Here are many kinds of Li-ion batteries but all have one common catchword “lithium-ion”.
These batteries vary in performance, and mostly, it’s the cathode material makes their own unique personalities.
These batteries vary in performance, and mostly, it’s the cathode material makes their own unique personalities.
To learn more about their own characters and limitations, we clarify
them by listing three of the most common lithium-ion batteries to compare.
Lithium Iron Phosphate(LiFePO4 or LFP)
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LFP is often used to replace the lead acid battery. It is targeted for use in areial work platform, floor machines, tractions, low speed vehicles and energy storage systems.
ILi-phosphate is more tolerant to full charge conditions and is less stressed than other lithium-ion systems if kept a high voltage for a pronged time. As trade-off, the lower voltage of 3.2V/cell reduces the specific energy. In addition, cold temperature reduces performance, and elevated storage temperature shortens the service life but is still better than lead acid, NiCd or NiMH. Li-phosphate has a higher self-discharge than other Li-ion batteries, which can cause balancing issues with aging.
ILi-phosphate is more tolerant to full charge conditions and is less stressed than other lithium-ion systems if kept a high voltage for a pronged time. As trade-off, the lower voltage of 3.2V/cell reduces the specific energy. In addition, cold temperature reduces performance, and elevated storage temperature shortens the service life but is still better than lead acid, NiCd or NiMH. Li-phosphate has a higher self-discharge than other Li-ion batteries, which can cause balancing issues with aging.
Lithium Iron Phosphate: LiFePO 4 , Graphite anode, Since 1996 Short form: LFP or Li-phosphate
Voltage, nominal
3.20V, 3.20V
Specific energy (capacity)
120–170Wh/kg
Charge (C-rate)
1C typical; 3.65V peak; 3h charge time
Discharge (C-rate)
1–3C continuous, 2.5V cut-off (lower that 2.5V causes damage)
Cycle life
3500–5000 (related to depth of discharge, temperature)
Thermal runaway
270°C (518°F) Very safe battery even if fully charged
Applications
Portable and stationary needing high load currents and endurance
Comments
Very flat voltage discharge curve but low capacity. One of safest Li-Ions. Elevated self-discharge
Lithium Cobalt Oxide (LiCoO2 or LCO)
The battery consists of a graphite carbon anode and a cobalt oxide cathode. The cathode has a layered structure and during discharge, lithium ions will move from the anode to the cathode. The flow reverses on charge.The disadvantages of Li-cobalt are a relatively short life span, limited load capabilities and low thermal stability.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. For – cing 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.
The mandatory battery protection circuit limits the charge and discharge rate to a safe The mandatory battery protection circuit limits the charge and discharge rate to a safe level of about 1C.
LCO’s high specific energy makes Li-cobalt the favored choice for mobile phones, laptops and digital cameras.
Lithium Cobalt Oxide: LiCoO2 (~60% Co ), Graphite anode, Since 1991 Short form: LCO or Li-cobalt
Voltage, nominal-3.60V
Specific energy (capacity)-150–250Wh/kg
Charge (C-rate)-0.8C, 1C maximum, 4.20V peak (most cells); 3h charge typical
Discharge (C-rate) 1C; 2.50V cut off
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, laptops, digital cameras
Comments-Very high specific energy, limited specific power. Cobalt is expensive. Serves as Energy Cell.
Lithium Nickel Manganese Cobalt Oxide
(LiNiMnCoO 2 or NMC)
TLeading battery manufacturers focus on a cathode combination of nickel-manganese -cobalt (NMC). Similar to Li-manganese, these systems can be tailored for high specific energy or high specific power, but not both. For example, NMC in an 18650 cell for moderate load condition has a capacity of about 2,800mAh and can deliver 4–5A; NMC in the same cell optimized for specific power has a capacity of only about 2,000mWh but delivers a continuous discharge current of 20A. A silicon-based anode will go to 4,000mAh but at reduced loading and shorter cycle life.
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 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 of typically 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. Other combinations, such as NCM, CMN, CNM, MNC and MCN are also being offered in which the metal content of the cathode deviates from the 1/3 – 1/3 – 1/3 formu-la. Manufacturers keep the exact ratio a well-guarded secret.
Lithium Nickel Manganese Cobalt Oxide: LiNiMnCoO 2 , Graphite anode, Since 2008 Short form: NMC (NCM, CMN, CNM, MNC, MCN are similar with different medal combination)
Voltage, nominal-3.60V, 3.70V
Specific energy (capacity)-150–220Wh/kg
Charge (C-rate)-1C, 4.20V peak; 3h charge time
Discharge (C-rate)-2C continuous; 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
Applications-E-bikes, medical devices, EVs, industrial
Comments-Provides high capacity and high power. Serves as Hybrid Cell. This chemistry is often used to enhance Li-manganese.
Comparing
Wh/kg for
Different
Battery technologies
Battery technologies
Summary comparison
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LFP
LCO
NMC
Voltage, nominal
3.20V
3.60V
3.60V
Specific energy (capacity)
120–170Wh/kg
150–250Wh/kg
150–220Wh/kg
Charge (C-rate)
1C typical; 3.65V peak;
3h charge time
0.8C, 1C maximum,
4.20V peak (most cells);
3h charge typical
1C, 4.20V peak;
3h charge time
Discharge (C-rate)
1-3C continuous,
2.5V cut-off (lower than 2.5V causes damage)
2.5V cut-off (lower than 2.5V causes damage)
1C; 2.50V cut off
2C continuous;
2.50V cut-off
2.50V cut-off
Cycle life (times)
3500–5000 (re-lated to depth of discharge, tempe-rature)
500–1000, related to depth of dischar ge, load, tempera ture
1000–2000 (re – lated to depth of discharge, tempe – rature)
Thermal runaway
270°C (518°F) Very safe battery even if fully charged
150°C (302°F). Full charge promotes thermal runaway
210°C (410°F) typical. High charge promotes thermal runaway
Applications
Areial work platform floor machines, trac- tions, low speed EVs energy storage system
Mobile phones,
laptops, digital cameras
laptops, digital cameras
E-bikes, medical devices, EVs, indu- strial
Comments
Very flat voltage discharge curve but low capacity.
One of safest Li-Ions. Elevated self-discharge
Very high specific energy, limited spe- cific power. Cobalt
is expensive. Serves
as Energy Cell.
is expensive. Serves
as Energy Cell.
Provides high capa – city and high power. Serves as Hybrid Cell.
This chemistry is often used to
enhance Li-mang – anese.
Conclusions
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For high specific energy, high safety and high cycle life applications all at reasonable cost are
important criterion when selecting your Lithium battery.
RoyPow believes the most suitable technology for applications of home, industry, or travelling – due to its high energy density,
long cycle life and low self-heating rate at a overall all attractive Total Cost of Ownership (TCO).
Lithium Iron Phospahte (LiFePO 4 or LFP) Li-phosphate has excellent safety and long life span but moderate specific energy and a lower voltage than other lithium-based batteries. LFP also has higher self-discharge compared to other lithium-ion systems.
Lithium Cobalt Oxide (LiCoO 2 or LCO) Li-cobalt excels on high specific
energy but offers only moderate performance of specific power, safety
and life span.
energy but offers only moderate performance of specific power, safety
and life span.
Lithium Nickel Manganese Cobalt Oxide (LiNiMnCoO 2 or NMC) NMC has good overall performance and preferred for the electric vehicle and has the lowest self-heating rate. excels on specific energy.
