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

Lithium ion battery is a type of rechargeable battery composed cells in which lithium ions moves from the negative electrode through an electrolyte to the positive electrode during discharged and back when charging. Lithium ion cell use an intercalated lithium compound as the material at the positive electrode and graphite is used to the negative electrode. Lithium ion batteries have high energy density and low self discharged

Lithium ion are involved in the reaction driving the battery. Bothe electrodes in a lithium ion cell are made of materials which can absorb lithium ions. Intercalation is when charged ions of an element can be held inside the structure of a host material without significantly disturbing.

In case of lithium ion battery lithium ion tied to an electron within the structure of the anode. When the battery is discharged the intercalated lithium ions are released from the anode and the travel through the electrolyte solution to be absorb in the cathode.

lithium-ion battery starts its life in a state of full discharge: All its lithium ions are intercalated within the cathode and its chemistry does not yet have the ability to produce any electricity. Before you can use the battery, you need to charge it. As the battery is charged, an oxidation reaction occurs at the cathode, meaning that it loses some negatively charged electrons. To maintain the charge balance in the cathode, an equal number of some of the positively charged intercalated lithium ions are dissolved into the electrolyte solution. These travel over to the anode, where they are intercalated within the graphite. This intercalation reaction also deposits electrons into the graphite anode, to tie up the lithium ion.

During discharge, the lithium ions are de-intercalated from the anode and travel back through the electrolyte to the cathode. This also releases the electrons that were tying them to the anode, and these flow through an external wire, providing the electric current that we used to do work. It’s the connection of the external wire that enables the reaction to proceed, when the electrons are free to travel, so are the positively charged lithium ions that will balance the movement of their negative charge.

When the cathode becomes full of lithium ions, the reaction stops and the battery is flat. Then we recharge our lithium-ion batteries again, and the external electric charge that we apply pushes the lithium ions back into the anode from the cathode.

ANODE:

The anode is usually graphite. However, the repeated insertion of lithium ions into the standard graphite structure in a typical lithium-ion battery eventually breaks apart the graphite. This reduces the battery’s performance and the graphite anode will eventually break down, and the battery will stop working.

CATHODE:

In the material used for the cathode, there are quite a few variations—generally made of a combination of lithium, oxygen, and some kind of metal.

The cathodes used in lithium-ion batteries:

• LITHIUM IRON PHOSPHATE (LiFePO4/ LFP)
• LITHIUM COBALT OXIDE (LiCoO2/ LCO)
• LITHIUM MANGANESE OXIDE (LiMn2O4/ LMO)
• LITHIUM NICKEL COBALT ALUMINIUM OXIDE (LiNiCoAlO2/ NCA)
• LITHIUM NICKEL MANGANESE COBALT OXIDE (LiNiMnCoO2/ NMC)
• LITHUIM TITANATE (LI2TiO3/ LTO)

LITHIUM IRON PHOSPHATE (LiFePO4):

This cell has a high discharge rate and, because phosphate (PO4) can cope with high temperatures, the battery has good thermal stability, improving its safety. This makes it a good choice for things like electric vehicles and power tools, and for storing energy at power stations. It also has a long cycle life, meaning it can be discharged and charged many times. However, it has a lower energy density than a lithium cobalt oxide cell, and a higher self-discharge rate.

A lithium iron phosphate battery cell is similar to the lithium cobalt oxide cell. The anode is still graphite and the electrolyte is also much the same. The difference is that the lithium cobalt dioxide cathode has been replaced with the more stable lithium iron phosphate. In fact, no lithium or iron ions remain in the iron phosphate (FePO4) cathode of a fully charged cell. The lithium ions can intercalate into or out of the cathode material through well-defined tunnels in its structure without significantly altering the iron phosphate framework.

The cathode of this type of cell is made of negatively charged phosphate anions, bonded with positively charged iron cations in a structure that is capable of storing lithium ions within the iron phosphate molecules. The bonding arrangement in this structure means that the oxygen atoms are tightly bonded into the structure, which gives the cathode its chemical stability.

In a battery with LiFePO4 as cathode and graphite is anode.

LFP has good safety, specific power and life span but it is moderate in specific energy and performance.

Lithium Iron Phosphate	LiFePO4
Voltages	3.20, 3.30V nominal; typical operating range 2.5–3.65V/cell
Specific energy (capacity)	90–120Wh/kg
Charge (C-rate)	1C typical, charges to 3.65V; 3h charge time typical
Discharge	1C, 25C on some cells; 40A pulse (2s); 2.50V cut-off
Cycle life	2000 and higher
Thermal runaway	270°C (518°F) Very safe battery even if fully charged
Cost	~$580 per kWh [1]
Applications	Portable and stationary needing high load currents and endurance

LITHIUM COBALT OXIDE (LiCoO2/ LCO)

Its high specific energy makes Li-cobalt the popular choice for mobile phones, laptops and digital cameras. The battery consists of a cobalt oxide cathode and a graphite carbon anode. The cathode has a layered structure and during discharge, lithium ions move from the anode to the cathode. The flow reverses on charge. The drawback of Li-cobalt is a relatively short life span, low thermal stability and limited load capabilities.

The drawback of Li-cobalt is a relatively short life span, low thermal stability and limited load capabilities. Like other cobalt-blended Li-ion, Li-cobalt has a graphite anode that limits the cycle life by a changing solid electrolyte interface (SEI), thickening on the anode and lithium plating while fast charging and charging at low temperature. Newer systems include nickel, manganese and aluminum to improve longevity, loading capabilities and cost.

LCO has a high specific energy but moderate performance in safety, lifespan and specific power.

Lithium Cobalt Oxide	LiCoO2
Voltages	3.60V nominal; typical operating range 3.0–4.2V/cell
Specific energy (capacity)	150–200Wh/kg. Specialty cells provide up to 240Wh/kg.
Charge (C-rate)	0.7–1C, charges to 4.20V (most cells); 3h charge typical. Charge current above 1C shortens battery life.
Discharge (C-rate)	1C; 2.50V cut off. Discharge current above 1C shortens battery life.
Cycle life	500–1000, related to depth of discharge, load, temperature
Thermal runaway	150°C (302°F). Full charge promotes thermal runaway
Applications	Mobile phones, tablets, laptops, cameras

LITHIUM MANGANESE OXIDE (LiMn2O4/ LMO)

The architecture forms a three-dimensional spinel structure that improves ion flow on the electrode, which results in lower internal resistance and improved current handling. A further advantage of spinel is high thermal stability and enhanced safety, but the cycle and calendar life are limited.

Low internal cell resistance enables fast charging and high-current discharging. In an 18650 package, Li-manganese can be discharged at currents of 20–30A with moderate heat buildup. It is also possible to apply one-second load pulses of up to 50A. A continuous high load at this current would cause heat buildup and the cell temperature cannot exceed 80°C. Li-manganese is used for power tools, medical instruments, as well as hybrid and electric vehicles.

LMO is a moderate overall performance, never design of Li- manganese offer improvement in specific power, life span and safety.

Lithium Manganese Oxide	LiMn2O4
Voltages	3.70V (3.80V) nominal; typical operating range 3.0–4.2V/cell
Specific energy (capacity)	100–150Wh/kg
Charge (C-rate)	0.7–1C typical, 3C maximum, charges to 4.20V (most cells)
Discharge (C-rate)	1C; 10C possible with some cells, 30C pulse (5s), 2.50V cut-off
Cycle life	300–700 (related to depth of discharge, temperature)
Thermal runaway	250°C (482°F) typical. High charge promotes thermal runaway
Applications	Power tools, medical devices, electric powertrains

LITHIUM NICKEL COBALT ALUMINIUM OXIDE (LiNiCoAlO2/ NCA)

Lithium nickel cobalt aluminum oxide battery, or NCA, has been around since 1999 for special applications. It shares similarities with NMC by offering high specific energy, reasonably good specific power and a long lifespan. Less flattering are safety and cost. NCA is a further development of lithium nickel oxide; adding aluminum gives the chemistry greater stability.

NCA has high energy and specific power as well as good life span make a candidate foe Ev powertrain. The disadvantages of NCA has less safety and high cost.

Lithium Nickel Cobalt Aluminum Oxide	LiNiCoAlO2
Voltages	3.60V nominal; typical operating range 3.0–4.2V/cell
Specific energy (capacity)	200-260Wh/kg; 300Wh/kg predictable
Charge (C-rate)	0.7C, charges to 4.20V (most cells), 3h charge typical, fast charge possible with some cells
Discharge (C-rate)	1C typical; 3.00V cut-off; high discharge rate shortens battery life
Cycle life	500 (related to depth of discharge, temperature)
Thermal runaway	150°C (302°F) typical, High charge promotes thermal runaway
Cost	~$350 per kWh
Applications	Medical devices, industrial, electric powertrain (Tesla)

LITHIUM NICKEL MANGANESE COBALT OXIDE (LiNiMnCoO2/ NMC)

NMC lies in combining nickel and manganese. An analogy of this is table salt in which the main ingredients, sodium and chloride, are toxic on their own but mixing them serves as seasoning salt and food preserver. Nickel is known for its high specific energy but poor stability; manganese has the benefit of forming a spinel structure to achieve low internal resistance but offers a low specific energy. Combining the metals enhances each other strengths.

NMC is the battery of choice for power tools, e-bikes and other electric powertrains. The cathode combination is typically one-third nickel, one-third manganese and one-third cobalt

Battery manufacturers move away from cobalt systems toward nickel cathodes because of the high cost of cobalt. Nickel-based systems have higher energy density, lower cost, and longer cycle life than the cobalt-based cells but they have a slightly lower voltage.

NMC is good overall performance. This battery is used in electric vehicle and has lowest self heating rate.

Lithium Nickel Manganese Cobalt Oxide	LiNiMnCoO2
Voltages	3.60V, 3.70V nominal; typical operating range 3.0–4.2V/cell, or higher
Specific energy (capacity)	150–220Wh/kg
Charge (C-rate)	0.7–1C, charges to 4.20V, some go to 4.30V; 3h charge typical. Charge current above 1C shortens battery life.
Discharge (C-rate)	1C; 2C possible on some cells; 2.50V cut-off
Cycle life	1000–2000 (related to depth of discharge, temperature)
Thermal runaway	210°C (410°F) typical. High charge promotes thermal runaway
Cost	$420 per kWh
Applications	E-bikes, medical devices, EVs, industrial

LITHUIM TITANATE (LI2TiO3/ LTO)

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 is good in safety, low temperature performance and good life span. In efforts are made to improve coat and specific energy.

Lithium Titanate	Li2TiO3
Voltages	2.40V nominal; typical operating range 1.8–2.85V/cell
Specific energy (capacity)	50–80Wh/kg
Charge (C-rate)	1C typical; 5C maximum, charges to 2.85V
Discharge (C-rate)	10C possible, 30C 5s pulse; 1.80V cut-off on LCO/LTO
Cycle life	3,000–7,000
Thermal runaway	One of safest Li-ion batteries
Cost	$1,005 per kWh
Applications	UPS, electric powertrain, solar-powered street lighting

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

Lithium-ion battery types	cost	lifespan	Safety	Specific energy	Specific power	Performance
Lithium cobalt oxide	low	low	Low	High	low	Medium
Lithium manganese oxide	low	low	Medium	Medium	Medium	Low
Lithium nickel manganese cobalt oxide	low	Medium	Medium	High	Medium	Medium
Lithium nickel cobalt aluminum oxide	medium	Medium	Low	High	Medium	Medium
Lithium iron phosphate	low	High	High	low	High	Medium
Lithium titanate	high	High	High	low	Medium	High