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.

AIM: To explain detail about Lithium ion cells of material & chemical reactions for the following types.

AIM: To explain detail about Lithium ion cells of material & chemical reactions for the following types.

Types of Lithium-ion Batteries

• Lithium Cobalt Oxide (LCO)
• Lithium Manganese Oxide (LMO)
• Lithium Iron Phosphate (LFP)
• Lithium Nickel Manganese Cobalt Oxide (NMC)
• Lithium Nickel Cobalt Aluminum Oxide (NCA)
• Lithium Titanate (LTO)
• Lithium Iron Phosphate (LFP)

I.LCO: LITHIIUM COBALT BATTERY (LiCoO2)

LCO stands for Lithium cobalt battery. Lithium cobalt oxide is one of the most common Lithium-ions, it has a chemical symbol which is LiCoO2. The most popular technology of the battery sector currently is the lithium ion battery.

The lithium ion batteries chemistry is the same across the different lithium-ion battery types; during discharge, Lithium-ions are moved to the positive cathode from the negative anode through the organic electrolyte. The anodes in all various technologies of lithium ion are all made from graphite. The differences are the cathode which contains changing cobalt, nickel or manganese concentrations. All various cathode types allow high lithium insertion and intercalation levels which result in large energy storage quantities.

Reduction takes place at the cathode. There, cobalt oxide combines with lithium ions to form lithium-cobalt oxide (LiCoO₂).

CoO₂ + Li⁺ + e^- → LiCoO₂

Oxidation takes place at the anode. There, the graphite intercalation compound LiC₆ forms graphite (C₆) and lithium ions.

LiC₆ → C₆ + Li⁺ + e^-

Here is the full reaction (left to right = discharging, right to left = charging):

LiC₆ + CoO₂ ⇄ C₆ + LiCoO₂

II.LMO: LITHIUM MANGANESE OXIDE (LiMn2O4)

The Manganese Oxide forms a 3D-spinel structure that improves the ion flow on the electrode. This results in lower internal resistance, which enables fast charging and high-current discharging. Adding to these, spinel structure also packs extra thermal stability. Making it safer compared to LCO. The LMO has a lower cycle life.

Most Li-manganese batteries blend with lithium nickel manganese cobalt oxide (NMC) to enhance the precise energy and prolong battery life. These three active metals, as well as silicon enhancement, can enhance specific energy (capacity), specific power (load capability) or longevity.

Li-manganese has high power and less capacity. It is used for power tools, medical devices as well as in electric vehicle powertrain.

III.NCA: Lithium Nickel Cobalt Aluminum Oxide (LiNiCoAlO2)
NCA is used as the cathode material for lithium ion batteries, and is mainly used in electric automobiles. NCA batteries are gaining importance in electric powertrains and grid storage. They are not common in the consumer industry but are promising for the automotive Sector.

NCA has the highest Specific Energy, good Specific Power, and a long life span. High cost and marginal safety are the negatives.

IV.NMC: Lithium Nickel Manganese Cobalt Oxide (LiNiMnCoO2)

NMC batteries offer a combination of Nickel, Manganese and Cobalt. They are sometimes known as Lithium Manganese Cobalt Oxide batteries. NMC batteries have a high specific energy or power. This limitation of either 'energy' or 'power' makes them more common for use in power tools or electric vehicles.

The advantage of Nickel is its high specific energy but it has poor stability. Whereas Manganese achieves low internal resistance by forming a spinal structure. Unlike Nickel, Manganese offers low specific energy.

V.LFP: Lithium Iron Phosphate (LiFePO4)

In this type, Li- Phosphate is used as the cathode since it has good electrochemical performance with low resistance. This is because of the Nano-scale phosphate cathode material.

Lithium Iron phosphate (LFP) is a popular, cost-effective cathode material for lithium-ion cells that is known to deliver excellent safety and long life span, which makes it particularly well-suited for specialty battery applications requiring high load currents and endurance.

Various advantages of this Lithium-ion battery chemistry include – long lifecycle, good thermal stability, high current rating, enhanced safety, and tolerance in case of abuse.

Other characteristics include a very flat voltage discharge curve but low capacity. LFP is one of the safest Li-ions in the market.

VI.LTO: Lithium Titanate (Li2TiO3)

Lithium Titanate / lithium titanium oxide (Li₄Ti₅O₁₂, also referred to as LTO) is an electrode material with exceptional electrochemical stability. It is often used as the anode in lithium ion batteries for applications that require high rate, long cycle life and high efficiency. LTO-based batteries are considered safer, and have a wider operating temperature rate.

Li-titanate excels in safety and has excellent low-temperature discharge characteristics and life span. The applications this lithium ion battery chemistry power include electric powertrains, UPS and solar-powered street lighting.

Chemical reaction in a lithium ion battery

Lithium ion batteries work by using the transfer of lithium ions and electrons from the anode to the cathode. At the anode, neutral lithium is oxidized and converted to Li+. This results in the reduction of Co(IV) to Co(III) when the electrons from the anode reaction are received at the cathode.

LITHIUM ION BATTERY RECATION:

	LITHIUM ION TYPES	ACTIVE MATERIAL	ELECTROCHEMISTRY			CURRENT COLLECTOR	CHEMICAL REACTION
			POSITIVE ELECTRONS (CATHODE)	NEGATIVE ELECTRONS (ANODE)	ELECTROLYTE		CATHODE	ANODE	OVERALL
1	LCO - Lithium cobalt battery (LiCoO2)	LiCoO2	cobalt oxide cathode (LibCoO2)	graphite carbon anode (LiaC6)	Lithium hexafluorophosphate (LiPF6) salt dissolved in organic carbonates, in particular, mixtures of ethylene carbonate (EC) with dimethyl carbonate (DMC), propylene carbonate (PC), diethyl carbonate (DEC),	Aluminum	CoO2 + Li+ + e- → LiCoO2	LiC6 → C6 + Li+ + e-	LiC6 + CoO2 ⇄ C6 + LiCoO2
2	LMO - Lithium Manganese Oxide	LiMn2O4	Manganese oxide	graphite carbon anode (LiaC6)		Aluminum	MnO2+ Li+ + e- → LiMnO2	LiC6 → C6 + Li+ + e-	LiC6 + CoO2 ⇄ C6 + LiCoO2
3	NCA - Nickel Cadmium batteries (NiCd )	LiNiCoAlO2	nickel oxide hydroxide	graphite carbon anode (LiaC6)		Aluminum	NiCoAlO2 +Li+ + e- → LiNiCoO2	LiC6 → C6 + Li+ + e-	LiC6 + CoO2 ⇄ C6 + LiCoO2
4	NMC - Lithium Nickel Manganese Cobalt Oxide	LiNiMnCoO2	Nickel Manganese Cobalt Oxide	graphite carbon anode (LiaC6)		Aluminum	NiMnCoO2+ Li+ + e- → LiNiMnCoO2	LiC6 → C6 + Li+ + e-	LiC6 + CoO2 ⇄ C6 + LiCoO2
5	LFP - Lithium Iron Phosphate	LiFePO4	Iron Phosphate	graphite carbon anode (LiaC6)		Aluminum	FePO4+Li+ + e- → LiFePO4	LiC6 → C6 + Li+ + e-	LiC6 + CoO2 ⇄ C6 + LiCoO2
6	LTO - Lithium Titanate	Li4Ti5O12	NAC,NMC,LCO	Lithium Titanate		Copper	4Mn2PO4+4Li+ + 4e- → 4LiMn2O4	L4Ti5O12+4Li+ +4 e- →4LIMn2O4	4Mn2O4+Li4Ti5O12⇄ 4LiMn2O4+Ti4O12

2.Compare the differences between each type of Li+ion batteries based on their characteristics

AIM: Characteristics of lithium ion battery

	LITHIUM ION TYPES	ACTIVE MATERIAL	CHARACTERISTICS
			NOMINAL VOLTAGE(V)	LIFE CYCLE	CHARGE CURRENT RATE©	DISCHARGE CURRENT RATE©	THERMAL RUNWAY(deg C)	ENERGY(Wh/Kg)	ADVANTAGES	DISADVANTAGES	APPLICATIONS
1	LCO - Lithium cobalt battery (LiCoO2)	LiCoO2	3.6(3.0-4.2)range	500-1000	0.7-1C	1C	150	150-200	1. High energy density. 2. Long runtime making it optimum for new technologies	1. It has a relatively low discharge current so high load can lead to pack overheat 2. The safety circuit of the LCO battery is typically limited to a 1C for charging and discharging. 3. The internal resistance increases with cycling and aging. This high internal resistance can cause the battery to become unserviceable due to a large voltage drop under the load after a couple of years of use.	1. laptops, Phone batteries
2	LMO - Lithium Manganese Oxide	LiMn2O4	3.7(3.0-4.2)range	300-700	0.7-1C	1C	250	100-150	1. Thermal stability. 2. Prise less & more energy density	1. Lees life cycle	1.power tools, medical devices andelectric vehicle powertrain.
3	NCA - Nickel Cadmium batteries (NiCd )	LiNiCoAlO2	3.6(3.0-4.2)range	500-1000	0.7C	1C	150	200-260	1. Low internal resistance (less than half the equivalent NiMH cells) 2.High rate charge and discharge rates possible Up to 10C discharge rates for short periods typical. Flat discharge characteristic (but falls off rapidly at the end of the cycle) 3. Tolerates deep discharges - can be deep cycled. Wide temperature range (Up to 70°C) 4. Typical cycle life is over 500 cycles. 5. Rapid charge of battery can happen in 2 hours, but can be as low as 10 to 15 minutes. 6. The coulombic efficiency of nickel cadmium is over 80% for a fast charge. 7. The sealed nickel-cadmium cell can be stored in the charged or discharged state without damage. 8.The electrolyte is low cost potassium hydroxide KOH and easily available. 9. Available in a large variety of sizes and capacities.	1.Memory Effect issues 2. Susceptible to damage due to Overcharging. 3. Cadmium is a highly costly and toxic metal. Nickel Cadmium batteries contain from 6- 18% cadmium, and because of the toxicity, it therefore requires special care during battery disposal.	1. A major drawback of this technology is that the Nickel Cadmium batteries suffer from the memory effect. 2. They have a low cell voltage of 1.2 Volts compared with primary alkaline cells that have 1.5 Volts and only quarter of the capacity of the alkaline cells.
4	NMC - Lithium Nickel Manganese Cobalt Oxide	LiNiMnCoO2	3.6(3.0-4.2)range	1000+	0.7-1C	1-2C	210	150-220	high specific energy	1.poor stability.	1.Ev bikes, mesdical devics
5	LFP - Lithium Iron Phosphate	LiFePO4	3.2(2.5-3.65)range	2000+	1C	1C	270	90-120	1.long lifecycle, good thermal stability, high current rating, enhanced safety	1.More tolerant to conditions of full charge and is less stressed at higher voltage for a long time. 2.lower nominal voltage which reduces the specific energy. 3.Higher self discharge than other types Li-ion batteries, which causes balancing issues with aging.	1.energy storage systems, power tools and electric vehicles.
6	LTO - Lithium Titanate	Li4Ti5O12	2.8	6000–+10000	1C	0.5c	100	60-110	excels in safety and has excellent low-temperature discharge, more life spane	High cost. Lower inherent voltage or lower energy density.	1.electric powertrains, UPS and solar-powered street lighting