Bateria LiFePO4

8/6/2019 Bateria LiFePO4

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Bateria LiFePO4

Lithium Iron Phosphate (Li-Fe) is new generation Li-Ion rechargeable battery for high

power applications, such as Electric Vehicles, Power Tool , RC hobby. Li-Fe/Li-Fe-

PSO4 cells features with high discharging current, much safe and non explosive, Soon,we'll probably be seeing Lithium Iron Phosphate (Li-Fe) batteries being used in mostelectric cars and bikes. This new battery type is set to dominate the market. Based

upon lithium ion technology, LiFePO4 batteries offer many advantages over lithiumcobalt dioxide (LiCoO2) batteries which are commonly used in laptops, mp3 players

and cell phones.

In electric vehicles, Li-Fe batteries offer greater range, power and safety. Li-Fechemistry is also environmentally friendly ² it's the least toxic of all the battery types.

For electric vehicles and plug-in electric cars, the Li-Fe batteries will typically performwell in temperatures up to 400-degrees F, last for 6 to 7 years at a charge-discharge

cycle of over 3,000.

Here's a list of all the advantages of Li-Fe batteries:Safe technology ² will not catch fire or explode with overcharge

Over 2000 discharge cycles life compared to typically around 300 for lead acidDouble the usable capacity of similar amp hour lead acid batteries

Virtually flat discharge curve means maximum power available until fully discharged(no ³voltage sag´ as with lead acid batteries)

High discharge rate capability, 10C continuous, 20C pulse discharge

Unlike lead acid batteries, can be left in a partially discharged state for extended

periods without causing permanent damage

Extremely low self discharge rate (unlike lead acid which will go flat quite quickly if

left sitting for long periods)

Does not suffer from ³thermal runaway´

Can be used safely in high ambient temperatures of up to 60C without any degradation

in performance

Maintenance free for the life of the battery

Can be operated in any orientation

Does not contain any toxic heavy metals such as lead, cadmium, nor any corrosive

acids or alkalies thus making Li-Fe batteries the most environmentally friendly battery

chemistry availableLi-Fe cells are of solid construction ² there are no fragile/brittle plates made of lead

which can be prone to failure over time as a result of vibration

Can be safely rapidly recharged ² when fully discharged can be brought to a state of over 90% fully charged in 15 minutes

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Advancing Technology to Change the World

lithium iron phosphate as cathode (LiFePO4 technology)

Due to the shortage of fossil fuels and environmental concerns, we're convinced that the

green energy industry and related industries will become the main stream in the coming

30-50 years. This causes a strong demand of rechargeable batteries. However, theexisting lithium ion cell systems including lithium cobalt oxide and lithium manganese

oxide still suffer from low discharge rate, safety concern and short cycle life.

To solve those issues, Dr. John Goodenough and his team at University of Texas patented as potential cathode material LiFePO4 as a potential cathode in 1996. It is a

very stable material due to the covalent P-O bonding which stabilize the fully chargedcathode versus O2 release. Scientists have developed the LiFePO4 battery using lithium

iron phosphate as cathode to answer concerns in the battery for electric vehicles andother battery useages.

Under its pure form, the olivine-structured material showed specific capacities up to 170

mAh/g.

Structures

Heterosite structure..........................Olivine structure

FePO4 ........................................LiFePO4

Currently, many electric vehicles use the lead acid battery for the 36V/10Ah mold with

360 W total energy, 26.4 lbs. (12 kg) weight, and can be used to drive 30 miles (50km)

under 100% optimal circumstances. Its cycle life is only about 100 - 300 times. Each

12v battery price is about 35 - 40 USD, and the service life is about 12 months. A big

problem is the pollution produced by lead acid batteries. If LiFePO4 material is adopted

as anode to make 10Ah batteries, it requires 12 battery pieces as series in a whole pack.The whole mold is only about 7 lbs. (3-4 kg) weight. If it can be made 11 lbs. (5 kg)

weight, the ebike can travel over 48 miles (80 km) in laboratory experiments.

Comparing LiFePO4 Batteries with Other EV BatteriesThere are three types of lithium ion cells based on different cathode materials. They are

lithium cobalt oxide, lithium manganese oxide and lithium iron phosphate types.Although lithium cobalt oxide cell has the advantage of high energy density, it suffers

from safety concerns. Lithium manganese oxide cell has been evaluated for the

application on high rate due to the better safety characteristics. However, its high

temperature performance is the major drawback.



Lithium iron phosphate cells have the best safety characteristics²long cycle life (up to2000 cycles) and good availability. They are very suitable for high discharge rate

occasions such as EV (including e-bike, electric scooter, and electric car), power tools,UPS and solar energy system. According to different applications, Liberty can modify

the design of battery packs to provide the best solution to satisfy our customer's needs.

COMPARISON DATA AMONG VARIOUS LITHIUM BASE BATTERIES:

Battery LiFePO4 LiCoO2 LiMn2O4 Li(NiCo)O2

Safety Safest Not Stable Acceptable Not Stable

Environmental

Concern

Most Enviro-

friendly

Very

Dangerous

Very

Dangerous

Cycle Life Best/ Excellent Acceptable Acceptable Acceptable

Power/Weight

Density

Acceptable Good Acceptable Best

Long Term Cost Most Economic/

Excellent

High Acceptable High

Temperature

Range

Excellent

(-20C to 70C)

Decay

Beyond

(-20C to

55C)

Decay Extremely

Fast over 50 C

-20C to 55C

REMARKS

1. Although, lead acid batteries are lower in cost and safety acceptable; however, theyare extremely toxic, worse for the environmental concern, short cycle life, heavy in

weight, therefore, we don't put it as a group for comparison.

2. Nickel Hydride battery has a characteristic of low power weight density, decayed

faster under the high temperature, worse in memory effect, not suitable for high output

usage.

3. The C-coated Lithium Iron Phosphate Battery has been proven as the most

environmental friendly battery. It is the safest and most suitable for high output usage. It

is also the best for storage battery usage. It is not necessary to use the equalizer and the

protecting PC Board module.

The LiFePO4 battery does not have the security hidden danger.



When phosphate batteries are overcharged under 3A 5V, the temperature of the batterycould not surpass 55°C. The battery is extremely safe; Heats up after 7-8 hour to 300°C

in hot box process, battery temperature nearly the same with temperature of hot box, the battery cannot appear hotly out of control; after extrusion or acupuncture, the battery

temperature cannot surpass 110°C.

The safety of lithium battery is guaranteed by using LiFePO4 as anode pole. LiFePO4 is

one kind of phosphate gathering the anion, the P-O chemical bond is extremely strong,

material is thermodynamically stable, do not worry about it can release the oxygen,

simultaneously LiFePO4's olivine crystal structure decides its crystal lattice deformation

smaller in the sufficient electric discharge process, its material structure is stable and

safe, and also its cycle life are extremely long. These characteristics also can make

LiFePO4 withstand oxidation and acidic environment, the battery has more electrolyte

choice, the battery performance can be optimized.



SUMMARY

The safety characteristics inherent to LiFePo4 technology result from the incorporation

of phosphates as the cathode material. Phosphates are extremely stable in overcharge or short circuit conditions and have the ability to withstand high temperatures without

decomposing. When abuse does occur, phosphates are not prone to thermal runaway

and will not burn. As a result, LiFePo4 technology possesses safety characteristics that

are fundamentally superior to those of lithium-ion batteries made with other cathode

materials.

LiFePo4 technology does not contain any heavy metals and does not exhibit the

"memory effect" of Nickel-Cadmium and Nickel-metal Hydride solutions. LiFePo4

technology demonstrates excellent shelf life, long cycle life and is maintenance free.

Another key benefit of LiFePo4 technology is its flexibility, both in terms of battery

application and cell design. It can be used in wound cylindrical, wound prismatic and polymer battery construction types and manufactured to fit smaller applications.

The advantages of traditional lithium-ion coupled with the safety features of phosphates, make LiFePo4 technology the lithium-ion technology for the future. Our

LiFePo4 technology utilizes natural, phosphate-based material and offers the greatestcombination of performance, safety, cost, reliability and environmental characteristics.

We all use and take for granted the benefits of lithium-ion energy storage systems in our

cell phones, notebooks, PDA's, consumer appliances and other devices. However, recentrecalls by the US Consumer Protection Commission have brought to light the potential

hazards of lithium-ion batteries. Just imagine what could happen to a large lithium-ion

battery if an electric/hybrid electric vehicle were rear-ended or if a manufacturing defect

or other abuse caused a thermal event in a mission critical telecom backup system. The

results could be devastating.

Liberty is intent on working on developing and making available to all EV applications

the LiFePo4 technology²the only safe large format lithium-ion rechargeable battery

technology. We sincerely hope to have a chance to cooperate with our customers all

over the world and contribute the latest world-wide technology to our customers'

prosperous business future.

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Bateria LiFePO4

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