Calcium molybdate lithium ion battery negative material and preparation method thereofTechnical field
The present invention relates to technical field of lithium ion, more particularly to a kind of calcium molybdate lithium ion battery negative material andIts preparation method.
Background technology
Since coming out from eighties of last century lithium ion battery at the beginning of the nineties, with graphitized carbon material as negative pole, cobalt acid lithium materialLithium ion battery technology for positive pole has obtained huge development.Lithium ion battery is due to output voltage height, energy densityThe advantages of high, little environmental pollution and memory-less effect, it is widely used in the fields such as various portable sets and electric automobile.
However, as the portable set with mobile phone, notebook computer etc. as representative is constantly to miniaturization, intellectualityAnd lightening direction is developed, and electric automobile to aspects such as the energy density of motive-power battery, security and costs more and moreHigh requirement, the performance of conventional lithium ion battery cannot gradually meet the demand of above-mentioned development, and wherein lithium ion battery is negativePole material is one of important restraining factors.Wherein, the subject matter that traditional graphite cathode material is present is：(1) artificial stoneInk need to be processed in 1900 DEG C～2800 DEG C Jing high temperature graphitizations and is obtained, and preparation temperature is high；(2) graphite cathode material theory specific volumeAmount is only 372mAh/g, cannot gradually meet the fields such as various portable sets and electric automobile to lithium ion battery higher-energyThe demand of density；(3) negative pole structure of the lithium ion battery with graphitized carbon material as negative pole is fragile, and security is poor.
Thus, the performance of the negative material of lithium ion battery how is improved, becomes the focus that people are devoted to studying alwaysAnd Important Problems.
The content of the invention
Based on this, it is necessary to for traditional graphite negative material of lithium ion battery specific capacity is relatively low, security is poor andA kind of larger technical problem of preparation technology difficulty, there is provided calcium molybdate lithium ion battery negative material and preparation method thereof, it is describedCalcium molybdate lithium ion battery negative material has the microstructure of symmetrical matrix pore sphere, and specific capacity is higher, and security is preferable,Electro-chemical activity is high, good cycle, prepares with excellent storage lithium performance and easily.
A kind of preparation method of calcium molybdate lithium ion battery negative material, comprises the steps：To the mixed of water and ethylene glycolGum arabic, ammonium molybdate and the thiocarbamide of preset quality are sequentially added in closing solution, is sufficiently stirred for, obtain target solution；Pre-If in temperature range and Preset Time, hydro-thermal reaction is carried out to the target solution, the first reactant is obtained；It is anti-to described firstAnswer thing to carry out washing, be dried and high-temperature calcination, obtain symmetrical matrix pore sphere micron calcium molybdate lithium ion battery negative material；Wherein, the calcium content of the gum arabic is 0.02%～2%.
Wherein in one embodiment, sequentially add in the mixed solution to water and ethylene glycol preset quality IUncle's natural gum, ammonium molybdate and thiocarbamide, are sufficiently stirred for, and obtain target solution, comprise the steps：
The gum arabic of the first mass is added in the mixed solution of water and ethylene glycol, is sufficiently stirred for obtaining the first reactionLiquid；The ammonium molybdate of the second mass is added in first reactant liquor, is stirred to the ammonium molybdate and is completely dissolved that to obtain second anti-Answer liquid；The thiocarbamide of the 3rd mass is added in second reactant liquor, is stirred to the thiocarbamide to be completely dissolved and is obtained the targetSolution.
Wherein in one embodiment, in the mixed solution, the volume ratio of water and ethylene glycol is 1: (0.9～1.2).
Wherein in one embodiment, the mass ratio 1 of the gum arabic and the mixed solution: (5～150).
Wherein in one embodiment, the ammonium molybdate is 1 with the mass ratio of the gum arabic: (1.3～2.1).
Wherein in one embodiment, the thiocarbamide is 1 with the mass ratio of the ammonium molybdate: (0.9～6.1).
Wherein in one embodiment, the preset temperature range is 150 DEG C～200 DEG C, and the Preset Time is 30min～360min.
Wherein in one embodiment, the mode of the drying is to adopt constant temperature drying.
Wherein in one embodiment, the temperature of the high-temperature calcination is 500 DEG C～700 DEG C.
Wherein in one embodiment, the calcium molybdate lithium ion battery negative material is by institute in above-mentioned any one embodimentThe preparation method for stating calcium molybdate lithium ion battery negative material is prepared.
Above-mentioned calcium molybdate lithium ion battery negative material and preparation method thereof, obtains micro- with symmetrical matrix pore sphereStructure micron order calcium molybdate lithium ion battery negative material is seen, with larger specific surface area, electricity in lithium ion battery is increasedSolution liquid and the contact area of electrode material, improve the effect of impregnation of electrolyte, so as to shorten the transmission of lithium ion and electronicsPath so that the embedded and abjection of lithium ion more fully, and then causes the specific capacity of lithium ion battery higher, electro-chemical activityHeight, good reversibility, good cycle, with excellent storage lithium performance, and chondritic is uniformly complete, the uniformity of size compared withIt is good so that the negative pole stability of the lithium ion battery prepared using calcium molybdate lithium ion battery negative material has obtained carrying wellIt is high.Additionally, the preparation method of above-mentioned calcium molybdate lithium ion battery negative material, process is simple is workable, favorable reproducibility,It is and raw material sources are extensively, cheap, preferably reduce production cost.
Description of the drawings
Fig. 1 is the schematic flow sheet of the preparation method of the calcium molybdate lithium ion battery negative material of an embodiment；
Fig. 2 is the schematic flow sheet of the preparation method of the S110 of another embodiment；
Fig. 3 is the ESEM of the symmetrical matrix pore sphere micron calcium molybdate lithium ion battery negative material of an embodimentFigure；
Fig. 4 is the projection Electronic Speculum of the symmetrical matrix pore sphere micron calcium molybdate lithium ion battery negative material of an embodimentFigure；
Fig. 5 is the XRD spectrum of the symmetrical matrix pore sphere micron calcium molybdate lithium ion battery negative material of an embodiment；
Fig. 6 is the XPS collection of illustrative plates of the symmetrical matrix pore sphere micron calcium molybdate lithium ion battery negative material of an embodiment；
Fig. 7 is the symmetrical matrix pore sphere micron calcium molybdate lithium ion battery negative material of an embodiment in 0.01-The 1st, 2,50 charging and discharging curve figures under 3.0V voltages, under 200mAh/g current densities；
Fig. 8 is the symmetrical matrix pore sphere micron calcium molybdate lithium ion battery negative material of an embodiment in 0.01-Circulation volume and its coulombic efficiency curve map under 3.0V voltages, under 200mAh/g current densities；
Fig. 9 is the symmetrical matrix pore sphere micron calcium molybdate lithium ion battery negative material of another embodiment in 0.01-Circulation volume and its coulombic efficiency curve map under 3.0V voltages, under 200mAh/g current densities；
Figure 10 is the symmetrical matrix pore sphere micron calcium molybdate lithium ion battery negative material of an embodiment in 0.01-Under 3.0V voltages, current density is respectively the high rate performance under 50mA/g, 100mA/g, 200mA/g, 400mA/g, 200mA/g and surveysAttempt.
Specific embodiment
It is understandable to enable the above objects, features and advantages of the present invention to become apparent from, below in conjunction with the accompanying drawings to the present inventionSpecific embodiment be described in detail.Elaborate many details in order to fully understand this in the following descriptionIt is bright.But the present invention can be implemented with being much different from alternate manner described here, and those skilled in the art can be notSimilar improvement is done in the case of running counter to intension of the present invention, therefore the present invention is not limited by following public specific embodiment.
In describing the invention, it is to be understood that term " first ", " second " are only used for describing purpose, and can notIt is interpreted as indicating or implying relative importance or the implicit quantity for indicating indicated technical characteristic.Thus, define " theOne ", at least one this feature can be expressed or be implicitly included to the feature of " second ".In describing the invention, " multiple "It is meant that at least two, such as two, three etc., unless otherwise expressly limited specifically.
The preparation method of calcium molybdate lithium ion battery negative material according to embodiments of the present invention is described below in conjunction with the accompanying drawings.
It should be noted that main body of the negative material of lithium ion battery primarily as storage lithium, in charge and discharge processRealize the embedded of lithium ion and deviate from.The specific capacity of traditional calcium molybdate is higher than graphite, in the process of lithium ion battery discharge and rechargeMiddle Stability Analysis of Structures.However, as the electric conductivity of material itself is poor, being unfavorable for that electronics is negative in traditional calcium molybdate lithium ion batterySpread in the material of pole, it is impossible to preferably realize the embedded of lithium ion and deviate from.
In order to solve the above problems, as shown in figure 1, the preparation side of the calcium molybdate lithium ion battery negative material of an embodimentMethod comprises the steps：
S110：Gum arabic, ammonium molybdate and the sulphur of preset quality are sequentially added in the mixed solution of water and ethylene glycolUrea, is sufficiently stirred for, and obtains target solution liquid.
For example, S110 specifically includes following steps：
S111：The gum arabic of the first mass is added in the mixed solution of water and ethylene glycol, is sufficiently stirred for obtainingOne reactant liquor.For example, mixing time is 20min～60min.
S112：The ammonium molybdate of the second mass is added in the first reactant liquor, is stirred to ammonium molybdate to be completely dissolved and is obtained secondReactant liquor.For example, mixing time is 20min～60min.
S113：The thiocarbamide of the 3rd mass is added in the second reactant liquor, is stirred to thiocarbamide to be completely dissolved and is obtained target solution.Wherein, target solution is brown yellow transparent liquid.For example, mixing time is 30min～90min.
For example, it is stirred under conditions of mechanical agitation so that gum arabic, ammonium molybdate and the thiocarbamide for sequentially addingIt is completely dissolved, obtains target solution.
In order that symmetrical matrix pore sphere micron calcium molybdate in subsequent reactions, is obtained in that, and in the present embodiment, choosingWith gum arabic as calcium source.Relative to calcium salts such as calcium chloride, calcium nitrate, gum arabic can not only provide calcium source, moreImportantly, gum arabic as structure inducer, can promote the calcium molybdate of the spherical special construction of symmetrical matrix macroporeFormation, this is that the calcium salts such as traditional calcium chloride, calcium nitrate cannot be realized.
In order that the ball calcium molybdate obtained in subsequent reactions has symmetrical concave structure, in the present embodiment, selectSource of the ammonium molybdate as molybdenum acid ion.Relative to other molybdates, such as sodium molybdate and potassium molybdate etc., by reactantAmmonium molybdate is added in system so that the spherical calcium molybdate obtained in subsequent reactions has symmetrical concave structure, and this is to adopt sodium molybdateOr other molybdates such as potassium molybdate cannot be realized as molybdenum acid ion.
In order that the chondritic of the symmetrical matrix pore sphere micron calcium molybdate obtained in subsequent reactions is more uniformThe uniformity of complete and size preferably, in the present embodiment, adds thiocarbamide in reaction system, so, thiocarbamide by with IUncle's natural gum, molybdate and mixed solution each component compounding, form special solution environmental, obtain in enabling to subsequent reactionsThe chondritic of symmetrical matrix pore sphere micron calcium molybdate is more uniform and complete.
S120：In preset temperature range and Preset Time, hydro-thermal reaction is carried out to the target solution, obtain first anti-Answer thing.
For example, target solution is proceeded in reactor, in preset temperature range and Preset Time, carries out hydro-thermal reaction.Hydro-thermal reaction is referred in closed reaction vessel, with the fluid such as the aqueous solution or steam as medium, high by heating creation oneThe reaction carried out by warm reaction under high pressure environment.And for example, reactor is polytetrafluoroethyllining lining reactor, due in polytetrafluoroethylene (PTFE)The characteristics of lining reactor has antiacid alkali resistant and resists various organic solvents, and high temperature resistant, coefficient of friction are extremely low, preferably avoidThe generation of side reaction in hydro-thermal reaction, and beneficial to the taking-up of follow-up symmetrical matrix pore sphere micron molybdic acid calcium product.And for example, insteadThe volume for answering kettle is 100ml～200ml.
For example, preset temperature range is 150 DEG C～200 DEG C.And for example, preset temperature range is 160 DEG C～180 DEG C.And for example,Preset temperature range is 170 DEG C～195 DEG C.And for example, preset temperature range is 178 DEG C.And for example, Preset Time be 30min～360min.And for example, Preset Time is 40min～230min.And for example, Preset Time is 130min～350min.And for example, when presettingBetween be 200min.One embodiment is, when preset temperature range is located at 150 DEG C～200 DEG C, Preset Time be 30min～During 360min, symmetrical matrix pore sphere micron calcium molybdate lithium ion battery negative material is obtained in that.
S130：First reactant is carried out washing, is dried and high-temperature calcination, symmetrical matrix pore sphere micron is obtainedCalcium molybdate lithium ion battery negative material.
For example, first reactant is carried out successively washing, is dried and high-temperature calcination, obtain symmetrical matrix pore sphereMicron calcium molybdate lithium ion battery negative material.In order that the first reactant is purer, for example, the first reactant is carried outWash for several times.And for example, the first reactant is washed for several times using deionized water and alcohol.So so that the first reactantIn unreacted reagent thoroughly removed so that the first reactant is purer.For example, adopt quality for the first reactant 5～100 times of deionized water carries out first time washing, and quality is adopted after filtration for the alcohol of 5～20 times of the first reactant carries out secondSecondary washing, adopting quality after filtration again for the deionized water of 5～10 times of the first reactant carries out third time washing, so, favorablyMore uniform and complete symmetrical matrix pore sphere micron calcium molybdate, i.e. calcium molybdate microballoon are obtained in subsequent step, also known asCalcium molybdate microparticle, can serve as negative material.
In order that the first reactant after washing is thoroughly dried, for example, dry mode is to adopt constant temperature drying.For example, by washing after the first reactant filter after be dried；For example, the drying includes drying or dries；And for example, willFirst reactant carries out constant temperature drying in proceeding to drying box.And for example, the temperature of drying is 50 DEG C～80 DEG C.And for example, the temperature of dryingSpend for 55 DEG C～70 DEG C.And for example, the temperature of drying is 65 DEG C～74 DEG C.And for example, the time of drying is 12h～24h.And for example, dryThe dry time is 13h～19h.And for example, the time of drying is 16h～22h.And for example, the time of drying is 18h.So so that JingThe first reactant crossed after washing is thoroughly dried, and is conducive to the high-temperature calcination of subsequent step.
In order to remove the organic impurities in the first reactant, meanwhile, the crystal property of the first reactant is improved, so as to obtainChondritic with symmetrical matrix pore sphere micron calcium molybdate, is being washed to first reactant and is being dried itAfterwards, high-temperature calcination is carried out to dried first reactant.For example, the temperature of high-temperature calcination is 500 DEG C～700 DEG C.And for example, it is highThe temperature of temperature calcining is 550 DEG C～650 DEG C.And for example, the temperature of high-temperature calcination is 600 DEG C～690 DEG C.And for example, high-temperature calcinationTemperature is 650 DEG C.And for example, high temperature is carried out in the atmosphere furnace that dried first reactant is proceeded to nitrogen～hydrogen gas mixtureCalcining.And for example, atmosphere furnace with 1.0 DEG C/min～1.5 DEG C/min ramps to 650 DEG C.And for example, atmosphere furnace is first preheated to 300DEG C～500 DEG C, dried first reactant is then placed in, then with 1.0 DEG C/min～1.5 DEG C/min ramps to 650℃.And for example, atmosphere furnace with 1.1 DEG C/min～1.3 DEG C/min ramps to 690 DEG C.And for example, atmosphere furnace with 1.2 DEG C/min～1.4 DEG C/min ramps are to 550 DEG C.And for example, atmosphere furnace with 1.0 DEG C/min ramps to 650 DEG C.So, on the one hand veryThe organic impurities in the first reaction is eliminated well, on the other hand, it is possible to increase the crystal property of the first reactant, and then, energyEnough to obtain the chondritic with symmetrical matrix pore sphere micron calcium molybdate and uniform complete, the uniformity of size is preferable.
By above-mentioned reaction, symmetrical matrix pore sphere micron calcium molybdate lithium ion battery negative material, phase are obtained in thatFor traditional calcium molybdate, the calcium molybdate lithium ion battery negative material obtained in the present embodiment has special symmetrical matrix bigThe spherical microstructure in hole, with larger specific surface area, preferably increases electrolyte and electrode material in lithium ion batteryContact area, improves the effect of impregnation of electrolyte, so as to shorten the transmission path of lithium ion and electronics so that lithium ionIt is embedded and deviate from more fully, and then so that the specific capacity of lithium ion battery is higher, and electro-chemical activity is high, good cycle,With excellent storage lithium performance.Additionally, whole course of reaction, process is simple is workable, favorable reproducibility, and raw material sourcesExtensively, it is cheap, preferably reduce preparation cost.
In another embodiment, in order that the follow-up gum arabic for adding, ammonium molybdate and thiocarbamide fully dissolve, and to obtainThe micron-sized calcium molybdate for obtaining symmetrical matrix pore sphere provides good solvent environment, for example, in S110, water in mixed solutionVolume ratio with ethylene glycol is 1: (0.9～1.2).And for example, in mixed solution, the volume ratio of water and ethylene glycol is 1: (0.9～1).And for example, in mixed solution, the volume ratio of water and ethylene glycol is 1: (0.99～1.1).And for example, water and ethylene glycol in mixed solutionVolume ratio is 1: 1 or 1: 1.05.In such manner, it is possible to so that the follow-up gum arabic for adding, ammonium molybdate and thiocarbamide fully dissolve, andMicron-sized calcium molybdate to obtain symmetrical matrix pore sphere provides good solvent environment.Wherein, it is purer in order to obtainCalcium molybdate lithium ion battery negative material, for example, water is deionized water.
In another embodiment, in order to promote the formation of the calcium molybdate of the spherical special construction of symmetrical matrix macropore, for example, AhThe main component of uncle's natural gum is drawn to include that macromolecule polysaccharide, the calcium salt of macromolecule polysaccharide, the magnesium salts of macromolecule polysaccharide and macromolecule are moreThe sylvite of sugar.And for example, macromolecule polysaccharide is one or more in pectinose, galactolipin and glucuronic acid.And for example, IThe calcium content of uncle's natural gum is 0.02%～2%.And for example, the calcium content of gum arabic is 0.02%～1.2%.And for example, IThe calcium content of uncle's natural gum is 1%～1.9%.And for example, the calcium content of gum arabic is 1%.Thus it is possible, on the one hand, Arabic treeGlue provides the calcium salt of calcium molybdate lithium ion battery negative material, and on the other hand, gum arabic can promote as structure inducerEnter the formation of the calcium molybdate of the spherical special construction of symmetrical matrix macropore.
In another embodiment, in order to obtain symmetrical matrix pore sphere micron calcium molybdate lithium ion battery negative material, andEnable to the chondritic of symmetrical matrix pore sphere micron calcium molybdate more uniform and complete, for example, gum arabic withThe mass ratio of mixed solution is 1: (5～150).And for example, gum arabic and the mass ratio of mixed solution are 1: (10～90).AgainSuch as, gum arabic and the mass ratio of mixed solution are 1: (80～130)；For example, the quality of gum arabic and mixed solutionThan for 1: 100.And for example, ammonium molybdate and the mass ratio of gum arabic are 1: (1.3～2.1).And for example, ammonium molybdate and Arabic treeThe mass ratio of glue is 1: (1.3～1.8).And for example, ammonium molybdate and the mass ratio of gum arabic are 1: (1.7～2)；For example, molybdenumSour ammonium is 1: 1.8 with the mass ratio of gum arabic.And for example, thiocarbamide and the mass ratio of ammonium molybdate are 1: (0.9～6.1).And for example,Thiocarbamide is 1 with the mass ratio of ammonium molybdate: (1.9～4.1).And for example, thiocarbamide and the mass ratio of ammonium molybdate are 1: (3.9～5.1)；ExampleSuch as, thiocarbamide and the mass ratio of ammonium molybdate are 1: 4.For example, the quality of mixed solution is 50g～500g；And for example, the matter of mixed solutionMeasure as 100g～200g；And for example, the quality of mixed solution is 120g；And for example, the quality of gum arabic be 1g～5g, i.e. AhThe quality for drawing uncle's natural gum is 1g～5g, similarly hereinafter.And for example, the quality of gum arabic is 1.3g～4g.And for example, gum arabicQuality is 3g～4g；For example, the quality of gum arabic is 3.5g.And for example, the quality of ammonium molybdate is 0.5g～2.5g.And for example,The quality of ammonium molybdate is 1g～1.5g.And for example, the quality of ammonium molybdate is 1.4g～2.3g；For example, the quality of ammonium molybdate is 1.5g.And for example, the quality of thiocarbamide is 0.4g～2.0g.And for example, the quality of thiocarbamide is 0.5g～1.0g.And for example, the quality of thiocarbamide is 0.9g～1.8g；For example, the quality of thiocarbamide is 1.3g.By the mixed solution of water and ethylene glycol, gum arabic, ammonium sulfate and thiocarbamideCompounding, form specific reaction system so that in follow-up hydro-thermal reaction, symmetrical matrix pore sphere micron can be obtainedCalcium molybdate lithium ion battery negative material, and it is more equal to enable to the chondritic of symmetrical matrix pore sphere micron calcium molybdateIt is even and complete.
The preparation method of above-mentioned calcium molybdate lithium ion battery negative material, obtains the microcosmic with symmetrical matrix pore sphereStructure micron order calcium molybdate lithium ion battery negative material, with larger specific surface area, preferably increases lithium ion batteryThe contact area of middle electrolyte and electrode material, improves the effect of impregnation of electrolyte, so as to shorten lithium ion and electronicsTransmission path so that the embedded and abjection of lithium ion is more abundant.Further so that the specific capacity of lithium ion battery is higher, electrificationLearn activity high, good reversibility, good cycle, with excellent storage lithium performance.
The preparation method of above-mentioned calcium molybdate lithium ion battery negative material, obtains the microcosmic with symmetrical matrix pore sphereStructure micron order calcium molybdate, and chondritic is uniformly complete, the uniformity of size is preferable so that using calcium molybdate lithium ion batteryThe negative pole stability of lithium ion battery prepared by negative material has obtained improving well, and then, it is possible to increase adopt calcium molybdateThe security of lithium ion battery prepared by lithium ion battery negative material.
The preparation method of above-mentioned calcium molybdate lithium ion battery negative material, process is simple are workable, favorable reproducibility,It is and raw material sources are extensively, cheap, preferably reduce production cost.
On the basis of the preparation method of above-mentioned calcium molybdate lithium ion battery negative material, the present invention also provides a kind of molybdic acidCalcium lithium ion battery negative material, the calcium molybdate lithium ion battery negative material are born by sour calcium described in any of the above-described embodimentThe preparation method of pole material is prepared, so as to calcium molybdate lithium ion battery negative material is with symmetrical matrix pore sphereMicrostructure, with larger specific surface area, preferably increase contact of the electrolyte with electrode material in lithium ion batteryArea, improves the effect of impregnation of electrolyte, shortens the transmission path of lithium ion and electronics so that lithium ion it is embedded and de-Go out more abundant.Further so that had using lithium ion battery prepared by above-mentioned calcium molybdate lithium ion battery negative material higherSpecific capacity, preferable electro-chemical activity, preferable cycle performance, and with excellent storage lithium performance.
It is below specific embodiment, is specifically described the preparation method of calcium molybdate lithium ion battery negative material.
Embodiment 1
Carry out being sufficiently stirred for obtaining first during 1.0g gum arabics are added to 30mL water and 30mL ethylene glycol mixturesReactant liquor；In the first reactant liquor, the ammonium molybdate stirring 20min of addition 0.5g is completely dissolved to solid particle and obtains the second reactionLiquid；The thiocarbamide of 0.3883g is added into the second reactant liquor to be sufficiently stirred for 30min and target solution is obtained to grain dissolution, then willTarget solution is transferred in 100mL teflon-lined reactors after 180 DEG C of high-temperature storage 6h, obtains the first reactant,First reactant is brown ceramic powder.
The first reactant is cleaned using deionized water and absolute ethyl alcohol, by the first reactant for completing to clean 60Constant temperature 12h in DEG C drying box, the first reactant for completing freeze-day with constant temperature is proceeded in the atmosphere furnace of nitrogen～hydrogen gas mixture,Atmosphere furnace obtains symmetrical matrix pore sphere micron calcium molybdate lithium ion with 1 DEG C/min ramps to 650 DEG C after high-temperature calcinationCell negative electrode material.
Embodiment 2
Carry out being sufficiently stirred for obtaining first during 1.5g gum arabics are added to 50mL water and 50mL ethylene glycol mixturesReactant liquor；In the first reactant liquor, the ammonium molybdate stirring 30min of addition 0.75g is completely dissolved to solid particle and obtains the second reactionLiquid；The thiocarbamide of 0.6g is added into the second reactant liquor to be sufficiently stirred for 30min and target solution is obtained to grain dissolution, then by targetSolution is transferred in 200mL teflon-lined reactors after 150 DEG C of high-temperature storage 3h, obtains the first reactant, and firstReactant is brown ceramic powder.
The first reactant is cleaned using deionized water and absolute ethyl alcohol, by the first reactant for completing to clean 60Constant temperature 12h in DEG C drying box, the first reactant for completing freeze-day with constant temperature is proceeded in the atmosphere furnace of nitrogen～hydrogen gas mixture,Atmosphere furnace obtains symmetrical matrix pore sphere micron calcium molybdate lithium ion with 1 DEG C/min ramps to 650 DEG C after high-temperature calcinationCell negative electrode material.
Embodiment 3
Carry out being sufficiently stirred for obtaining first during 0.8g gum arabics are added to 30mL water and 30mL ethylene glycol mixturesReactant liquor；In the first reactant liquor, the ammonium molybdate stirring 20min of addition 0.4g is completely dissolved to solid particle and obtains the second reactionLiquid；The thiocarbamide of 0.325g is added into the second reactant liquor to be sufficiently stirred for 30min and target solution is obtained to grain dissolution, then by meshMark solution is transferred in 100mL teflon-lined reactors after 180 DEG C of high-temperature storage 1h, obtains the first reactant, theOne reactant is brown ceramic powder.
The first reactant is cleaned using deionized water and absolute ethyl alcohol, by the first reactant for completing to clean 60Constant temperature 12h in DEG C drying box, the first reactant for completing freeze-day with constant temperature is proceeded in the atmosphere furnace of nitrogen-hydrogen mixed gas,Atmosphere furnace obtains symmetrical matrix pore sphere micron calcium molybdate lithium ion with 1 DEG C/min ramps to 650 DEG C after high-temperature calcinationCell negative electrode material.
To symmetrical matrix pore sphere micron calcium molybdate lithium ion battery negative is obtained in above-described embodiment 1 to embodiment 3Material carries out performance test.
Fig. 3 is referred to, Fig. 3 is the ESEM of symmetrical matrix pore sphere micron calcium molybdate lithium ion battery negative materialFigure (SEM).Sample obtains symmetrical matrix pore sphere micron calcium molybdate lithium ion battery negative into embodiment 3 for embodiment 1Material.Wherein, the instrument used by sem analysis is the Quanta400F type projection electron microscopes of Dutch FEI Co., for observingThe microscopic appearance of specimen surface, accelerating potential is 10KV, and sample preparation is using being added dropwise in conducting resinl surface, air after absolute ethyl alcohol dispersionMiddle drying.Intuitively can know from Fig. 3, about 1.5 microns of the particle diameter of the molybdic acid calcium product of acquisition, obtained sample is in micro-Rice is spherical, and spherical sample has two symmetrical matrix macropores at two ends, and pattern is highly uniform, good dispersion, particle diameter unification.
Fig. 4 is referred to, Fig. 4 is the projection Electronic Speculum of symmetrical matrix pore sphere micron calcium molybdate lithium ion battery negative materialFigure (TEM).Sample obtains symmetrical matrix pore sphere micron calcium molybdate lithium ion battery negative into embodiment 3 for embodiment 1Material.Wherein, the instrument used by tem analysis is the instrument that is usually used in prior art.From Fig. 4, further intuitively obtainKnow, about 1.5 microns of the particle diameter of the molybdic acid calcium product of acquisition, obtained sample are spherical in micron, and spherical sample is deposited at two endsIn two symmetrical matrix macropores, pattern is highly uniform, good dispersion, particle diameter unification.
Fig. 5 is referred to, Fig. 5 is the XRD spectrum of symmetrical matrix pore sphere micron calcium molybdate lithium ion battery negative material.Sample be embodiment 1 in obtain symmetrical matrix pore sphere micron calcium molybdate lithium ion battery negative material.Wherein, XRD analysisInstrument used characterizes the crystalline phase of prepared final product for Dutch PANalytical company Empyrean type X-ray diffractometers (XRD)Structure.Test condition be Cu targets, K α radiation, 36kV, 30mA, step width 0.02o, 10～80o of sweep limits.Sample is placed in for powderSample stage groove is flattened, direct detection.As can be known from Fig. 3, the symmetrical matrix pore sphere micron calcium molybdate lithium that prepared by embodiment 1Main peak of the ion battery cathode material in 2 θ=28.8 ° positions corresponds to (112) of calcium molybdate crystal (JCPD NO.29-0351)Crystal face, the position of other diffraction maximums and intensity are also matched with corresponding PDF Ka Ku.It can also be seen that master from diffracting spectrumPeak intensity is very high, and the peak shape of other diffraction maximums is also very sharp, while no miscellaneous peak, illustrates the calcium molybdate lithium of the preparation method synthesisIon battery cathode material crystallinity is good and purity is very high.Same test is carried out to embodiment 2 and embodiment 3, acquisitionAs a result it is similar to, no longer states one by one.
Refer to Fig. 6, Fig. 6 is symmetrical matrix pore sphere micron calcium molybdate lithium ion battery negative to be obtained in embodiment 1The XPS collection of illustrative plates of material, in collection of illustrative plates, (a) represents Ca elements, (b) represents Mo elements, (c) represents O elements, shows that the product for obtaining is trueActually calcium molybdate.Wherein, the instrument used by XPS analysis characterizes material for the ESCALab250 types x-ray photoelectron spectroscopy in the U.S.Material surface-element information.Same test is carried out to embodiment 2 and embodiment 3, the result of acquisition is similar to, no longer states one by one.
To the symmetrical matrix pore sphere micron calcium molybdate lithium ion battery negative material obtained in embodiment 1 to embodiment 3Material carries out electrochemical property test.
By symmetrical matrix pore sphere micron calcium molybdate and conductive agent, binding agent Vingon (PVDF) in mass ratio 7:2: 1 quality is more uniform than ground and mixed to make electrode slice, and such as conductive agent is acetylene black, is, to electrode, to adopt with metal lithium sheetCelgard2400 barrier films, electrolyte are EC: the 1mol/LiPF6 of DMC: DEC volume ratio 1: 1: 1, are assembled into buckle type lithium-ion electricityPond.Charge-discharge performance test is carried out with the Xin Wei Electronics Co., Ltd.s CT-3008-5V20mA-S4 type test systems of Shenzhen, is testedVoltage range be 0.01V～3.0V.
The test result of specific discharge capacity is as follows：
The symmetrical matrix pore sphere micron calcium molybdate lithium ion battery negative material obtained in embodiment 1 0.01～Under 3.0V, 100mA/g current density, specific discharge capacity reaches 1029mAh/g, circulates specific discharge capacity through 50 times and is maintained at435mAh/g, specifically, refers to Fig. 7 and Fig. 8.
The symmetrical matrix pore sphere micron calcium molybdate lithium ion battery negative material obtained in embodiment 2 0.01～Under 3.0V, 100mA/g current density, first discharge specific capacity reaches 997mAh/g, circulates specific discharge capacity through 50 times and keepsIn 434mAh/g.Specifically, refer to Fig. 9.
The symmetrical matrix pore sphere micron calcium molybdate lithium ion battery negative material obtained in embodiment 3 0.01～Under 3.0V, 100mA/g current density, first discharge specific capacity reaches 1018mAh/g, circulates specific discharge capacity through 50 times and keepsIn 438mAh/g.
It should be noted that in prior art, after molybdic acid calcium material circulates 50 times under 100mA/g current densities, electric dischargeSpecific capacity is 276Ah/g.Obviously, the symmetrical matrix pore sphere micron that embodiment 1 is obtained into any embodiment in embodiment 3The specific discharge capacity of calcium molybdate lithium ion battery negative material is above the specific discharge capacity of molybdic acid calcium material of the prior art.
The result of high rate performance test is as follows：
The symmetrical matrix pore sphere micron calcium molybdate lithium ion battery negative material obtained in embodiment 1 is in current densityHigh rate performance test respectively under 50mA/g, 100mA/g, 200mA/g, 400mA/g and 200mA/g.Reversible capacity is respectively551mAh/g, 525mAh/g, 506mAh/g mAh/g, 454mAh/g and 510mAh/g.
The symmetrical matrix pore sphere micron calcium molybdate lithium ion battery negative material obtained in embodiment 2 is in current densityHigh rate performance test respectively under 50mA/g, 100mA/g, 200mA/g, 400mA/g and 200mA/g.Reversible capacity is respectively545mAh/g, 521mAh/g, 503mAh/g mAh/g, 453mAh/g and 505mAh/g.
The symmetrical matrix pore sphere micron calcium molybdate lithium ion battery negative material obtained in embodiment 3 is in current densityHigh rate performance test respectively under 50mA/g, 100mA/g, 200mA/g, 400mA/g and 200mA/g.Reversible capacity is respectively534mAh/g、515mAh/g、501mAh/g mAh/g、451mAh/g、507mAh/g.Specifically, result is obtained such as in embodiment 3Shown in Figure 10.
Symmetrical matrix pore sphere micron calcium molybdate lithium prepared by the result explanation said method of above-mentioned high rate performance testIon battery cathode material possesses preferable material invertibity and high rate performance, and then causes symmetrical matrix pore sphere micron molybdenumLithium ion battery prepared by sour calcium lithium ion battery negative material has preferable invertibity and high rate performance.
Above-mentioned electrochemical property test result shows, symmetrical matrix pore sphere micron calcium molybdate lithium prepared by said methodIon battery cathode material specific capacity is higher, and electro-chemical activity is high, good reversibility, good cycle, with excellent storage lithiumCan, and then cause the specific volume of the lithium ion battery of symmetrical matrix pore sphere micron calcium molybdate lithium ion battery negative material preparationAmount is higher, and electro-chemical activity is high, good reversibility, good cycle, with excellent storage lithium performance.
Each technical characteristic of embodiment described above arbitrarily can be combined, to make description succinct, not to above-mentioned realityApply all possible combination of each technical characteristic in example to be all described, as long as however, the combination of these technical characteristics is not depositedIn contradiction, the scope of this specification record is all considered to be.
Embodiment described above only expresses the several embodiments of the present invention, and its description is more concrete and detailed, but andTherefore can not be construed as limiting the scope of the patent.It should be pointed out that for one of ordinary skill in the art comesSay, without departing from the inventive concept of the premise, some deformations and improvement can also be made, these belong to the protection of the present inventionScope.Therefore, the protection domain of patent of the present invention should be defined by claims.