquid solvent containing dissolved chemicals the solution that provides the ionic conductivity
- The Lithium-ion cels use non-aqueous electrolytes
Cathode and Anode
- The Cathode ad Anoide is the two electrodes that are connected by a wire in an external circuit The electrons are passing through the external wire and so an electric current is perorated
- The Anode refers to the Electrode through which the conventional current enters into a polarized electrical device.
- The Cathode refers to the electrode through which conventional current leaves an electrical device.
Separator
- The Separator physically isolates the positive and negative electrodes. The separator is an ionic conductor but an electronic insulator
- It prevents the internal short-circuiting between the two electrodes
Current Collectors:
• The current collectors are the electronic conductors with which the electrodes are mixed It does not take part in chemical reactions of the cell but instead, it either allows simple electronic connection to reduce the electronic resistance of an electrode
Various LI Ion Battery materials & chemical reactions occurring at the anode and cathode:
1)Lithium cobalt oxide(LCO) battery
LCO (Lithium cobalt oxide) was invented in the year 1991. Its anode material is LiaC6, the cathode material is LibCoO2 and the carrier is Li+.It is used in various applications ranging from electronic devices to all laptops and phone batteries. The majority of lithium-ion batteries for portable devices are cobalt-based. The system contains a cobalt oxide cathode (positive electrode) and graphite carbon anode (negative electrode).
2)Lithium-ion manganese oxide (LMO)battery
A lithium-ion manganese oxide battery (LMO) is a lithium ion cell that uses manganese dioxide, MnO2, as the cathode material. They function through the same intercalation/de-intercalation mechanism as other commercialized secondary battery technologies, such as LiCoO2. Cathodes based on manganese-oxide components are earth-abundant, inexpensive, non-toxic, and provide better thermal stability.
3)Lithium nickel cobalt aluminium oxides (NCA) battery
4)Lithium Nickel Manganese Cobalt Oxide (NMC) battery
LFP batteries stands for Lithium iron phosphate(LiFePO4) batteries, which is known as li-phosphate batteries as well. They use phosphate as cathode material. In addition, they benefit from the low resistance properties that enhance their thermal stability and safety.
| TYPE OF LI ION BATTERY | Voltages | Specific energy | Charge (C-rate) | Discharge (C-rate) | Cycle life | Thermal runaway |
| LITHIUM COBALT OXIDE (LCO) | 3.60V nominal | 150–200Wh/kg | 0.7–1C | 1C | 500–1000 | 150°C (302°F) |
| LITHIUM MANGANESE OXIDE (LMO) | 3.70V (3.80V) nominal | 100–150Wh/kg | 0.7–1C | 1C; 10C possible with some cells | 300 -700 | 250°C (482°F) |
| LITHIUM IRON PHOSPHATE (LIPO) | 3.20, 3.30V nominal | 90–120Wh/kg | 1C | 1C | 2000 & above | 270°C (518°F) |
| LITHIUM MANGANESE COBALT OXIDE (NMC) | 3.60V, 3.70V nominal | 150–220Wh/kg | 0.7–1C | 1C; 2C possible on some cells | 1000-2000 | 210°C (410°F) |
| LITHIUM NICKEL COBALT ALUMINIUM OXIDE (NCA) | 3.60V nominal | 200-260Wh/kg | 0.7C | 1C | 500 | 150°C (302°F) |
| LITHIUM TITANATE OXIDE (LTO) | 2.40V nominal | 50–80Wh/kg | 1C | 10C Possible | 3000–7000 | Safest |
Advantages of Lithium-Ion Battery
Following are the benefits or advantages of Lithium-Ion batteries:
➨As mentioned it has a high energy density which is two times compare to Ni-Cd.
➨The Lithium-Ion battery is rechargeable.
➨There is no memory effect. Hence it is not needed to discharge them completely before recharging.
➨The battery can handle many charge/discharge cycles.
➨The battery can hold the charge and it can lose only 5% of its charge every month.
Disadvantages of Lithium-Ion Battery
Following are the disadvantages of Lithium-Ion Battery:
➨It lasts only two to three years after the manufacturer.
➨It is sensitive to high temperatures.
➨If the battery is completely discharged, it can no longer be recharged again.
➨It is relatively expensive.
➨If the "separator" gets damaged, it can burst into flames.
Schematic Comparison:
Conclusion:
Thus, each Type of LI Ions Batteries Material, Chemical Reactions & Comparision have Been Tabulated and Explained.