How is the lithium iron phosphate battery maintained?

Lithium iron battery is a kind of battery that anode material is lithium iron phosphate. It is called lithium iron batteries for short. Compared with the conventional lead-acid batteries, lithium ion batteries have distinct advantage on the working voltage, energy density, cycle life, etc.

Lithium iron batteries compared with conventional lead-acid batteries, has the following advantages: high energy density, safety, good high temperature performance, high power output, long cycle life, light weight, save room reinforcement cost, small volume, long battery life, good security, etc.

In 1990, SONY has introduced in the laboratory with LiCoO2 as cathode material of lithium ion battery and in 1991 began to industrialization production. Compared with the conventional lead-acid batteries, lithium ion battery in the working voltage, energy density, cycle life, etc., all have distinct advantage. So, in the past twenty years, lithium ion batteries are widely used in portable electronic equipment, electric tools, etc. But in recent years, with the global focus on energy conservation and emissions reduction, lithium ion battery also gradually be applied to communication, national grid and electric cars, and other industries. For communication power supply industry energy conservation and emissions reduction requirements of battery, smaller volume, lighter weight, longer service life, high temperature resistant, maintenance more easy, more stable performance, more environmental protection, etc., so in order to comply with these requirements, lithium ion batteries are also gradually shift to the large capacity battery, communication lithium iron phosphate batteries arises at the historic moment. The ABC of lithium iron batteries are a group of batteries, lithium battery in the family the anode materials for lithium iron phosphate material. And lithium iron batteries for short.

Lithium iron batteries, is not as safe as online some friends said. The danger of explosion. The technique requires to be honest, want to have a rigour.

Lithium iron phosphate battery 26650-3 ah 3 c10v overcharge, the battery explosion. Repeat the test, similar results.

(note, this experiment is of a forming products, and tell people cannot provide photos)

When large current charging and discharging lithium battery, battery internal growing, activation of gas in the process of inflation, the battery internal pressure increase, pressure reaches a certain extent, such as shell have scars, which will burst and cause leakage, fire, or even an explosion. So, when they use, must pay attention to safety.

But in the process of normal use, generally used for battery management system power lithium battery protect, so almost no explosion phenomenon. But for mobile phone batteries, due to the protection does not reach the designated position, instead more easily exploded.

Lithium iron batteries full name is lithium ion battery, lithium iron phosphate due to its application performance is particularly suitable for power, and also some people call it "lithium iron power battery".(hereinafter referred to as the "lithium iron batteries")

Working principle of lithium iron batteries (LiFePO4)

The internal structure of LiFePO4 battery as shown in figure 1.On the left is structure of olivine LiFePO4 as the positive pole of the battery, connected to the battery positive electrode by aluminum foil and polymer diaphragm is among, it separates the positive and negative, but lithium ion Li + and electronic e - cannot pass, the right is composed of carbon (graphite) battery cathode, copper foil and negative connection of the battery. Between the top and bottom side is the battery electrolyte battery, the battery by the metal casing airtight packaging.

LiFePO4 battery when charging, the anode of lithium ion Li + through the polymer membrane to the cathode migration; In the process of discharge, the cathode of lithium ion Li + migration through the diaphragm to the positive. Lithium ion battery is due to the lithium ion migration and named after the back and forth during charging and discharging.

LiFePO4 battery performance

LiFePO4 battery's nominal voltage is 3.2 V, termination of charging voltage is 3.6 V, termination voltage is 2.0 V. Because of the various manufacturers adopt positive and negative electrode materials and electrolyte material quality and process is different, its performance will be some difference. For example the same models (the same kind of packaging standard cell), the battery capacity has a bigger difference (10% ~ 20%).

Lithium iron phosphate batteries is the lithium iron phosphate as the anode material of lithium ion battery, and about the lithium ion battery, the positive good multiple data points such as cobalt acid lithium, lithium manganese acid lithium, nickel, ternary material, lithium iron phosphate, etc., during which the lithium iron phosphate is the lithium electricity industry one of the most commonly used materials.

Lithium iron phosphate batteries by aluminum foil and battery anode connection, polymer left is it put the positive and negative from the gap, but the beginning and end of the lithium ion Li can and electronic e - can't, on the right is composed of carbon battery cathode, the copper foil and battery cathode connection, between upper and lower end is the battery electrolyte battery, the battery by the metal shell sealed packaging, LiFePO4 battery when charging, the anode in the beginning and end of the lithium ion Li polymer barrier to negative move; In the process of discharge, the beginning and end of the cathode of lithium ion Li barriers to the positive move, lithium ion battery is due to the lithium ions move back and forth when charging and discharging.

Lithium ion batteries work principle, the battery, Li from lithium iron phosphate crystal 010 moved to crystal appearance, under the effect of electric field force, into the electrolyte, across the barriers, and then through the electrolyte to move to the appearance of graphite crystal, and then embedded in graphite lattice, lithium ion from lithium iron phosphate, embedded into the iron phosphate lithium iron phosphate; Battery discharge, Li from graphite crystals embedded out, into the electrolyte, across the barriers, and then through the electrolyte to lithium iron phosphate crystal appearance, and then back to the 010 face embedded in the crystal lattice of the lithium iron phosphate, then through the conductive body to lithium iron phosphate anode and began to discharge.

On conductive lithium iron phosphate batteries are negative, must attend conductive agent in battery is negative, so the activity of the battery (guess, in the process of theory to describe and theory in the process of produce, how to end the above three equations, also need to describe a series of experiments to verify, sets up the mathematical model may establish record formula, and then exploring these models may be formula for lithium ion batteries.

Old at the time, the domestic lithium ion battery skills, with the world leading level, the industry is still focused on the lithium iron phosphate material for the anode of lithium ion battery, there are many countries have developed a new lithium ion battery materials, just not mass produce at the time, some scholars pointed out that at least 10 in lithium iron phosphate anode materials is the main industry.

1, the output efficiency: standard discharge for 2 ~ 5 c, continuous high discharge current can be up to 10 c, instantaneous pulse discharge (10 s) up to 20 c;

2, when the temperature: external temperature 65 ℃ when the internal temperature is as high as 95 ℃, at the end of the battery discharge temperature can reach 160 ℃.

3, the safety of the battery, there is a certain improvement, but not completely, there are dangers.

4, good cycle life, through 500 - cycle, its discharge capacity is greater than 95%;

5, discharge to zero volts no security issues;

6, fast charging;

7, the cost is low;

8, Environmental pollution-free

Lithium iron phosphate battery compared with the conventional lead-acid batteries, has the following advantages:

(1) High energy density: nominal voltage of 3.2 V, the energy density is about four times that of lead-acid batteries, small volume, light weight;

(2) security: lithium iron phosphate cathode material with good electrochemical performance, charge and discharge platform is very smooth, stable structure, in the process of charging and discharging the battery not combustion, explosion and safety;

(3) high temperature performance is good, the external temperature of 55 ℃ when the battery work normally;

High power output (4) : standard discharge of 0.2 C, but the 3 C;

(5) The long cycle life: normal temperature 1 c to charge and discharge, monomer capacity is still greater than 80% after 2000 cycles;

(6) Environmental protection: the whole production process clean non-toxic, all ingredients are nontoxic.

Communication lithium iron phosphate battery application compared to conventional lead-acid batteries more "energy saving", "power", "day" and so on energy conservation and emissions reduction work requirements.

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