What is Lithium iron phosphate batteries?
Lithium iron phosphate is an electrode material for lithium-ion batteries, with the chemical formula LiFePO4 (LFP), mainly used in various lithium-ion batteries, and it called lithium iron phosphate batteries, lifepo4 battery.
Specification
High energy density
Its theoretical specific capacity is 170 mAh/g, and the actual specific capacity of the product can exceed 140 mAh/g (0.2 ° C, 25 ° C).
Security
It is the safest positive electrode material for lithium-ion batteries and does not contain any harmful heavy metal elements to the human body;
Long lifespan
Under 100% DOD conditions, it can be charged and discharged more than 4000 times. (Reason: Lithium iron phosphate has good lattice stability, and the insertion and extraction of lithium ions have little effect on the lattice, so it has good reversibility. The disadvantage is the poor ion conductivity of the electrode, which is not suitable for high current charging and discharging, and is hindered in application. Solution: Coating the electrode surface with conductive materials and doping for electrode modification.)
The service life of lithium iron phosphate batteries is closely related to their operating temperature. If the operating temperature is too low or too high, it can cause significant adverse hazards during the charging, discharging, and usage processes. Especially used in electric vehicles in northern China, in autumn and winter, lithium iron phosphate batteries cannot supply power normally or the power supply is too low, so it is necessary to adjust the working environment temperature to maintain their performance. In order to solve the problem of space limitation in the constant temperature working environment of lithium iron phosphate battery in China, the common solution is to use aerogel felt as the insulation layer.
Charging performance
Lithium batteries with lithium iron phosphate cathode materials can be charged at high rates and can be fully charged in as little as 1 hour.
The theoretical density of lithium cobalt oxide is 5.1g/cm3, while the actual density of commercial lithium cobalt oxide is generally 2.0-2.4g/cm3; The theoretical density of lithium iron phosphate is only 3.6g/cm3, which is much lower than that of lithium cobalt oxide.
To improve conductivity, conductive carbon materials are added, which significantly reduces the bulk density of the material, resulting in a true density of only 1.0-1.2g/cm3 for carbon doped lithium iron phosphate. Such a low packing density makes the volumetric capacity of lithium iron phosphate much lower than that of lithium cobalt oxide, resulting in a battery with a very large volume, which not only has no advantage but is also difficult to apply in practice.
Therefore, improving the packing density and volumetric capacity of lithium iron phosphate is of decisive significance for its practical application. The particle morphology, particle size, and distribution of powder materials directly affect the bulk density of the material.
purpose
Application situation
Energy storage equipment
Energy storage equipment for solar and wind power generation systems, uninterruptible power supply (UPS), used in conjunction with solar cells as energy storage devices.
Electric tools
High power electric tools (wireless), drills, lawnmowers, etc.
Light electric vehicles
Electric scooters, electric bicycles, recreational vehicles, golf carts, electric hoists, cleaning vehicles, hybrid electric vehicles (HEVs).
Small equipment
Medical equipment (electric wheelchairs, electric scooters), toys (remote-controlled electric airplanes, cars, boats).
Other small electrical appliances
Mining lamps and implantable medical devices (lithium iron phosphate is non-toxic, and only iron lithium batteries can meet the requirements) are used to replace lead-acid, nickel hydrogen, nickel cadmium, lithium cobalt, and lithium manganese batteries in small electrical appliances.
