Week 1 Understanding Different Battery Chemistry

Week1 Assignment

Q1)

	ANODE		CATHODE
	Material	Reaction	Material	Reaction
LCO	Graphite	`C_6 Li→6C+Li^++e^-`	Lithium Cobalt Oxide	`Li_(1-x) CoO_2 (s)+x Li^++xe^-→ LiCoO_2 (s)`
LMO	Graphite	`C_6 Li→6C+Li^++e^-`	Lithium Manganese	`MnO_2+Li^++e^-→LiMnO_2`
NCA	Graphite	`C_6 Li→6C+Li^++e^-`	Nickel Cobalt aluminum	`NiCoAlO_2+Li^++e^-→LiNiCoAlO_2`
NMC	Graphite	`C_6 Li→6C+Li^++e^-`	Nickel manganese	`NiMnCoO_2+Li^++e^-→LiNiMnCoO_2`
LFP	Graphite	`C_6 Li→6C+Li^++e^-`	Lithium Iron Phosphate	`FePO_4+Li^++e^-→LiFePO_4`
LTO	Graphite	`Li_4 Ti_5 O_12→Ti_5 O_12+4Li^++4e^-`	Lithium Titanate	`4Mn_2 O_4+4Li^++4e^-→4LiMn_2 O_4`

The separator used is the same in all types of batteries `→` Polyolefin

The electrolyte is the same in all types of batteries

1. Salt `→` Lithium hexafluorophosphate
2. Solvent `→` Ethylene carbonate

Lithium Cobalt Oxide (LCO):

The anode material used in LCO is graphite and cathode material is Lithium Cobalt oxide. They are widely used to charge laptops, mobiles, and other electronic gadgets. These batteries are not only a potential environmental hazard at the end of use but a valuable resource for cobalt as well. The cobalt content in Li-ion batteries is much higher than in ores, varying from 5 to 20% (w/w). Most of the Li-ion batteries used for portable electronics are based on cobalt.

Lithium Manganese Oxide(LMO):

The anode material used in LMO is graphite and cathode material is Lithium Manganese. LMO spinel powder is a cost-effective and thermally stable cathode material. It has a three-dimensional framework that is useful in the fabrication of lithium-ion batteries for hybrid electrical vehicles (HEVs). Cathode Materials for High Energy Density Li-Ion Rechargeable Batteries; sub-micron particle size results in increased surface area of electrodes. The composition listed allows the preparation of battery electrodes with enhanced performance and durability.

Lithium Nickel Cobalt Aluminum Oxide (NCA):

The anode material used in NCA is graphite and cathode material is Nickel Cobalt Aluminum. Lithium nickel cobalt aluminum oxide (LNCO) can be used as a thermally stable cathode material. It shows good cyclic performance and can be operated around 3.65V. It is further utilized in the fabrication of lithium-ion batteries for hybrid electric vehicles. NCA is Aluminium doped Lithium nickel cobalt oxide (LNCO). Al doping is found very effective to suppress the cell impedance rise by stabilizing the charge-transfer impedance on the cathode side besides increasing the thermal stability of the material. NCA shows excellent electrochemical performance. High specific reversible capacity, good cycling stability, and good thermal stability.

Lithium Nickel Manganese Cobalt Oxide (NMC):

The anode material used in NMC is graphite and cathode material is Nickel Manganese. NMC electrode sheet has a layered structure and can be used as an active cathode material. It can further be used in combination with single electrolyte interphase (SEI) for the fabrication of lithium-ion batteries.

Lithium Iron Phosphate (LFP):

The anode material used in LFP is graphite and cathode material is Lithium Iron Phosphate. LiFePO₄ is a widely used cathode for rechargeable Li batteries. It has high energy density, wide operating temperature, thermal stability, long cycle life and application life, environmental friendliness, and safety that make it a promising electrode material for greener and safer lithium-ion batteries.

Lithium Titanate Oxide (LTO):

The anode material used in LFP is graphite and cathode material is Lithium Titanate. LiFePO₄ is a widely used cathode for rechargeable Li

batteries. It has high energy density, wide operating temperature, thermal stability, long cycle life and application life, environmental friendliness, and safety that make it a promising electrode material for greener and safer lithium-ion batteries.

Q2)

There are 6 different types of batteries

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

Important terms specific to Lithium-ion battery chemistry:

1. Nominal Voltage: It is the system voltage at which the device is designed to operate. To ensure the safe operation of the device the nominal voltage is usually lower than the rated voltage.
2. Cycle: The charge and discharge make a Cycle
3. The current rate (C): This is used to determine the fast charging capability of a battery.
4. Thermal Runaway: It is a condition where an increase in temperature changes the conditions which increase the temperature further, often leading to disaster.
5. Specific Energy: It is the amount of energy stored per unit mass (Wh/Kg).

1. Lithium Cobalt Oxide (LiCoO2) — LCO:

It has high specific energy but low specific power which means that charging and discharging with a Current Rate (C) above rated values shorten the battery’s life. It has a cobalt Oxide Cathode and Graphite anode. The cathode is layered. During discharge, the Li-ions move from anode to the cathode. The flow reverses during charging. The graphite anode limits its cycle life hence it has a short life span. It has low thermal stability. Its main applications are mobile phones, laptops, cameras, etc.

2. Lithium Manganese Oxide (LiMn2O4) — LMO:

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, the 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 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.

3. Lithium Nickel Manganese Cobalt Oxide (LiNiMnCoO2) — NMC:

The cathodic combination of Nickel Manganese Cobalt is successful as it can be tailored to be either Energy cells or Power Cells. NMC has a good performance and excels in specific energy. This Lithium-ion battery can deliver a continuous discharge current. 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. Their combination enhances each other’s performances. New electrolytes can boost capacity. It has the lowest self-heating rate and improved cycle life. This is a battery of choice for electric powertrains and industrial applications

4. Lithium Iron Phosphate (LiFePO4) — LFP:

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. Various advantages of this Lithium-ion battery chemistry include – a long lifecycle, good thermal stability, high current rating, enhanced safety, and tolerance in case of abuse. Li-Phosphate is often used to replace lead-acid batteries as it has a moderate specific energy and a very low tolerance for moisture, which reduces its cycle life drastically. Other characteristics include a very flat voltage discharge curve but low capacity. LFP is one of the safest Li-ions in the market.

5. Lithium Nickel Cobalt Aluminium Oxide (LiNiCoAlO2) — NCA:

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. Tesla, the US-based EV manufacturer researches this technology and uses this Lithium-ion battery chemistry.

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

6. Lithium Titanate (Li2TiO3) — LTO:

In this technology, Li-titanate replaces the graphite in the anode of a typical Lithium-ion battery, and the material forms into a spinel structure.

The cathode can be lithium manganese oxide or NMC. Li-titanate can be fast-charged and delivers a high discharge current 10 times the rated capacity. The cycle count is higher than the regular Li-ion batteries.

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