CN104752716A - Lithium iron phosphate and its preparation method and use - Google Patents
Lithium iron phosphate and its preparation method and use Download PDFInfo
- Publication number
- CN104752716A CN104752716A CN201310739960.5A CN201310739960A CN104752716A CN 104752716 A CN104752716 A CN 104752716A CN 201310739960 A CN201310739960 A CN 201310739960A CN 104752716 A CN104752716 A CN 104752716A
- Authority
- CN
- China
- Prior art keywords
- lithium
- product
- water
- lifepo4
- preparation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- 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
- H01M4/5825—Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B25/00—Phosphorus; Compounds thereof
- C01B25/16—Oxyacids of phosphorus; Salts thereof
- C01B25/26—Phosphates
- C01B25/45—Phosphates containing plural metal, or metal and ammonium
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Landscapes
- Chemical & Material Sciences (AREA)
- Inorganic Chemistry (AREA)
- Organic Chemistry (AREA)
- Crystallography & Structural Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
The invention provides a preparation method of lithium iron phosphate, the lithium iron phosphate and a use of the lithium iron phosphate as a positive pole active material. The preparation method of the lithium iron phosphate is characterized in that a water-soluble divalent iron source, a water-soluble phosphor source and a water-soluble lithium source contact and undergo a reaction, the water-soluble phosphor source is phosphoric acid and/or water-soluble phosphate, the reaction metohd comprises adjusting pH of the contacting product to more than 7, fast heating the alkaline product to a temperature of 80-240 DEG C, carrying out a first reaction process, cooling the product obtained by the first reaction to 20-50 DEG C, adjusting pH of the product to less than 7, fast heating the acidic product to a temperature of 80-240 DEG C, and carrying out a second reaction process, and the fast heating process has a heating rate greater than or equal to 10 DEG/s. The lithium iron phosphate has small particle sizes and excellent electrochemical performances.
Description
Technical field
The present invention relates to the application as positive electrode active materials of a kind of preparation method of LiFePO4, the LiFePO4 prepared by the method and described LiFePO4.
Background technology
Lithium ion battery has been widely used in the fields such as mobile communication, notebook computer, video camera, camera, portable instrument as the chemical power source of height ratio capacity, the electric automobile that Ye Shi various countries are studied energetically, the supporting power supply of the first-selection of space power system, become the first-selection of fungible energy source.
LiFePO4 (LiFePO
4) be the study hotspot of active substance of lithium ion battery anode.Primary Study shows, LiFePO
4concentrate LiCoO
2, LiNiO
2, LiMnO
4deng material advantage separately, if not containing precious metal, cheaper starting materials, aboundresources, operating voltage moderate (3.4V), platform identity is good, voltage is steady, good (oxygen and phosphorus are with strong covalent bond strong bonded for theoretical capacity large (170mAh/g), Stability Analysis of Structures, security performance, make material be difficult to analyse oxygen to decompose), high-temperature behavior and good cycle, charging time volume-diminished, bulk effect when coordinating with carbon negative pole material good, and most of electrolyte system compatibility is good, storge quality is good and nontoxic etc., can as real green energy resource.
Traditional water heat transfer LiFePO4 is generally one-shot forming granulation, that is, the presoma of synthesis only need synthesize through an autoclave temperature reaction, can not introduce other variable again to change its physico-chemical property in temperature-rise period.But, although adopt the process of the method simple, but the presoma that the essence due to water heat transfer LiFePO4 is indissoluble at normal temperatures at high temperature generating portion can dissolve, dissolves completely or in-situ crystallization thus form new thing phase, self also can there is phase transition, thing phased soln and thing phase nucleation in presoma, therefore require higher to the physico-chemical property of presoma in the process heated up.If presoma thing phase is too stable or be at high temperature not easily converted into LiFePO4, its formation condition will be harsher, part presoma is so notably made to be converted into LiFePO4, also the conversion ratio of the material of LiFePO4 not only can be made to reduce, and the LiFePO4 that non-fully transforms also can increase mutually, thus cause chemical property such as capacity, compacted density, cycle performance etc. all will be a greater impact.
Meanwhile, the method for traditional water heat transfer LiFePO4 generally has two kinds.A kind of first prepare lithium phosphate under normal temperature, and then add copperas solution, then raised temperature reacts to synthesis temperature, and then product is lowered the temperature, washing, filters and can obtain LiFePO4.The particle diameter of the LiFePO4 synthesized under this condition is less, mainly concentrates on sub-micron, and under the pressure of 4MPa, the compacted density of this LiFePO4 maintains between 1.9-2.0g/cc substantially, but the chemical property of the LiFePO4 obtained like this is poor.Another kind is mixed with ferrous sulfate by phosphoric acid at normal temperatures completely, then is mixed with it by lithium hydroxide solution, is warming up to synthesis temperature and reacts after reacting completely, and then product cooling, washing, filtration can be obtained LiFePO4.The particle diameter of the LiFePO4 synthesized under this condition is comparatively large, be substantially greater than 3um, and under the pressure of 4MPa, the compacted density of this LiFePO4 maintains between 2.0-2.1g/cc substantially.In addition, existing hydro thermal method is prepared the pH value that LiFePO4 adopts and is single pH value.The charging capacity of the LiFePO4 adopting existing hydro thermal method to prepare maintains 155-160mAh/g substantially, and discharge capacity maintains 153-158mAh/g substantially.
Summary of the invention
The object of the invention is to solve and adopt existing method can not obtain the little and defect of the LiFePO4 of electrochemical performance of particle diameter simultaneously, and provide a kind of preparation method of new LiFePO4, the LiFePO4 prepared by the method and described LiFePO4 as the application of positive electrode active materials.Adopt the method can obtain the little and LiFePO4 of electrochemical performance of particle diameter.
The invention provides a kind of preparation method of LiFePO4, the method comprises watersoluble divalent source of iron, water-soluble phosphorus source and water-soluble lithium source is contacted and reacted, described water-soluble phosphorus source is phosphoric acid and/or water-soluble phosphate, wherein, the mode of described reaction comprises the pH value of product of contact is adjusted to alkalescence, and alkaline product is rapidly heated to 80-240 DEG C and carries out the first reaction, then the product of described first reaction be down to 20-50 DEG C and its pH value is adjusted to acidity, then acid product being rapidly heated to 80-240 DEG C and carrying out the second reaction; Described being rapidly heated refers to that heating rate is not less than 10 DEG C/s.
Present invention also offers the LiFePO4 prepared by said method.
In addition, present invention also offers the application of described LiFePO4 as positive electrode active materials.
The present inventor finds through further investigation, existing hydro thermal method is prepared LiFePO4 and is normally mixed at normal temperatures to generate presoma by reaction raw materials (as watersoluble divalent source of iron, water-soluble phosphorus source and water-soluble lithium source), then temperature is slowly risen to synthesis temperature reaction, and the pH value adopted in course of reaction is single pH value, the chemical property of the LiFePO4 obtained like this is usually poor.Infer its reason, may be due to: on the one hand, when the temperature of described presoma is risen to 45-80 DEG C, described presoma very easily generates the intermediate product being at high temperature difficult to be converted into LiFePO4, and the purity of the LiFePO4 finally obtained can be caused so lower; On the other hand, under single pH value, carry out reaction there is following defect: in acid condition, owing to having part thing in presoma mutually as Fe
3(PO
4)
2.8h
2the degree of crystallinity of O can increase, and solubility and activity can reduce, and final LiFePO 4 material performance will decline; In the basic conditions, although can reduce the degree of crystallinity of thing phase, other thing as alkali formula ferrous phosphate, ferrous hydroxide thing are met increase, therefore, still can reduce the performance of final LiFePO 4 material mutually; In neutral conditions, the comparatively large and skewness of the particle diameter of the LiFePO4 obtained, thus will greatly suppress its chemical property.
And the present invention is rapidly heated by secondary and can control the nucleation and crystallization of LiFePO4 in conjunction with the adjustment of pH value, and and then obtain the little and LiFePO4 of electrochemical performance of particle diameter.Infer its reason, may be due to: on the one hand, the present invention adopts the mode be rapidly heated that the temperature of described alkaline product and acid product is risen to rapidly more than 80 DEG C, the thing of presoma in temperature-rise period effectively can be avoided to change in non-controlling direction in opposite directions, and then reduce the generation of unfavorable thing phase; On the other hand, the degree of crystallinity of presoma can be reduced in the basic conditions, at Hydrothermal Synthesis temperature, the nucleation rate of LiFePO4 obviously will be greater than the speed of growth, the lithium iron phosphate particles now formed is mainly Nano grade, in addition, still has more intermediate not to be converted into LiFePO4 completely mutually in the basic conditions, and unconverted LiFePO4 basic bit is in particle surface, thus be convenient to follow-up further participation reaction; And acid condition is the suitable synthesis pH value of LiFePO4, the unconverted intermediate for LiFePO4 in the basic conditions can be made substantially to be converted into LiFePO4 mutually, thus to improve the purity of the LiFePO4 obtained.
A preferred embodiment of the invention, when the pH value of described alkaline product is 7.5-14, when the pH value of described acid product is 4-6.5, can obtain electrochemistry can better LiFePO4.
According to another kind of preferred implementation of the present invention, when the preparation method of described LiFePO4 also comprise surfactant and watersoluble divalent source of iron, water-soluble phosphorus source and water-soluble lithium source are carried out contacting and reacting together time, the volume energy density of the LiFePO4 obtained can also be increased, thus be more conducive to obtaining the less battery of volume.Infer its reason, may be due to: surfactant to add the ferric lithium phosphate precursor particle that can make to obtain coated by described surfactant, thus prevent the growth of LiFePO4 on described granular precursor, the growth course of described LiFePO4 becomes dissolution-crystallization mechanism, namely, described presoma slowly releases ion, and then between ion, fast reaction generates LiFePO4 again, thus can improve the controllability of described LiFePO4 preparation process and improve its volume energy density.
Other features and advantages of the present invention are described in detail in embodiment part subsequently.
Accompanying drawing explanation
Accompanying drawing is used to provide a further understanding of the present invention, and forms a part for specification, is used from explanation the present invention, but is not construed as limiting the invention with embodiment one below.In the accompanying drawings:
Fig. 1 is the stereoscan photograph of LiFePO4 prepared by embodiment 1, and multiplication factor is 50000 times;
Fig. 2 is the stereoscan photograph of LiFePO4 prepared by embodiment 1, and multiplication factor is 20000 times;
Fig. 3 is the stereoscan photograph of LiFePO4 prepared by embodiment 4, and multiplication factor is 50000 times;
Fig. 4 is the stereoscan photograph of LiFePO4 prepared by embodiment 4, and multiplication factor is 20000 times;
Fig. 5 is the stereoscan photograph of LiFePO4 prepared by comparative example 1, and multiplication factor is 20000 times;
Fig. 6 is the stereoscan photograph of LiFePO4 prepared by comparative example 1, and multiplication factor is 50000 times;
Fig. 7 is the stereoscan photograph of LiFePO4 prepared by comparative example 2, and multiplication factor is 50000 times;
Fig. 8 is the stereoscan photograph of LiFePO4 prepared by comparative example 2, and multiplication factor is 20000 times.
Embodiment
Below the specific embodiment of the present invention is described in detail.Should be understood that, embodiment described herein, only for instruction and explanation of the present invention, is not limited to the present invention.
The preparation method that the invention provides LiFePO4 comprises watersoluble divalent source of iron, water-soluble phosphorus source and water-soluble lithium source is contacted and reacted, described water-soluble phosphorus source is phosphoric acid and/or water-soluble phosphate, wherein, the mode of described reaction comprises the pH value of product of contact is adjusted to alkalescence, and alkaline product is rapidly heated to 80-240 DEG C and carries out the first reaction, then the product of described first reaction be down to 20-50 DEG C and its pH value is adjusted to acidity, then acid product being rapidly heated to 80-240 DEG C and carrying out the second reaction; Described being rapidly heated refers to that heating rate is not less than 10 DEG C/s.
According to the present invention, as long as although the described heating rate be rapidly heated is controlled be not less than 10 DEG C/s, but as a rule, heating rate is more conducive to the raising of LiFePO4 purity more soon, but this also can propose harsher requirement to heating mode and condition simultaneously, therefore, combined factors is from every side considered, described alkaline product being rapidly heated can be identical with the heating rate be rapidly heated by described acid product, also can be different, and is 30-250 DEG C/s independently of one another.
According to the present invention, preferably, the pH value of described alkaline product is 7.5-14, the pH value of described acid product is 4-6.5, namely, the pH value of described product of contact is adjusted to 7.5-14, the pH value of the product of described first reaction is adjusted to 4-6.5, the more excellent LiFePO4 of chemical property can be obtained like this.The pH value of described product of contact controlled in alkalescence, preferably control to add alkaline matter in reaction system in the mode of 7.5-14.Described alkaline matter can be such as one or more in ammoniacal liquor, potassium hydroxide, NaOH, lithium hydroxide, sodium carbonate and potash, is particularly preferably lithium hydroxide, can avoids the introducing of impurity like this.The pH value of described first product controlled in acidity, preferably control to add acidic materials in reaction system in the mode of 4-6.5.Described acidic materials can be such as one or more in phosphoric acid, sulfuric acid, nitric acid and hydrochloric acid.Described acidic materials use with the form of its aqueous solution usually, and during use, its concentration can be 0.01-1mol/L.The consumption of described alkaline matter and acidic materials is to control pH value to be as the criterion in above-mentioned scope, and therefore not to repeat here.In addition, when described alkaline matter is lithium hydroxide and/or described acidic materials are phosphoric acid, the consumption for the lithium hydroxide and phosphoric acid that regulate pH value of reaction system is not counted in the consumption of reaction raw materials.
The present invention is to described alkaline product being rapidly heated to 80-240 DEG C and being rapidly heated by described acid product to the mode of 80-240 DEG C and being not particularly limited, such as, described alkaline product or acid product can be dropped to temperature is in the water of 80-240 DEG C, the temperature of alkaline product or acid product can be raised rapidly like this by described alkaline product or the heat exchange between acid product and water.As a rule, the boiling point of water is 100 DEG C at ambient pressure, therefore, in order to obtain the water of higher such as 240 DEG C of temperature, can increase pressure to improve the boiling point of water.In addition, with the described alkaline product of 1L for benchmark, described temperature is the consumption of the water of 80-240 DEG C can be 1-10L; With the described acid product of 1L for benchmark, described temperature is the consumption of the water of 80-240 DEG C can be 1-10L.Described alkaline product can be identical with the drop rate of acid product, also can be different, and the water being 80-240 DEG C with the temperature of 1L is for benchmark, the drop rate of described alkaline product and acid product can be 1-100mL/s independently of one another, is preferably 1-10mL/s.It should be noted that, when adopt above-mentioned alkaline product and acid product dropped to temperature be realize in the water of 80-240 DEG C being rapidly heated time, may regard as and temperature is risen to 80-240 DEG C by described alkaline product and acid product in the time of 1 second, heating rate is (final temperature-initial temperature) ÷ 1.Such as, in embodiment 1, be that the alkaline product instillation temperature of 45 DEG C is in the deionized water of 130 DEG C by temperature, the temperature in reactor fluctuates between 125-135 DEG C, then heating rate is (125-45) ÷ 1 DEG C/s to (135-45) ÷ 1 DEG C/s, is 80-90 DEG C/s.
The condition of the present invention to described first reaction is not particularly limited, and such as, the condition of described first reaction comprises: reaction temperature can be 80-240 DEG C, is preferably 120-240 DEG C; Reaction pressure can be 0-5MPa, is preferably 0-2.5MPa; Reaction time can be 0.5-5 hour, is preferably 0.5-2.5 hour.
The condition of the present invention to described second reaction is not particularly limited, and such as, the condition of described second reaction comprises: reaction temperature can be 80-240 DEG C, is preferably 120-240 DEG C; Reaction pressure can be 0-5MPa, is preferably 0-2.5MPa; Reaction time can be 2-14 hour, is preferably 2-5 hour.
In the present invention, described pressure all refers to gauge pressure.
It should be noted that, the temperature described alkaline product risen to fast may be different from the temperature that described first reacts, and now, first described alkaline product can be risen to predetermined temperature fast, and then slowly be adjusted to the temperature of the first reaction; The temperature risen to fast by described acid product and the temperature that described second reacts also may be different, also first described acid product can be risen to predetermined temperature fast, and then slowly be adjusted to the temperature of the second reaction.
In addition, in order to avoid the oxygen in air is to the oxidation of ferrous ion in material, preferably, described first reaction and the second reaction are carried out in an inert atmosphere.Wherein, the mode of inert atmosphere is kept for pass into replace the non-inert gas in described reaction system in reaction system by inert gas, and then the reaction system after gas displacement can be sealed.Described inert gas can be nitrogen and/or helium.
The consumption of the present invention to described watersoluble divalent source of iron, water-soluble phosphorus source and water-soluble lithium source is not particularly limited, such as, the consumption in the consumption of described watersoluble divalent source of iron, the consumption in described water-soluble phosphorus source and described water-soluble lithium source can make Fe in the product of contact obtained
2+, PO
4 3-with Li
+mol ratio be (0.95-1.05): (0.95-1.05): 3, be preferably (0.97-1.03): (0.97-1.03): 3.
Described watersoluble divalent source of iron can be existing various can be water-soluble containing the compound of ferrous ion, its instantiation includes but not limited to: one or more in frerrous chloride, ferrous bromide, ferrous fluosilicate, ferrous nitrate, ferrous perchlorate, ferrous sulfate and ferrous acetate.In addition, described ferrous sulfate can for not to be with the crystallization water, can with the crystallization water yet, is specifically as follows one or more in anhydrous slufuric acid ferrous iron, ferrous sulfate monohydrate, ferrous sulfate heptahydrate etc.
The example of described water-soluble phosphate includes but not limited to: one or more in lithium dihydrogen phosphate, sodium phosphate, ammonium dihydrogen phosphate, diammonium hydrogen phosphate and potassium phosphate.
Described water-soluble lithium source can be existing various can be water-soluble containing the compound of lithium, its instantiation includes but not limited to: one or more in lithium hydroxide, lithium acetate, lithium benzoate, lithium bromate, lithium bromide, lithium chlorate, lithium chloride, lithium fluoride, lithium fluorosilicate, lithium formate, lithium iodide, lithium nitrate, lithium perchlorate, lithium tartrate and lithium carbonate, is particularly preferably lithium hydroxide.In addition, described lithium hydroxide can not be with the crystallization water, also can with the crystallization water (as monohydrate lithium hydroxide).
It should be noted that, when the raw material preparing described LiFePO4 contains lithium dihydrogen phosphate, described lithium dihydrogen phosphate is regarded as and is added as described water-soluble phosphate, and the consumption of described lithium dihydrogen phosphate is counted simultaneously in the consumption in water-soluble phosphate and water-soluble lithium source, that is, lithium contained in described lithium dihydrogen phosphate need be deducted when adding other lithium source.
According to the present invention, the preparation method of described LiFePO4 also comprises and is carried out together contacting and reacting in surfactant and watersoluble divalent source of iron, water-soluble phosphorus source and water-soluble lithium source, the volume energy density of the LiFePO4 obtained can be increased like this, thus be more conducive to obtaining the less battery of volume.Normally, the mol ratio of the consumption of described surfactant and the consumption in described water-soluble lithium source can be (0.0001-0.01): 1, is preferably (0.0002-0.008): 1.In addition, the example of described surfactant includes but not limited to: one or more in softex kw, laurate quaternary ammonium salt, cetyl benzenesulfonic acid sodium, citric acid, polyethylene glycol, sodium hexadecyl sulfate, Gemini quaternary ammonium salt and DGE carboxylate.
The mode of the present invention to described contact is not particularly limited, such as, the surfactant that can first watersoluble divalent molysite, water-soluble phosphorus source and selectivity be contained is soluble in water, obtain water solution A, and by soluble in water for water-soluble lithium source, obtain aqueous solution B, then under agitation, described aqueous solution B is slowly dropped in described water solution A, continues to be uniformly mixed to temperature constant after reinforced; Or under agitation, described water solution A is slowly dropped in described aqueous solution B, continue to be uniformly mixed to temperature constant after reinforced; Or under agitation, described water solution A and aqueous solution B are dropped in same reactor simultaneously, continue to be uniformly mixed to temperature constant after reinforced.
According to the present invention, the preparation method of described iron manganese phosphate for lithium also comprises described product filtration, washing also drying.Wherein, described washing first can spend deionized water 1-3 time, then uses absolute ethanol washing 1-3 time.
According to the present invention, preferably, the preparation method of described LiFePO4 also comprises and described second product and organic carbon source is carried out mixing and spraying dry, then the Spray dried products obtained is carried out roasting, can improve the chemical property of the LiFePO4 obtained so further.
The present invention is not particularly limited the kind of described organic carbon source and consumption.As a rule, described organic carbon source can be existing various can the organic substance of carbonization below 500 DEG C, its instantiation includes but not limited to: one or more in glucose, sucrose, lactose, maltose, phenolic resins and epoxy resin.In addition, the consumption of described organic carbon source should be selected according to the amount of product, and such as, with the dry weight basis of described second product of 100 weight portions, the consumption of described organic carbon source can be 2-20 weight portion, is preferably 5-15 weight portion.
According to the present invention, described spray-dired concrete operation method and condition are known to the skilled person.Particularly, the slurry be made into by described second product and organic carbon source and water to be joined in atomizer High Rotation Speed to realize spraying dry.Described spray-dired temperature can be 60-150 DEG C, is preferably 80-120 DEG C.It should be noted that, described second product can be through dried product, also can be the product of undried.When described second product is the product through super-dry, can by the mixing of the second product of solid, organic carbon source and additional water to obtain described slurry; When described second product is the product of undried, itself directly can be mixed to obtain described slurry with organic carbon source containing the product of certain water, if during water shortage contained by product, also can additionally add a certain amount of water.In addition, in described slurry, the amount of water can be the routine selection of this area, and as well known to those skilled in the art to this, therefore not to repeat here.
The condition of the present invention to described roasting is not particularly limited, as long as can by described organic carbon source carbonization, such as, it can be 600-750 DEG C that the condition of described roasting comprises sintering temperature, and roasting time can be 3-12 hour.In addition, described roasting is carried out usually in an inert atmosphere.
Present invention also offers the LiFePO4 prepared by said method.
In addition, present invention also offers the application of described LiFePO4 as positive electrode active materials.
Below will be described the present invention by embodiment.
In following examples and comparative example, the SSX-550 type scanning electron microscopy that scanning electron microscopy (SEM) is produced for Japanese Shimadzu Corporation (Shimadzu), test voltage is 5KV.X-ray diffractometer is the XD-2 type X-ray diffractometer that Beijing Puxi General Instrument Co., Ltd produces, and wherein, test condition comprises: pipe pressure is 200mA, and electric current is 200mA, and step-length is 1 °, and test angle is 10 °-90 °.
Embodiment 1
This embodiment is for illustration of LiFePO4 provided by the invention and preparation method thereof.
By 30mol ferrous sulfate heptahydrate, (purity is 100 % by weight, down together), (purity is 100 % by weight to 30mol phosphoric acid, lower with), 0.03mol softex kw (Tianjin great Mao chemical reagent factory, lower with) and 40kg deionized water mix and dissolves complete after obtain water solution A.90mol monohydrate lithium hydroxide (purity is 100 % by weight, lower same) and 30kg deionized water are mixed and dissolve completely and obtains aqueous solution B.At 25 DEG C, slowly joined in water solution A by described aqueous solution B, and open dispersion machine and cooling water simultaneously, the temperature of this process mixed solution rises to 39 DEG C from 20 DEG C.Disperse a period of time again after reinforced, now the temperature of mixed solution is increased to 45 DEG C and remains unchanged, and then utilizes lithium hydroxide that the pH value of mixed solution is adjusted to 8.5, obtains alkaline product.20L deionized water being joined 110L gauge pressure is in the autoclave of 1MPa, and be warming up to 130 DEG C with the speed of 2 DEG C/min, alkaline product is dropped to the speed of 500mL/min temperature is housed is in the autoclave of the deionized water of 130 DEG C, in the process, in reactor, the temperature of solution fluctuates (heating rate of alkaline product is equivalent to 80-90 DEG C/s) between 125-135 DEG C.After treating that alkaline product adds, isothermal reaction 30min at 130 DEG C, is then down to room temperature 30 DEG C, and utilizes hydrochloric acid that the pH value of product is adjusted to 6.5, obtains acid product.20L deionized water being joined 110L gauge pressure is in the autoclave of 1MPa, and be warming up to 130 DEG C with the speed of 2 DEG C/min, acid product is dropped to the speed of 500mL/min temperature is housed is in the autoclave of the deionized water of 130 DEG C, in the process, in reactor, the temperature of solution fluctuates (heating rate of acid product is equivalent to 95-105 DEG C/s) between 125-135 DEG C.After treating that acid product adds, temperature is risen to 180 DEG C and isothermal reaction 10h at such a temperature, be then down to room temperature 30 DEG C, filter, wash and dry, obtain LiFePO4 L1.As can be seen from the XRD spectra of described LiFePO4 L1 and LiFePO4 standard specimen, the diffraction maximum of LiFePO4 L1 adopting the present embodiment to prepare is identical with the peak position of the diffraction maximum of standard specimen, peak shape is narrow and symmetrical, do not observe dephasign peak in diffraction pattern, visible employing the method really obtains LiFePO4 and purity is very high.
400g glucose is dissolved in 20kg water, and add the above-mentioned LiFePO4 L1 of 4kg wherein, at 80 DEG C, carry out spraying dry after stirring, then Spray dried products is placed in the atmosphere furnace of 700 DEG C, controlling nitrogen flow is 50L/h roasting 8h, obtains composite ferric lithium phosphate material S1.
Wherein, the scanning electron microscopy result of described composite ferric lithium phosphate material S1 as depicted in figs. 1 and 2.Wherein, the multiplication factor of Fig. 1 is 50000 times, and the multiplication factor of Fig. 2 is 20000 times.As can be seen from the SEM photo of Fig. 1 and Fig. 2, described composite ferric lithium phosphate material S1 is made up of a large amount of granules (particle diameter is 100-150nm) and the medium-sized particle of sheet (particle diameter is 400-600nm), and the Contact of these two kinds of particles is tight, does not have obvious agglomeration.
Embodiment 2
This embodiment is for illustration of LiFePO4 provided by the invention and preparation method thereof.
9.5mol ferrous acetate (purity is 100 % by weight), 9.5mol sodium phosphate (purity is 100 % by weight), 0.02mol softex kw (Tianjin great Mao chemical reagent factory) and 40kg deionized water are mixed and dissolves completely and obtain water solution A.30mol lithium chloride (purity is 100 % by weight) and 30kg deionized water are mixed and dissolves completely and obtain aqueous solution B.At 25 DEG C, slowly joined in water solution A by described aqueous solution B, and open dispersion machine and cooling water simultaneously, the temperature of this process mixed solution rises to 39 DEG C from 20 DEG C.Disperse a period of time again after reinforced, now the temperature of mixed solution is increased to 45 DEG C and remains unchanged, and then utilizes lithium hydroxide that the pH value of mixed solution is adjusted to 8.0, obtains alkaline product.20L deionized water being joined 110L gauge pressure is in the autoclave of 2.5MPa, and be warming up to 240 DEG C with the speed of 2 DEG C/min, alkaline product is dropped to the speed of 500mL/min temperature is housed is in the autoclave of the deionized water of 240 DEG C, in the process, in reactor, the temperature of solution fluctuates (heating rate of alkaline product is equivalent to 190-200 DEG C/s) between 235-245 DEG C.After treating that alkaline product adds, isothermal reaction 30min at 240 DEG C, is then down to room temperature 20 DEG C, and utilizes hydrochloric acid that the pH value of product is adjusted to 6.5, obtains acid product.20L deionized water being joined 110L gauge pressure is in the autoclave of 2.5MPa, and be warming up to 240 DEG C with the speed of 2 DEG C/min, acid product is dropped to the speed of 500mL/min temperature is housed is in the autoclave of the deionized water of 240 DEG C, in the process, in reactor, the temperature of solution fluctuates (heating rate of acid product is equivalent to 215-225 DEG C/s) between 235-245 DEG C.After treating that acid product adds, cool the temperature to 180 DEG C and isothermal reaction 5h at such a temperature, be then down to room temperature 20 DEG C, filter, wash and dry, obtain LiFePO4 L2.As can be seen from the XRD spectra of described LiFePO4 L2 and LiFePO4 standard specimen, the diffraction maximum of LiFePO4 L2 adopting the present embodiment to prepare is identical with the peak position of the diffraction maximum of standard specimen, peak shape is narrow and symmetrical, do not observe dephasign peak in diffraction pattern, visible employing the method really obtains LiFePO4 and purity is very high.
500g glucose is dissolved in 20kg water, and add the above-mentioned LiFePO4 L2 of 5kg wherein, at 100 DEG C, spraying dry is carried out after stirring, then Spray dried products is placed in the atmosphere furnace of 600 DEG C, controlling nitrogen flow is 50L/h roasting 12h, obtains composite ferric lithium phosphate material S2.
Wherein, as can be seen from the SEM photo of described composite ferric lithium phosphate material S2, described composite ferric lithium phosphate material S2 is made up of a large amount of granules (particle diameter is 50-200nm) and the medium-sized particle of sheet (particle diameter is 300-500nm), and the Contact of these two kinds of particles is tight, does not have obvious agglomeration.
Embodiment 3
This embodiment is for illustration of LiFePO4 provided by the invention and preparation method thereof.
10.5mol frerrous chloride (purity is 100 % by weight), 10.5mol phosphoric acid (purity is 100 % by weight), 0.02mol softex kw (Tianjin great Mao chemical reagent factory) and 40kg deionized water are mixed and dissolves completely and obtain water solution A.30mol monohydrate lithium hydroxide (purity is 100 % by weight) and 30kg deionized water are mixed and dissolves completely and obtain aqueous solution B.At 25 DEG C, slowly joined in water solution A by described aqueous solution B, and open dispersion machine and cooling water simultaneously, the temperature of this process mixed solution rises to 39 DEG C from 20 DEG C.Disperse a period of time again after reinforced, now the temperature of mixed solution is increased to 45 DEG C and remains unchanged, and then utilizes lithium hydroxide that the pH value of mixed solution is adjusted to 13, obtains alkaline product.20L deionized water being joined 110L gauge pressure is in the autoclave of 0.8MPa, and be warming up to 120 DEG C with the speed of 2 DEG C/min, alkaline product is dropped to the speed of 500mL/min temperature is housed is in the autoclave of the deionized water of 120 DEG C, in the process, in reactor, the temperature of solution fluctuates (heating rate of alkaline product is equivalent to 70-80 DEG C/s) between 115-125 DEG C.After treating that alkaline product adds, isothermal reaction 30min at 120 DEG C, is then down to room temperature 20 DEG C, and utilizes hydrochloric acid that the pH value of product is adjusted to 4, obtains acid product.20L deionized water being joined 110L gauge pressure is in the autoclave of 0.8MPa, and be warming up to 120 DEG C with the speed of 2 DEG C/min, acid product is dropped to the speed of 500mL/min temperature is housed is in the autoclave of the deionized water of 120 DEG C, in the process, in reactor, the temperature of solution fluctuates (heating rate of acid product is equivalent to 95-105 DEG C/s) between 115-125 DEG C.After treating that acid product adds, temperature is risen to 240 DEG C and isothermal reaction 2h at such a temperature, be then down to room temperature 20 DEG C, filter, wash and dry, obtain LiFePO4 L3.As can be seen from the XRD spectra of described LiFePO4 L3 and LiFePO4 standard specimen, the diffraction maximum of LiFePO4 L3 adopting the present embodiment to prepare is identical with the peak position of the diffraction maximum of standard specimen, peak shape is narrow and symmetrical, do not observe dephasign peak in diffraction pattern, visible employing the method really obtains LiFePO4 and purity is very high.
500g glucose is dissolved in 20kg water, and add the above-mentioned LiFePO4 L3 of 4kg wherein, at 120 DEG C, carry out spraying dry after stirring, then Spray dried products is placed in the atmosphere furnace of 750 DEG C, controlling nitrogen flow is 50L/h roasting 3h, obtains composite ferric lithium phosphate material S3.
Wherein, as can be seen from the SEM photo of described composite ferric lithium phosphate material S3, described composite ferric lithium phosphate material S3 is made up of a large amount of granules (particle diameter is 50-200nm) and the medium-sized particle of sheet (particle diameter is 300-500nm), and the Contact of these two kinds of particles is tight, does not have obvious agglomeration.
Embodiment 4
This embodiment is for illustration of LiFePO4 provided by the invention and preparation method thereof.
LiFePO4 is prepared according to the method for embodiment 1, unlike, the described softex kw laurate quaternary ammonium salt of identical molal quantity substitutes, and obtains LiFePO4 L4 and composite ferric lithium phosphate material S4.Wherein, as can be seen from the XRD spectra of described LiFePO4 L4 and LiFePO4 standard specimen, the diffraction maximum of LiFePO4 L4 adopting the present embodiment to prepare is identical with the peak position of the diffraction maximum of standard specimen, peak shape is narrow and symmetrical, do not observe dephasign peak in diffraction pattern, visible employing the method really obtains LiFePO4 and purity is very high.In addition, the SEM photo of described composite ferric lithium phosphate material S4 as shown in Figure 3 and Figure 4.Wherein, the multiplication factor of Fig. 3 is 50000 times, and the multiplication factor of Fig. 4 is 20000 times.As can be seen from the SEM photo of Fig. 3 and Fig. 4, described composite ferric lithium phosphate material S4 is made up of a large amount of granules (particle diameter is 50-200nm) and the medium-sized particle of sheet (particle diameter is 300-500nm), and the Contact of these two kinds of particles is tight, does not have obvious agglomeration.
Embodiment 5
This embodiment is for illustration of LiFePO4 provided by the invention and preparation method thereof.
LiFePO4 is prepared according to the method for embodiment 1, unlike, the described softex kw cetyl benzenesulfonic acid sodium of identical molal quantity substitutes, and obtains LiFePO4 L5 and composite ferric lithium phosphate material S5.Wherein, as can be seen from the XRD spectra of described LiFePO4 L5 and LiFePO4 standard specimen, the diffraction maximum of LiFePO4 L5 adopting the present embodiment to prepare is identical with the peak position of the diffraction maximum of standard specimen, peak shape is narrow and symmetrical, do not observe dephasign peak in diffraction pattern, visible employing the method really obtains LiFePO4 and purity is very high.In addition, as can be seen from the SEM photo of described composite ferric lithium phosphate material S5, described composite ferric lithium phosphate material S5 is made up of a large amount of granules (particle diameter is 50-200nm) and the medium-sized particle of sheet (particle diameter is 300-500nm), and the Contact of these two kinds of particles is tight, does not have obvious agglomeration.
Embodiment 6
This embodiment is for illustration of LiFePO4 provided by the invention and preparation method thereof.
LiFePO4 is prepared according to the method for embodiment 1, unlike, do not add softex kw, obtain LiFePO4 L6 and composite ferric lithium phosphate material S6.Wherein, as can be seen from the XRD spectra of described LiFePO4 L6 and LiFePO4 standard specimen, the diffraction maximum of LiFePO4 L6 adopting the present embodiment to prepare is identical with the peak position of the diffraction maximum of standard specimen, peak shape is narrow and symmetrical, do not observe dephasign peak in diffraction pattern, visible employing the method really obtains LiFePO4 and purity is very high.In addition, as can be seen from the SEM photo of described composite ferric lithium phosphate material S6, described composite ferric lithium phosphate material S6 is made up of a large amount of granules (particle diameter is 50-200nm) and the medium-sized particle of sheet (particle diameter is 300-500nm), and the Contact of these two kinds of particles is tight, does not have obvious agglomeration.
Embodiment 7
This embodiment is for illustration of LiFePO4 provided by the invention and preparation method thereof.
30mol ferrous sulfate heptahydrate, 30mol phosphoric acid, 0.03mol softex kw and 40kg deionized water are mixed and dissolves completely and obtain water solution A.90mol monohydrate lithium hydroxide and 30kg deionized water are mixed and dissolves completely and obtain aqueous solution B.At 25 DEG C, slowly joined in water solution A by described aqueous solution B, and open dispersion machine and cooling water simultaneously, the temperature of this process mixed solution rises to 39 DEG C from 20 DEG C.Disperse a period of time again after reinforced, now the temperature of mixed solution is increased to 45 DEG C and remains unchanged, and then utilizes lithium hydroxide that the pH value of mixed solution is adjusted to 8.5, obtains alkaline product.20L deionized water being joined 110L gauge pressure is in the autoclave of 1.5MPa, and be warming up to 180 DEG C with the speed of 2 DEG C/min, alkaline product is dropped to the speed of 500mL/min temperature is housed is in the autoclave of the deionized water of 180 DEG C, in the process, in reactor, the temperature of solution fluctuates (heating rate of alkaline product is equivalent to 130-140 DEG C/s) between 175-185 DEG C.After treating that alkaline product adds, isothermal reaction 30min at 180 DEG C, is then down to room temperature 30 DEG C, and utilizes hydrochloric acid that the pH value of product is adjusted to 6.5, obtains acid product.20L deionized water being joined 110L gauge pressure is in the autoclave of 1.5MPa, and be warming up to 180 DEG C with the speed of 2 DEG C/min, acid product is dropped to the speed of 500mL/min temperature is housed is in the autoclave of the deionized water of 180 DEG C, in the process, in reactor, the temperature of solution fluctuates (heating rate of acid product is equivalent to 145-155 DEG C/s) between 175-185 DEG C.After treating that acid product adds, isothermal reaction 10h at 180 DEG C, is then down to room temperature 30 DEG C, filters, washs and dry, obtain LiFePO4 L7.As can be seen from the XRD spectra of described LiFePO4 L7 and LiFePO4 standard specimen, the diffraction maximum of LiFePO4 L7 adopting the present embodiment to prepare is identical with the peak position of the diffraction maximum of standard specimen, peak shape is narrow and symmetrical, do not observe dephasign peak in diffraction pattern, visible employing the method really obtains LiFePO4 and purity is very high.
400g glucose is dissolved in 20kg water, and add the above-mentioned LiFePO4 L7 of 4kg wherein, at 80 DEG C, carry out spraying dry after stirring, then Spray dried products is placed in the atmosphere furnace of 700 DEG C, controlling nitrogen flow is 50L/h roasting 8h, obtains composite ferric lithium phosphate material S7.
Wherein, as can be seen from the SEM photo of described composite ferric lithium phosphate material S7, described composite ferric lithium phosphate material S7 is made up of a large amount of granules (particle diameter is 50-200nm) and the medium-sized particle of sheet (particle diameter is 300-500nm), and the Contact of these two kinds of particles is tight, does not have obvious agglomeration.
Embodiment 8
This embodiment is for illustration of LiFePO4 provided by the invention and preparation method thereof.
30mol ferrous sulfate heptahydrate, 30mol phosphoric acid, 0.03mol softex kw and 40kg deionized water are mixed and dissolves completely and obtain water solution A.90mol monohydrate lithium hydroxide and 30kg deionized water are mixed and dissolves completely and obtain aqueous solution B.At 25 DEG C, slowly joined in water solution A by described aqueous solution B, and open dispersion machine and cooling water simultaneously, the temperature of this process mixed solution rises to 39 DEG C from 20 DEG C.Disperse a period of time again after reinforced, now the temperature of mixed solution is increased to 45 DEG C and remains unchanged, and then utilizes lithium hydroxide that the pH value of mixed solution is adjusted to 8.5, obtains alkaline product.20L deionized water being joined 110L gauge pressure is in the autoclave of 0.1MPa, and be warming up to 80 DEG C with the speed of 2 DEG C/min, alkaline product is dropped to the speed of 500mL/min temperature is housed is in the autoclave of the deionized water of 80 DEG C, in the process, in reactor, the temperature of solution fluctuates (heating rate of alkaline product is equivalent to 30-40 DEG C/s) between 75-85 DEG C.After treating that alkaline product adds, isothermal reaction 5h at 80 DEG C, is then down to room temperature 30 DEG C, and utilizes hydrochloric acid that the pH value of product is adjusted to 6.5, obtains acid product.20L deionized water being joined 110L gauge pressure is in the autoclave of 0.1MPa, and be warming up to 80 DEG C with the speed of 2 DEG C/min, acid product is dropped to the speed of 500mL/min temperature is housed is in the autoclave of the deionized water of 80 DEG C, in the process, in reactor, the temperature of solution fluctuates (heating rate of acid product is equivalent to 45-55 DEG C/s) between 75-85 DEG C.After treating that acid product adds, temperature is risen to 80 DEG C and isothermal reaction 14h at such a temperature, be then down to room temperature 30 DEG C, filter, wash and dry, obtain LiFePO4 L8.As can be seen from the XRD spectra of described LiFePO4 L8 and LiFePO4 standard specimen, the diffraction maximum of LiFePO4 L8 adopting the present embodiment to prepare is identical with the peak position of the diffraction maximum of standard specimen, peak shape is narrow and symmetrical, do not observe dephasign peak in diffraction pattern, visible employing the method really obtains LiFePO4 and purity is very high.
400g glucose is dissolved in 20kg water, and add the above-mentioned LiFePO4 L8 of 4kg wherein, at 80 DEG C, carry out spraying dry after stirring, then Spray dried products is placed in the atmosphere furnace of 700 DEG C, controlling nitrogen flow is 50L/h roasting 8h, obtains composite ferric lithium phosphate material S8.
Wherein, as can be seen from the SEM photo of described composite ferric lithium phosphate material S8, described composite ferric lithium phosphate material S8 is made up of a large amount of granules (particle diameter is 50-200nm) and the medium-sized particle of sheet (particle diameter is 300-500nm), and the Contact of these two kinds of particles is tight, does not have obvious agglomeration.
Embodiment 9
This embodiment is for illustration of LiFePO4 provided by the invention and preparation method thereof.
LiFePO4 is prepared according to the method for embodiment 1, unlike, utilize lithium hydroxide that the pH value of mixed solution is adjusted to 7.5, obtain LiFePO4 L9 and composite ferric lithium phosphate material S9.Wherein, as can be seen from the XRD spectra of described LiFePO4 L9 and LiFePO4 standard specimen, the diffraction maximum of LiFePO4 L9 adopting the present embodiment to prepare is identical with the peak position of the diffraction maximum of standard specimen, peak shape is narrow and symmetrical, do not observe dephasign peak in diffraction pattern, visible employing the method really obtains LiFePO4 and purity is very high.In addition, as can be seen from the SEM photo of described composite ferric lithium phosphate material S9, described composite ferric lithium phosphate material S9 is made up of a large amount of granules (particle diameter is 50-200nm) and the medium-sized particle of sheet (particle diameter is 300-500nm), and the Contact of these two kinds of particles is tight, does not have obvious agglomeration.
Embodiment 10
This embodiment is for illustration of LiFePO4 provided by the invention and preparation method thereof.
LiFePO4 is prepared according to the method for embodiment 1, unlike, utilize hydrochloric acid that the pH value of product is adjusted to 5.5, obtain LiFePO4 L10 and composite ferric lithium phosphate material S10.Wherein, as can be seen from the XRD spectra of described LiFePO4 L10 and LiFePO4 standard specimen, the diffraction maximum of LiFePO4 L10 adopting the present embodiment to prepare is identical with the peak position of the diffraction maximum of standard specimen, peak shape is narrow and symmetrical, do not observe dephasign peak in diffraction pattern, visible employing the method really obtains LiFePO4 and purity is very high.In addition, as can be seen from the SEM photo of described composite ferric lithium phosphate material S10, described composite ferric lithium phosphate material S10 is made up of a large amount of granules (particle diameter is 50-200nm) and the medium-sized particle of sheet (particle diameter is 300-500nm), and the Contact of these two kinds of particles is tight, does not have obvious agglomeration.
Embodiment 11
This embodiment is for illustration of LiFePO4 provided by the invention and preparation method thereof.
LiFePO4 is prepared according to the method for embodiment 10, unlike, utilize hydrochloric acid that the pH value of product is adjusted to 3, obtain LiFePO4 L11 and composite ferric lithium phosphate material S11.Wherein, as can be seen from the XRD spectra of described LiFePO4 L11 and LiFePO4 standard specimen, the diffraction maximum of LiFePO4 L11 adopting the present embodiment to prepare is identical with the peak position of the diffraction maximum of standard specimen, peak shape is narrow and symmetrical, do not observe dephasign peak in diffraction pattern, visible employing the method really obtains LiFePO4 and purity is very high.In addition, as can be seen from the SEM photo of described composite ferric lithium phosphate material S11, described composite ferric lithium phosphate material S11 is made up of a large amount of granules (particle diameter is 50-200nm) and the medium-sized particle of sheet (particle diameter is 300-500nm), and the Contact of these two kinds of particles is tight, does not have obvious agglomeration.
Comparative example 1
This comparative example is for illustration of the LiFePO4 and preparation method thereof of reference.
30mol ferrous sulfate heptahydrate, 30mol phosphoric acid, 0.03mol softex kw and 40kg deionized water are mixed and obtains aqueous solution DA1.90mol monohydrate lithium hydroxide and 30kg deionized water are mixed and dissolves completely and obtain aqueous solution DB1.At 25 DEG C, slowly join in aqueous solution DA1 by described aqueous solution DB1, open dispersion machine and cooling water, the temperature of this process mixed solution rises to 39 DEG C from 20 DEG C simultaneously.Disperse a period of time again after reinforced, now the temperature of mixed solution is increased to 45 DEG C and remains unchanged, and obtains presoma DC1.Then presoma DC1 is joined in autoclave, and temperature is risen to 180 DEG C with the speed of 5 DEG C/s by described presoma, and at 180 DEG C, isothermal reaction 10h under 0.8MPa, then product is down to room temperature 30 DEG C, filter, wash and dry, obtain the LiFePO4 DL1 of reference.As can be seen from the LiFePO4 DL1 of described reference and the XRD spectra of LiFePO4 standard specimen, the diffraction maximum of LiFePO4 DL1 of the reference adopting this comparative example to prepare is identical with the peak position of the diffraction maximum of standard specimen, a small amount of dephasign peak is there is in diffraction pattern, as can be seen here, the purity of the LiFePO4 DL1 of reference is lower.
400g glucose is dissolved in 20kg water, and add the above-mentioned LiFePO 4 of 4kg wherein, at 80 DEG C, spraying dry is carried out after stirring, then Spray dried products is placed in the atmosphere furnace of 700 DEG C, controlling nitrogen flow is 50L/h roasting 8h, obtains the composite ferric lithium phosphate material DS1 of reference.
Wherein, the scanning electron microscopy result of the composite ferric lithium phosphate material DS1 of described reference as shown in Figure 5 and Figure 6.Wherein, the multiplication factor of Fig. 5 is 20000 times, and the multiplication factor of Fig. 6 is 50000 times.As can be seen from the SEM photo of Fig. 5 and Fig. 6, the composite ferric lithium phosphate material DS1 of described reference is made up of a large amount of granules (particle diameter is 100-300nm) and rectangular medium-sized particle (particle diameter is 500-800nm), and have obvious space between these two kinds of particles, there is no obvious agglomeration.
Comparative example 2
This comparative example is for illustration of the LiFePO4 and preparation method thereof of reference.
LiFePO4 is prepared according to the method for comparative example 1, unlike, do not add softex kw, obtain the composite ferric lithium phosphate material DS2 of reference LiFePO4 DL2 and reference.Wherein, as can be seen from the LiFePO4 DL2 of described reference and the XRD spectra of LiFePO4 standard specimen, the diffraction maximum of LiFePO4 DL2 of the reference adopting this comparative example to prepare is identical with the peak position of the diffraction maximum of standard specimen, a small amount of dephasign peak is there is in diffraction pattern, as can be seen here, the purity of the LiFePO4 DL2 of reference is lower.In addition, the microscopic appearance of the composite ferric lithium phosphate material DS2 of described reference as shown in Figure 7 and Figure 8.Wherein, the multiplication factor of Fig. 7 is 50000 times, and the multiplication factor of Fig. 8 is 20000 times.As can be seen from the SEM photo of Fig. 7 and Fig. 8, the composite ferric lithium phosphate material DS2 of described reference is made up of a large amount of granules (particle diameter is 150-300nm) and rectangular medium-sized particle (particle diameter is 500-800nm), and have obvious space between these two kinds of particles, there is no obvious agglomeration.
Test case
Test case is for illustration of the test of LiFePO4 and composite ferric lithium phosphate material chemical property.
By positive electrode active materials (the composite ferric lithium phosphate material DL1-DL2 of the reference that the composite ferric lithium phosphate material L1-L11 that embodiment 1-11 obtains and comparative example 1-2 obtains), acetylene black, Kynoar (purchased from Dongguan City Qing Feng plastic material Co., Ltd, the trade mark is FR900) by weight to be dissolved in 1-METHYLPYRROLIDONE for 90:5:5 and to stir, at 110 DEG C ± 5 DEG C, then after vacuum drying, be pressed into that thickness is 0.2mm, diameter is that the disk of Φ 12mm is as positive pole.Using metal lithium sheet as negative pole, barrier film is microporous polypropylene membrane (Celgard2300), electrolyte be the LiPF6/ (EC+DMC) of 1.0mol/L (wherein, EC is ethylene carbonate, DMC is dimethyl carbonate, the volume ratio of EC and DMC is 1:1), seal in the glove box being full of argon gas, make R2025 button cell.At room temperature 30 DEG C, R2025 button cell is carried out discharge and recharge with 0.1C and measures its charge/discharge capacity, wherein, end of charge voltage is 3.8V, and discharge cut-off voltage is 2.5V.The first charge-discharge capacity of R2025 button cell under 0.1C and efficiency for charge-discharge (efficiency for charge-discharge (%)=discharge capacity ÷ charging capacity × 100%) as shown in table 1.In addition, its volume energy density (mWh/cm is calculated as follows
3), result is as shown in table 1:
Volume energy density (mWh/cm
3)=compacted density (g/cm
3) × discharge capacity (mAh/g).
Table 1
As can be seen from the above results, adopt the particle diameter of the LiFePO4 prepared by method provided by the invention little and electrochemical performance.
More than describe the preferred embodiment of the present invention in detail; but the present invention is not limited to the detail in above-mentioned execution mode, within the scope of technical conceive of the present invention; can carry out multiple simple variant to technical scheme of the present invention, these simple variant all belong to protection scope of the present invention.
It should be noted that in addition, each the concrete technical characteristic described in above-mentioned embodiment, in reconcilable situation, can be combined by any suitable mode.In order to avoid unnecessary repetition, the present invention illustrates no longer separately to various possible compound mode.
In addition, also can carry out combination in any between various different execution mode of the present invention, as long as it is without prejudice to thought of the present invention, it should be considered as content disclosed in this invention equally.
Claims (16)
1. the preparation method of a LiFePO4, the method comprises watersoluble divalent source of iron, water-soluble phosphorus source and water-soluble lithium source is contacted and reacted, described water-soluble phosphorus source is phosphoric acid and/or water-soluble phosphate, it is characterized in that, the mode of described reaction comprises the pH value of product of contact is adjusted to alkalescence, and alkaline product is rapidly heated to 80-240 DEG C and carries out the first reaction, then the product of described first reaction be down to 20-50 DEG C and its pH value is adjusted to acidity, then acid product being rapidly heated to 80-240 DEG C and carrying out the second reaction; Described being rapidly heated refers to that heating rate is not less than 10 DEG C/s.
2. preparation method according to claim 1, wherein, is rapidly heated described alkaline product identical or different with the heating rate be rapidly heated by described acid product, and is 30-250 DEG C/s independently of one another.
3. preparation method according to claim 1 and 2, wherein, the pH value of described alkaline product is 7.5-14, and the pH value of described acid product is 4-6.5.
4. preparation method according to claim 1 and 2, wherein, described alkaline product being rapidly heated to the method for 80-240 DEG C is that described alkaline product to be dropped to temperature be in the water of 80-240 DEG C; Being rapidly heated by described acid product to the method for 80-240 DEG C is that described acid product to be dropped to temperature be in the water of 80-240 DEG C.
5. preparation method according to claim 1 and 2, wherein, the condition of described first reaction comprises: reaction temperature is 80-240 DEG C, and reaction pressure is 0-5MPa, and the reaction time is 0.5-5 hour.
6. preparation method according to claim 1 and 2, wherein, the condition of described second reaction comprises: reaction temperature is 80-240 DEG C, and reaction pressure is 0-5MPa, and the reaction time is 2-14 hour.
7. preparation method according to claim 1 and 2, wherein, the consumption in the consumption of described watersoluble divalent source of iron, the consumption in described water-soluble phosphorus source and described water-soluble lithium source makes Fe in the product of contact obtained
2+, PO
4 3-with Li
+mol ratio be (0.95-1.05): (0.95-1.05): 3.
8. preparation method according to claim 7, wherein, described watersoluble divalent source of iron be selected from frerrous chloride, ferrous bromide, ferrous fluosilicate, ferrous nitrate, ferrous perchlorate, ferrous sulfate and ferrous acetate one or more; Described water-soluble phosphate be selected from lithium dihydrogen phosphate, sodium phosphate, ammonium dihydrogen phosphate, diammonium hydrogen phosphate and potassium phosphate one or more; Described water-soluble lithium source be selected from lithium hydroxide, lithium acetate, lithium benzoate, lithium bromate, lithium bromide, lithium chlorate, lithium chloride, lithium fluoride, lithium fluorosilicate, lithium formate, lithium iodide, lithium nitrate, lithium perchlorate, lithium tartrate and lithium carbonate one or more.
9. preparation method according to claim 1, wherein, the method also comprises carries out contacting and reacting by surfactant and watersoluble divalent source of iron, water-soluble phosphorus source and water-soluble lithium source together; The mol ratio of the consumption of described surfactant and the consumption in described water-soluble lithium source is (0.0001-0.01): 1.
10. preparation method according to claim 9, wherein, described surfactant is selected from one or more in softex kw, laurate quaternary ammonium salt, cetyl benzenesulfonic acid sodium, citric acid, polyethylene glycol, sodium hexadecyl sulfate, Gemini quaternary ammonium salt and DGE carboxylate.
11. preparation methods according to claim 1,2,9 or 10, wherein, the method also comprises is undertaken mixing and spraying dry by described second product and organic carbon source, then the Spray dried products obtained is carried out roasting.
12. preparation methods according to claim 11, wherein, with the dry weight basis of described second product of 100 weight portions, the consumption of described organic carbon source is 2-20 weight portion; Described organic carbon source be selected from glucose, sucrose, lactose, maltose, phenolic resins and epoxy resin one or more.
13. preparation methods according to claim 11, wherein, described spray-dired temperature is 60-150 DEG C.
14. preparation methods according to claim 11, wherein, the condition of described roasting comprises: sintering temperature is 600-750 DEG C, and roasting time is 3-12 hour.
15. LiFePO4s prepared by the preparation method in claim 1-14 described in any one.
16. LiFePO4s according to claim 15 are as the application of positive electrode active materials.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310739960.5A CN104752716B (en) | 2013-12-27 | 2013-12-27 | Lithium iron phosphate and its preparation method and use |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310739960.5A CN104752716B (en) | 2013-12-27 | 2013-12-27 | Lithium iron phosphate and its preparation method and use |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104752716A true CN104752716A (en) | 2015-07-01 |
| CN104752716B CN104752716B (en) | 2017-02-15 |
Family
ID=53592060
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201310739960.5A Active CN104752716B (en) | 2013-12-27 | 2013-12-27 | Lithium iron phosphate and its preparation method and use |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104752716B (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106684379A (en) * | 2015-11-11 | 2017-05-17 | 中国科学院金属研究所 | Method for synthesizing ultrathin nano-scale LiFePO4 flakes having superhigh large multiplying power charge and discharge performances |
| CN108470888A (en) * | 2018-03-05 | 2018-08-31 | 南京理工大学 | PH regulates and controls the method that growth period prepares assembly type diamond shape LiFePO4/silver/graphene oxide compound |
| 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 |
| CN114361448A (en) * | 2021-12-31 | 2022-04-15 | 欣旺达电动汽车电池有限公司 | Lithium iron phosphate, preparation method thereof and lithium ion battery |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101327922A (en) * | 2008-07-07 | 2008-12-24 | 杭州赛诺索欧电池有限公司 | Preparation of LiFePO4 |
| CN101332985A (en) * | 2008-07-31 | 2008-12-31 | 福建师范大学 | Method for preparing conducting phosphide-doped positive electrode material of LiFePO4 |
| CN101407319A (en) * | 2008-09-16 | 2009-04-15 | 杭州龙威能源科技有限公司 | Method of preparing lithium iron phosphate having high conductivity and superior low temperature discharge property |
| CN102070132A (en) * | 2009-12-18 | 2011-05-25 | 清华大学 | Lithium iron phosphate and ferrous phosphate, and preparation methods thereof |
| CN102381693A (en) * | 2010-09-06 | 2012-03-21 | 李文宝 | Preparation method of lithium iron phosphate |
| CN102569791A (en) * | 2010-12-16 | 2012-07-11 | 中国科学院福建物质结构研究所 | Lithium iron phosphate with flower-like structure and preparation method thereof |
-
2013
- 2013-12-27 CN CN201310739960.5A patent/CN104752716B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101327922A (en) * | 2008-07-07 | 2008-12-24 | 杭州赛诺索欧电池有限公司 | Preparation of LiFePO4 |
| CN101332985A (en) * | 2008-07-31 | 2008-12-31 | 福建师范大学 | Method for preparing conducting phosphide-doped positive electrode material of LiFePO4 |
| CN101407319A (en) * | 2008-09-16 | 2009-04-15 | 杭州龙威能源科技有限公司 | Method of preparing lithium iron phosphate having high conductivity and superior low temperature discharge property |
| CN102070132A (en) * | 2009-12-18 | 2011-05-25 | 清华大学 | Lithium iron phosphate and ferrous phosphate, and preparation methods thereof |
| CN102381693A (en) * | 2010-09-06 | 2012-03-21 | 李文宝 | Preparation method of lithium iron phosphate |
| CN102569791A (en) * | 2010-12-16 | 2012-07-11 | 中国科学院福建物质结构研究所 | Lithium iron phosphate with flower-like structure and preparation method thereof |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106684379A (en) * | 2015-11-11 | 2017-05-17 | 中国科学院金属研究所 | Method for synthesizing ultrathin nano-scale LiFePO4 flakes having superhigh large multiplying power charge and discharge performances |
| CN106684379B (en) * | 2015-11-11 | 2019-05-10 | 中国科学院金属研究所 | Synthesize the method with the ultrathin nanometer sheet LiFePO4 of superelevation high rate charge-discharge performance |
| CN108470888A (en) * | 2018-03-05 | 2018-08-31 | 南京理工大学 | PH regulates and controls the method that growth period prepares assembly type diamond shape LiFePO4/silver/graphene oxide compound |
| CN108470888B (en) * | 2018-03-05 | 2020-09-11 | 南京理工大学 | Method for preparing assembled diamond-shaped lithium iron phosphate/silver/graphene oxide compound by growth at pH regulation stage |
| 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 |
| CN113896181B (en) * | 2021-10-09 | 2023-02-10 | 四川裕宁新能源材料有限公司 | Method for producing low-cost nano battery grade iron phosphate |
| CN114361448A (en) * | 2021-12-31 | 2022-04-15 | 欣旺达电动汽车电池有限公司 | Lithium iron phosphate, preparation method thereof and lithium ion battery |
| CN114361448B (en) * | 2021-12-31 | 2023-07-14 | 欣旺达电动汽车电池有限公司 | Lithium iron phosphate, preparation method thereof and lithium ion battery |
Also Published As
| Publication number | Publication date |
|---|---|
| CN104752716B (en) | 2017-02-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102583292B (en) | Ferric phosphate having micro-nano structure and preparation method thereof as well as lithium iron phosphate material | |
| US10957903B2 (en) | Layered lithium-rich manganese-based cathode material with olivine structured LIMPO4 surface modification and preparation method thereof | |
| CN102655231B (en) | A kind of method preparing high power performance anode material for lithium-ion batteries LiMn2O4 | |
| CN104752718B (en) | A kind of LiMnxFe1‑xPO4Positive electrode active materials and preparation method thereof | |
| CN101337666A (en) | Method for preparing spherical ferric lithium phosphate by oxidation control crystal-carbon thermal reduction method | |
| CN102299322B (en) | Ion hot preparation method for lithium iron phosphate positive electrode material | |
| CN103825024B (en) | A kind of battery-grade iron phosphate and preparation method thereof | |
| CN105236486B (en) | A kind of high performance lithium ion battery anode material vanadium pentoxide hollow microsphere and preparation method | |
| CN103606676B (en) | A kind of lithium iron phosphate/carbon nanocomposite and preparation method thereof | |
| CN105226273B (en) | A kind of iron manganese phosphate for lithium and preparation method and application | |
| CN103956493B (en) | The preparation method of carbon cladding hierarchical organization LiFePO4 | |
| CN102881903A (en) | Preparation method of porous lithium iron phosphate powder | |
| CN110233261B (en) | Preparation method of single crystal ternary lithium battery positive electrode material and lithium ion battery | |
| CN104752715A (en) | Precursor, manganese-iron-lithium phosphate and their preparation methods and use | |
| CN104891570B (en) | A kind of liquid phase synthesis Zr4+Doping fluorination bismuth anode material for lithium-ion batteries and preparation method thereof | |
| CN112952080A (en) | Application of tripolyphosphoric acid mixed transition metal sodium salt in preparation of lithium ion battery or zinc ion battery | |
| CN104362341A (en) | High-density nano-lithium iron phosphate material and preparation method thereof | |
| CN105024065A (en) | Lithium ion battery cathode material and preparation method thereof | |
| CN107230771A (en) | A kind of method of vanadium phosphate coated lithium ion battery anode material nickel cobalt manganic acid lithium | |
| CN104752716B (en) | Lithium iron phosphate and its preparation method and use | |
| CN102832381A (en) | Preparation method of high-voltage cathode material Lil+xMn3/2-yNil/2-zMy+zO4 of lithium ion battery with long service life | |
| CN104752697A (en) | Mixed ion phosphate positive electrode material and preparation method thereof | |
| Zhang et al. | Novel synthesis of LiMnPO4· Li3V2 (PO4) 3/C composite cathode material | |
| CN103441239A (en) | Synthetic method for nanoscale ternary cathode material | |
| CN104752720A (en) | Lithium manganese ferric phosphate, preparation method and application thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| EXSB | Decision made by sipo to initiate substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |