Week 1 Understanding Different Battery Chemistry
| Type of battery | Materials | Chemical Reactions | Explanation |
| LCO(Lithium Cobalt Oxide) |
Lithium(Li), Cobalt(Co),Graphite(6C),Oxygen - at Cathode it has Layered oxide as Li(x)CoO2 -Polyanian material like LiFePO4 and Li(2)FeSiO4 -Contains Spinel Oxides like LiMn(2)O(4) |
Anode: C6Li-->6C+Li(+)+e(-) Cathode:Li(1-x)(s)CoO2 +xLi(+)+xe(-)--> LiCoO2(s) |
Lithium is oxidized from Li to Li(+) in the lithium graphite at anode i.e lithium goes from 0 to +1 oxidized stage. This lithium ion migrate to cathode where the come in contact with lithium cobalt oxide following the chemical reaction.The electrolyte is generally made of liquid solvent (LiPF6) rather then solid stage solvent.Lithinated Graphite sheets that are incorporated with lithium at anode has an HCP structure per unit cell.The LCO battery have Higher specific energy and performance while the soecific power and life span of battery is relatively low.DUe to overheating of the battery there are more safety concerns since it offers high resistance to charging which detorioates the life of the battery. |
| LMO ( Lithium Manganese Oxide) |
Lithium , Manganese , oxygen. it generally contains - Spinnel LiMnO4 -Layered Li2MnO3 -Layered LiMnO2 -Layered Li2MnO2 (<-->)- Reversible reaction xLi2MnO3.yLi(1+a)Mn(2-a)O4.2LiMnO2 composites here x+y+z=1 |
xLi2MnO3.yLi(1+a)Mn(2-a)O4.2LiMnO2 composites here x+y+z=1 |
Lithium manganes oxide battery in the lithium ion cell generally uses Manganese dioxide MnO2 as cathode material.The function is same as intercalination and decalination Process. cathode based Manganese is earth abandant , non toxic and inexpensive provide better thermal stability to battery.Li(+) ions occupy tetrahedral sites within Mn2O4 Polyhydral Frame works Adjacent to empty octahedral sites. LiMnO2 demonstrates higher rate of compability campared to materials with 2D frameworks.The major disadvantage is surface degradation takes place at cathode due to oxidation of manganese with drops below +3.5. loss of oxygen from the electrode leads to poor cycle stability. |
| NCA (Nickel Cobalt Aluminium) battery | Nickel, Cobalt , Aluminium |
step 1: LiNiO2+(4n-4)*HCl/(2n-1)<-->(2n-2)*LiCl/(2n-1)+(n-1)*NiCl2/(2n-1)+n*Li(1/n)NiO2/(2n-1)+(2n-2)*H2O/(2n-1) Step 2: Li(1/n)NiO2+4HCl<-->(1/n)*LiCl+NiCl2+2H2O+(1-1/(2n))Cl2 (g) Final rxn: 2LiNiO2+8HCl<-->2LiCl+NiCl2+4H2O+Cl2(g) |
Its anode material is LiaC6, the cathode material is LibNi0.8Co0.15Al0.05O2 and the carrier is Li+.The NCA batteries have high specific energy, moderate specific power , high performance, and longer life span. It is used in Power grid and wide varietty of electric vehicles. |
| NMC (Nickel Manganese Cobalte battery) | Nickel Manganese Cobalt, LiNi0.8Mn0.1Co0.1O2 |
step 1: LiMnO2+(4n-4)*HCl/(2n-1)<-->(2n-2)*LiCl/(2n-1)+(n-1)*MnCl2/(2n-1)+n*Li(1/n)MnO2/(2n-1)+(2n-2)*H2O/(2n-1) Step 2: Li(1/n)MnO2+4HCl<-->(1/n)*LiCl+MnCl2+2H2O+(1-1/(2n))Cl2 (g) Final rxn(leaching Mechanism): 2LiMnO2+8HCl<-->2LiCl+MnCl2+4H2O+Cl2(g) |
Li-ion Batteries is leached with Hydrocloric acid.The disolution of lithium is much faster then that of othe materials such as N,Mn,Co. The n in the above reactions is considered between 2.8 to 3.6. Cobalt and Lithium are classified as crtical energy parameters by US, E and UN. NMC Batteries Covers the wide area of graph . i.e The rating of battery is quite near optimum value . The 1st step does not involve chlorine evolution. NMC to HCL molar ratio is 1/x. Leaching efficiency is as follows ; 1) If x>= LE(Li)=100% 2)If x<=(4n-4)/(2n-1), then LE(Li)=x/2 |
| LFP (Lithium Iron Phosphate battery) | Lithium, Iron and Phosphate | LiFe^(ll)Po4<-->Fe^(lll)Po4+Li(+)+e(-) | It is an inorganic compound with LiFePo4.It is grey , Red grey, brown or black solid i.e insoluble in water. LFP exist in mineral Triphylite- which has Olivine structure and LiMPO4, where M stands for Fe,Co,Mn,Ti.Olivine compounds have same crystal structure.The volume of unit cell is 291.4A^(0.3). The conductivity of LI is quite Low at ambient Temp.They Have an operating voltage of 3.3v, Charge density of 170mAh/g,High power density ,Long life and stable at elevated temp.They have a common shared concern of overheating, Low conductivity and low diffusion constant both limiting the charge and discharge rate. Ni:Mn1:Co today are used in propotion of 8:1:1. |
| LiTO(Lithium Tiatanium Oxide Battery) | lithiun, titanium and oxygen |
-Li4Ti5O12 -Li4Ti5O12+3Li(+)+3e(-)<-->Li7Ti5O12 -Li7Ti5O12+2Li(+)+2e(-)<-->Li9Ti5O12 |
It has a spinel structure, Specific capacity upto 175mAh/g and potential of 1-3V.kIt has an added advantage of being faster to charge. It has low specific energy , high specific power , safety ratings, performance life span and cost in compare to other batteries. |
| Type of Battery/ Characteristics | LCO | LMO | NCA | NMC | LFP | LTO |
| Specific Power | Low | Moderate |
Moderate |
Moderate | Moderate | High |
| Specific Energy | High | Moderate | High | High | Low | Low |
| Cost | High | High | Low | High | High | High |
| Life Span | Less | Low | Moderate | Moderate | High | High |
| Safety | Low | Moderate | Low | Moderate | High | High |
| Performance | High | Low | High | High | High | High |
| Voltage(Nominal) | 3.6V | 3.7V | 3.6V | 3.6V | 3.3V | 2.4 V |
| Charge rate | 0.7-1 C | 0.7-1C | 0.7C | 0.7-1 | 1C | 1C |
| Discharge rate | 1C | 1C | 1C | 1C | 1C | 10C |
| Cycle life | 500-1000 | 300-700 | 500 | 1000-2000 | 2000 | 3000-7000 |