Week 1 Understanding Different Battery Chemistry
1.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.
Ans:
Energy can be Transfered from one form to another form.
Electrical energy can be converted into chemical form and again it can be converted back to electric form.
Every atom in a nature want to become stable. Inert gases are stable atoms in nature because their outermost shell is completely filled with electrons.
This elements are helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), radon (Rn), and oganesson (Og).
Other atom want to become stable either by gaining or loosing an electron.
For this atoms will combine with other atom to become inert and stable.
If an atom looses an electron then this process is called Oxidation.
If an atom or molecule gains an electron then this process is called Reduction.
Entire process is called as Redox reaction.
Battery: Battery is a device which can store electrical energy into chemical energy at the time of charging and agian it will produce electrical energy at the time of discharging.
Working Principal of a battery:
Battery consist of anode electrode, cathode electrode and electrolyte.
Anode:
If a current enters into the ploarized device or if electron leave the electrode, then that electrode is called anode.
Cathode:
If a current leaves the ploarized device or if electron enters the electrode then that electrode is calledcathode.
Lithium atom has atomic number of 3, if it is looses one electron then it will become stable.Therfore Lithium is highly reactive element.
Lithium available in the form of Lithium-metal oxides are used in the cathode and lithium-carbon compounds are used in the anode.
Discharging
Positively charged lithium ions (Li+) move from the negative anode to the positive cathode.
They do this by moving through the electrolyte until they reach the positive electrode.
The electrons, on the other hand, move from the anode to the cathode.
Charging:
while charging a lithium-ion battery, the exact opposite process happens. The lithium ions move back from the cathode to the anode.
The electrons move from the anode to the cathode.
Chemistry involved in Lithium ion batteries:
Lithium ion in Anode material:
1: Metal oxides: NCA(Lithium nickle cobalt aluminium oxide), NMC(Lithium nickle cobalt aluminium oxide),LCO (Lithium cobalt oxide).
2:Spinels: LMO(Lithium manganese oxide) ,LTO(Lithium titnate)
3:Olivines: LIFEPO4(Lithium iron phosphate).
Lithium ion in cathode material:
Graphite and hard carbon
| S.No | Name | Anode reaction | cathode reaction | complete reaction |
| 1 | LCO (Lithium cobalt oxide) | LiC6 → C6 + Li+ + e- | CoO2 + Li+ + e- → LiCoO2 | LiC6 + CoO2 ⇄ C6 + LiCoO2 |
| 2 | LMO(Lithium manganese oxide) | LiC6 → C6 + Li+ + e- | MnO2 + Li+ + e- → MnO2 | C6 + LiMn2O4 ⇄Lic6+Mn2O4 |
| 3 | LIFEPO4(Lithium iron phosphate) | LiC6 → C6 + Li+ + e- | FePO4+Li+ + e- →LiFePo4 | C6 +LiFePo4⇄LiC6+FePO4 |
| 4 | NCA(Lithium nickle cobalt aluminium oxide) | LiC6 → C6 + Li+ + e- | NiCoAlO2+Li+ + e- →LiNiCoAlO2 | C6 +LiNiCoAlO2⇄Lic6+NiCoAlO2 |
| 5 | NMC(Lithium nickle cobalt aluminium oxide) | LiC6 → C6 + Li+ + e- | NiMnCoO2+Li+ + e- →LiNiMnCoO2 | C6 +LiNiMnCoO2⇄Lic6+NiMnColO2 |
| 6 | LTO(Lithium titnate) | Liti5O12→ Ti5O12+4Li++4e- | 4Mn2O4+4Li++4e→LiMn2O4 | 4Mn2O4+Liti5O12⇄4LiMn2O4+Ti5O12 |
2.Compare the differences between each type of Li+ion batteries based on their characteristics
Ans:
Lithium ion materials:
1: Metal oxides: NCA(Lithium nickle cobalt aluminium oxide), NMC(Lithium nickle cobalt aluminium oxide),LCO (Lithium cobalt oxide).
2:Spinels: LMO(Lithium manganese oxide) ,LTO(Lithium titnate)
3:Olivines: LIFEPO4(Lithium iron phosphate).
| S.No | Name | LIFEPO4(Lithium iron phosphate) | NMC(Lithium nickle cobalt aluminium oxide) | LCO (Lithium cobalt oxide) | LMO(Lithium manganese oxide) | LTO(Lithium titnate) |
| 1 | Voltage | 3.2V | 3.6V | 3.6V | 3.7V | 2.4V |
| 2 | Specific Energy | 90-120 Wh/kg | 150-220 Wh/kg | 150-200Wh/kg | 100-150Wh/kg | 50-80Wh/kg |
| 3 | Energy Density | 330Wh/l | 580Wh/l | 560Wh/l | 420Wh/l | 177Wh/l |
| 4 | Charge Rate | 1C | 0.7-1C | 0.7-1C | 0.7-1C | 1C |
| 5 | Discharge Rate | 1C 2.0Vcutoff | 1C 2.5 Vcutoff | 1C 2.5 Vcutoff | 1C 2.5Vcutoff | 1C 1.8Vcutoff |
| 6 | Thermal Runaway | 270C | 210 | 150 | 250 | - |
| 7 | Applications | Motoive power and stationary needing high currents | E bikes, Medical devides , EV industry | Mobilephones,Laptops | Electrical power trains | Ups,Electrical power trains |
| 8 | Cycles | 2000-4000 | 1000-2000 | 500-1000 | 300-700 | 3000-7000 |
Conclusions:
Important term for customer is battery life. Here LTO has best battery life but specific energy and energy desnity is very poor compare to other elements.
After Trade off between all types of batteries, NMC has best properties because it has Good specfic energy, Energy density, number cycles.