CN108390057A - The preparation method of additive Mn lithium iron phosphate electrode material - Google Patents
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- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
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- H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
- H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
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Abstract
The invention discloses a kind of preparation methods of additive Mn lithium iron phosphate electrode material.The method is respectively using a hydronium(ion) lithia, green vitriol, phosphoric acid as lithium source, source of iron and phosphorus source, ascorbic acid is as reducing agent and part carbon source, stabilizer and reducing agent of the ethylene glycol as solvent-thermal method, first precipitation method synthesizing iron lithium phosphate presoma under agitation, again using Manganous sulfate monohydrate as the manganese source of doping, it is added dropwise in precursor solution, then it is 7~10 ammonium hydroxide to be added dropwise in solution and adjust pH value of solution, it washed after hydro-thermal reaction, be dried to obtain nano bar-shape, uniformly, the additive Mn lithium iron phosphate electrode material of good dispersion.Process of the present invention is simple, and raw material sources are extensive, is conducive to large-scale industrial production, and there is additive Mn lithium iron phosphate positive material obtained excellent high rate performance and excellent cycle performance, charging/discharging voltage platform stable to have higher specific capacity.
Description
Technical field
The invention belongs to technical field of new energy material preparation, are related to a kind of preparation of additive Mn lithium iron phosphate electrode material
Method.
Background technology
" heart " of the battery as electric vehicle, the height of performance directly restrict the industrialized development of electric vehicle.
LiFePO4 (LiFePO4) received significant attention as cell positive material of new generation.LiFePO4Theoretical capacity is 170mAh/g,
It has the following advantages：Service life is very long (7-8), has a safety feature, the fast (30min or so under the conditions of 1.5C of charging rate
Can be full of), high temperature resistant (350-500 DEG C), capacity is big and does not have memory effect, and environmentally protective, raw material sources are extensive, valence
Lattice are cheap.LiFePO at present4Not yet in large-scale application to the power battery materials such as electric vehicle, electric tool, mainly because
For it, there is also many urgent problems to be solved.For example, when temperature is relatively low, LiFePO4Chemical property declines obviously, also limits
Applicable external environment condition is made；Smaller (the 1.0g.cm of tap density-3), lead to LiFePO4Lower energy density per unit volume, gives
LiFePO4Battery smart proposes challenge；Lower electron conductivity (10-7-10-9Scm), lithium ion battery is in charge and discharge
In the process, electronics cannot be shifted timely, generate larger capacitive reactance；Meanwhile smaller Li+Diffusion rate (1.8*10-16-2.2*10-14cm-2·s-1), lead to the Li in charge and discharge process+Deintercalation lags, to reduce LiFePO4Charge/discharge capacity and forthright again
Energy.In addition, LiFePO4 as positive electrode in use some materials also can by organic electrolyte corrode dissolving to
Influence the capacity and stability of battery.To widen application field of the LiFePO4 in electric vehicle, it would be highly desirable to which solution is exactly to contract
Short lithium ion deintercalation path expands diffusion duct, promotes ionic conductivity, increases the electric conductivity inside LiFePO4.
Metal ion mixing LiFePO4 is to change its inner ion conductivity at present, promoted the most basic of electric conductivity and compared with
Effective approach.The metal cation for the state that overprices is adulterated in lithium position can pass through p-Type and n-Type conduction increases material monolithic conductive
Property.First-principles calculations are disclosed about LiMPO4(M=Fe, Mn, Co, and Ni) Li on nonlinear path+Minimum moves
Energy is moved, so the doping of iron position, which is more effective way, promotes material internal conductivity.Equivalent cation (Mg2+,Cu2+,Co2+
Deng) be easy in LiFePO4In occupy Fe, reduce crystal distortion, more deintercalation spaces provided for Li.1 (Amol of document
Naik, et al.Rapid and facile synthesis of Mn doped porous LiFePO 4/C from iron
Carbonyl complex [J] .Journal of Energy Institude, 2015,1-9) it is closed using microwave-assisted Solid-state method
At the doped meso-porous shape carbon coating LiFePO of Mn4/C.Wherein Mn：Fe=1:99,0.1C first discharge specific capacities are 163.2mAh/g.
But most cation doping mostly uses solid phase method, has disadvantages that：If Solid raw materials mix it is uneven, impurity in products compared with
It is more；Very high temperature is generally required, energy consumption is big；Low-valent metal is easily aoxidized, and it is of high cost to lead to protection gas；Synthesize target product metal
Doping is difficult to accurately control；Pattern is poor, reunites serious, cannot get ideal cell positive material.Document 2 (Chen, et
al.Mn-doped modification of lithium iron phosphate nanoplates with{010}plane
preferential growth[J].Journal of Southwest University for
Nationalities.Natural Science Edition, May.2015Vol.41 No.3) using hydro-thermal method doping Mn, and
The LiMn under 0.1C electric currents0.03Fe0.97PO4First discharge specific capacity has reached 165.26mAh/g.But its cyclical stability compared with
Difference, the structure change of material is serious in charge and discharge process.
Invention content
To increase LiFePO4Specific capacity, improve its cycle and high rate performance be high, maintain stable charge and discharge platform, this
Invention provides a kind of preparation method of additive Mn lithium iron phosphate electrode material.
The technical scheme is that：
The preparation method of additive Mn lithium iron phosphate electrode material, includes the following steps：
Step 1, it is in mass ratio 3:1:1 respectively using a hydronium(ion) lithia, green vitriol, phosphoric acid as lithium source,
Source of iron and phosphorus source, ascorbic acid are stirred as reducing agent and part carbon source, stabilizer and reducing agent of the ethylene glycol as solvent-thermal method
Synthesizing iron lithium phosphate presoma is precipitated under the conditions of mixing；
Step 2, the manganese source adulterated using Manganous sulfate monohydrate as LiFePO4, is added dropwise in precursor solution；
Step 3, ammonium hydroxide is added dropwise in the mixed solution that step 2 obtains, it is 7~10,170~200 to adjust pH value of solution
Hydro-thermal reaction is carried out at DEG C, is reacted 11~13h, is washed, is dried to obtain additive Mn lithium iron phosphate electrode material.
Preferably, in step 1, the additive amount of the ascorbic acid is the 5wt% of LiFePO4 theoretical yield, ethylene glycol
Mass ratio with water is about 1:4.
Preferably, in step 3, the doping of Mn is the 1wt% of LiFePO4 theoretical yield.
Preferably, in step 3, it is 8~9 to adjust pH value of solution, and hydrothermal temperature is 180 DEG C, and the hydro-thermal time is 12h.
Compared with prior art, the present invention has the following advantages：
(1) ascorbic acid and ethylene glycol play reduction, prevent Fe2+It is aoxidized, while ascorbic acid is as a small amount of carbon
Source, ethylene glycol play the role of stabilizing material structure and promote material morphology uniformly；
(2) Mn is controlled：Fe=1.5：98.5~3.5:96.5 LiMnxFe1-xPO4The incorporation of middle Mn is conducive to shorten Li+
Diffusion admittance increases the ionic conductivity of material, the crystal structure of stabilizing material；
(3) it is 8~9 to adjust pH by ammonium hydroxide, obtains rodlike LiMnxFe1-xPO4Nano material, made from hydro-thermal reaction
LiMnxFe1-xPO4, the specific capacity and cyclical stability of material be obviously improved, and capacity retention ratio is 95% or more after 60 cycles.
The raw materials used in the present invention derives from a wealth of sources, and cheap, and technical process is simple, additive Mn LiFePO4 electricity obtained
The chemical property of pole material is ideal, is produced on a large scale, and has great economic benefit.
Description of the drawings
Fig. 1 is undoped with not plus ethylene glycol LiFePO4, undoped with LiFePO4, LiMn0.025Fe0.975PO4TEM figures, a is
It is undoped not add ethylene glycol LiFePO4, b is undoped with LiFePO4, c is LiMn0.025Fe0.975PO4。
Fig. 2 is undoped LiFePO4And LiMn0.025Fe0.975PO4SEM figure, a is undoped LiFePO4, b is
LiMn0.025Fe0.975PO4。
Fig. 3 is LiFePO4Standard, undoped LiFePO4And LiMn0.025Fe0.975PO4XRD diagram.
Fig. 4 is the LiMn prepared0.025Fe0.975PO4Electrode material first charge-discharge curve graph under the conditions of different multiplying.
Fig. 5 is the LiMn prepared0.025Fe0.975PO4The decay pattern of electrode material cycle charge-discharge 60 times under different multiplying.
Specific implementation mode
With reference to embodiment and attached drawing, the invention will be further described.
Embodiment 1
LiMn0.025Fe0.975PO4It is made by following steps：
(1) the stirring precipitation method prepare LiFePO4Presoma：According to molar ratio 1:1:3 weigh phosphoric acid 2.49g, seven water respectively
It closes ferrous sulfate 7.06g, hydronium(ion) a lithia 3.2g, ascorbic acid 0.2g and is configured to aqueous solution respectively.Phosphoric acid is added
To white precipitate is formed in lithium hydroxide solution, measure 50mL ethylene glycol and ascorbic acid and ferrous sulfate mixing, dropwise
It is added drop-wise in lithium phosphate and generates greenish precipitate, be kept stirring state, and there is nitrogen slowly to blast in solution to exclude to be dissolved in
Oxygen in water；
(2) sources Mn are added dropwise and carry out Mn doping：Manganous sulfate monohydrate 0.11g is weighed, aqueous solution is configured to, before being slowly dropped to
It drives in liquid solution, is kept stirring 0.5h, and there is nitrogen slowly to blast in solution；
(3) pH adjusts the rod-shaped LiMn of hydro-thermal control one direction preferential growth0.025Fe0.975PO4：Solution is adjusted with the ammonium hydroxide of 1M
PH to 8-9 transfers the solution into rapidly in the hydrothermal reaction kettle of 4 80mL after stirring 0.5h, is placed in Muffle furnace 180 DEG C, instead
Answer 12h.It is to be cooled to room temperature when, three times, ethyl alcohol washs three times for centrifugation washing, is placed in 80 DEG C of baking ovens dry 12h, takes out grinding
Obtain LiMn0.025Fe0.975PO4Electrode material.
The pattern of product is observed and analyzed using transmission electron microscope TEM, Fig. 1 does not add ethylene glycol to be undoped
LiFePO4, undoped with LiFePO4, LiMn0.025Fe0.975PO4TEM figures be as can be seen from the figure to undope to be not added with ethylene glycol
LiFePO4Although being also bar-like poor dispersion between particle, and grain size is uneven.It is undoped to add ethylene glycol
LiFePO4, LiMn0.025Fe0.975PO4Pattern be rodlike, uniform particle sizes, good dispersion.Fig. 2 is undoped LiFePO4
And LiMn0.025Fe0.975PO4SEM figure, it can be seen from the figure that the two pattern is corynebacterium, long 400-500nm is wide
The addition of 200nm, Mn do not change LiFePO4Pattern has only been doped into lattice.Fig. 3 is LiFePO4Standard, it is undoped
LiFePO4And LiMn0.025Fe0.975PO4XRD diagram, it can be seen from the figure that undoped LiFePO4With
LiMn0.025Fe0.975PO4XRD diffraction maximums with base peak correspond, explanation is the LiFePO of pure phase4,
LiMn0.025Fe0.975PO4Peak intensity obviously increase, illustrate under the conditions of the ratio doped with conducive to improving the crystallization of crystal
Degree.And LiMn0.025Fe0.975PO4Diffraction maximum have offset slightly, also illustrate that the incorporation of Mn changes lattice parameter, only
Micro incorporation changes little.Fig. 4 is the LiMn prepared0.025Fe0.975PO4Electrode material first charge-discharge under the conditions of different multiplying
Obtained dopant material is fabricated to anode of the electrode slice as button cell by curve graph, using lithium piece as cathode, is carried out to it
Charge-discharge test and cycle performance test, are shown in Fig. 4 and Fig. 5.Test result is shown, under the conditions of different multiplying charge and discharge, battery
Can there are preferable charge and discharge platform, charging/discharging voltage to stablize smooth-going, under low range current condition, obtain 165mAh/g almost
The specific capacity (170mAh/g) of theoretical value is obtained, and obtained charge and discharge platform is still put down under the conditions of high rate charge-discharge
Surely, specific capacity is maintained at higher level.The polarizability of battery material is very low.After carrying out lower 100 charge and discharge of different multiplying, material
Specific capacity almost without decaying, and after being restored to initial multiplying power 0.2C, the specific capacity of material is almost without changing, capacity
Conservation rate is 95% or more.Illustrate the LiMn prepared0.025Fe0.975PO4Cycle performance is excellent, and material is in multiple, large current density
The structure of material has almost no change under electricity condition, and structural stability is good.It can be seen that the LiMn of preparation0.025Fe0.975PO4As lithium from
Sub- battery anode material has excellent chemical property, application prospect extensive.
Embodiment 2
LiMn0.015Fe0.985PO4It is made by following steps：
(1) the stirring precipitation method prepare LiFePO4Presoma：According to molar ratio 1:1:3 weigh phosphoric acid 2.49g, seven water respectively
It closes ferrous sulfate 7.06g, hydronium(ion) a lithia 3.2g, ascorbic acid 0.2g and is configured to aqueous solution respectively.Phosphoric acid is added
To white precipitate is formed in lithium hydroxide solution, measure 50mL ethylene glycol and ascorbic acid and ferrous sulfate mixing, dropwise
It is added drop-wise in lithium phosphate and generates greenish precipitate, be kept stirring state, and there is nitrogen slowly to blast in solution to exclude to be dissolved in
Oxygen in water；
(2) sources Mn are added dropwise and carry out Mn doping：Manganous sulfate monohydrate 0.064g is weighed, aqueous solution is configured to, is slowly dropped to
In precursor solution, it is kept stirring 0.5h, and there is nitrogen slowly to blast in solution；
(3) pH adjusts the rod-shaped LiMn of hydro-thermal control one direction preferential growth0.015Fe0.985PO4：Solution is adjusted with the ammonium hydroxide of 1M
PH to 8-9 transfers the solution into rapidly in the hydrothermal reaction kettle of 4 80mL after stirring 0.5h, is placed in Muffle furnace 180 DEG C, instead
Answer 12h.It is to be cooled to room temperature when, three times, ethyl alcohol washs three times for centrifugation washing, is placed in 80 DEG C of baking ovens dry 12h, takes out grinding
Obtain LiMn0.015Fe0.985PO4Electrode material.
Obtained LiMn0.015Fe0.985PO4First charge-discharge specific capacity is 154mAh/g, 60 cycles under the conditions of 0.2C
Capacity retention ratio is 88% afterwards.
Embodiment 3
LiMn0.035Fe0.965PO4It is made by following steps：
(1) the stirring precipitation method prepare LiFePO4Presoma：According to molar ratio 1:1:3 weigh phosphoric acid 2.49g, seven water respectively
It closes ferrous sulfate 7.06g, hydronium(ion) a lithia 3.2g, ascorbic acid 0.2g and is configured to aqueous solution respectively.Phosphoric acid is added
To white precipitate is formed in lithium hydroxide solution, measure 50mL ethylene glycol and ascorbic acid and ferrous sulfate mixing, dropwise
It is added drop-wise in lithium phosphate and generates greenish precipitate, be kept stirring state, and there is nitrogen slowly to blast in solution to exclude to be dissolved in
Oxygen in water；
(2) sources Mn are added dropwise and carry out Mn doping：Manganous sulfate monohydrate 0.15g is weighed, aqueous solution is configured to, before being slowly dropped to
It drives in liquid solution, is kept stirring 0.5h, and there is nitrogen slowly to blast in solution；
(3) pH adjusts the rod-shaped LiMn of hydro-thermal control one direction preferential growth0.035Fe0.965PO4：Solution is adjusted with the ammonium hydroxide of 1M
PH to 8-9 transfers the solution into rapidly in the hydrothermal reaction kettle of 4 80mL after stirring 0.5h, is placed in Muffle furnace 180 DEG C, instead
Answer 12h.It is to be cooled to room temperature when, three times, ethyl alcohol washs three times for centrifugation washing, is placed in 80 DEG C of baking ovens dry 12h, takes out grinding
Obtain LiMn0.035Fe0.965PO4Electrode material.
Obtained LiMn0.035Fe0.965PO4First charge-discharge specific capacity is 157mAh/g, 60 cycles under the conditions of 0.2C
Capacity retention ratio is 92% afterwards.
Embodiment 4
LiMn0.025Fe0.975PO4It is made by following steps：
(1) the stirring precipitation method prepare LiFePO4Presoma：According to molar ratio 1:1:3 weigh phosphoric acid 2.49g, seven water respectively
It closes ferrous sulfate 7.06g, hydronium(ion) a lithia 3.2g, ascorbic acid 0.2g and is configured to aqueous solution respectively.Phosphoric acid is added
To white precipitate is formed in lithium hydroxide solution, measure 50mL ethylene glycol and ascorbic acid and ferrous sulfate mixing, dropwise
It is added drop-wise in lithium phosphate and generates greenish precipitate, be kept stirring state, and there is nitrogen slowly to blast in solution to exclude to be dissolved in
Oxygen in water；
(2) sources Mn are added dropwise and carry out Mn doping：Manganous sulfate monohydrate 0.15g is weighed, aqueous solution is configured to, before being slowly dropped to
It drives in liquid solution, is kept stirring 0.5h, and there is nitrogen slowly to blast in solution；
(3) pH adjusts the rod-shaped LiMn of hydro-thermal control one direction preferential growth0.025Fe0.975PO4：Solution is adjusted with the ammonium hydroxide of 1M
PH to 7-8 transfers the solution into rapidly in the hydrothermal reaction kettle of 4 80mL after stirring 0.5h, is placed in Muffle furnace 180 DEG C, instead
Answer 12h.It is to be cooled to room temperature when, three times, ethyl alcohol washs three times for centrifugation washing, is placed in 80 DEG C of baking ovens dry 12h, takes out grinding
Obtain LiMn0.025Fe0.975PO4Electrode material.
Obtained LiMn0.025Fe0.975PO4, the peaks XRD are low, and grain size is smaller, and crystallinity is low.The charge and discharge for the first time under the conditions of 0.2C
Electric specific capacity is 148mAh/g.
Embodiment 5
LiMn0.025Fe0.975PO4It is made by following steps：
(1) the stirring precipitation method prepare LiFePO4Presoma：According to molar ratio 1:1:3 weigh phosphoric acid 2.49g, seven water respectively
It closes ferrous sulfate 7.06g, hydronium(ion) a lithia 3.2g, ascorbic acid 0.2g and is configured to aqueous solution respectively.Phosphoric acid is added
To white precipitate is formed in lithium hydroxide solution, measure 50mL ethylene glycol and ascorbic acid and ferrous sulfate mixing, dropwise
It is added drop-wise in lithium phosphate and generates greenish precipitate, be kept stirring state, and there is nitrogen slowly to blast in solution to exclude to be dissolved in
Oxygen in water；
(2) sources Mn are added dropwise and carry out Mn doping：Manganous sulfate monohydrate 0.15g is weighed, aqueous solution is configured to, before being slowly dropped to
It drives in liquid solution, is kept stirring 0.5h, and there is nitrogen slowly to blast in solution；
(3) pH adjusts the rod-shaped LiMn of hydro-thermal control one direction preferential growth0.025Fe0.975PO4：Solution is adjusted with the ammonium hydroxide of 1M
PH to 9-10 transfers the solution into rapidly in the hydrothermal reaction kettle of 4 80mL after stirring 0.5h, is placed in Muffle furnace 180 DEG C,
React 12h.It is to be cooled to room temperature when, three times, ethyl alcohol washs three times for centrifugation washing, is placed in 80 DEG C of baking ovens dry 12h, and taking-up is ground
Mill obtains LiMn0.025Fe0.975PO4Electrode material.
Obtained LiMn0.025Fe0.975PO4, first charge-discharge specific capacity is 162mAh/g, 60 cycles under the conditions of 0.2C
Capacity retention ratio is 93% afterwards.
Comparative example 1
Product is compared undoped with LiFePO4It is made by following steps：
(1) the stirring precipitation method prepare LiFePO4Presoma：According to molar ratio 1:1:3 weigh phosphoric acid 2.49g, seven water respectively
It closes ferrous sulfate 7.06g, hydronium(ion) a lithia 3.2g, ascorbic acid 0.2g and is configured to aqueous solution respectively.Phosphoric acid is added
To white precipitate is formed in lithium hydroxide solution, measure 50mL ethylene glycol and ascorbic acid and ferrous sulfate mixing, dropwise
It is added drop-wise in lithium phosphate and generates greenish precipitate, be kept stirring state, and there is nitrogen slowly to blast in solution to exclude to be dissolved in
Oxygen in water；
(2) pH adjusts the rod-shaped LiFePO of hydro-thermal control one direction preferential growth4：PH value of solution is adjusted with the ammonium hydroxide of 1M to 8-9,
It after stirring 0.5h, transfers the solution into rapidly in the hydrothermal reaction kettle of 4 80mL, is placed in Muffle furnace 180 DEG C, react 12h.It waits for
When being cooled to room temperature, three times, ethyl alcohol washs three times for centrifugation washing, is placed in 80 DEG C of baking ovens dry 12h, takes out grinding and obtains
LiFePO4Electrode material.
Obtained LiFePO4, under the conditions of 0.2C first charge-discharge specific capacity be 131mAh/g, 60 times cycle after capacity protect
Holdup is 75%.And discharge platform is uneven, charge and discharge platform voltage difference is big, internal structure serious polarization in charge and discharge.
Comparative example 2
Compare product overdoping LiMn0.045Fe0.955PO4It is made by following steps：
(1) the stirring precipitation method prepare LiFePO4Presoma：According to molar ratio 1:1:3 weigh phosphoric acid 2.49g, seven water respectively
It closes ferrous sulfate 7.06g, hydronium(ion) a lithia 3.2g, ascorbic acid 0.2g and is configured to aqueous solution respectively.Phosphoric acid is added
To white precipitate is formed in lithium hydroxide solution, measure 50mL ethylene glycol and ascorbic acid and ferrous sulfate mixing, dropwise
It is added drop-wise in lithium phosphate and generates greenish precipitate, be kept stirring state, and there is nitrogen slowly to blast in solution to exclude to be dissolved in
Oxygen in water；
The sources Mn are added dropwise and carry out Mn doping：Manganous sulfate monohydrate 0.192g is weighed, aqueous solution is configured to, is slowly dropped to forerunner
In liquid solution, it is kept stirring 0.5h, and there is nitrogen slowly to blast in solution；
(3) pH adjusts the rod-shaped LiMn of hydro-thermal control one direction preferential growth0.045Fe0.955PO4：Solution is adjusted with the ammonium hydroxide of 1M
PH to 8-9 transfers the solution into rapidly in the hydrothermal reaction kettle of 4 80mL after stirring 0.5h, is placed in Muffle furnace 180 DEG C, instead
Answer 12h.It is to be cooled to room temperature when, three times, ethyl alcohol washs three times for centrifugation washing, is placed in 80 DEG C of baking ovens dry 12h, takes out grinding
Obtain LiMn0.045Fe0.955PO4Electrode material.
Obtained LiMn0.045Fe0.955PO4, first charge-discharge specific capacity is 143mAh/g, 60 cycles under the conditions of 0.2C
Capacity retention ratio is 68% afterwards.And discharge platform is uneven, charge and discharge platform voltage difference is big, and internal structure polarizes sternly in charge and discharge
Weight.Since the overdoping of Mn causes material lattice to be destroyed after multiple charge and discharge, Li+Deintercalation duct is blocked, material cycling behavior
Rapid drawdown.
Claims (4)
1. the preparation method of additive Mn lithium iron phosphate electrode material, which is characterized in that include the following steps：
Step 1, it is in mass ratio 3:1:1 respectively using a hydronium(ion) lithia, green vitriol, phosphoric acid as lithium source, source of iron
And phosphorus source, ascorbic acid is as reducing agent and part carbon source, stabilizer and reducing agent of the ethylene glycol as solvent-thermal method, stirring bar
Synthesizing iron lithium phosphate presoma is precipitated under part；
Step 2, the manganese source adulterated using Manganous sulfate monohydrate as LiFePO4, is added dropwise in precursor solution；
Step 3, ammonium hydroxide is added dropwise in the mixed solution that step 2 obtains, it is at 7~10,170~200 DEG C to adjust pH value of solution
Hydro-thermal reaction is carried out, 11~13h is reacted, washs, is dried to obtain additive Mn lithium iron phosphate electrode material.
2. preparation method according to claim 1, which is characterized in that in step 1, the additive amount of the ascorbic acid is
The mass ratio of the 5wt% of LiFePO4 theoretical yield, ethylene glycol and water is about 1:4.
3. preparation method according to claim 1, which is characterized in that in step 3, the doping of Mn is that LiFePO4 is theoretical
The 1wt% of yield.
4. preparation method according to claim 1, which is characterized in that in step 3, it is 8~9 to adjust pH value of solution, hydro-thermal temperature
Degree is 180 DEG C, and the hydro-thermal time is 12h.
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| CN109244424A (en) * | 2018-10-24 | 2019-01-18 | 东莞理工学院 | A kind of preparation method of alumina-coated additive Mn lithium iron phosphate positive material |
| CN110416541A (en) * | 2019-07-12 | 2019-11-05 | 大连恒超锂业科技有限公司 | A kind of preparation method of the modified phosphate iron lithium of morphology controllable |
| CN111354947A (en) * | 2020-03-11 | 2020-06-30 | 西南石油大学 | Manganese-doped composite cathode material and preparation method thereof |
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| CN113896181A (en) * | 2021-10-09 | 2022-01-07 | 四川裕宁新能源材料有限公司 | Method for producing low-cost nano battery grade iron phosphate |
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| CN117117177B (en) * | 2023-10-20 | 2024-02-02 | 中创新航科技集团股份有限公司 | Battery cell |
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