CN105514422B - A kind of presoma and iron manganese phosphate for lithium and its preparation method and application - Google Patents
A kind of presoma and iron manganese phosphate for lithium and its preparation method and application Download PDFInfo
- Publication number
- CN105514422B CN105514422B CN201410506146.3A CN201410506146A CN105514422B CN 105514422 B CN105514422 B CN 105514422B CN 201410506146 A CN201410506146 A CN 201410506146A CN 105514422 B CN105514422 B CN 105514422B
- Authority
- CN
- China
- Prior art keywords
- lithium
- manganese
- water
- iron
- source
- 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.)
- Active
Links
Classifications
-
- 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
- Battery Electrode And Active Subsutance (AREA)
Abstract
The present invention provides a kind of presoma and iron manganese phosphate for lithium and its preparation method and application.The preparation method of the iron manganese phosphate for lithium includes mixing the presoma with water-soluble lithium source, water-soluble phosphorus source and organic carbon source, and by the drying of obtained mix products and roast；The water solubility phosphorus source is phosphoric acid and/or water-soluble phosphate.The iron manganese phosphate for lithium that manganese iron dissolves out less, cycle performance is excellent can be obtained using this method.
Description
Technical field
The present invention relates to a kind of presoma, the preparation method of the presoma, a kind of preparation method of iron manganese phosphate for lithium, by
Application of the iron manganese phosphate for lithium and the iron manganese phosphate for lithium that this method is prepared as positive electrode active materials.
Background technique
Power-type lithium ion battery has the advantages that high-energy-density, high-specific-power, high security and long circulation life, is not
Carry out the ideal source of electric vehicle and various electric tools.Olivine-type lithium manganese phosphate (abbreviation LMP) positive electrode has work
The advantages that voltage is high, synthesis condition is mild, raw material sources are extensive and no pollution to the environment.But lithium manganese phosphate has in latter stage of charging
A large amount of Mn3+, the Mn of high-spin3+It can cause Jahn-Teller effect, the structure of lithium manganese phosphate material is made to be distorted and break
It splits, seriously affects its cyclicity.In addition, the manganese element in lithium manganese phosphate material is easy to happen under the acid corrosion action of electrolyte
Disproportionated reaction, that is, 2Mn3+→Mn2+ + Mn4+, lead to Mn2+It can gradually be dissolved into electrolyte, make the crystal knot of lithium manganese phosphate material
Structure changes, and influences the security performance and cycle performance of material.Therefore, iron manganese phosphate for lithium (abbreviation LMFP) is most to be closed at present
Note and most promising one of the positive electrode active materials for preparing power-type lithium ion battery.
For example, being prepared using soluble manganese salt, molysite and oxalates by coprecipitation method in CN201210565398.4
Then manganese oxalate iron presoma will be added the lithium salts and phosphate of metering ratio, be sanded laggard after precursor powder washing, drying
Row drying and sintering obtains the single-phase LMFP that manganese iron is evenly distributed.But wherein, manganese and iron are all uniform in the particle of entire material
It is existing, therefore be dissolved with easy after electrolyte contacts also with the presence of the manganese ion of high concentration in outer layer, cause LMFP material
Structural instability, final cycle performance are deteriorated.
A kind of preparation method of the LMFP material of core-shell structure is disclosed in CN103794789A, first passes through soluble manganese salt
Reaction is heated in liquid phase with phosphate and generates manganese phosphate, molysite is then added, is reacted by heating, after ion exchange, is formed
Outer layer is iron, and inner layer is the iron manganese phosphate presoma of the core-shell structure of manganese, and lithium salts is then added and carbon source passes through high temperature sintering, shape
It is the LMFP material of LiFePO4 (LFP), the core-shell structure that inner layer is LMP at outer layer.Although the LMFP material energy of this structure
Contact of the manganese with electrolyte is reduced to a certain extent, is reduced the dissolution degree of manganese, is promoted the cycle life of material.But due to inner layer
LMP and outer layer LFP is not formed to dissolve each other well, and LMP impedance is three orders of magnitude greater compared with LFP, final LMFP material globality
Can be poor, it is low (only 140mAh/g or so) to be mainly reflected in discharge capacity, and first charge discharge efficiency is low (only 78% or so), recycles
Efficiency is unable to reach ideal effect, and capacity retention ratio only has 88.1% after recycling 250 times under 1C multiplying power.
Summary of the invention
The present invention solves the discharge capacity of the iron manganese phosphate for lithium of prior art preparation and first charge discharge efficiency is low, multiplying power and circulation
The technical problem of performance difference, and preparation method, a kind of system of iron manganese phosphate for lithium of the new presoma of one kind, the presoma are provided
The application of Preparation Method, the iron manganese phosphate for lithium and the iron manganese phosphate for lithium being prepared by this method as positive electrode active materials.
Specifically, the technical solution of the present invention is as follows:
A kind of presoma, the general formula of the presoma are MnxFe1-x-yMyC2O4·2H2O, wherein Mn and Fe is divalent,
M is selected from one of magnesium, nickel, zinc, calcium, vanadium and titanium, 0 < x < 1,0≤y < 1, and x+y < 1；The presoma is from a surface to interior
Layer, Fe content gradually decrease, and Mn content gradually rises；And the Mn content on the presoma surface is 0.
A kind of preparation method of above-mentioned presoma, this method include by watersoluble divalent manganese source, watersoluble divalent source of iron, remove
Water-soluble divalent metal M salt and precipitant mix outside manganese salt and molysite simultaneously react, and obtain pre- powder after dry；It then will be pre-
Powder is dispersed in water, and soluble decomposable ferrous salt is added, after drying under inert atmosphere protection at 200 ~ 500 DEG C of heat
Reason, obtains the presoma；The precipitating reagent is oxalic acid and/or water soluble oxalate.
A kind of preparation method of iron manganese phosphate for lithium, wherein this method includes by above-mentioned presoma and water-soluble lithium source, water-soluble
Property phosphorus source and organic carbon source mixed, and it is obtained mix products are dry and roast；The water solubility phosphorus source is phosphoric acid
And/or water-soluble phosphate.
The present invention also provides iron manganese phosphate for lithium prepared by the above method.
Finally, the application the present invention also provides the iron manganese phosphate for lithium as positive electrode active materials.
The present inventor by further investigation discovery, using above-mentioned specific presoma as reaction raw materials can obtain by
The outer single phase solid solution LMFP in the concentration gradient that iron content gradually decreases, manganese content gradually increases.Specifically, this hair
Bright LMFP internal layer is iron manganese phosphate for lithium framework, and bivalent manganese and ferrous iron are uniformly distributed, and is not in that local ferrimanganic proportion is uneven
Even phenomenon；And outer layer continues to coat ferrous iron, the ferrous iron of the clad can penetrate into the iron manganese phosphate for lithium of internal layer, so that outside
Without obvious boundary, generally single phase solid solution structure between layer and internal layer, thus formed iron content from outside to inside gradually decrease it is dense
Spend gradient；And internal layer manganese is still to be uniformly distributed, then can due to iron infiltration and make its content formed from outside to inside accordingly by
Gradually raised concentration gradient, the defect that one side can effectively avoid manganese and electrolyte contacts that it is caused to dissolve, another aspect energy
Iron and the respective advantage of manganese are given full play to, guarantees that the LMFP material has good cycle performance.
Other features and advantages of the present invention will the following detailed description will be given in the detailed implementation section.
Detailed description of the invention
The drawings are intended to provide a further understanding of the invention, and constitutes part of specification, with following tool
Body embodiment is used to explain the present invention together, but is not construed as limiting the invention.
Fig. 1 is the X-ray diffraction spectrum for the sample CL1 that the LMFP sample L1 of embodiment 1 is mixed with LMFP, LFP simple physical
Figure.
The TEM line that Fig. 2 is the LMFP sample L1 of embodiment 1 scans manganese content variation diagram.
The TEM line that Fig. 3 is the LMFP sample L1 of embodiment 1 scans iron content variation diagram.
Fig. 4 is that capacity is kept in LMFP material L1, DL1 and DL2 cyclic process of embodiment 1, comparative example 1 and comparative example 2
Rate curve graph.
Specific embodiment
Detailed description of the preferred embodiments below.It should be understood that described herein specific
Embodiment is merely to illustrate and explain the present invention, and is not intended to restrict the invention.
The present invention provides a kind of presoma, the general formula of the presoma is MnxFe1-x-yMyC2O4·2H2O, wherein Mn
It is divalent with Fe, M is selected from one of magnesium, nickel, zinc, calcium, vanadium and titanium, 0 < x < 1,0≤y < 1, and x+y < 1；Before described
Body is driven from a surface to internal layer, Fe content gradually decreases, and Mn content gradually rises；And the Mn content on the presoma surface is 0.
As previously mentioned, the M in the presoma is doped chemical, the electric conductivity of material can be promoted.In the present invention, make
For a kind of preferred embodiment of the invention, can be free of in the presoma has doped chemical, at this point, its general formula is
MnxFe1-xC2O4·2H2O.Under preferable case, 0.5≤X≤0.8, more preferably 0.6≤X≤0.8.
In the present invention, the presoma is the LMFP of single phase solid solution, and internal manganese is uniformly distributed, from outside to inside iron content by
It gradually reduces, correspondingly manganese content then gradually increases, and the Mn content on surface layer is 0.
The present invention also provides a kind of preparation method of above-mentioned presoma, this method includes by watersoluble divalent manganese source, water
Soluble divalent source of iron, the water-soluble divalent metal M salt in addition to manganese salt and molysite and precipitant mix are simultaneously reacted, and are obtained after dry
Pre- powder；Then pre- powder is dispersed in water, and soluble decomposable ferrous salt is added, in inert atmosphere protection after drying
Lower 200 ~ 500 DEG C of heat treatment, obtains the presoma；The precipitating reagent is oxalic acid and/or water soluble oxalate.
The present invention is to the watersoluble divalent manganese source, watersoluble divalent source of iron, the watersoluble divalent in addition to manganese salt and molysite
The dosage of metal M salt and precipitating reagent is not particularly limited, for example, the dosage of the watersoluble divalent manganese source, described water-soluble
The dosage of property divalent source of iron, the dosage of the water-soluble divalent metal M salt in addition to manganese salt and molysite and the precipitating reagent
Mn in the mix products that dosage makes2+、Fe2+And M2+Total mole number and C2O4 2-Molal quantity ratio be (0.01-1):
1, wherein M is selected from one of magnesium, nickel, zinc, calcium, vanadium and titanium or a variety of.
Further, with Mn2+Meter the watersoluble divalent manganese source dosage, with Fe2+The watersoluble divalent iron of meter
The dosage in source with M2+The molar ratio of dosage of the water-soluble divalent metal M salt in addition to manganese salt and molysite of meter is preferably
(0.05-100): (0.05-100): 1, more preferably (1-20): (1-20): 1.
The watersoluble divalent manganese source can be the existing various compounds containing divalent manganesetion that can be dissolved in water,
Specific example includes but is not limited to: protochloride manganese, manganese bromide, Mn nitrate, perchloric acid Asia manganese, manganese sulfate and acetic acid Asia manganese
One of or it is a variety of.
The watersoluble divalent source of iron can be the existing various compounds containing ferrous ion that can be dissolved in water,
Specific example includes but is not limited to: frerrous chloride, ferrous bromide, ferrous fluosilicate, ferrous nitrate, ferrous perchlorate, sulfuric acid are sub-
One of iron and ferrous acetate are a variety of.In addition, the ferrous sulfate can also have the crystallization water without the crystallization water,
It is specifically as follows one of anhydrous slufuric acid ferrous iron, ferrous sulfate monohydrate, ferrous sulfate heptahydrate etc. or a variety of.
The water-soluble divalent metal M salt in addition to manganese salt and molysite can be the existing various demanganizations that can be dissolved in water
Divalent metal salt except salt and molysite, for example, can with the sulfate of magnesium, nickel, zinc, calcium, vanadium and titanium, nitrate, acetate and
One of chloride is a variety of.Its specific example includes but is not limited to: magnesium sulfate, zinc sulfate, titanium sulfate, magnesium nitrate, nitric acid
Zinc, calcium nitrate, nitric acid vanadium, magnesium acetate, zinc acetate, calcium acetate, acetic acid vanadium, acetic acid titanium, magnesium chloride, zinc chloride, calcium chloride and two
One of vanadium chloride is a variety of.
In the preparation process of the presoma, the oxalic acid and oxalates play ferrous ion and divalent manganesetion
The effect of precipitating reagent.Ingredient in the presoma of generation can be effectively ensured that as precipitating reagent using oxalic acid and/or oxalates
Uniformity.Wherein, the example of the oxalates includes but is not limited to: one of ammonium oxalate, sodium oxalate, potassium oxalate and lithium oxalate
Or it is a variety of.
The present invention is to golden by watersoluble divalent manganese source, watersoluble divalent source of iron, the watersoluble divalent in addition to manganese salt and molysite
Belong to the mode that M salt and precipitating reagent are mixed to be not particularly limited, for example, watersoluble divalent manganese source, water can will be contained
First solution of soluble divalent source of iron and the water-soluble divalent metal M salt in addition to manganese salt and molysite is added drop-wise to containing the precipitating
In second solution of agent, the second solution containing the precipitating reagent can be added drop-wise to containing watersoluble divalent manganese source, water solubility
In first solution of divalent source of iron and the water-soluble divalent metal M salt in addition to manganese salt and molysite, it will preferably contain water solubility two
First solution of valence manganese source, watersoluble divalent source of iron and the water-soluble divalent metal M salt in addition to manganese salt and molysite with containing
The second solution for stating precipitating reagent is added dropwise in reaction system in parallel, enables to the fluctuation of pH value in reaction system smaller in this way,
The object of slurry is consistent before reactions, to obtain the more excellent iron manganese phosphate for lithium of chemical property.In addition, described water-soluble
Property bivalent manganese source, watersoluble divalent source of iron, the water-soluble divalent metal M salt in addition to manganese salt and molysite and mixed between precipitating reagent
It closes and usually carries out in presence of water with reacting.Wherein, the dosage of the water can be selected reasonably according to the actual situation,
Therefore not to repeat here.
The present invention is not particularly limited the condition of the reaction, for example, the condition of the reaction includes: reaction temperature
It can be 0-100 DEG C, the reaction time can be 0.5-48 hours, and the pH value of reaction system can be 2-14.Preferably, described anti-
The condition answered includes: that reaction temperature is 40-60 DEG C, and the reaction time is 2-12 hours, and the pH value of reaction system is 6-7.It is preferred that feelings
Under condition, in the present invention, the reaction pressure can be 0-2MPa, and preferably 0-0.2MPa, in the present invention, the pressure are referred both to
Gauge pressure.Acid can be added in 2-14, the mode for being preferably controlled in 6-7 in the control of the pH value of reaction system into reaction system
Matter or alkaline matter.The acidic materials for example can be one of phosphoric acid, sulfuric acid, nitric acid and hydrochloric acid or a variety of.It is described
Alkaline matter for example can be one of ammonium hydroxide, potassium hydroxide, sodium hydroxide, lithium hydroxide, sodium carbonate and potassium carbonate or more
Kind.The acidic materials and alkaline matter can be used with pure state, can also be used in the form of its aqueous solution, and its dosage
It is subject to and controls the pH value of reaction system in above range, therefore not to repeat here.
According to the present invention, the oxidation in order to avoid the oxygen in air to divalent manganesetion in material and ferrous ion,
Preferably, the contact and reaction carry out in an inert atmosphere.Wherein, the mode for keeping inert atmosphere can be by protective gas
It is passed through the non-inert atmosphere replaced in the reaction system in reaction system, then again by the reaction system after gas displacement
Sealing.The protective gas can be nitrogen and/or various inert gases.
The preparation method provided according to the present invention is made after pre- powder, can carry out ferrous iron packet to pre- powder surface
Cover processing, Low Temperature Heat Treatment again after cladding realizes the diffusion of ferrous ion, thus formed concentration of iron from outside to inside successively decrease, manganese
The concentration gradients of increasing concen-trations.Wherein, the concrete operations of polarity ferrous iron cladding processing, then be: pre- powder be dispersed in water,
Then soluble decomposable ferrous salt is added, is uniformly dispersed, can dry to it, ferrous salt component then uniformly coats after dry
In pre- powder surface；Then the pre- powder of the ferrous salt Low Temperature Heat Treatment under inert atmosphere protection will be coated with.
Wherein, the decomposable ferrous salt of solubility selected from ferrous acetate, ferrous nitrate, formic acid ferrous iron at least one
Kind.In the present invention, the content of the decomposable ferrous salt of solubility is without excessively, only needing it to be able to achieve the packet of pre- powder surface
It covers and penetrates into form concentration of iron gradient.Under preferable case, on the basis of the pre- powder of 100 parts by weight, the solubility can
The dosage of the ferrous salt of decomposition is 0.1-50 parts by weight, more preferably 0.5-20 parts by weight.The temperature of Low Temperature Heat Treatment be 200 ~
500 DEG C, preferably 400 DEG C.The time of Low Temperature Heat Treatment is 6 ~ 24 hours, preferably 8 ~ 10 hours.
It should be noted that needing first to be dried to obtain pre- powder, and subsequent pre- powder during preparing presoma
Drying is also required to after cladding is ferrous.Herein, the existing skill such as spray drying, freeze-drying can be used in related drying steps
Common drying mode, the present invention are not particularly limited in art.
Accordingly, as a kind of preferred embodiment of the invention, the preferred presoma Mn is preparedxFe1-xC2O4·
2H2O(is not contain doped chemical) preparation method then are as follows: by watersoluble divalent manganese source, watersoluble divalent source of iron and precipitating
Agent is mixed and is reacted, and obtains the pre- powder of manganese oxalate iron after dry；Then the pre- powder of manganese oxalate iron is dispersed in water, and added
Enter soluble decomposable ferrous salt, which is uniformly wrapped on the pre- powder surface of manganese oxalate iron, after being then dried
200 ~ 500 DEG C of Low Temperature Heat Treatments under inert atmosphere protection, can be obtained the MnxFe1-xC2O4·2H2O presoma.More preferably
In the case of, when preparing the pre- powder of manganese oxalate iron, ferrous, sub- manganese and oxalates molar ratio are 0.01 ~ 1:0.01 ~ 1:1 ~ 1.2, optimal
It is selected as 0.2 ~ 0.5:0.5 ~ 0.8:1.2.
The present invention also provides a kind of preparation methods of iron manganese phosphate for lithium, wherein this method include by above-mentioned presoma with
Water-soluble lithium source, water-soluble phosphorus source and organic carbon source are mixed, and by the drying of obtained mix products and are roasted；The water
Dissolubility phosphorus source is phosphoric acid and/or water-soluble phosphate.
In the LMFP material of the core-shell structure prepared in the prior art, LFP and LMP does not form effective gradient and dissolves each other,
For the double-layer structure with obvious interface, and the LFP finite thickness of shell, cause the impedance of material still larger, final performance
Also poor.And in the present invention, as previously mentioned, can obtain by reaction raw materials of specific presoma provided by the invention by outside extremely
The interior single phase solid solution LMFP with the concentration gradient that iron content gradually decreases, manganese content gradually increases.Specifically, of the invention
LMFP internal layer is iron manganese phosphate for lithium framework, and bivalent manganese and ferrous iron are uniformly distributed, and is not in that local ferrimanganic proportion is non-uniform
Phenomenon；And outer layer continues to coat ferrous iron, the ferrous iron of the clad can penetrate into the iron manganese phosphate for lithium of internal layer, so that outside
Demarcate between layer and internal layer without obvious, generally single phase solid solution structure, rather than nucleocapsid layered structure, to be formed from outside to inside
The concentration gradient that iron content gradually decreases；And internal layer manganese is still to be uniformly distributed, then can due to iron infiltration and make its content
The concentration gradient accordingly gradually risen is formed from outside to inside, and one side can effectively avoid manganese and electrolyte contacts from leading to its dissolution
Defect, on the other hand can give full play to iron and the respective advantage of manganese, guarantee the LMFP material have good cycle performance.
The present invention is to the dosage of the presoma, water-soluble lithium source, water-soluble phosphorus source and organic carbon source without particularly
It limits.For example, with C2O4 2-Meter the presoma dosage, with Li+The dosage of the water-soluble lithium source of meter with PO4 3-Meter
The molar ratio of dosage of the water-soluble phosphorus source can be (0.8-1.2): (0.8-1.2): 1, preferably (0.9-1.1):
(0.9-1.1): 1.In addition, relative to presoma described in 100 parts by weight, the water-soluble lithium source and the water-soluble phosphorus acid source
Total dosage, the dosage of the organic carbon source can be 0.1-20 parts by weight, preferably 0.5-10 parts by weight.
It is described water solubility lithium source can be the existing various lithium-containing compounds that can be dissolved in water, specific example include but
It is not limited to: lithium hydroxide, lithium dihydrogen phosphate, lithium acetate, lithium benzoate, lithium bromate, lithium bromide, lithium chlorate, lithium chloride, fluorination
One of lithium, lithium fluorosilicate, lithium formate, lithium iodide, lithium nitrate, lithium perchlorate, lithium tartrate, lithium carbonate are a variety of.
The example of the water-soluble phosphate includes but is not limited to: lithium dihydrogen phosphate, sodium phosphate, ammonium dihydrogen phosphate, phosphoric acid
One of hydrogen diammonium and potassium phosphate are a variety of.
It should be noted that when the raw material for preparing the LiFePO4 contains lithium dihydrogen phosphate, the lithium dihydrogen phosphate
Regard as the water-soluble phosphate be added, and by the dosage of the lithium dihydrogen phosphate simultaneously be included in water-soluble phosphate and
In the dosage of water-soluble lithium source, that is, lithium contained in the lithium dihydrogen phosphate need to be deducted when other lithium sources are added.
Usually, the organic carbon source can be the existing various organic matters that can be carbonized at 800 DEG C or less, tool
Body example includes but is not limited to: one in glucose, sucrose, lactose, maltose, phenolic resin, carbon nanotube and epoxy resin
Kind is a variety of.
According to the present invention, in order to enable the iron manganese phosphate for lithium arrived has superior chemical property, it is preferable that this method
It further include that will carried out in the mixed process of the presoma, water-soluble lithium source, water-soluble phosphorus source and organic carbon source to particle
Refinement, the condition of the refinement is preferably so that the partial size of the product arrived is no more than 100nm.In the present invention, the side of the refinement
Formula all can be sanded in sand mill, to be divided mixture paste by shearing force, pressure and impact force
A kind of scattered mode, is specifically known to the skilled person, therefore not to repeat here.
According to the present invention, in order to enable the final iron manganese phosphate for lithium arrived has preferable particle shape, the side of the drying
Formula is usually to be spray-dried.The concrete operation method and condition of the spray drying are known to the skilled person.Specifically,
Slurry containing hybrid particles is added in atomizer high speed rotation to realize spray drying.The temperature of the spray drying can
Think 100-300 DEG C, preferably 200-280 DEG C.
It should be noted that the presoma can be the product after drying, or undried product.
It, can be by the presoma of solid, water-soluble phosphorus source, organic carbon source and additional when the presoma is by dry product
Water mix to obtain the slurry；When the presoma is undried product, itself can be contained to certain water
Presoma is directly mixed with water-soluble phosphorus source salt and organic carbon source to obtain the slurry, if the water contained in the presoma
When amount is insufficient, a certain amount of water can also be additionally added.In addition, the amount of water can be the conventional choosing of this field in the slurry
It selects, well known to those skilled in the art to this, therefore not to repeat here.
The present invention is not particularly limited the condition of the roasting, as long as the organic carbon source can be carbonized,
For example, the condition of the roasting, which includes: maturing temperature, to be 100-800 DEG C, preferably 400-500 DEG C；Calcining time can be with
It is 1-25 hours, preferably 10-25 hours.In addition, the roasting usually carries out in an inert atmosphere.
The present invention also provides iron manganese phosphate for lithium prepared by the above method.
In addition, the application the present invention also provides the iron manganese phosphate for lithium as positive electrode active materials.
The present invention will be described in detail by way of examples below.
In following embodiment and comparative example, the X-ray diffractometer that XRD test uses is D/max-2500 model (Japan's reason
Learn), test condition are as follows: pipe pressure is 40kV, electric current 200mA, and step-length is 0.04 °, and test angle is 10 ° -90 °.TEM test is adopted
With FEI Tecnai G2F30 equipment, after sample to be tested is inlayed with bakelite powder, sanding and polishing is carried out, is randomly selected with TEM
Grain sample progress line is swept to be swept with face.1 sample of embodiment chooses particle after polishing grinding and does transversal upper thread scanning, observes the particle
The variation of manganese and iron content from the inside to the outside.
Embodiment 1
The embodiment is for illustrating presoma and iron manganese phosphate for lithium provided by the invention and preparation method thereof.
35.97 grams of ferrous nitrates and 200.81 grams of Mn nitrates are dissolved in respectively in the deionized water of 5L, by 184.23
Gram potassium oxalate is dissolved in 10L deionized water, then by ferrous nitrate with Mn nitrate is parallel simultaneously is added drop-wise to Potassium Oxalate Solution
In, while being 6.5 with the PH of dust technology control reaction solution, it is stirred to react 4 hours, will react under 50 DEG C of circulating water heat insulation
Afterwards after solution left standstill aging 8 hours, light yellow Mn is obtained after filtration washing is dry0.8Fe0.2C2O4·2H2O material, is denoted as QQT-
A1。
In N228.79 grams of ferrous nitrates are dissolved in 2L deionized water under protection, after emulsion dispersion is uniform, by 179.12
Gram Mn0.8Fe0.2C2O4·2H2O powder is slowly added into the solution, side edged emulsion dispersion 40 minutes.By scattered solution
It is spray-dried (N2For carrier gas), then the powder after drying is placed in tube furnace, in N2Protect lower 300 DEG C of sintering 12 small
When, QQT-B1 is obtained after cooling.
The phosphoric acid that 89.56 grams of QQT-B1 powder, 43.09 grams of lithium hydroxides, 69.42 grams of purity are 84.7% is separately added into
Into 1L deionized water, by mixed solution ball milling 2 hours in the ball mill, solution after ball milling is then transferred to hydrothermal reaction kettle
In, in N2Room temperature is naturally cooled to after protecting lower 200 DEG C, 1000rpm stirring lower reaction 24 hours, 4 are carried out to solution after reaction
Secondary filtration washing is dried to obtain LiMn0.73Fe0.27PO4Material.
By 40 grams of LiMn0.73Fe0.27PO4, 3.6 grams of phenolic resin and 8 grams of solid contents be 5% carbon nanotube be added to 500mL
In deionized water, it is spray-dried after carrying out emulsion dispersion with spray dryer.Powder after spray drying is placed on tubular type
In furnace, in N2Under protection, Isothermal sinter 12 hours at 450 DEG C naturally cool to after room temperature and obtain the LMFP of the present embodiment
Material, general formula LiMn0.73Fe0.27PO4/ C, average grain diameter 97nm, is denoted as L1.
The X-ray diffraction spectrogram (XRD spectra) of the iron manganese phosphate for lithium L1 is as shown in Figure 1.Also contain LMFP in general formula Fig. 1
The XRD spectra of the sample CL1 mixed with LFP simple physical.It will be seen from figure 1 that the LMFP sample L1 that embodiment 1 is prepared
For the pure LMFP material of single phase solid solution, do not occur shown in sample CL1 as shown in figure 1~Shown in peak, be individual
The peak LFP；Illustrate embodiment 1 prepare LMFP sample L1 in internal layer LMFP and outer layer LFP formed it is good it is mutual seep dissolve each other, obtain iron
The single phase solid solution LMFP material of manganese concentration gradient distribution, rather than simple LMFP one layer of LFP material of external sheath.
The TEM line scanning manganese content variation diagram of the iron manganese phosphate for lithium L1 is as shown in Figure 2.As shown in Figure 2, by the LMFP material
Expect L1 inside toward outside direction test, manganese concentration be in reduced trend, i.e., its there are apparent concentration gradient, the material granules
Center manganese concentration counts about 18, to particle outer layer position manganese concentration counting remaining 1 ~ 2, does not have to 300 ~ 450nm width position
Manganese element is detected.
The TEM line scanning iron content variation diagram of the iron manganese phosphate for lithium L1 is as shown in Figure 3.From the figure 3, it may be seen that by the LMFP material
Expect L1 inside toward outside direction test, concentration of iron be in increased trend, i.e., its there are apparent concentration gradient, the material granules
Center concentration of iron counts only 5 or so, 12 or so is increased to the counting of particle outer layer position concentration of iron, in 300 ~ 450nm width
Position does not detect with the presence of manganese element but has a large amount of ferro element.
It can be seen from Fig. 2 and Fig. 3 from the granular center position of LMFP material L1 to particle surface direction, manganese content by
It is decrescence small, and iron content is gradually increased, to particle surface substantially without manganese presence and with the presence of a large amount of iron.Therefore, from particle
On center to particle surface direction, Fe/Mn ratio is gradually increased, and Mn/Fe is gradually reduced, and iron and manganese all have apparent concentration
Gradient.
Comparative example 1
The comparative example is for illustrating presoma and iron manganese phosphate for lithium of reference and preparation method thereof.
QQT-A1 is prepared using step same as Example 1, specifically: by 35.97 grams of ferrous nitrates and 200.81 grams
Mn nitrate is dissolved in respectively in the deionized water of 5L, 184.23 grams of potassium oxalates is dissolved in 10L deionized water, then by nitre
Sour ferrous and Mn nitrate is parallel simultaneously to be added drop-wise in Potassium Oxalate Solution, while being 6.5 with the PH of dust technology control reaction solution,
It is stirred to react under 50 DEG C of circulating water heat insulation 4 hours, behind after reaction solution left standstill aging 8 hours, after filtration washing is dry
Obtain light yellow Mn0.8Fe0.2C2O4·2H2O material, is denoted as QQT-A1.
The phosphoric acid that 89.56 grams of QQT-A1 powder, 43.09 grams of lithium hydroxides, 69.42 grams of purity are 84.7% is separately added into
Into 1L deionized water, by mixed solution ball milling 2 hours in the ball mill, solution after ball milling is then transferred to hydrothermal reaction kettle
In, in N2Room temperature is naturally cooled to after protecting lower 200 DEG C, 1000rpm stirring lower reaction 24 hours, 4 are carried out to solution after reaction
Secondary filtration washing is dried to obtain LiMn0.8Fe0.2PO4Material.
By 40 grams of LiMn0.8Fe0.2PO4, 3.6 grams of phenolic resin and 8 grams of solid contents be 5% carbon nanotube be added to 500mL
In ionized water, it is spray-dried after carrying out emulsion dispersion with spray dryer.Powder after spray drying is placed on tube furnace
In, in N2Under protection, Isothermal sinter 12 hours at 450 DEG C naturally cool to after room temperature and obtain the LMFP material of this comparative example
Material, general formula LiMn0.8Fe0.2PO4/ C, average grain diameter 97nm, is denoted as DL1.
Comparative example 2
The comparative example is for illustrating iron manganese phosphate for lithium of reference and preparation method thereof.
First 125.01 grams of manganese nitrates are dissolved in 1L deionized water and obtain solution A, 101.57 grams of phosphoric acid ammonia are dissolved in 1L
Solution B is obtained in deionized water, solution A is slowly dropped in solution B, after being stirred to react 4 hours, at 80 DEG C after solution is washed
Lower drying 10 hours obtains stratum nucleare manganese phosphate precursor powder QQT-DA1.
119.95 grams of QQT-DA1 dispersions are formed into solution C in deionized water, 55.6 grams of ferrous sulfate heptahydrates are dissolved in
Solution D is formed in deionized water, and solution D is slowly added in solution C, whole process N2It is protected, solution is stirred
It mixes, after reaction being carried out at 50 DEG C 5 hours, solution is washed, obtained with core after 10 hours dry at 80 DEG C
The ferrous phosphate manganese presoma QQT-DB1 of shell structure.
After mixing by 37.68 grams of lithium carbonates, 75.06 grams of QQT-DB1,5.64 grams of sucrose, in N2Protect lower ball milling 2 small
Shi Hou is dried, and the powder after drying is in N2It under atmosphere, is sintered 2 hours for 500 DEG C in tube furnace, obtains core after cooling
The lithium ferric manganese phosphate presoma of shell structure, is then crushed, then in N2Sintering 20 is small at 700 DEG C in tube furnace under protection
When, the LMFP material of this comparative example is obtained after cooling, with core-shell structure, kernel LMP, shell LFP are denoted as DL2.
Embodiment 2
The embodiment is for illustrating iron manganese phosphate for lithium provided by the invention and preparation method thereof.
139.12 grams of Iron dichloride tetrahydrates and 257.28 gram of four chloride hydrate Asia manganese are dissolved in the deionization of 10L respectively
In water, 267.98 grams of sodium oxalates are dissolved in 20L deionized water, then by frerrous chloride and the parallel dropwise addition simultaneously of protochloride manganese
It is 6 into sodium oxalate solution, while with the PH of dilute hydrochloric acid control reaction solution, is stirred to react 2 under 60 DEG C of circulating water heat insulation
Hour, behind after reaction solution left standstill aging 24 hours, light yellow Mn is obtained after filtration washing is dry0.65Fe0.35C2O4·2H2O
Material is denoted as QQT-A2.
In N28.7 grams of ferrous acetates are dissolved in 2L deionized water under protection, after emulsion dispersion is uniform, by 179.26 grams
Mn0.65Fe0.35C2O4·2H2O powder is slowly added into the solution, side edged emulsion dispersion 60 minutes.By scattered solution
It is spray-dried (N2For carrier gas), then the powder after drying is placed in tube furnace, in N2Protect lower 360 DEG C of sintering 12 small
When, QQT-B2 is obtained after cooling.
Phosphoric acid, 7.85 grams of Portugals by 89.63 grams of QQT-B2 powder, 11.97 grams of lithium hydroxides, 57.85 grams of purity for 84.7%
The graphene that grape sugar and 15.7 grams of solid contents are 5% is added separately in 1L deionized water, and it is small then to carry out sand milling 4 with sand mill
When, it is spray-dried later with spray dryer.Powder after spray drying is placed in tube furnace, in N2Under protection,
Isothermal sinter 24 hours at 600 DEG C, naturally cool to after room temperature and obtain the LMFP material of the present embodiment, and general formula is
LiMn0.62Fe0.38PO4/ C, average grain diameter 72nm, is denoted as L2.
Embodiment 3
The embodiment is for illustrating presoma and iron manganese phosphate for lithium provided by the invention and preparation method thereof.
278.1 grams of ferrous sulfate and 158.76 grams of manganese sulfates are dissolved in respectively in the deionized water of 5L, by 248.2 grams
Ammonium oxalate is dissolved in 10L deionized water, is then added drop-wise to ferrous sulfate and manganese sulfate are parallel simultaneously in oxalic acid ammonia solution,
It is simultaneously 7 with the PH of ammonium hydroxide control reaction solution, is stirred to react under 40 DEG C of circulating water heat insulation 3 hours, by solution after reaction
After standing aging 24 hours, light yellow Mn is obtained after filtration washing is dry0.52Fe0.48C2O4·2H2O material QQT-A3.
In N28.99 grams of ferrous nitrates are dissolved in 2L deionized water under protection, after emulsion dispersion is uniform, by 179.4 grams
Mn0.52Fe0.48C2O4·2H2O powder is slowly added into the solution, side edged emulsion dispersion 30 minutes.By scattered solution
Carry out spraying spray drying (N2For carrier gas), then the powder after drying is placed in tube furnace, in N2Protect lower 400 DEG C of sintering 8
Hour, QQT-B3 is obtained after cooling；
The phosphoric acid that 89.7 grams of QQT-B3 powder, 36.27 grams of lithium hydroxides, 58.43 grams of purity are 84.7% is added separately to
In 1L deionized water, by mixed solution ball milling 1 hour in the ball mill, solution after ball milling is then transferred to hydrothermal reaction kettle
In, in N2Room temperature is naturally cooled to after protecting lower 180 DEG C, 1000rpm stirring lower reaction 16 hours, 4 are carried out to solution after reaction
Secondary filtration washing is dried to obtain LiMn0.5Fe0.5PO4Material.
By 10 grams of LiMn0.5Fe0.5PO4The carbon nanotube for being 5% with 6 grams of solid contents is added in 500ml deionized water, is carried out
It is spray-dried after emulsion dispersion with spray dryer.Powder after spray drying is placed in high temperature process furnances, in N2It protects
Under shield, Isothermal sinter 12 hours at 480 DEG C naturally cool to after room temperature and obtain the LMFP material of the present embodiment, general formula
For LiMn0.5Fe0.5PO4/ C, average grain diameter 78nm, is denoted as L3.
Embodiment 4
The embodiment is for illustrating iron manganese phosphate for lithium provided by the invention and preparation method thereof.
139.12 grams of Iron dichloride tetrahydrates, 257.28 gram of four chloride hydrate Asia manganese and 4.76 grams of magnesium chlorides are dissolved respectively
In the deionized water of 10L, 267.98 grams of sodium oxalates are dissolved in 20L deionized water, then by frerrous chloride and protochloride
Manganese is added drop-wise in sodium oxalate solution in parallel simultaneously, while being 6 with the PH of dilute hydrochloric acid control reaction solution, is protected in 60 DEG C of recirculated waters
It is stirred to react under temperature 2 hours, behind after reaction solution left standstill aging 24 hours, is obtained after filtration washing is dry light yellow
Mn0.62Fe0.33Mg0.05C2O4·2H2O material, is denoted as QQT-A4.
In N28.7 grams of ferrous acetates are dissolved in 2L deionized water under protection, after emulsion dispersion is uniform, by 179.21 grams
Mn0.62Fe0.33Mg0.05C2O4·2H2O powder is slowly added into the solution, side edged emulsion dispersion 60 minutes.It will be scattered
Solution is spray-dried (N2For carrier gas), then the powder after drying is placed in tube furnace, in N2Protect lower 360 DEG C of sintering
12 hours, QQT-B4 was obtained after cooling.
Phosphoric acid, 15.7 grams of Portugals by 89.52 grams of QQT-B4 powder, 11.97 grams of lithium hydroxides, 57.85 grams of purity for 84.7%
Grape sugar is added separately in 1L deionized water, then be sanded 4 hours with sand mill, is sprayed later with spray dryer
It is dry.Powder after spray drying is placed in tube furnace, in N2Under protection, Isothermal sinter 24 hours, naturally cold at 600 DEG C
But to the LMFP material for obtaining the present embodiment after room temperature, general formula LiMn0.59Fe0.36 Mg0.05PO4/ C, average grain diameter are
68nm is denoted as L4.
Embodiment 5
The embodiment is for illustrating iron manganese phosphate for lithium provided by the invention and preparation method thereof.
35.97 grams of ferrous nitrates and 200.81 grams of Mn nitrates are dissolved in respectively in the deionized water of 5L, by 184.23
Gram potassium oxalate is dissolved in 10L deionized water, then by ferrous nitrate with Mn nitrate is parallel simultaneously is added drop-wise to Potassium Oxalate Solution
In, while being 6.5 with the PH of dust technology control reaction solution, it is stirred to react 4 hours, will react under 50 DEG C of circulating water heat insulation
Afterwards after solution left standstill aging 8 hours, light yellow Mn is obtained after filtration washing is dry0.8Fe0.2C2O4·2H2O material, is denoted as QQT-
A5。
In N20.9 gram of ferrous nitrate is dissolved in 2L deionized water under protection, after emulsion dispersion is uniform, by 179.12 grams
Mn0.8Fe0.2C2O4·2H2O powder is slowly added into the solution, side edged emulsion dispersion 40 minutes.By scattered solution into
Row spray drying (N2For carrier gas), then the powder after drying is placed in tube furnace, in N2Lower 300 DEG C are protected to be sintered 12 hours,
QQT-B5 is obtained after cooling
The phosphoric acid that 89.57 grams of QQT-B5 powder, 43.09 grams of lithium hydroxides, 69.42 grams of purity are 84.7% is separately added into
Into 1L deionized water, by mixed solution ball milling 2 hours in the ball mill, solution after ball milling is then transferred to hydrothermal reaction kettle
In, in N2Room temperature is naturally cooled to after protecting lower 200 DEG C, 1000rpm stirring lower reaction 24 hours, 4 are carried out to solution after reaction
Secondary filtration washing is dried to obtain LiMn0.797Fe0.203PO4Material.
By 40 grams of LiMn0.797Fe0.203PO4, 3.8 grams of sucrose be added in 500mL deionized water, carry out after emulsion dispersion with spray
Mist drying machine is spray-dried.Powder after spray drying is placed in tube furnace, in N2Under protection, the constant temperature at 450 DEG C
Sintering 12 hours naturally cools to after room temperature and obtains the LMFP material of the present embodiment, general formula LiMn0.797Fe0.203PO4/
C, average grain diameter 83nm, is denoted as L5.
Embodiment 6
The embodiment is for illustrating iron manganese phosphate for lithium provided by the invention and preparation method thereof.
35.97 grams of ferrous nitrates and 200.81 grams of Mn nitrates are dissolved in respectively in the deionized water of 5L, by 184.23
Gram potassium oxalate is dissolved in 10L deionized water, then by ferrous nitrate with Mn nitrate is parallel simultaneously is added drop-wise to Potassium Oxalate Solution
In, while being 6.5 with the PH of dust technology control reaction solution, it is stirred to react 4 hours, will react under 50 DEG C of circulating water heat insulation
Afterwards after solution left standstill aging 8 hours, light yellow Mn is obtained after filtration washing is dry0.8Fe0.2C2O4·2H2O material, is denoted as QQT-
A6。
In N289.56 grams of ferrous nitrates are dissolved in 2L deionized water under protection, after emulsion dispersion is uniform, by 179.12
Gram Mn0.8Fe0.2C2O4·2H2O powder is slowly added into the solution, side edged emulsion dispersion 40 minutes.By scattered solution
It is spray-dried (N2For carrier gas), then the powder after drying is placed in tube furnace, in N2Protect lower 300 DEG C of sintering 12 small
When, QQT-B6 is obtained after cooling
The phosphoric acid that 89.43 grams of QQT-B6 powder, 43.09 grams of lithium hydroxides, 69.42 grams of purity are 84.7% is separately added into
Into 1L deionized water, by mixed solution ball milling 2 hours in the ball mill, solution after ball milling is then transferred to hydrothermal reaction kettle
In, in N2Room temperature is naturally cooled to after protecting lower 200 DEG C, 1000rpm stirring lower reaction 24 hours, 4 are carried out to solution after reaction
Secondary filtration washing is dried to obtain LiMn0.53Fe0.47PO4Material.
By 60 grams of LiMn0.53Fe0.47PO4, 36 grams of solid contents be 5% carbon nanotube be added in 500mL deionized water, carry out
It is spray-dried after emulsion dispersion with spray dryer.Powder after spray drying is placed in tube furnace, in N2Under protection,
Isothermal sinter 12 hours at 450 DEG C, naturally cool to after room temperature and obtain the LMFP material of the present embodiment, and general formula is
LiMn0.53Fe0.47PO4/ C, average grain diameter 99nm, is denoted as L6.
Embodiment 7
The embodiment is for illustrating iron manganese phosphate for lithium provided by the invention and preparation method thereof.
35.97 grams of ferrous nitrates and 200.81 grams of Mn nitrates are dissolved in respectively in the deionized water of 5L, by 184.23
Gram potassium oxalate is dissolved in 10L deionized water, then by ferrous nitrate with Mn nitrate is parallel simultaneously is added drop-wise to Potassium Oxalate Solution
In, while being 6.5 with the PH of dust technology control reaction solution, it is stirred to react 4 hours, will react under 50 DEG C of circulating water heat insulation
Afterwards after solution left standstill aging 8 hours, light yellow Mn is obtained after filtration washing is dry0.8Fe0.2C2O4·2H2O material, is denoted as QQT-
A7。
In N228.79 grams of ferrous nitrates are dissolved in 2L deionized water under protection, after emulsion dispersion is uniform, by 179.12
Gram Mn0.8Fe0.2C2O4·2H2O powder is slowly added into the solution, side edged emulsion dispersion 40 minutes.By scattered solution
It is spray-dried (N2For carrier gas), then the powder after drying is placed in tube furnace, in N2Protect lower 300 DEG C of sintering 12 small
When, QQT-B7 is obtained after cooling
The phosphoric acid that 89.56 grams of QQT-B7 powder, 43.09 grams of lithium hydroxides, 69.42 grams of purity are 84.7% is separately added into
Into 1L deionized water, by mixed solution ball milling 2 hours in the ball mill, solution after ball milling is then transferred to hydrothermal reaction kettle
In, in N2Room temperature is naturally cooled to after protecting lower 200 DEG C, 1000rpm stirring lower reaction 24 hours, 4 are carried out to solution after reaction
Secondary filtration washing is dried to obtain LiMn0.73Fe0.27PO4Material.
By 40 grams of LiMn0.73Fe0.27PO4, 0.8 gram of solid content be 5% graphene be added in 500mL deionized water, carry out
It is spray-dried after emulsion dispersion with spray dryer.Powder after spray drying is placed in tube furnace, in N2Under protection,
Isothermal sinter 12 hours at 450 DEG C, naturally cool to after room temperature and obtain the LMFP material of the present embodiment, and general formula is
LiMn0.73Fe0.27PO4/ C, average grain diameter 96nm, is denoted as L7.
Performance test
1, the molten manganese test of LMFP material
By positive electrode active materials (the LMFP material that embodiment 1-7 and comparative example 1-2 are obtained), acetylene black, Kynoar
(being purchased from Dongguan City Qing Feng plastic material Co., Ltd, trade mark FR900) is dissolved in N- methylpyrrole by weight for 80:10:10
It in alkanone, and by the slurry coating obtained after mixing evenly on aluminium foil, and is toasted at 110 DEG C ± 5 DEG C, obtains positive plate.
Using metal lithium sheet as negative electrode tab, diaphragm is microporous polypropylene membrane (Celgard 2300), and electrolyte is 1.0mol/L's
(wherein, LiPF6 is lithium hexafluoro phosphate to LiPF6/ (EC+DMC), and EC is ethylene carbonate, and DMC is dimethyl carbonate, EC and DMC
Volume ratio be 1:1), full of argon gas glove box in seal, CR2025 button cell is made, and carry out in the following manner molten
Manganese test, charge/discharge capacity test, mass energy density test, discharge-rate test, Efficiency at Low Temperature test and powder resistance are surveyed
Examination.
(1) molten manganese test
By battery at 0.1C it is fully charged after after 60 DEG C of baking oven high temperatures store 7 days, take out battery it is cooling after dismantle electricity
Pond dissolves lithium cathode sheet with the HCL aqueous solution of 0.1mol/L concentration, with the manganese and iron ion in AAS test HCl solution
Amount, then using the quality of the manganese of dissolution and iron with the ratio of the gross mass of active material LMFP in corresponding positive plate as manganese
The degree of iron dissolution.Test result is as shown in table 1.
(2) charge/discharge capacity is tested:
At 30 DEG C of room temperature, by CR2025 button cell, CCCV is charged to 4.3V under 0.1C multiplying power, and cut-off current is
0.01C, then CC discharges into 2.5V under 0.1C multiplying power, and obtained charge/discharge capacity is as shown in table 1.
(3) cycle performance is tested
It carries out repeating charge and discharge cycles under room temperature environment 1C multiplying power.Capacity retention ratio after record circulation 300 times.
Test result is as shown in table 2.
Fig. 3 is that capacity is kept in LMFP material L1, DL1 and DL2 cyclic process of embodiment 1, comparative example 1 and comparative example 2
Rate curve graph.From the figure 3, it may be seen that charge and discharge cycles are carried out under 1C multiplying power, L1 specific discharge capacity conservation rate after 300 circulations
99% or more is substantially remained in, illustrates that L1 material structure is stablized.And the decaying of DL1 discharge capacity is very fast, DL2 material (i.e. core-shell structure
Material) dissolution of manganese iron can be reduced to a certain extent, play the role of rock-steady structure, discharge capacity decaying is slower, follows for 300 times
Still there is 88% or so specific capacity conservation rate after ring, but compared to the LMFP material of the present embodiment, performance is still poor.
Table 1
Note: in table 1, M/LMFP is the ratio that manganese the amount of dissolution accounts for LMFP gross mass, and the total M of M/ is then that manganese the amount of dissolution accounts for LMFP
The ratio of manganese content in material.Accordingly, Fe/LMFP is the ratio that iron the amount of dissolution accounts for LMFP gross mass, and the total F of F/ is then that iron is molten
Output accounts for the ratio of iron content in LMFP material.
Table 2
。
From the results shown in Table 1, the LMFP material L1-L7 being prepared using method provided by the invention, manganese
Iron dissolution is all fewer, hence it is evident that better than the sample DL1-DL2 of comparative example.Although the dissolution of manganese iron can be also effectively reduced in DL2, its
Effect is without significant in the present invention.
Meanwhile the discharge capacity for the battery being prepared using iron manganese phosphate for lithium provided by the invention can reach
157mAh/g or more, and specific discharge capacity conservation rate substantially remains in 98% or more after 300 circulations, has good cyclicity
Energy.
The preferred embodiment of the present invention has been described above in detail, still, during present invention is not limited to the embodiments described above
Detail within the scope of the technical concept of the present invention can be with various simple variants of the technical solution of the present invention are made, this
A little simple variants all belong to the scope of protection of the present invention.
It is further to note that specific technical features described in the above specific embodiments, in not lance
In the case where shield, it can be combined in any appropriate way.In order to avoid unnecessary repetition, the present invention to it is various can
No further explanation will be given for the combination of energy.
In addition, various embodiments of the present invention can be combined randomly, as long as it is without prejudice to originally
The thought of invention, it should also be regarded as the disclosure of the present invention.
Claims (17)
1. a kind of presoma, which is characterized in that the general formula of the presoma is MnxFe1-x-yMyC2O4·2H2O, wherein Mn and Fe
It is divalent, M is selected from one of magnesium, nickel, zinc, calcium, vanadium and titanium, 0 < x < 1,0≤y < 1, and x+y < 1；The presoma
From a surface to internal layer, Fe content is gradually decreased, and Mn content gradually rises；And the Mn content on the presoma surface is 0.
2. presoma according to claim 1, which is characterized in that the general formula of the presoma is MnxFe1-xC2O4·2H2O,
Wherein 0.5≤x≤0.8.
3. a kind of preparation method of presoma described in claim 1, which is characterized in that this method includes by watersoluble divalent manganese
Source, watersoluble divalent source of iron, the water-soluble divalent metal M salt in addition to manganese salt and molysite and precipitant mix are simultaneously reacted, dry
After obtain pre- powder；Then pre- powder is dispersed in water, and soluble decomposable ferrous salt is added, in indifferent gas after drying
Lower 200 ~ 500 DEG C of heat treatments of atmosphere protection, obtain the presoma；The precipitating reagent is oxalic acid and/or water soluble oxalate.
4. preparation method according to claim 3, wherein the dosage of the watersoluble divalent manganese source, described water-soluble two
The dosage of the dosage of valence source of iron, the dosage of the water-soluble divalent metal M salt in addition to manganese salt and molysite and the precipitating reagent
Mn in the mix products made2+、Fe2+And M2+Total mole number and C2O4 2-Molal quantity ratio be (0.01-1): 1.
5. the preparation method according to claim 4, wherein with Mn2+Meter the watersoluble divalent manganese source dosage, with
Fe2+Meter the watersoluble divalent source of iron dosage with M2+The water-soluble divalent metal M in addition to manganese salt and molysite of meter
The molar ratio of the dosage of salt is (0.05-100): (0.05-100): 1.
6. the preparation method according to any one of claim 3-5, wherein the watersoluble divalent manganese source is selected from chlorination
One of sub- manganese, manganese bromide, Mn nitrate, perchloric acid Asia manganese, manganese sulfate, formic acid Asia manganese and acetic acid Asia manganese are a variety of；
It is sub- that the watersoluble divalent source of iron is selected from frerrous chloride, ferrous bromide, ferrous fluosilicate, formic acid ferrous iron, ferrous nitrate, perchloric acid
One of iron, ferrous sulfate and ferrous acetate are a variety of；The water-soluble divalent metal M salt in addition to manganese salt and molysite is selected from
Magnesium sulfate, zinc sulfate, titanium sulfate, nickel sulfate, magnesium nitrate, zinc nitrate, calcium nitrate, nitric acid vanadium, nickel nitrate, magnesium acetate, zinc acetate,
One of calcium acetate, acetic acid vanadium, acetic acid titanium, nickel acetate, magnesium chloride, zinc chloride, calcium chloride, nickel chloride and vanadium dichloride are more
Kind；The water soluble oxalate is selected from one of ammonium oxalate, sodium oxalate, potassium oxalate and lithium oxalate or a variety of.
7. the preparation method according to any one of claim 3-5, wherein the mixed method is will be containing described
Watersoluble divalent manganese source, the watersoluble divalent source of iron and the water-soluble divalent metal M salt in addition to manganese salt and molysite
First solution is added dropwise in reaction system with containing the second solution of the precipitating reagent is parallel.
8. the preparation method according to any one of claim 3-5, wherein the condition of the reaction includes: reaction temperature
Degree is 0-100 DEG C, and the reaction time is 0.5-48 hours, and the pH value of reaction system is 2-14.
9. preparation method according to claim 3, it is sub- that the decomposable ferrous salt of solubility is selected from ferrous acetate, nitric acid
At least one of iron, formic acid ferrous iron.
10. preparation method according to claim 3, described soluble decomposable on the basis of the pre- powder of 100 parts by weight
Ferrous salt dosage be 0.1-50 parts by weight.
11. a kind of preparation method of iron manganese phosphate for lithium, which is characterized in that this method includes by presoma described in claim 1
It is mixed with water-soluble lithium source, water-soluble phosphorus source and organic carbon source, and by the drying of obtained mix products and is roasted；It is described
Water-soluble phosphorus source is phosphoric acid and/or water-soluble phosphate.
12. preparation method according to claim 11, wherein with C2O4 2-Meter the presoma dosage, with Li+Meter
It is described water solubility lithium source dosage with PO4 3-The molar ratio of the dosage of the water-soluble phosphorus source of meter is (0.8-1.2): (0.8-
1.2): 1.
13. preparation method according to claim 11, wherein relative to presoma described in 100 parts by weight, the water solubility
Total dosage of lithium source and the water-soluble phosphorus source, the dosage of the organic carbon source are 0.1-20 parts by weight.
14. preparation method described in any one of 1-13 according to claim 1, wherein the water solubility lithium source is selected from hydrogen-oxygen
Change lithium, lithium dihydrogen phosphate, lithium acetate, lithium benzoate, lithium bromate, lithium bromide, lithium chlorate, lithium chloride, lithium fluoride, lithium fluorosilicate,
One of lithium formate, lithium iodide, lithium nitrate, lithium perchlorate, lithium tartrate, lithium carbonate are a variety of；The water-soluble phosphate
Selected from one of lithium dihydrogen phosphate, sodium phosphate, ammonium dihydrogen phosphate, diammonium hydrogen phosphate and potassium phosphate or a variety of；The organic carbon
Source is selected from one of glucose, sucrose, lactose, maltose, phenolic resin, carbon nanotube and epoxy resin or a variety of.
15. preparation method according to claim 11, wherein the condition of the roasting includes: that maturing temperature is 100-800
DEG C, calcining time is 1-25 hours.
16. the iron manganese phosphate for lithium that the method as described in any one of claim 11-15 is prepared.
17. application of the iron manganese phosphate for lithium described in claim 16 as positive electrode active materials.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410506146.3A CN105514422B (en) | 2014-09-26 | 2014-09-26 | A kind of presoma and iron manganese phosphate for lithium and its preparation method and application |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410506146.3A CN105514422B (en) | 2014-09-26 | 2014-09-26 | A kind of presoma and iron manganese phosphate for lithium and its preparation method and application |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105514422A CN105514422A (en) | 2016-04-20 |
| CN105514422B true CN105514422B (en) | 2018-12-21 |
Family
ID=55722232
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410506146.3A Active CN105514422B (en) | 2014-09-26 | 2014-09-26 | A kind of presoma and iron manganese phosphate for lithium and its preparation method and application |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN105514422B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104577119B (en) * | 2015-01-04 | 2017-02-01 | 合肥国轩高科动力能源有限公司 | Preparation method of cathode material LiMn1-xFexPO4 for lithium ion cell |
| CN113942990B (en) | 2021-08-25 | 2023-06-20 | 北京当升材料科技股份有限公司 | Lithium iron manganese phosphate precursor, lithium iron manganese phosphate positive electrode material, preparation method of lithium iron manganese phosphate positive electrode material, electrode, and lithium ion battery |
| CN114725340B (en) * | 2022-04-12 | 2023-12-26 | 贵州大龙汇成新材料有限公司 | Ferric manganese lithium phosphate positive electrode material with iron and manganese elements distributed in full concentration gradient and preparation method thereof |
| CN115020678A (en) * | 2022-07-12 | 2022-09-06 | 远景动力技术(江苏)有限公司 | Positive electrode active material, electrochemical device, and electronic device |
| CN117577830A (en) * | 2023-11-29 | 2024-02-20 | 中南大学 | Ferric sodium pyrophosphate material, and preparation method and application thereof |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103078107A (en) * | 2013-02-22 | 2013-05-01 | 郑州大学 | Polybasic layered oxide lithium ion battery material and preparation method thereof |
| CN103887491A (en) * | 2012-12-24 | 2014-06-25 | 上海比亚迪有限公司 | Preparation method of lithium ion battery positive electrode active material LiMnxFe1-xPO4/C |
-
2014
- 2014-09-26 CN CN201410506146.3A patent/CN105514422B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103887491A (en) * | 2012-12-24 | 2014-06-25 | 上海比亚迪有限公司 | Preparation method of lithium ion battery positive electrode active material LiMnxFe1-xPO4/C |
| CN103078107A (en) * | 2013-02-22 | 2013-05-01 | 郑州大学 | Polybasic layered oxide lithium ion battery material and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN105514422A (en) | 2016-04-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Shi et al. | Enhanced electrochemical performance of LiF-modified LiNi1/3Co1/3Mn1/3O2 cathode materials for Li-ion batteries | |
| Yuan et al. | Surface modification of Li (Li0. 17Ni0. 2Co0. 05Mn0. 58) O2 with CeO2 as cathode material for Li-ion batteries | |
| CN101595581B (en) | Li-ni composite oxide particle powder for rechargeable battery with nonaqueous electrolyte, process for producing the li-ni composite oxide particle powder, and rechargeable battery with nonaqueous el | |
| CN103855380B (en) | Positive active material, methods for making them and the lithium secondary battery comprising it | |
| CN102348634B (en) | Method for producing iron lithium phosphate | |
| CN105514422B (en) | A kind of presoma and iron manganese phosphate for lithium and its preparation method and application | |
| CN104752715B (en) | A kind of presoma and iron manganese phosphate for lithium and its preparation method and application | |
| CN103904311B (en) | Lithium-rich manganese-based anode material that a kind of surface is coated compound and preparation method thereof | |
| KR101670664B1 (en) | Cathode active material coated with F-dopped lithium metal manganese oxide, lithium-ion secondary battery comprising the same and the prepration method thereof | |
| WO2014077277A1 (en) | Lithium composite oxide, method for producing same, positive electrode active material for secondary batteries containing said lithium composite oxide, positive electrode for secondary batteries containing said positive electrode active material, and lithium ion secondary battery using said positive electrode | |
| CN102332580B (en) | Fluorinated ferric sulfate salt compound as well as preparation method and application thereof | |
| CN104752718B (en) | A kind of LiMnxFe1‑xPO4Positive electrode active materials and preparation method thereof | |
| Han et al. | Solid-state synthesis of Li4Ti5O12 for high power lithium ion battery applications | |
| CN101855755A (en) | Li-Ni-based composite oxide particle powder for rechargeable battery with nonaqueous elctrolyte, process for producing the powder, and rechargeable battery with nonaqueous electrolyte | |
| CN102694168B (en) | Lithium manganese phosphate positive pole material and preparation method thereof | |
| CN104810517A (en) | Li-Ni composite oxide particles for non-aqueous electrolyte secondary battery, process for producing the same, and non-aqueous electrolyte secondary battery | |
| CN103459321A (en) | Li-Ni composite oxide particle powder and process for producing same, and non-aqueous electrolyte secondary battery | |
| CN105140492A (en) | Cobalt-nickel lithium manganate composite positive electrode material with surface wrapped by lithium zirconate and preparation method | |
| CN105742629B (en) | A kind of in-situ preparation method of lithium ion battery anode material lithium iron phosphate/graphene complex | |
| CN106887583A (en) | A kind of positive electrode and its preparation method and application | |
| JP4939670B2 (en) | Spinel type lithium transition metal oxide and cathode active material for lithium battery | |
| CN105745174B (en) | Spinel-type lithium-metal composite oxides | |
| CN106207158B (en) | The preparation method of rich lithium manganate cathode material for lithium | |
| Xiang et al. | Improved electrochemical performance of Li1. 2Ni0. 2Mn0. 6O2 cathode material for lithium ion batteries synthesized by the polyvinyl alcohol assisted sol-gel method | |
| CN101081695A (en) | Preparation method of doped modified ferric phosphate lithium |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |