Week 1 Understanding Different Battery Chemistry
ANS(1). LITHIUM ION BATTERIES: A lithium-ion (Li-ion) battery is an advanced battery technology that uses lithium ions as a key component of its electrochemistry. During a discharge cycle, lithium atoms in the anode are ionized and separated from their electrons. The lithium ions move from the anode and pass through the electrolyte until they reach the cathode, where they recombine with their electrons and electrically neutralize. The lithium ions are small enough to be able to move through a micro-permeable separator between the anode and cathode. In part because of lithium’s small size (third only to hydrogen and helium), Li-ion batteries are capable of having a very high voltage and charge storage per unit mass and unit volume.
Li-ion batteries can use a number of different materials as electrodes. The most common combination is that of lithium cobalt oxide (cathode) and graphite (anode), which is most commonly found in portable electronic devices such as cellphones and laptops. Other cathode materials include lithium manganese oxide (used in hybrid electric and electric automobiles) and lithium iron phosphate. Li-ion batteries typically use ether (a class of organic compounds) as an electrolyte.
- Safety. Inherently safe chemistry. ...
- Drop-in Replacement. Available in standard industry sizes.
- Lightweight. 50-60% less weight than lead-acid equivalent.
- Longest Life. ...
- More Usable Capacity. ...
- Constant Power. ...
- Temperature Tolerant. ...
- Charging - Fast & Safe
Lithium Battery Disadvantages
- Protection / battery management system required
- Ageing
- Transportation
- Cost
- Developing technology
Lithium Cobalt Oxide(LiCoO2) — LCO
Lithium cobalt oxide, sometimes called lithium cobaltate or lithium cobaltite, is a chemical compound with formula LiCoO
. The cobalt atoms are formally in the +3 oxidation state, hence the IUPAC name lithium cobalt(III) oxide.
Lithium cobalt oxide is a dark blue or bluish-gray crystalline solid, and is commonly used in the positive electrodes of lithium ion batteries
Lithium Manganese Oxide (LiMn2O4) — LMO
A lithium ion manganese oxide battery (LMO) is a lithium ion cell that uses manganese dioxide, MnO
as the cathode material. They function through the same intercalation/de-intercalation mechanism as other commercialized secondary battery technologies, such as LiCoO
. Cathodes based on manganese-oxide components are earth-abundant, inexpensive, non-toxic, and provide better thermal stability.
Lithium Nickel Cobalt Aluminum Oxide (LiNiCoAlO2) — NCA
It is a group of mixed metal oxides. They are significant because of their applications in lithium-ion batteries. On the positive pole, NCAs are utilized as an active material. When the battery is discharged, the cathode is the positive pole. Cation of the chemical elements like aluminum, cobalt, nickel, and lithium make up NCAs. LiNixCoyAlzO2 is the general formula of the most significant representatives to date with x + y + z = 1. The voltage of the currently available NCA comprising batteries is between 3.6 V-4.0 V, at 3.6 V-3.7V of nominal voltage.
Lithium Nickel Manganese Cobalt Oxide (LiNiMnCoO2) — NMC
Lithium-Nickel-Manganese-Cobalt-Oxide (LiNiMnCoO2), abbreviated as NMC, has become the go-to cathode powder to develop batteries for power tools, e-bikes and other electric powertrains. It delivers strong overall performance, excellent specific energy, and the lowest self-heating rate of all mainstream cathode powders, which makes it the preferred option for automotive batteries.
While NMC powder can refer to a variety of blends, the formula typically consists of 33% nickel, 33% manganese and 33% cobalt. This blend, sometimes referred to as 1-1-1, is a popular option for mass-produced cells in applications requiring frequent cycling (automotive, energy storage) due to the reduced material cost resulting from lower cobalt content.
Lithium Iron Phosphate(LiFePO4) — LFP
Lithium Ferro Phosphate technology (also known as LFP or LiFePO4), which appeared in 1996, is replacing other battery technologies because of its technical advantages and very high level of safety.
Due to its high power density, this technology is used in medium-power traction applications (robotics, AGV, E-mobility, last mile delivery, etc.) or heavy-duty traction applications (marine traction, industrial vehicles, etc.)
The long service life of the LFP and the possibility of deep cycling make it possible to use LiFePO4 in energy storage applications (stand-alone applications, Off-Grid systems, self-consumption with battery) or stationary storage in general.
Lithium Titanate (Li2TiO3) — LTO
The LTO is a rechargeable battery based on the, or modified from, the Lithium-Ion (li-ion) battery technology. Li-titanate oxide (LTO) replaces the graphite in the anode of the typical Li-Ion battery and forms the materials into a spinel 3D crystal structure. Having a nominal a cell voltage of 2.40V, it releases a high current discharge current that is 10 times the capacity of the other types of lithium batteries. Instead of using carbon particles on its surface as other lithium batteries do, Lithium Titanate utilizes lithium-titanate nanocrystals.
ANS(2).There are different types of lithium-ion batteries and the main difference between them lies in their cathode materials. Different kinds of lithium-ion batteries offer different features, with trade-offs between specific power, specific energy, safety, lifespan, cost, and performance.
The six lithium-ion battery types that we will be comparing are Lithium Cobalt Oxide, Lithium Manganese Oxide, Lithium Nickel Manganese Cobalt Oxide, Lithium Iron Phosphate, Lithium Nickel Cobalt Aluminum Oxide, and Lithium Titanate. Firstly, understanding the key terms below will allow for a simpler and easier comparison.
Battery Terms
Specific energy: This defines the battery capacity in weight (Wh/kg). The capacity relates to the runtime. Products requiring long runtimes at moderate load are optimized for high specific energy.
Specific power: It's the ability to deliver a high current and indicates loading capability. Batteries for power tools are made for high specific power and come with a reduced specific energy.
A high specific power usually comes with reduced specific energy and vice versa. The pouring of bottled water into a glass is a perfect analogy of the relationship between specific power and specific energy. The water in the bottle can be thought of as specific energy. Pouring the water at a slow rate doesn’t provide enough force (low specific power), but the water lasts longer in the bottle (high specific energy). On the other hand, if we pour the water out at a faster rate, it provides a greater impact (high specific power). However, the water wouldn’t last very long in the bottle ( low specific energy).
Performance: This measures how well the battery works over a wide range of temperatures. Most batteries are sensitive to heat and cold and require climate control. Heat reduces life, and cold lowers performance temporarily.
Lifespan: This reflects cycle life and longevity and is related to factors such as temperature, depth of discharge, and load. Hot climates accelerate capacity loss. Cobalt blended lithium-ion batteries also usually have a graphite anode that limits the cycle life.
Safety: This relates to factors such as the thermal stability of the materials used in the batteries. The materials should have the ability to sustain high temperatures before becoming unstable. Instability can lead to thermal runaway in which flaming gases are vented. Fully charging the battery and keeping it beyond the designated age reduces safety.
Cost: Demand for electric vehicles has generally been lower than anticipated, mainly due to the cost of lithium-ion batteries. Hence cost is a huge factor when selecting the type of lithium-ion battery.
| Lithium-ion battery Types | SP | SE | SF | LS | CS | PF |
|---|---|---|---|---|---|---|
|
Lithium Cobalt Oxide |
L |
H |
L |
L |
L |
M |
|
Lithium Manganese Oxide |
M |
M |
M |
L |
L |
L |
|
Lithium Nickel Manganese Cobalt Oxide |
M |
H |
M |
M |
L |
M |
|
Lithium Iron Phosphate |
H |
L |
H |
H |
L |
M |
|
Lithium Nickel Cobalt Aluminum Oxide |
M |
H |
L |
M |
M |
M |
|
Lithium Titanate |
M |
L |
H |
H |
H |
H |
- SP stands for specific power
- SE stands for specific energy
- SF stands for safety
- LS stands for lifespan
- CS stands for cost
- PF stands for performance
- L stands for low
- M stands for moderate
- H stands for high
-
Summary of the Table
Lithium Cobalt Oxide has high specific energy compared to the other batteries, making it the preferred choice for laptops and mobile phones. It also has a low cost and a moderate performance. However, it is highly unfavorable in all the other aspects when compared to the other lithium-ion batteries. It has low specific power, low safety, and a low lifespan.
Lithium Manganese Oxide has moderate specific power, moderate specific energy, and a moderate level of safety when compared to the other types of lithium-ion batteries. It has the added advantage of a low cost. The downsides are its low performance and low lifespan. It is usually used in medical devices and power tools.
Lithium Nickel Manganese Cobalt Oxide has two major advantages as compared to the other batteries. The first one is its high specific energy, which makes it desirable in electric powertrains, electric vehicles, and electric bikes. The other is its low cost. It is moderate in terms of specific power, safety, lifespan, and performance when compared to the other lithium-ion batteries. It can be optimized to either have high specific power or high specific energy.
Lithium Iron Phosphate only has one major disadvantage when compared to other types of lithium-ion batteries, and that is its low specific energy. Other than that, it has moderate to high ratings in all the other characteristics. It has high specific power, offers a high level of safety, has a high lifespan, and comes at a low cost. The performance of this battery is also moderate. It is often employed in electric motorcycles and other applications that require a long lifespan and a high level of safety.
Lithium Nickel Cobalt Aluminum Oxide offers one strong advantage compared to the five other batteries: high specific energy. It is pretty moderate in the rest of the characteristics like performance, cost, specific power, and lifespan. The only downside to this battery type is its low level of safety. Its high specific energy and moderate lifespan make it a good candidate for electric powertrains.
Lithium Titanate offers high safety, high performance, and a high lifespan which are very important features every battery should have. Its specific energy is low compared to the five other lithium-ion batteries, but it compensates for this with moderate specific power. The only major disadvantage of lithium titanate as compared to the other lithium-ion batteries is its extremely high cost. Another important feature of this battery worthy of mention is its remarkably fast recharge time. It can be used for storing solar energy and creating smart grids.
