1) High energy density
The theoretical specific capacity is 170mAh/g, and the actual specific
capacity of the product can exceed 140mAh/g (0.2C, 25°C);
2) Security
is currently the safest cathode material for lithium-ion batteries; it does
not contain any heavy metal elements harmful to the human body;
3) Long life
Under the condition of 100% DOD, it can charge and discharge more than 2000
times; (reason: lithium iron phosphate lattice stability is good, the insertion
and extraction of lithium ions have little effect on the lattice, so it has good
reversibility. Existing shortcomings The electrode has poor ion conductivity,
which is not suitable for high-current charging and discharging, and is hindered
in application. The solution: coating the electrode surface with conductive
material and doping to modify the electrode.)
The service life of a lithium iron phosphate battery is closely related to
its use temperature. Too low or too high a use temperature will cause great
hidden dangers during the charging and discharging process and the use process.
Especially used in electric vehicles in northern China, in autumn and winter,
the lithium iron phosphate battery cannot supply power normally or the power
supply is too low, and its working environment temperature needs to be adjusted
to maintain its performance. At present, the domestic solution to the constant
temperature working environment of lithium iron phosphate batteries requires
consideration of space limitations. The most common solution is to use aerogel
felt as an insulation layer.
4) Charging performance
The lithium battery with lithium iron phosphate cathode material can be
charged at a high rate, and the battery can be fully charged within 1 hour at
the fastest.
, 1, iron phosphate drying to remove water
(1) Drying process in the drying room: The stainless steel sagger is filled
with raw material iron phosphate and placed in the drying room, and the
temperature of the drying room is adjusted to 220±
20℃, 6-10 hours drying. The discharge is transferred to the next process to
the rotary furnace for sintering.
(2) Rotary kiln sintering process: After the rotary kiln is heated up and
the nitrogen flow reaches the requirements, the material is fed (from the drying
room of the upper process)
materials), adjust the temperature to 540±20℃, and sinter for 8-12
hours.
2, grinding machine mixing process
During normal production, the two grinding machines are put into operation
at the same time, and the specific feeding and operation of the two equipment
are the same (one can run separately during debugging), and the procedure is as
follows:
(1) Lithium carbonate grinding: weigh 13Kg of lithium carbonate, 12Kg of
sucrose, and 50Kg of pure water, mix and grind for 1-2 hours. pause.
(2) Mixing and grinding: Add 50Kg of iron phosphate and 25Kg of pure water
to the above-mentioned mixed solution, and mix and grind for 1-3 hours. Shut
down, the output is transferred to the dispersing machine. Sampling to measure
particle size.
(3) Cleaning: Weigh 100Kg of pure water, clean the grinder 3-5 times, and
transfer all the lotion to the disperser.
3, dispersing machine material dispersion process
(1) Transfer the material about 500Kg (including the material for cleaning
the grinder) to the dispersing machine together with the materials that have
been mixed by two grinders (or two grinders) in 2.2, and then add 100Kg of pure
water, adjust the stirring speed, and fully Stir and disperse for 1-2 hours,
waiting to be pumped into the spray drying equipment.
4, spray drying process
(1) Adjust the inlet temperature of the spray drying equipment to 220±20°C,
the outlet temperature to 110±10°C, and the feed rate of 80Kg/hr, and then start
spray drying to obtain dry materials.
(2) The solid content can be adjusted to 15%~30% according to the spray
particle size.
5. Hydraulic press material briquetting and charging adjust the pressure of
the hydraulic press to 150 tons and 175 tons respectively, and load the
spray-dried material into the mold, hold the pressure for a certain period of
time, and compact it into a block. Load the sagger into the push plate furnace.
At the same time, several sets of bulk samples were put in to compare with the
compressed materials.
6. The pusher furnace is sintered and the temperature is increased first,
nitrogen is passed, and the atmosphere is below 100ppm. Push the sagger into the
pusher furnace, press the heating section 300-550℃, 4-6 hours; the constant
temperature section 750℃ 8-10 hours; cooling down The section is carried out for
6-8 hours, and the material is discharged.
7, roll superfine grinding
The material burned in the pusher furnace is input into the ultra-fine
grinding, the rotation speed is adjusted, and the roller grinding is carried out
and then sent to the ultra-fine grinding for grinding. Each batch is sampled to
test the particle size.
8. Screening, packaging
The grinding materials are screened and packaged. Two specifications: 5Kg
and 25Kg.
9, inspection, warehousing
Product inspection, labeling and storage. Including: product name,
inspector, material batch, date.
