Week 1 Understanding Different Battery Chemistry
Q1) Table including materials and chemical reactions occuring at anode and cathode of LCO, LMO,NCA,NMC,LFP and LTO
A) Lithium ion batteries can be designed for optimal capacity with the drawback of limited loading, slow charging and reduced longiviety.An industrial battery may have a moderate amphere rating but the focus is on the durability.
b) Before looking into the materials and chemical reactions of different types of lithium ion batteries , A battery is made up of anode and cathode,seperator, electrolyte and two current collectors ( +ve, -ve ) . The anode and cathode store the lithium.
c) The electrolyte carries positively charged lithium ions from the anode to cathode and viceversa through the seperator. The movement of the lithium ions creates free electrons in the anode which creates the charge at the positive current collectors. The electric current then flows from the current collector through a device being powered to the negative current collector. The separator blocks the flow of electrons inside the battery.
Parts of lithium ion Battery:
While the battery is discharge and providing an electric current the anode releases the lithium ions to the cathode , generating the flow of electrons from one side to the other. when plugging the device, the opposite will happen than the lithium ions are released by the cathode and received by the anode. The charging and discharging process are as shown
The 6 common lithium ion batteries used are
i) Lithium cobalt oxide (liCoO2) -LCO
ii)Lithium manganese oxide (liMnO2)-LMO
iii)Lithium Nickel manganese cobalt oxide (liNiMnCoO2) -NMC
iV) Lithium iron phosphate(liFePO4)-LFP
V) Lithium nickel cobalt Aluminium oxide ( liNiCoAlO2) -NCA
Vi) Lithium Titanate (li2TiO3) -LTO
Each lithium ion batteries provide different characteristics and are used in different applications accordingly
| Materials and chemical reactions in different types of Li-ion Cells | ||||||
| Battery Type | Cathode | Anode | Electrolyte | cathode reaction | Anode reaction | |
| Salt | Solvent | |||||
| Lithium Cobalt (LCO) | Lithium Cobalt oxide (LicoO2) | Graphite (C6) | Lithium hexa Fluoro phosphate (LiphF6) | Ethylene Carbonate |
Li(1-x)CoO2(s)+ xLi(+)+Xe(-) <-> LiCoO2(s) |
C6Li<->6C + Li(+) + e(-) |
| Lithium manganese (LMO) | Lithium Mnaganese Oxide (LiMn2O4) | Graphite (C6) | Lithium hexa Fluoro phosphate (LiphF6) | Ethylene Carbonate | Li(1-x)Mn2O4(s) + xLi(+)+ Xe(-) <->LiMn2O4(s) | C6Li<->6C + Li(+) + e(-) |
| Lithium aluminium (NCA) | Lithium nickel Cobalt oxide (LiNimnCoAlO2) | Graphite (C6) | Lithium hexa Fluoro phosphate (LiphF6) | Ethylene Carbonate |
Li(1-x)NiCoAlO2(s) + xLi(+)+ Xe(-) <->LiNiCoAlO2(s) |
C6Li<->6C + Li(+) + e(-) |
| Lithium Nickel manganese Cobalt(NMC) | Lithium nickelManganese Cobalt Oxide(LiNiMnCoO2) | Graphite (C6) | Lithium hexa Fluoro phosphate (LiphF6) | Ethylene Carbonate | Li(1-x)NiMnCoO2(s) +XLi(+) +Xe(-) <->LiNiMnCoO2(s) | C6Li<->6C + Li(+) + e(-) |
| Lithium iron Phosphate (LFP) | LithiumIron Phosphate(LifePO4) | Graphite (C6) | Lithium hexa Fluoro phosphate (LiphF6) | Ethylene Carbonate | Li(1-x)FePO4(s)+Xli(+) +Xe(-)<->LiFePO4(s) | C6Li<->6C + Li(+) + e(-) |
| Lithium Titanate(LTO) | Lithium ManganeseOxide(Limn2O4) |
Titanate (Ti3O12) |
Lithium hexa Fluoro phosphate (LiphF6) | Ethylene Carbonate |
Li(1-x)Mn2O4(s)+ XLi(+)+Xe(-) <-> LiMn2O4(S) |
Li2Ti3O12 <-> Li2Ti3O12+3Li(+)+3e(-) |
| Lithium Nickel manganeseCobalt Oxide (LiNiMnCoO2) |
Li(1-x)NiMnCoO2(s)+ XLi(+) + Xe(-) <-> LiNiMnCoO2(s) |
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Lithium cobalt oxide (LCO) battery 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).
Lithium ion manganese oxide battety (LMO) is a lithium ion cell that uses manganese dioxide MnO2 as a cathode material. They function through the same intercalation/ de-intercalation mechanism as other commercilized secondary battery technologies such as LiCoO2. Cathodes based on manganeseoxide components are earth - abundant, inexpensive, non - toxic and provide better thermal stability
Lithium Nickel cobalt aluminium oxides (NCA) battery has been around since 1999 for special applications. It shares similarities with NMC by offering highspecific energy, reasonably good specific power and a long life span.
Lithium Nickel Manganese Cobalt Oxide (NMC) battery offer a combination a nickel, Manganese and cobalt. They are sometimes known as Lithium Manganese Cobalt oxide batteries. NMC batteries have a high specific energy or power
Lithium iron phosphate battery (LiFeO4) 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 enchance their thermal stability and safety.
Lithium Titanate oxide (LTO) batteries is a type of rechargable battery which has the advantage of being faster to charge than other lithium ion batteries but its disadvantage of having a much lower energy density.
Q2) Compare the differences between each type of Li+ion batteries based on their characteristics
A) The major 6 types of lithium ion batteries was discussed early .Now the major differences in the characteristics can be found when choosing battery. The Major things that can be differentiated from one another
Nominal voltage : It is the system voltage at which the device is designed to operate .The rated voltage is usually higher than the nominal voltage to ensure the safe operation of the device
Cycle : The charge and discharge action for a single time makes a cycle .Higher the cycles indicates higher the lifespan
Thermal Runaway : The thermal Runwaybegins when the heat generated with in the battery exceeds the amount of heat that is dissipated to its surroundings . Internal temperature of the battery will continue to rise , causing the battery current to rise creating domino effect.The rise in temperature ina single battery will begin to effect other batteries near by and pattern will continue.
Specific Energy : It is the amount of energy stored per unit mass (wh/kg) . This is a very important deciding factor that decides how much energy or power from different batteries with the same amount of weight
Specific Energies of different types of lithium ion batteries
The main difference between the lithium ion batteries can be differentiated on the characteristics
| Li-ion battery Chemistry | Nominal Voltage(v) | Cycle ( life ) | Charge current Rate (C) | Discharge Current rate (C) | Thermal run away (oC) | Packaging (Typical) | Specific Energy (wh/kg) | Applications | Remarks | Compatible with Ion'sBMS |
| Nickel Manganese Cobalt Oxide (NMC) | 36(30-42) | 1000+ | 0.7-1C | 1-2C | 210(410F) | 18650,21700 | 150-220 | Ebikes, medical devices , Evs industrial | HIgh Specific Energy , Low Self heating rate | YEs |
| Lithium iron phosphate (LFP) | 3.2(2.5-3.65) | 2000+ | 1C | 1C | 270(518F) | 18650,32650prismatic | 90-120 | Stationary Applications with high capacity Ev | Flat discharge Voltage, high power , low capacity safe | Yes |
| Lithium Nickel Cobalt Aluminium oxide (NCA) | 3.6(3.0-4.2) | 500-1000 | 0.7C | 1C | 150(302F) | 18650 | 200-260 | Medical,Industrial, Electric power train | Long life,Fast charge, wide temperature, safe & expensive | Yes |
| Lithium Titanate oxide (LTO) | 2.4(1.8-2.85) | 3000-7000 | 1C | 10C | highest | prismatic | 50-80 | Electric vehicle,and energy storage systems | highest capacity with moderate power | yes |
| Lithium cobalt oxide(LCO) | 3.6(3.0-4.2) | 500-1000 | 0.7C-1C | 1C | 150(302F) | 18650Prismatic &pouch cell | 150-200 | Laptops , mobile,phones,Tablets, Cameras | HIgh energy , limited power |
Yes |
| Lithium Manganese Oxide (LMO) | 3.7(3.0-4.2) | 300-700 | 0.7C-1C | 1C | 250(482F) | Prismatic | 100-150 | Medical devices, Electrical power trains, power tools | High power ,Less capacity,Safer thanLCO | YEs |
Nominal Voltage : Most of the batteries ar e very close . LMO (3.7) has the highest Range and LTO(2.4) has the lowest range
Cycle life : LTO battery has the longest life cycle , so it can last longer period of time,and its exactly oppositefor the LMO type batteries
Charge current rate : Higher the charger current, less the time battery will get charged .LTO and LTPare highest NCA comes closes to it.
Discharge current rate : LTO has the discharge rate 10 times higher than the others and it is the one of the safest batteries
Thermal runaway: A thermal runaway occurs in situations where an increase in temperature changes the conditions in a way that causes increase in temperature often leading a destructive result. LTO has the highest temperature rating in this and NCA and LCP has its lowest.
Specific energy : The specific energy density can be calculated by integrating from 0 to t_cutoff. We can obtain the specific energy density in Wh/kg. Lithium ion with cobalt cathodes offer the highest energy densities.
For ease of choosing a battery from laymans perspective, the 6 key features are given a value within 0-5 range for all of the, are given with the same parameters which are considered in case of 5 point hexagonal analysis of the batteries. They are
1. Specific energy.
2. Specific power.
3. Safety.
4. Performance.
5. Life span.
6. Cost.
LCO :
Li-Cobalt excels on high specific energy but offers moderate performance specific power, safety,lifespan
LMO :
Moderate in over all performance ,
NMC :
NMC has overall good performance and excels on specific energy . this battery is highly preferable for electric vehicles which has the lowest self heating rate
LFP :
Li-phosphate has excellent safety and long life span but moderate specific energy and elevated self discharge.
NCA :
High energy and power densities as well as a good life span make NCA a candidate for EV powertrains. High cost and marginal safety are negative.
LTO :
Li-titanate excels in safety, low temperature performance and life span. Efforts are being made to improve the specific energy and lower the cost.These types of lithium ion batteries are some of the most popular. As technology is continously seeing more development, new lithium technologies are always being developed and those which exists are being developed