Types of Lithium-ion

The casual battery user may think there is only one lithium-ion battery. As there are many species of apple trees, so do also lithium-ion batteries vary and the difference lies mainly in the cathode materials. Innovative materials are also appearing in the anode to modify or replace graphite.

Scientists prefer to name batteries by their chemical name and the material used, and unless you are a chemist, these terms might get confusing. Table 1 offers clarity by listing these batteries by their full name, chemical definition, abbreviations and short form. (When appropriate, this essay will use the short form.) To complete the list of popular Li-ion batteries, the table also includes NCA and Li-titanate, two lesser-known members of the Li-ion family. 
 

Chemical name

Material

Abbreviation

Short form

                  Notes

Lithium Cobalt Oxide1
Also Lithium Cobalate or lithium-ion-cobalt)

LiCoO2
(60% Co)

LCO

Li-cobalt
 

High capacity; for cell phone laptop, camera

Lithium
Manganese Oxide
1
Also Lithium Manganate
or lithium-ion-manganese

LiMn2O4

LMO

Li-manganese, or spinel
 

Most safe; lower capacity than Li-cobalt but high specific power and long life.

Power tools,
e-bikes, EV, medical, hobbyist.

Lithium
Iron Phosphate
1

LiFePO4

LFP

Li-phosphate

Lithium Nickel Manganese Cobalt Oxide1, also lithium-manganese-cobalt-oxide

LiNiMnCoO2
(10–20% Co)

NMC

NMC
 

Lithium Nickel Cobalt Aluminum Oxide1

LiNiCoAlO2
9% Co)

NCA

NCA

Gaining importance
in electric powertrain and grid storage

Lithium Titanate2

Li4Ti5O12

LTO

Li-titanate

Table 1: Reference names for Li-ion batteries.We willuse the short form when appropriate.

1  Cathode material        2  Anode material

To learn more about the unique characters and limitations of the six most common lithium-ion batteries, we use spider charts and look at the overall performance. We begin with Li-cobalt, the most commonly used battery for high-end consumer products, and then move to Li-manganese and Li- phosphate, batteries deployed in power tools, and finally address the newer players such as NME, NCA and Li-titanate. 

Lithium Cobalt Oxide(LiCoO2)

Its high specific energy make Li-cobalt the popular choice for cell 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 and limited load capabilities (specific power). Figure 2 illustrates the structure.

Li-cobalt structure

 

Figure 2: Li-cobalt structure

The cathode has a layered structure. Duringdischarge the lithium ions move from the anode to the cathode; on charge the flow is from anode to cathode.

Courtesy of Cadex

Li-cobalt cannot be charged and discharged at a current higher than its rating. This means that an 18650 cell with 2,400mAh can only be charged and discharged at 2,400mA. Forcing a fast charge or applying a load higher than 2,400mA causes overheating and undue stress. For optimal fast charge, the manufacturer recommends a C-rate of 0.8C or 1920mA. [BU-402, What is C-rate?] The mandatory battery protection circuit limits the charge and discharge rate to a safe level of about 1C.

Figure 3 summarizes the performance of Li-cobalt in terms of specific energy,or capacity; specific power,or the ability to deliver high current; safety; performanceat hot and cold temperatures; life spanreflecting cycle life and longevity; and cost.The hexagonal spider web provides a quick and easy performance analysis of the battery characteristics.

Snapshot of an average Li-cobalt battery

 

Figure 3: Snapshot of an average Li-cobalt battery

Li-cobalt excels on high specific energy but offers only moderate performance specific power, safety and life span.

Courtesy of Cadex

 

 

Lithium Manganese Oxide (LiMn2O4)

Lithium insertion in manganese spinels was first published in the Materials Research Bulletin in 1983. In 1996, Moli Energy commercialized a Li-ion cell with lithium manganese oxide as a cathode material. The architecture forms a three-dimensional spinel structure that improves ion flow on the electrode, which results in lower internal resistance and improves current handling. A further advantage of spinel is high thermal stability and enhanced safety, but the cycle and calendar life is limited. 

Low internal cell resistance is key to 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 (176°F). Li-manganese is used for power tools, medical instruments, as well as hybrid and electric vehicles.

Figure 4 shows the crystalline formation of the cathode in a three-dimensional framework. This spinel structure, which is usually composed of diamond shapes connected into a lattice, appears after initial formation.

Li-manganese structure

Figure 4: Li-manganese structure

The cathode crystalline formation of lithium manganese oxide has a three-dimensional framework structure that appears after initial formation. Spinel provides low resistance but has a more moderate specific energy than cobalt. 

Courtesy of Cadex

Li-manganese has a capacity that is roughly one-third lower compared to Li-cobalt but
the battery still offers about 50 percent more energy than nickel-based chemistries. Design flexibility allows engineers to maximize the battery for either optimal longevity (life span), maximum load current (specific power) or high capacity (specific energy). For example, the long-life version in the 18650 cell has a moderate capacity of 1,100mAh; the high-capacity version is 1,500mAh but has a reduced service life. Laptop manufacturers would likely choose the high-capacity version for maximum runtime; whereas the maker of cars with the electric powertrain would take the long-life version with high specific power and sacrifice on runtime.

Figure 5 shows the spider web of a typical Li-manganese battery. In this chart, all characteristics are marginal; however, newer designs have improved in terms of specific power, safety and life span.
 

Snapshot of a typical Li-manganese battery

Figure 5: Snapshot of a typical Li-manganese battery

Although moderate in overall performance, newer designs of Li-manganese offer improvements in specific power, safety and life span.

Courtesy of BCG research

Lithium Iron Phosphate(LiFePO4)

In 1996, the University of Texas (and other contributors) discovered phosphate as cathode material for rechargeable lithium batteries. Li-phosphate offers good electrochemical performance with low resistance. This is made possible with nano-scale phosphate cathode material. The key benefits are enhanced safety, good thermal stability, tolerant to abuse, high current rating and long cycle life. Storing a fully charged battery has minimal impact on the life span. As trade-off, the lower voltage of 3.3V/cell reduces the specific energy to slightly less than Li-manganese. In addition, cold temperature reduces performance, and elevated storage temperature shortens the service life (better than lead acid, NiCd or NiMH). Figure 6 summarizes the attributes of Li-phosphate.

 

Snapshot of a typical Li-phosphate battery

 

 

Figure 6: Snapshot of a typical Li-phosphate battery

Li-phosphate has excellent safety and long life span but moderate specific energy and and a lower voltage than other lithium-based batteries.

Courtesy of BCG research

Lithium Nickel Manganese Cobalt Oxide (LiNiMnCoO2)

Leading battery manufacturers focus on a cathode combination of nickel-manganese-cobalt (NMC). Similar to Li-manganese, these systems can also be tailored to high specific energy or high specific power, but not both. For example, NMC in an 18650 cell for consumer use can be tweaked to 2,250mAh, but the specific power is moderate. NMC in the same cell optimized for high specific power has a capacity of only 1,500mAh. A silicon-based anode will be able to go to 4,000mAh; however, the specific power and the cycle life may be compromised.

The secret of NMC lies in combining nickel and manganese. An analogy of this is table salt, in which the main ingredients of 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 low stability; manganese has the benefit of forming a spinel structure to achieve very low internal resistance but offers a low specific energy. Combining the metals brings out the best in each.

NMC is the battery of choice for power tools and powertrains for vehicles. The cathode combination of one-third nickel, one-third manganese and one-third cobalt offers a unique blend that also lowers raw material cost due to reduced cobalt content. Striking the right balance is important and manufacturers keep their recipes a well-guarded secret. Figure 7 demonstrates the characteristics of the NMC.
 

Snapshot of NMC

 

 

Figure 7: Snapshot of NMC

NMC has good overall performance and excels on specific energy. This battery is the preferred candidate for the electric vehicle and has the lowest self-heating rate.

Courtesy of BCG research

Lithium Nickel Cobalt Aluminum Oxide (LiNiCoAlO2)

The Lithium Nickel Cobalt Aluminum Oxide battery, or NCA, is less commonly used in the consumer market; however, high specific energy and power densities, as well as a long life span, get the attention of the automotive industry. Less flattering are safety and cost. Figure 8 demonstrates the strong points against areas for further development.

Snapshot of NCA

 

 

Figure 8: Snapshot of NCA

High energy and power densities, as well as good life span, make the NCA
a candidate for EV powertrains. High cost and marginal safety are negatives.

Courtesy of BCG research

Lithium Titanate (Li4Ti5O12)

Batteries with lithium titanate anodes have been known since the 1980s. Li-titanate replaces the graphite in the anode of a typical lithium-ion battery and the material forms into a spinel structure. Li-titanate has a nominal cell voltage of 2.40V, can be fast-charged and delivers a high discharge current of 10C, or 10 times the rated capacity. The cycle count is said to be higher than that of a regular Li-ion; the battery is safe, has excellent low-temperature discharge characteristics and obtains a capacity of 80 percent at –30°C (–22°F). At 65Wh/kg, the specific energy is low. Li-titanate charges to 2.80V/cell, and the end of discharge is 1.80V/cell. Figure 9 illustrates the characteristics of the Li-titanate battery.
 

Snapshot of Li-titanate

 

 

Figure 9: Snapshot of Li-titanate

Li-titanate excels in safety, low-temperature performance and life span. Efforts are being made to improve the specific energy and lower cost.

Courtesy of BCG research

Figure 10 compares the specific energy of lead, nickel- and lithium-based systems. While Li-cobalt is the clear winner by being able to store more capacity than other systems, this only applies to specific energy. In terms of specific power (load characteristics) and thermal stability, Li-manganese and Li-phosphate are superior. As we move towards electric powertrains, safety and cycle life will become more important than capacity.

Typical energy densities of lead, nickel- and lithium-based batteries

Figure 10: Typical energy densities of lead, nickel- and lithium-based batteries
Lithium-cobalt enjoys the highest specific energy; however, manganese and phosphate are superior in terms of specific power and thermal stability.

Courtesy of Cadex

Comments

On April 19, 2011 at 1:45pm
Mike wrote:

Not correct: “on charge the flow is from anode to cathode”

On charge, Li+ ion flow is from cathode to anode. On discharge, flow is from anode to cathode.  This is easy to remember.  The battery is assembled in a discharged state, where only the cathode contains lithium (e.g. LiCoO2) and the anode is pure carbon containing no lithium.  Thus on charging, the Li+ flow must be from cathode to anode.

On July 10, 2011 at 4:08am
Ken Neal wrote:

I just want decent battery life for my Mesmerise Phone.

On July 21, 2011 at 9:59am
karl wrote:

Danke für die vergleichende Darstellung der verschiedenen Li-Elemente.
Die Parameter.Grafiken geben einen raschen Überblick.
MFG karl!

On February 1, 2012 at 12:47am
Victor wrote:

Not Correct “Not correct: “on charge the flow is from anode to cathode” “

Lithium ion flow is ALWAYS from anode to cathode, both charge and discharge.  You are confusing the negative and positive electrodes (which are the same on charge and discharge) with the sites of oxidation and reduction (which are respectively the anode and cathode and reverse on charge to discharge and vice / versa).  Battery engineers (me included) use this mistaken nomenclature for the electrodes as a historical artifact of primary (non-rechargeable) batteries which operate only in the discharge mode.

On March 14, 2012 at 2:08pm
Tom Blakley wrote:

Victor’s comments clear up the misunderstanding that Mike voiced concerning the phrase “on charge, the flow is from anode to cathode”, which is found in the first paragraph of the section describing Lithium Cobalt Oxide.
Another (more wordy) way of stating what Victor is teaching is to say that: On Discharge, the negative electrode is called the anode and the positive electrode is called the cathode. However, on Charge, the negative electrode is now called the cathode, while the positive electrode is called the anode.
We swap the names (functions) of the physical negative and positive electrodes depending on whether discharging or charging is occuring.
Another point: The negative electode is always labeled as the negative terminal (-) and the positive electrode is always the positive terminal (+).

On March 20, 2012 at 2:01am
Shivbraham Singh Rajawat wrote:

Very Good Material on Batteries

On March 28, 2012 at 12:44pm
Robert Bernal wrote:

MORE info for the LiFePo4 (lithium iron phosphate) battery… please!
They should not be grouped with the other li-ion chemistries in the “safety” table.
Anyways, they (and I guess, all li-ion types) need to be charged constant current until reaching charged voltage, then constant voltage just for maintaining. I hear that CC/CV is how the li-ion smart chargers do it.
What I want to know, is if it is alright to simply put a low drop out voltage regulator on a 6v SOLAR panel, set to the 3.5 or 3.6v (not 4.2v as with li-ion), would it be Ok? I visualize such that “it can’t get filled up past that point no matter how large the charging source is, as long as the input voltage remains below the recommended charge cut off”. I tried to search this many times but nobody’s doing it.
Bty, they do not have thermal issues and have about 4x the charge discharge cycles (about 2,000 complete) wheras li-ion is prone to thermal issues (catch fire) and only last a few hundred cycles.
For this reason, the LiFePO4 battery should be on the top of everybody’s list and that we all should DEMAND robotic factories that mass produce them cheap enough to be used in solar and electric car applications. The ONLY trade off (other than current high costs) is that it is not quite as energy dense as li-ion. There are enough raw materials in this planet’s crust to safely mine and base an entire global infrastructure on it, too!

On May 15, 2012 at 9:53am
ron davison wrote:

Robert,
Add a current limiting diode to your idea and whne the battery voltage is very low you will not draw more current than the battey will take without damage.

Caveat…at very very low voltages this current limit is very low and mAY NOT ALLOW FOR A FAST ENOUGH CHARGE if you protect current fore below cot-off chARGING.

a SERIES RESistor with a fet across it (in //) that closes when the battery voltage is above the cut-off voltage (without charge current). So the state of the switch needs to be set with the LDO off. So a timing circuit that turns off the LDo and checks voltage is needed this can be low duty cycle. Starting to not be a simple circuit…

On November 21, 2012 at 6:29am
krishna wrote:

great material ! I have a question though..for motor driven applications like power tools, is it okay to use Li-Cobalt batteries? Is there some precautions to take care of ?
would Li-Manganese be a good choice for tradeoff between power and energy capacity in such applications?

On January 11, 2013 at 9:52pm
John Paul wrote:

Is specific energy and specific capacity the same thing? If yes, are the units of specific energy (W-hr/kg) and specific capacity (mA-hr/kg) are equivalent?

On February 4, 2013 at 6:44am
Tushar Dobhal wrote:

I am involved in a project for making an electric vehicle for the Shell Eco Marathon Asia. I want to know which of the above Li ion batteries will be suitable if I need an energy output of 3 KWhr, and efficiency of the vehicle (Km / KWhr) is of prime importance.

On February 4, 2013 at 1:14pm
ron davison wrote:

LIFEPO4 is your best bet for energy density and power density at this time.
also does not have the level of safety issues, some brands claim they have solved the issue.

On February 4, 2013 at 4:11pm
Victor wrote:

For a (smallish) 3kWh battery in a normal sized EV, the km / kWh of the vehicle will be dominated by the vehicle’s weight and aerodynamics.  The battery type can simply be chosen on energy density considerations.

On March 11, 2013 at 7:46am
Josh wrote:

Request for clarity on the section on Lithium Manganese Oxide:

“An 18650 package can be discharged with currents of 20-30 amps.”

Later:

“The long-life version in the 18650 cell has a moderate capacity of 1,100mAh; the high-capacity version is 1,500mAh but has a reduced service life.”

Is this stating that this single 1,100 - 1,500mAh cell can take discharge currents of 20-30 amps, or is it saying that a package of cells in a string can take a such currents?

 

On May 22, 2013 at 5:09am
Ranjusha wrote:

Hi
  I am currently working on manganese oxide based lithium ion battery. I am looking for the best electrolyte for this system. I went through the literature but there are plenty of lithium based electrolytes. Can anyone recommend the best composition for the electrolyte so that the best performance can be attained?

Thanks in advance

Ranjusha

On May 24, 2013 at 3:55am
John Hardy wrote:

This is excellent material. The only statement I would suggest you look at again is the “... Li-phosphate has a higher self-discharge than other Li-ion batteries, which can cause balancing issues with aging…”

I have done long term cycle testing on LiFePO4 battery packs and have seen no drift in cell voltages in almost 600 cycles in one test and almost 400 cycles in another. From my observations I see no benefit in balancing a battery of this kind unless there are parasitic loads such as a poorly designed voltage monitoring system. I have also seen no self discharge. I checked some of the cells from the earlier test after 7 - 8 months. The cell voltages were all within 10 mV and were approximately 10 - 20 mV HIGHER than the last recorded ones at the end of the test.

If you would like any of the test data (available as CSVs) give me a shout

John

On June 10, 2013 at 1:01pm
Rob wrote:

Hi,

The battery of my ebike is composed of ncr18650b cells.
It will not be used for 3 weeks.
Is it ok to store it loaded at 40% in the fridge ( about 6 degrees celcius) ?
Thanks
Rob

On July 10, 2013 at 5:27am
Mark McElroy wrote:

I am not a battery engineer but, as a chemist, find battery technology fascinating. However, my question is about the PV system I have on my roof. Would it be possible to use a Toyota Prius battery (one that has been replaced because it`s capacity has become too low for efficient use)  to store energy generated from my roof PV panels for use at night?

On August 24, 2013 at 9:17am
Mark McElroy wrote:

I am not sure ow this applies to my query

On October 13, 2013 at 8:19pm
Justin wrote:

Could a Prius cell/cells be used to store energy from a PV, sure but a cell that is already reaching considerable drift won’t be much use as designing both a circuit to compensate for the ESR of the cell and the degrading performance will be tad of a waste of expensive components.  A Prius individual cell is not extremely expensive if Ni-Mh is your goal.  Li-MN in SP arrangement would be far better albeit more complicated to charge.

On November 22, 2013 at 3:54pm
Peter Hasek wrote:

Which of the above-mentioned Lithium battery formulas is closest to the typical Lithium Polymer formulas that are widely used in RC aircraft?

On December 2, 2013 at 9:40pm
Md. Asadur Rahman Dolon wrote:

hi,
i need the equipment list and process of lithium ferrous phosphate battery manufacturing.

thanking you

On December 3, 2013 at 2:50am
Mark McElroy wrote:

Thanks Justin, I get your point, although I was thinking of the whole battery from a prius and not an individual cell. I understand that the whole battery has to be replaced when its capacity has reduced to, 40% (not too sure of this figure). So my thought is that at 40% of original capacity it might just do as a storage unit for PV generated energy.

On February 15, 2014 at 10:27am
Nisei wrote:

As I understand, the maximum/minimum charge/discharge voltages for these different Lithium-ion batteries aren’t the same. Would it be possible to add these to the article or can someone point me to a page where I can find them?
Thanks in advance.

On March 18, 2014 at 8:45am
Martyn Adams wrote:

I have the quintessential simple Lithium installation.
Boat, 40ah LiFePO4 “12V” battery,75W solar panel, MPPT controller.
Location NW WA.
Battery seems to maintain a 14.8-15.1V charge after a period of no use which may be temperature dependent.
Anyone see any problems?

Cheers,Martyn

On April 10, 2014 at 2:44am
Robert W Best wrote:

Are LFP batteries always conditioned in the factory? Or should I condition new batteries before use?

On May 29, 2014 at 5:43am
Vijay wrote:

Very well explained for better understanding of Li batteries and it’s function for various application.

On July 1, 2014 at 12:59am
John wrote:

needed for my research. Thanks a lot. hope to see more

On July 7, 2014 at 2:15pm
Mohammad wrote:

Does any body know what is the chemistry of LG chem 18650 MG1 2900 Ah battery? What does MG1 stands for?
Thanks

On August 3, 2014 at 9:40am
Edward wrote:

Here many commented but no one concluded what is the best Lithium battery ?

Can anyone suggest me best battery based on over all performance. High power, Long duration, high cycles, normal charging time,

Thanks

On August 9, 2014 at 2:29am
Kam wrote:

Is there any easy and non-destructive way to determine the chemistry of an unknown 18650 cell?  And for charging and discharging purposes, does it matter?

I have obtained a number of cells made by EPT out of a computer battery, and I would like to learn how they are best charged and maintained.  By the way, I’m using an imax B6AC charger.