The preparation method of the coated nickel-cobalt lithium manganate cathode material of a kind of magnesium oxide
Technical field
The invention belongs to battery material technical field, relate to a kind of preparation method of nickel-cobalt lithium manganate cathode material, particularly relate to the preparation method of the coated nickel-cobalt lithium manganate cathode material of a kind of magnesium oxide.
Background technology
Lithium-ion-power cell is the most potential on-vehicle battery of generally acknowledging both at home and abroad at present, primarily of part compositions such as positive electrode, negative material, barrier film, electrolyte; Wherein, positive electrode is the important component part of lithium ion battery, is also the key factor determining performance of lithium ion battery; Therefore, from the viewpoint of resource, environmental protection and security performance, the ideal electrode active material finding lithium ion battery is still an international energy material supplier author primary difficult problem to be solved.
Current anode material for lithium-ion batteries mainly contains cobalt acid lithium, LiMn2O4, cobalt nickel lithium manganate ternary material, LiFePO 4 etc.Wherein with the cobalt acid lithium lithium ion battery that is positive electrode, there is the features such as lightweight, capacity is large, specific energy is high, operating voltage is high, electric discharge is steady, applicable heavy-current discharge, good cycle, life-span are grown, compact battery has the advantage that cannot replace, and is the maximum anode material for lithium-ion batteries of current production rate.But cobalt acid lithium is expensive, toxicity is comparatively large, and there is certain safety issue.LiMn2O4 cost is low, and fail safe is good, but cycle performance, especially high temperature cyclic performance are poor, and have certain dissolubility in the electrolytic solution, storge quality is poor.LiFePO 4 because the consistency of material is poor, complicated process of preparation hinders its applying on lithium battery, at present also in the concern of people.Therefore, research and development electrical property and the close and low-cost anode material of lithium battery of cobalt acid lithium have become the important directions that lithium battery develops.
Recently, cobalt nickel lithium manganate ternary material is attracted attention day by day, by to the data test of this material property as aspects such as volume and capacity ratio, weight ratio capacity, circulation, safety, show nickel-cobalt lithium manganate material some excellent properties as novel lithium battery positive electrode generally, the advantages such as high in voltage platform, reversible specific capacity is large, Stability Analysis of Structures, security performance are good.Although cobalt nickel lithium manganate ternary material development rapidly, also there are some defects in it in actual applications.As low in coulombic efficiency first, high rate performance and cycle performance is poor, composition and pattern are difficult to control, tap density is low.At present, people improve its coulombic efficiency first mainly through reducing cation mixing, and by increasing electronic conductivity and ionic conductivity improves its high rate performance, by preparing pattern rule, particle that specific area is little increases its tap density.
One of method of synthesis nickle cobalt lithium manganate is high temperature solid-state method, is by lithium source, nickel source, cobalt source, manganese source ground and mixed together, calcining synthesis under about 1000 DEG C of high temperature.But this mode must bring the inhomogeneities of material, thus cause the product after sintering to be difficult to obtain the material without dephasign, such that capacity attenuation is fast, comprehensive electrochemical properties reduction.Another kind method is sol-gal process, but this method dries the difficulty that dewaters, and have impact on its industrialization.
Summary of the invention
Goal of the invention of the present invention is: for above-mentioned Problems existing, provides that a kind of technique is simple, specific capacity is large, the preparation method of the coated nickel-cobalt lithium manganate cathode material of magnesium oxide of good cycle.
The technical solution used in the present invention is as follows:
A preparation method for the coated nickel-cobalt lithium manganate cathode material of magnesium oxide, comprises the following steps:
(1) raw material mixing: lithium carbonate, nanometer spherical nickel cobalt manganese hydroxide precursor, polyacrylate and deionized water water are carried out disperseing, mix and filtering, forms uniform intermediate mixture;
(2) once sintered: the intermediate mixture of step (1) gained is loaded saggar, send into pushed bat kiln to sinter, produce nickel-cobalt lithium manganate material, sintering process is continual is filled with oxygen, sintering temperature is 650 ~ 750 DEG C, and sintering time is 3 ~ 7h;
(3) adulterate: select nano level ZnO, MgO, Al
2o
3or TiO
2in one, add in the nickle cobalt lithium manganate of step (2) gained with account for total mixture quality 0.1 ~ 0.2%, and to add polyurethane ball be batch mixing medium, in oblique mixed machine, carry out batch mixing;
(4) double sintering: the nickle cobalt lithium manganate through overdoping is sent into pushed bat kiln and carries out double sintering, sintering process is continual is filled with air;
(5) coated: preparation Mg solion, joins the nickle cobalt lithium manganate after double sintering in the middle of solution and mix, pass into ammonia spirit, stir, cleans, filters, dries, obtain by the coated nickle cobalt lithium manganate material positive electrode of MgO.
Further, the mol ratio of step (1) described lithium carbonate, nanometer spherical nickel cobalt manganese hydroxide precursor is 1:0.50 ~ 0.56, the mass ratio that polyacrylate accounts for total mixture is 0.1% ~ 0.5%, and adds deionized water and make the solid content of slurry be 40 ~ 60%.
Further, the proportion of the described polyurethane ball of step (3) is >=1.3, and ratio of grinding media to material is 3:4:3, and mixing time is 2 ~ 4h.
Further, the sintering temperature of step (4) described double sintering is 900 ~ 1000 DEG C, and sintering time is 2 ~ 8h.
Further, the molar concentration of step (5) described ammonia spirit is 0.5 ~ 2mol/L.
Further, the described Mg solion of step (5) is the one in magnesium acetate, magnesium sulfate or magnesium chloride solution, and the molar concentration of described Mg solion is 0.01 ~ 0.06mol/L.
Further, described polyacrylate is the one in Sodium Polyacrylate, polyacrylic acid potassium or calcium polyacrylate (CPA).
In sum, owing to have employed technique scheme, the invention has the beneficial effects as follows:
(1) the present invention take lithium carbonate as lithium source, and once sintered temperature is low, and sintering time is short, has saved the energy; After adopting first low temperature, the heat treating regime of high temperature is conducive to the material obtaining structure improvement simultaneously, is also conducive to the electrochemistry cycle performance improving material;
(2) pattern of nickle cobalt lithium manganate finished product and granularity depend primarily on presoma, the present invention directly with nanometer spherical nickel cobalt manganese hydroxide precursor for raw material, each element can be made to mix in molecular level level, make product component homogeneous, thus reduce cation mixing; This programme control point is few, decreases production stage, is easy to produce, and technique is simple, properties of product good stability;
(3) adulterate to finished product, and carry out coated with magnesium oxide, the product granularity of production is moderate and be evenly distributed, and tap density is large, makes to have good processing characteristics in lithium ion battery production process;
(4) spheroidization of positive electrode powder granule can improve material bulk density and volume and capacity ratio, and spherical product also has excellent mobility, dispersiveness and processability, be conducive to the coating making electrode material slurry and electrode slice, improve electrode slice quality;
(5) there is the advantages such as investment is less, technically reliable, operating cost are low, there is good economic benefit and market popularization value.
Accompanying drawing explanation
Fig. 1 is the process route chart producing the coated nickel-cobalt lithium manganate cathode material of magnesium oxide.
Embodiment
The technological means realized to make the present invention, creation characteristic, reaching object and effect is easy to understand, below in conjunction with concrete diagram and embodiment, setting forth the present invention further.Should be appreciated that specific embodiment described herein only in order to explain the present invention, be not intended to limit the present invention.
Embodiment 1
A preparation method for the coated nickel-cobalt lithium manganate cathode material of magnesium oxide, comprises the following steps:
(1) raw material mixing: 1:0.53 takes lithium carbonate, nanometer spherical nickel cobalt manganese hydroxide precursor and accounts for the Sodium Polyacrylate that total mixture mass ratio is 0.2% in molar ratio, and add deionized water and make the solid content of slurry be 40% carry out disperseing, mix and filtering, form uniform intermediate mixture;
(2) once sintered: the intermediate mixture of step (1) gained is loaded saggar, send into pushed bat kiln and sinter, produce nickel-cobalt lithium manganate material, sintering process is continual is filled with oxygen, and sintering temperature is 650 DEG C, and sintering time is 3h;
(3) adulterate: select nano level ZnO, doping treatment is carried out to the nickle cobalt lithium manganate of step (2) gained, mass percent with account for total solid material mass 0.2% adds in the nickle cobalt lithium manganate of step (2) gained, and add proportion be 1.3 polyurethane ball be batch mixing medium, ratio of grinding media to material is 3:4:3, is tiltedly mixing batch mixing 2h in machine;
(4) double sintering: the nickle cobalt lithium manganate through overdoping is sent into pushed bat kiln and carries out double sintering, sintering process is continual is filled with air, and sintering temperature is 900 DEG C, and sintering time is 12h;
(5) coated: the magnesium acetate solution of preparation 0.03mol/L, the nickle cobalt lithium manganate after burning two joins in the middle of solution and mixes, and passes into the ammonia spirit of 1mol/L, and 75 DEG C are stirred 4h; Use distilled water cleaning and filtering, at 500 DEG C, dry 12h, obtain by the coated nickle cobalt lithium manganate material positive electrode of MgO.
Embodiment 2
(1) raw material mixing: 1:0.535 takes lithium carbonate, nanometer spherical nickel cobalt manganese hydroxide precursor and accounts for the Sodium Polyacrylate that total mixture mass ratio is 0.1% in molar ratio, and add deionized water and make the solid content of slurry be 50% carry out disperseing, mix and filtering, form uniform intermediate mixture;
(2) once sintered: the intermediate mixture of step (1) gained is loaded saggar, send into pushed bat kiln and sinter, produce nickel-cobalt lithium manganate material, sintering process is continual is filled with oxygen, and sintering temperature is 700 DEG C, and sintering time is 3h;
(3) adulterate: select nano level MgO, doping treatment is carried out to the nickle cobalt lithium manganate of step (2) gained, add in the nickle cobalt lithium manganate of step (2) gained with account for total solid material mass 0.5%, and add proportion be 1.4 polyurethane ball be batch mixing medium, ratio of grinding media to material is 3:4:3, is tiltedly mixing batch mixing 3h in machine;
(4) double sintering: send into pushed bat kiln carry out double sintering by through overdoping, coated nickle cobalt lithium manganate, sintering process is continual is filled with air, and sintering temperature is 1000 DEG C, and sintering time is 10h;
(5) coated: the magnesium acetate solution of preparation 0.05mol/L, the nickle cobalt lithium manganate after burning two joins in the middle of solution and mixes, and passes into the ammonia spirit of 2mol/L, and 80 DEG C are stirred 5h; Use distilled water cleaning and filtering, at 500 DEG C, dry 16h, obtain by the coated nickle cobalt lithium manganate material positive electrode of MgO.
Embodiment 3
(1) raw material mixing: in molar ratio 1:0.55 take lithium carbonate, nanometer spherical nickel cobalt manganese hydroxide precursor and account for total mixture mass ratio be 0.2% polyacrylic acid potassium, and add deionized water and make the solid content of slurry be 60% carry out disperseing, mix and filtering, form uniform intermediate mixture;
(2) once sintered: the intermediate mixture of step (1) gained is loaded saggar, send into pushed bat kiln and sinter, produce nickel-cobalt lithium manganate material, sintering process is continual is filled with oxygen, and sintering temperature is 750 DEG C, and sintering time is 5h;
(3) adulterate: select nano level Al
2o
3doping treatment is carried out to the nickle cobalt lithium manganate of step (2) gained, add in the nickle cobalt lithium manganate of step (2) gained with account for total solid material mass 0.2%, and add proportion be 1.4 polyurethane ball be batch mixing medium, ratio of grinding media to material is 3:4:3, is tiltedly mixing batch mixing 4h in machine;
(4) double sintering: send into pushed bat kiln carry out double sintering by through overdoping, coated nickle cobalt lithium manganate, sintering process is continual is filled with air, and sintering temperature is 1000 DEG C, and sintering time is 11h;
(5) coated: the Adlerika of preparation 0.01mol/L, the nickle cobalt lithium manganate after burning two joins in the middle of solution and mixes, and passes into the ammonia spirit of 2mol/L, and 75 DEG C are stirred 6h; Use distilled water cleaning and filtering, at 600 DEG C, dry 20h, obtain by the coated nickle cobalt lithium manganate material positive electrode of MgO.
Embodiment 4
(1) raw material mixing: 1:0.56 takes lithium carbonate, nanometer spherical nickel cobalt manganese hydroxide precursor and accounts for the polyacrylic acid potassium that total mixture mass ratio is 0.2% in molar ratio, and add deionized water and make the solid content of slurry be 40% carry out disperseing, mix and filtering, form uniform intermediate mixture;
(2) once sintered: the intermediate mixture of step (1) gained is loaded saggar, send into pushed bat kiln and sinter, produce nickel-cobalt lithium manganate material, sintering process is continual is filled with oxygen, and sintering temperature is 700 DEG C, and sintering time is 7h;
(3) adulterate: select nano level TiO
2doping treatment is carried out to the nickle cobalt lithium manganate of step (2) gained, add in the nickle cobalt lithium manganate of step (2) gained with account for total solid material mass 0.2%, and add proportion be 1.5 polyurethane ball be batch mixing medium, ratio of grinding media to material is 3:4:3, batch mixing 2h in oblique mixed machine;
(4) double sintering: send into pushed bat kiln carry out double sintering by through overdoping, coated nickle cobalt lithium manganate, sintering process is continual is filled with air, and sintering temperature is 1000 DEG C, and sintering time is 11h;
(5) coated: the Adlerika of preparation 0.03mol/L, the nickle cobalt lithium manganate after burning two joins in the middle of solution and mixes, and passes into the ammonia spirit of 1mol/L, and 75 DEG C are stirred 5h; Use distilled water cleaning and filtering, at 600 DEG C, dry 24h, obtain by the coated nickle cobalt lithium manganate material positive electrode of MgO.
Embodiment 5
A preparation method for the coated nickel-cobalt lithium manganate cathode material of magnesium oxide, comprises the following steps:
(1) raw material mixing: 1:0.53 takes lithium carbonate, nanometer spherical nickel cobalt manganese hydroxide precursor and accounts for the calcium polyacrylate (CPA) that total mixture mass ratio is 0.2% in molar ratio, and add deionized water and make the solid content of slurry be 40% carry out disperseing, mix and filtering, form uniform intermediate mixture;
(2) once sintered: the intermediate mixture of step (1) gained is loaded saggar, send into pushed bat kiln and sinter, produce nickel-cobalt lithium manganate material, sintering process is continual is filled with oxygen, and sintering temperature is 650 DEG C, and sintering time is 3h;
(3) adulterate: select nano level ZnO, doping treatment is carried out to the nickle cobalt lithium manganate of step (2) gained, mass percent with account for total solid material mass 0.2% adds in the nickle cobalt lithium manganate of step (2) gained, and add proportion be 1.3 polyurethane ball be batch mixing medium, ratio of grinding media to material is 3:4:3, is tiltedly mixing batch mixing 2h in machine;
(4) double sintering: the nickle cobalt lithium manganate through overdoping is sent into pushed bat kiln and carries out double sintering, sintering process is continual is filled with air, and sintering temperature is 900 DEG C, and sintering time is 12h;
(5) coated: the magnesium chloride solution of preparation 0.03mol/L, the nickle cobalt lithium manganate after burning two joins in the middle of solution and mixes, and passes into the ammonia spirit of 1mol/L, and 75 DEG C are stirred 4h; Use distilled water cleaning and filtering, at 500 DEG C, dry 12h, obtain by the coated nickle cobalt lithium manganate material positive electrode of MgO.
Embodiment 6
A preparation method for the coated nickel-cobalt lithium manganate cathode material of magnesium oxide, comprises the following steps:
(1) raw material mixing: 1:0.53 takes lithium carbonate, nanometer spherical nickel cobalt manganese hydroxide precursor and accounts for the calcium polyacrylate (CPA) that total mixture mass ratio is 0.2% in molar ratio, and add deionized water and make the solid content of slurry be 40% carry out disperseing, mix and filtering, form uniform intermediate mixture;
(2) once sintered: the intermediate mixture of step (1) gained is loaded saggar, send into pushed bat kiln and sinter, produce nickel-cobalt lithium manganate material, sintering process is continual is filled with oxygen, and sintering temperature is 650 DEG C, and sintering time is 3h;
(3) adulterate: select nano level ZnO, doping treatment is carried out to the nickle cobalt lithium manganate of step (2) gained, mass percent with account for total solid material mass 0.2% adds in the nickle cobalt lithium manganate of step (2) gained, and add proportion be 1.3 polyurethane ball be batch mixing medium, ratio of grinding media to material is 3:4:3, is tiltedly mixing batch mixing 2h in machine;
(4) double sintering: the nickle cobalt lithium manganate through overdoping is sent into pushed bat kiln and carries out double sintering, sintering process is continual is filled with air, and sintering temperature is 900 DEG C, and sintering time is 12h;
(5) coated: the magnesium chloride solution of preparation 0.03mol/L, the nickle cobalt lithium manganate after burning two joins in the middle of solution and mixes, and passes into the ammonia spirit of 1mol/L, and 75 DEG C are stirred 4h; Use distilled water cleaning and filtering, at 500 DEG C, dry 12h, obtain by the coated nickle cobalt lithium manganate material positive electrode of MgO.
The coated nickel-cobalt lithium manganate cathode material performance test of magnesium oxide that distinct methods is obtained