Chemical reaction equation of lithium iron phosphate battery

The electrode reaction of lithium ion batteries discharge

Negative reaction: C6Li - xe - = = C6Li1 - x + xLi + (C6Li lithium atoms embedded graphite to form composite materials)

The positive reaction: Li (1 -) x MO2 + xLi++ xe - = = LiMO2 (LiMO2 lithium transition metal oxides)

It is ok to change LiMO2 LiFePO4

Lithium ion battery anode is lithium metal compounds, usually for lithium iron phosphate (LiFePO4 lithium iron phosphate, phosphoric acid lithium cobalt LiCoO2, etc.), the cathode is graphite or carbon (general use graphite), is to use organic solvent as the electrolyte between the cathode. On battery charging, the anode decomposition generated on lithium ion, lithium ion through the electrolyte into the battery cathode, anode carbon layer embedded micro hole. In the process of battery (discharge) embedded in the lithium ions in the cathode microporous movement back to the anode. Back to the anode of lithium ion, the more the higher discharge capacity, we usually refer to battery capacity is the discharge capacity. In this way, the battery charge and discharge process, the lithium ions are constantly running back and forth between the cathode and so the lithium ion battery is also called a rocking-chair batteries.

The positive reaction: LiFePO4?Li1 - xFePO4 + xLi++ xe -;

Negative reactions: xLi++ xe - + 6 c?LixC6;

Total reactive: LiFePO4 xc + 6?Li1 - xFePO4 + LixC6.

Lithium iron phosphate batteries, refers to the use of lithium iron phosphate as the anode material of lithium ion batteries. Lithium ion battery anode materials mainly have cobalt acid lithium, lithium manganese acid lithium, nickel, ternary material, lithium iron phosphate, etc. The cobalt acid lithium is at present most of the lithium ion battery cathode material.

To improve the performance of security

Lithium iron phosphate crystals in P - solid O key, difficult to decompose, even in high temperature or overcharge when also won't like cobalt acid lithium structure collapse fever or strong oxidizing substances, thus having good security. A report pointed out that the practice of acupuncture or short circuit experiment found combustion phenomenon in a small number of samples, but no one explosion occurred, and overcharge experiments using several times greatly beyond their discharge voltage of high voltage charging, found that there are explosive. Even so, the overcharge safety than common liquid electrolyte cobalt acid lithium batteries, has been greatly improved.

The improvement of the life

Lithium iron phosphate battery refers to the use of lithium iron phosphate as the anode material of lithium ion battery.

Long life cycle life of lead-acid battery in about 300 times, the highest is 500 times

Lithium iron phosphate batteries

Lithium iron phosphate batteries

And the lithium iron phosphate power battery, cycle life reached more than 2000 times, the standard charging rate (5 hours) to use, can reach 2000 times. With the quality of the lead-acid battery is "new half a year, half a year, maintenance, maintenance and half year old", at most 1-1.5 years, while the lithium iron phosphate batteries used under the same conditions, the theory of life will reach 7 ~ 8 years. Comprehensive consideration, the price performance ratio in theory for lead-acid battery is more than four times. Large current discharge can be as big 2 C fast charge and discharge current, under the special charger, 1.5 C can make battery charging 40 minutes, starting current can be up to 2 C, lead-acid battery is the performance.

High temperature performance is good

Lithium iron phosphate can reach 350 ℃ to 500 ℃ and the electric peak and cobalt acid lithium manganese acid lithium only at about 200 ℃.Wide range of operating temperature (20 c -- - + 75 c), have a high temperature resistant properties of lithium iron phosphate can reach 350 ℃ to 500 ℃ heating peak lithium cobalt and lithium manganese acid and acid only at about 200 ℃.

The large capacity

With greater than ordinary battery (lead-acid, etc.) capacity.5 ah - 1000 (monomer)

No memory effect

Rechargeable battery under the condition of are often filled with not to put the work, the capacity will quickly lower than the rated capacity values, this phenomenon is called memory effect. Memory like nickel metal hydride, nickel cadmium battery, and lithium iron phosphate batteries do not have this phenomenon, the battery no matter in what condition, can use increases with the increasing charge, do not need to first put the recharging.

Light weight

The same specification of lithium iron phosphate battery capacity volume is two-thirds the size of lead-acid battery, weight is the 1/3 of lead-acid batteries.

Environmental protection

The battery is generally regarded as do not contain any heavy metals and rare metals (nickel metal hydride battery of rare metals), non-toxic (through the SGS certification), no pollution, comply with European RoHS, is absolutely green battery certificate. So the lithium battery is favored by the industry, mainly environmental considerations, so the battery and listed in the "863" during the tenth five-year national high-tech development plan, has become the national key support and encourage the development of project. With China's accession to the WTO, Chinese exports of electric bikes will increase rapidly, and into Europe and the United States of electric bicycle has asked equipped with battery from pollution.

But experts say, lead-acid battery caused by environmental pollution, mainly in non-standard production process and recycling. By the same token, the lithium battery belongs to new energy industry is good, but it can't avoid the problem of heavy metal pollution. In the metal material processing such as lead, arsenic, cadmium, mercury, chromium is likely to be released into the dust and the water. The battery itself is a kind of chemicals, so is likely to produce two kinds of pollution: one is the production engineering process of waste pollution;2 it is scrapped after the battery pollution.

Lithium iron phosphate battery also has its disadvantages: low temperature performance is poor, for example, tap density is small, the anode materials such as volume of lithium iron phosphate battery capacity than cobalt acid lithium and other lithium ion battery, so don't have an advantage in terms of micro cells. And when used for power battery, lithium iron phosphate batteries and other batteries, battery consistency issues needs to face.

The contrast of power battery

Is currently the most promising application in power type lithium ion battery cathode material basically has modified lithium manganese acid (LiMn2O4), lithium iron phosphate (LiFePO4) and nickel cobalt manganese acid lithium (Li (Ni, Co, Mn) O2) ternary material. Nickel cobalt manganese acid lithium cobalt ternary material due to the lack of resources and nickel and cobalt into high price fluctuation and large, is generally believed that it's hard to become the electric car with the mainstream of power type lithium ion battery, but can and spinel lithium manganese acid mixed in a certain range.

Industry application

Coated carbon foil bring lithium electricity industry technical innovation and industry promotion

Improve lithium electricity product performance, and improve the discharge ratio [1]

As the requirement of domestic battery manufacturers of battery performance is increasing day by day, generally recognized by the domestic new energy battery materials: conducting materials and conductive coating aluminum foil/copper foil.

Its advantage lies in: in the treatment of battery materials, often have high rate charge and discharge performance is good, bigger specific capacity, but the cycle stability is poorer, attenuation serious wait for a reason, have to do choose to give up.

Product application, golf in the charter in the battery pack

Product application, golf in the charter in the battery pack

This is a magical coating, would improve the performance of the battery, into a new era.

Conductive coating is good by decentralizing nano conductive graphite coated particles, etc. It can provide excellent static conductivity, it is a layer of protection energy absorption layer. It can also provide a good cover protection performance. Coating with water and solvent resistance, can be used in aluminum, copper, stainless steel, aluminum and titanium plate.

Coated carbon coating on the performance of lithium-ion batteries with the following promotion

1. Reduce the battery internal resistance, inhibition of charge and discharge cycle in the process of dynamic resistance increase;

2. Improve the consistency of the battery pack, decrease the cost of the battery pack;

3. Improve the active material and fluid collection of glue adhesion, reduce the pole piece manufacturing cost;

4. Reduce the polarization, improve the rate performance, reduce the heating effect;

5. To prevent the electrolyte to set fluid corrosion;

6. The comprehensive factor and prolong the service life of the battery.

7. Coating thickness: conventional single 1 ~ 3 microns thick.

Japan and South Korea in recent years, the main development in modification and nickel cobalt manganese acid lithium manganese acid lithium ternary material as the anode material of power type lithium ion battery, such as Toyota and Panasonic EV energy of a joint venture company, new kobe motor, NEC, Hitachi, SONY, Sanyo, Samsung, LG, etc. The main development of the anode materials for lithium iron phosphate power type lithium ion battery, such as A123 systems, Valence, but the major automobile manufacturers in the PHEV and EV is the choice of manganese base power type lithium ion battery cathode material system, and it is said that the A123 company in the field of consideration into manganese acid lithium materials, and Germany and other European countries mainly adopt the battery company cooperation with other countries to develop electric vehicles, such as Daimler and French Saft alliance, Volkswagen of Germany and Japan Sanyo cooperation agreement, etc. Currently Volkswagen of Germany and France's Renault sa with the support of their governments are development and production of power type lithium ion battery.

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