Summary of the invention
For overcoming the defect of prior art, an object of the present invention is the preparation method of the surface coated graphite cathode material providing a kind of lithium ion battery, and preparation method provided by the invention can at graphite cathode material uniformly coated one deck aluminum fluoride and reach the object of moderate multiplying factor (0.5C, 1C, 2C) performance and the long circulating capability retention increasing substantially graphite cathode material.
The present invention adopts native graphite and Delanium to be raw material, adopt alcohols solvent as the dispersant of graphite material, adopt high speed dispersion or spray dried form the aluminum fluoride generated by aluminium salt and fluoride is coated on graphite surface and is prepared into aluminum fluoride coated graphite material, or adopt high speed dispersion mode aluminum fluoride is directly coated on graphite surface and is prepared into aluminum fluoride coated graphite material.Aluminum fluoride coated natural graphite prepared by the present invention and the coated artificial graphite material of aluminum fluoride have high power capacity, Gao Shouxiao, high magnification, high power capacity conservation rate and coated evenly, be easy to the feature of industrialization.
For reaching above-mentioned purpose, the present invention adopts following technical scheme:
A preparation method for surface coated graphite cathode material, comprises the steps:
(1) add fluoride aqueous solution after graphite, aluminum salt solution and alcohol being mixed and obtain suspension; Can assist in the process of supending to stir;
(2) step (1) gained suspension is carried out following steps: be stirred to whole solvent evaporates or/and after spraying dry, be fired into surface coated graphite cathode material.
Preferably, the mass ratio of described graphite, aluminium salt, alcohol, fluoride is 80 ~ 95:0.5 ~ 10:25 ~ 35:0.5 ~ 5.
Preferably, described aluminium salt is a kind or combination at least of more than two kinds of aluminium chloride, aluminum acetate, aluminum nitrate, aluminum sulfate.
Preferably, described fluoride is a kind or combination at least of more than two kinds of sodium fluoride, ammonium fluoride, potassium fluoride, aluminum fluoride.
Or adopt following technical scheme:
A preparation method for surface coated graphite cathode material, comprises the steps:
(1) graphite, aluminun fluoride solution and alcohol are mixed to get suspension; Can assist in the process of supending to stir;
(2) step (1) gained suspension is carried out following steps: be stirred to whole solvent evaporates or/and after spraying dry, be fired into surface coated graphite cathode material.
Preferably, the mass ratio of described graphite, aluminum fluoride, alcohol is 85 ~ 99:0.2 ~ 5:25 ~ 35.
Preferably, described aluminum fluoride is AlF
3or/and AlF
33H
2o.
The present invention adopts alcohols as the dispersant of graphite-like raw material thus aluminum fluoride can be made evenly coated, and spray-dired coated mode is applicable to industrialized mass aluminum fluoride coated graphite product and coated aluminum fluoride uniformity is good.The aluminum fluoride coated graphite negative material that the present invention obtains significantly can promote moderate multiplying factor (0.5C, 1C, 2C) performance of material.
For preparation method of the present invention, the equipment of described stirring is the one in multifunctional stirring definite purpose motor, single-phase series motor, electric mixer, high speed dispersor, homogenizer.
Preferably, rotating speed during described stirring is 600-1200r/min.
Preferably, temperature during described stirring is 60-110 DEG C.
Preferably, described spray-dired inlet temperature is 200-360 DEG C; Spray-dired outlet temperature is 100-180 DEG C.
Preferably, described spray-dired atomizer pressure is 0.05-1MPa.
Preferably, the equipment burnt till described in is the one in vacuum furnace, box atmosphere furnace, tube furnace.
Preferably, the temperature of burning till is 300-1200 DEG C.
Preferably, the time of burning till is 3-12h.
Preferably, described graphite is the combination of in native graphite, Delanium a kind or 2 kinds.
Preferably, the average grain diameter of described graphite is 1 ~ 26 μm.
Preferably, the carbon content of described graphite is >=99.95wt%.
Preferably, described alcohol is a kind or combination at least of more than two kinds in ethanol, propyl alcohol, isopropyl alcohol, n-butanol, isobutanol.
For preparation method of the present invention, described in burn till and to also have screening after step, except magnetic, screening step.
Two of object of the present invention is to provide a kind of surface coated graphite cathode material, and described surface coated graphite cathode material is prepared by preparation method of the present invention.
Three of object of the present invention is to provide a kind of lithium ion battery, and described lithium ion battery comprises surface coated graphite cathode material of the present invention.
Beneficial effect of the present invention is:
Compared with prior art, the moderate multiplying factor of native graphite, Delanium (0.5C, 1C, 2C) performance significantly can be promoted, prepared aluminum fluoride coated graphite have doff lithium high rate performance, cycle performance excellent, first de-lithium specific capacity be greater than 360mAh/g, first discharging efficiency and be greater than 93% and resultant battery normal temperature 300 weeks charge and discharge cycles capability retentions feature of being greater than 88%;
Preparation technology of the present invention is simple, easy to operate, be applicable to suitability for industrialized production, mode of production environmental protection.
Aluminum fluoride coated graphite negative material of the present invention is applicable to the lithium ion batteries such as mobile phone, digital electrical apparatus, electric tool, electric automobile, energy storage, is specially adapted to as rate, power-type, has the negative material of the lithium ion batteries such as fast charging and discharging performance.
Embodiment
Below in conjunction with embodiment, embodiment of the present invention are described in detail.It will be understood to those of skill in the art that following examples are only the preferred embodiments of the present invention, so that understand the present invention better, thus should not be considered as limiting scope of the present invention.For a person skilled in the art, the present invention can have various modifications and variations, within the spirit and principles in the present invention all, and any amendment done, equivalent replacement or improvement etc., all should be included within protection scope of the present invention.
Experimental technique in following embodiment, if no special instructions, is conventional method; Experiment material used, if no special instructions, is and is purchased available from routine biochemistry chemical reagent work.
Embodiment 1
(1) be the liquor alumini chloridi of 0.03mol/L by 1L concentration, 200ml ethanol and 500g average grain diameter 15 ~ 18 μm, carbon content >=99.95% natural graphite powder to be added to successively in agitator tank and to stir and prepare graphite suspension, the mixing speed of multifunctional stirring definite purpose motor is 600r/min, is that the sodium fluoride of 0.75mol/L slowly drops in graphite suspension afterwards in whipping process by 200ml concentration;
(2) then, by thermostat water bath, graphite suspension is heated to 60 DEG C, 60 DEG C continue high-speed stirred to the aqueous solvent of aluminium chloride, sodium fluoride and ethanol volatilization dry, finally, burn till stirring dry graphite material in a vacuum furnace, firing temperature is 300 DEG C, firing time is 12h;
(3) material through burning till process being carried out sieve, obtaining lithium ion battery aluminum fluoride coated graphite negative material except magnetic, screening process.
The specific area of gained aluminum fluoride coated graphite negative material is 3.99m
2/ g, tap density is 1.041g/cm
3, compacted density is 1.560g/cm
3, crystal layer spacing d
002for 0.33567nm.Gained aluminum fluoride coated graphite negative material surface scan electromicroscopic photograph as shown in Figure 1.The energy dispersion X-ray spectrum (EDX) of gained aluminum fluoride coated graphite negative material as shown in Figure 2.
Electrochemical property test: (1) capacity, efficiency test: embodiment 1 gained aluminum fluoride coated graphite negative material, CMC, SBR are applied in copper foil current collector after mixing by 96.5:1.5:2 mass ratio, by dry, punching is for subsequent use.Button cell is assembled in the glove box being full of argon gas and carries out, and metal lithium sheet is to electrode, and electrolyte is 1mol/L LiPF
6+ EC+EMC, barrier film is poly-second/propylene composite micro porous film, and electrochemical property test carries out on cell tester, and charging/discharging voltage scope is 0.001 ~ 2V, and charge-discharge velocity is 0.2C, and doff lithium specific capacity, first discharging efficiency list in table 2 to test gained first.(2) high rate performance test: adopt and carry out high rate performance test with capacity, button cell that efficiency test is identical, charging/discharging voltage scope is 0.001 ~ 2V, multiplying power test condition, for first to use 0.1C discharge and recharge 3 weeks, uses 0.2C, 0.5C, 1C, 2C, 5C difference charge and discharge cycles 5 weeks afterwards.The high rate performance data of gained aluminum fluoride coated graphite negative material are as shown in Fig. 3 and table 3.
Resultant battery is tested: embodiment 1 gained aluminum fluoride coated graphite negative material, conductive agent conductive black, binding agent CMC and SBR are applied in copper foil current collector after mixing by the mass ratio of 95.0:1:1.8:2.2 and prepare cathode pole piece.Positive active material cobalt acid lithium, conductive agent conductive black, binding agent Kynoar (PVDF) are applied in aluminum foil current collector after mixing by the mass ratio of 96.8:2:1.2 and prepare anode pole piece.Electrolyte is 1mol/L LiPF
6+ EC+EMC+DEC, barrier film is poly-second/propylene composite micro porous film, and carry out normal temperature charge and discharge cycles with the speed of 1C, charging/discharging voltage scope is 4.25 ~ 3.0V.Resultant battery normal temperature circulation volume conservation rate as shown in Figure 4.As can be seen from Figure 4, the capability retention after embodiment 1 aluminum fluoride coated graphite negative material normal temperature 300 weeks charge and discharge cycles is 88.4%.
Embodiment 2
(1) be the Burow's Solution of 0.06mol/L by 1L concentration, 200ml propyl alcohol and 500g average grain diameter 18 ~ 22 μm, the native graphite of carbon content >=99.95% and the composite stone ink powder of Delanium to be added to successively in agitator tank and to stir and prepare graphite suspension, the mixing speed of single-phase series motor is 1000r/min, is that the ammonium fluoride of 1.5mol/L slowly drops in graphite suspension afterwards in whipping process by 200ml concentration;
(2) then, by the water-bath of circulating-heating groove, graphite suspension is heated to 90 DEG C, 90 DEG C continue high-speed stirred to the aqueous solvent of aluminum acetate, ammonium fluoride and propyl alcohol volatilization dry, finally, to stir dry graphite material at box atmosphere kiln roasting, firing temperature is 400 DEG C, firing time is 8h;
(3) material through burning till process being carried out sieve, obtaining lithium ion battery aluminum fluoride coated graphite negative material except magnetic, screening process.
The specific area of gained aluminum fluoride coated graphite negative material is 3.96m
2/ g, tap density is 1.026g/cm
3, compacted density is 1.515g/cm
3, crystal layer spacing d
002for 0.33571nm.Gained aluminum fluoride coated graphite negative material describes the specific capacity of doff lithium first, first the discharging efficiency data that record in table 2 by electrochemical property test, and high rate performance data are in table 3.
Embodiment 3
(1) be the aluminum nitrate solution of 0.06mol/L by 1L concentration, 200ml isobutanol and 500g average grain diameter 10 ~ 13 μm, carbon content >=99.95% natural graphite powder to be added to successively in agitator tank and to stir and prepare graphite suspension, the mixing speed of electric mixer is 800r/min, is that the ammonium fluoride of 1.5mol/L slowly drops in graphite suspension afterwards in whipping process by 200ml concentration;
(2) then, by the water-bath of circulating-heating groove, graphite suspension is heated to 100 DEG C, 100 DEG C continue high-speed stirred to the aqueous solvent of aluminum acetate, ammonium fluoride and propyl alcohol volatilization dry, finally, to stir dry graphite material at box atmosphere kiln roasting, firing temperature is 600 DEG C, firing time is 5h;
(3) material through burning till process being carried out sieve, obtaining lithium ion battery aluminum fluoride coated graphite negative material except magnetic, screening process.
The specific area of gained aluminum fluoride coated graphite negative material is 3.70m
2/ g, tap density is 1.002g/cm
3, compacted density is 1.438g/cm
3, crystal layer spacing d
002for 0.33571nm.Gained aluminum fluoride coated graphite negative material describes the specific capacity of doff lithium first, first the discharging efficiency data that record in table 2 by electrochemical property test, and high rate performance data are in table 3.
Embodiment 4
(1) be the aluminum nitrate solution of 0.12mol/L by 1L concentration, 200ml isopropyl alcohol and 500g average grain diameter 17 ~ 20 μm, carbon content >=99.95% the Delanium prepared by needle coke to be added to successively in agitator tank and to stir and prepare graphite suspension, the mixing speed of high speed dispersor is 1100r/min, is that the potassium fluoride of 3mol/L slowly drops in graphite suspension afterwards in whipping process by 200ml concentration;
(2) then, by electric hot water bath, graphite suspension is heated to 80 DEG C, 80 DEG C continue high-speed stirred to the aqueous solvent of aluminum nitrate, potassium fluoride and isopropyl alcohol volatilization dry, finally, to stir dry graphite material at tubular type kiln roasting, firing temperature is 800 DEG C, firing time is 5h;
(3) material through burning till process being carried out sieve, obtaining lithium ion battery aluminum fluoride coated graphite negative material except magnetic, screening process.
The specific area of gained aluminum fluoride coated graphite negative material is 4.53m
2/ g, tap density is 0.892g/cm
3, compacted density is 1.696g/cm
3, crystal layer spacing d
002for 0.33579nm.Gained aluminum fluoride coated graphite negative material describes the specific capacity of doff lithium first, first the discharging efficiency data that record in table 2 by electrochemical property test, and high rate performance data are in table 3.
Embodiment 5
(1) be the liquor alumini chloridi of 0.03mol/L by 1L concentration, 200ml ethanol and 500g average grain diameter 15 ~ 18 μm, carbon content >=99.95% natural graphite powder to be added to successively in agitator tank and to stir and prepare graphite suspension, the mixing speed of multifunctional stirring definite purpose motor is 600r/min, is that the sodium fluoride of 0.75mol/L slowly drops in graphite suspension afterwards in whipping process by 200ml concentration;
(2) graphite suspension prepared is carried out spray drying treatment, spraying dry inlet temperature is 200 DEG C, outlet temperature is 100 DEG C, atomizer pressure 0.05MPa, finally, burnt till in a vacuum furnace by the graphite material of spray-dried process, firing temperature is 300 DEG C, firing time is 12h;
(3) material through burning till process being carried out sieve, obtaining lithium ion battery aluminum fluoride coated graphite negative material except magnetic, screening process.
The specific area of gained aluminum fluoride coated graphite negative material is 3.54m
2/ g, tap density is 1.048g/cm
3, compacted density is 1.557g/cm
3, crystal layer spacing d
002for 0.33561nm.Gained aluminum fluoride coated graphite negative material describes the specific capacity of doff lithium first, first the discharging efficiency data that record in table 2 by electrochemical property test, and high rate performance data are in table 3.
Embodiment 6
(1) be the Burow's Solution of 0.06mol/L by 1L concentration, 200ml propyl alcohol and 500g average grain diameter 18 ~ 22 μm, the native graphite of carbon content >=99.95% and the composite stone ink powder of Delanium to be added to successively in agitator tank and to stir and prepare graphite suspension, the mixing speed of single-phase series motor is 1000r/min, is that the ammonium fluoride of 1.5mol/L slowly drops in graphite suspension afterwards in whipping process by 200ml concentration;
(2) graphite suspension prepared is carried out spray drying treatment, spraying dry inlet temperature is 260 DEG C, outlet temperature is 120 DEG C, atomizer pressure 0.2MPa, finally, by the graphite material of spray-dried process at box atmosphere kiln roasting, firing temperature is 400 DEG C, firing time is 8h;
(3) material through burning till process being carried out sieve, obtaining lithium ion battery aluminum fluoride coated graphite negative material except magnetic, screening process.
The specific area of gained aluminum fluoride coated graphite negative material is 4.02m
2/ g, tap density is 0.862g/cm
3, compacted density is 1.516g/cm
3, crystal layer spacing d
002for 0.33571nm.Gained aluminum fluoride coated graphite negative material describes the specific capacity of doff lithium first, first the discharging efficiency data that record in table 2 by electrochemical property test, and high rate performance data are in table 3.
Embodiment 7
(1) be the aluminum nitrate solution of 0.06mol/L by 1L concentration, 200ml isobutanol and 500g average grain diameter 10 ~ 13 μm, carbon content >=99.95% natural graphite powder to be added to successively in agitator tank and to stir and prepare graphite suspension, the mixing speed of electric mixer is 800r/min, is that the ammonium fluoride of 1.5mol/L slowly drops in graphite suspension afterwards in whipping process by 200ml concentration;
(2) graphite suspension prepared is carried out spray drying treatment, spraying dry inlet temperature is 300 DEG C, outlet temperature is 150 DEG C, atomizer pressure 0.5MPa, finally, will stir dry graphite material at box atmosphere kiln roasting, firing temperature is 600 DEG C, firing time is 5h;
(3) material through burning till process being carried out sieve, obtaining lithium ion battery aluminum fluoride coated graphite negative material except magnetic, screening process.
The specific area of gained aluminum fluoride coated graphite negative material is 3.76m
2/ g, tap density is 0.944g/cm
3, compacted density is 1.276g/cm
3, crystal layer spacing d
002for 0.33566nm.Gained aluminum fluoride coated graphite negative material describes the specific capacity of doff lithium first, first the discharging efficiency data that record in table 2 by electrochemical property test, and high rate performance data are in table 3.
Embodiment 8
(1) be the aluminum nitrate solution of 0.12mol/L by 1L concentration, 200ml isopropyl alcohol and 500g average grain diameter 17 ~ 20 μm, carbon content >=99.95% the Delanium prepared by needle coke to be added to successively in agitator tank and to stir and prepare graphite suspension, the mixing speed of high speed dispersor is 1100r/min, is that the potassium fluoride of 3mol/L slowly drops in graphite suspension afterwards in whipping process by 200ml concentration;
(2) graphite suspension prepared is carried out spray drying treatment, spraying dry inlet temperature is 320 DEG C, outlet temperature is 155 DEG C, atomizer pressure 0.8MPa, finally, will stir dry graphite material at tubular type kiln roasting, firing temperature is 800 DEG C, firing time is 5h;
(3) material through burning till process being carried out sieve, obtaining lithium ion battery aluminum fluoride coated graphite negative material except magnetic, screening process.
The specific area of gained aluminum fluoride coated graphite negative material is 4.06m
2/ g, tap density is 0.889g/cm
3, compacted density is 1.693g/cm
3, crystal layer spacing d
002for 0.33583nm.Gained aluminum fluoride coated graphite negative material describes the specific capacity of doff lithium first, first the discharging efficiency data that record in table 2 by electrochemical property test, and high rate performance data are in table 3.
Embodiment 9
(1) be the aluminun fluoride solution of 0.03mol/L by 2.8L concentration, 200ml ethanol and 1kg average grain diameter 15 ~ 18 μm, carbon content >=99.95% natural graphite powder to be added to successively in agitator tank and to stir and prepare graphite suspension, the mixing speed of multifunctional stirring definite purpose motor is 600r/min;
(2) graphite suspension prepared is carried out spray drying treatment, spraying dry inlet temperature is 200 DEG C, outlet temperature is 100 DEG C, atomizer pressure 0.05MPa, finally, burnt till in a vacuum furnace by the graphite material of spray-dried process, firing temperature is 300 DEG C, firing time is 12h;
(3) material through burning till process being carried out sieve, obtaining lithium ion battery aluminum fluoride coated graphite negative material except magnetic, screening process.
The specific area of gained aluminum fluoride coated graphite negative material is 3.67m
2/ g, tap density is 1.058g/cm
3, compacted density is 1.569g/cm
3, crystal layer spacing d
002for 0.33562nm.Gained aluminum fluoride coated graphite negative material describes the specific capacity of doff lithium first, first the discharging efficiency data that record in table 2 by electrochemical property test, and high rate performance data are in table 3.
Embodiment 10
(1) be the aluminun fluoride solution of 0.06mol/L by 2.8L concentration, 200ml ethanol and 1kg average grain diameter 15 ~ 18 μm, the native graphite of carbon content >=99.95% and the composite stone ink powder of Delanium to be added to successively in agitator tank and to stir and prepare graphite suspension, and the mixing speed of single-phase series motor is 1000r/min;
(2) graphite suspension prepared is carried out spray drying treatment, spraying dry inlet temperature is 260 DEG C, outlet temperature is 120 DEG C, atomizer pressure 0.2MPa, finally, by the graphite material of spray-dried process at box atmosphere kiln roasting, firing temperature is 400 DEG C, firing time is 8h;
(3) material through burning till process being carried out sieve, obtaining lithium ion battery aluminum fluoride coated graphite negative material except magnetic, screening process.
The specific area of gained aluminum fluoride coated graphite negative material is 3.91m
2/ g, tap density is 1.029g/cm
3, compacted density is 1.518g/cm
3, crystal layer spacing d
002for 0.33569nm.Gained aluminum fluoride coated graphite negative material describes the specific capacity of doff lithium first, first the discharging efficiency data that record in table 2 by electrochemical property test, and high rate performance data are in table 3.
Embodiment 11
(1) be the aluminun fluoride solution of 0.06mol/L by 2.8L concentration, 200ml isobutanol and 1kg average grain diameter 10 ~ 13 μm, carbon content >=99.95% natural graphite powder to be added to successively in agitator tank and to stir and prepare graphite suspension, the mixing speed of electric mixer is 800r/min;
(2) graphite suspension prepared is carried out spray drying treatment, spraying dry inlet temperature is 300 DEG C, outlet temperature is 150 DEG C, atomizer pressure 0.5MPa, finally, will stir dry graphite material at box atmosphere kiln roasting, firing temperature is 600 DEG C, firing time is 5h;
(3) material through burning till process being carried out sieve, obtaining lithium ion battery aluminum fluoride coated graphite negative material except magnetic, screening process.
The specific area of gained aluminum fluoride coated graphite negative material is 3.59m
2/ g, tap density is 0.972g/cm
3, compacted density is 1.434g/cm
3, crystal layer spacing d
002for 0.33567nm.Gained aluminum fluoride coated graphite negative material describes the specific capacity of doff lithium first, first the discharging efficiency data that record in table 2 by electrochemical property test, and high rate performance data are in table 3.
Embodiment 12
(1) be the aluminum fluoride trihydrate solution of 0.12mol/L by 2.8L concentration, 200ml isopropyl alcohol and 1kg average grain diameter 17 ~ 20 μm, carbon content >=99.95% the Delanium prepared by needle coke to be added to successively in agitator tank and to stir and prepare graphite suspension, the mixing speed of high speed dispersor is 1100r/min;
(2) graphite suspension prepared is carried out spray drying treatment, spraying dry inlet temperature is 320 DEG C, outlet temperature is 155 DEG C, atomizer pressure 0.8MPa, finally, will stir dry graphite material at tubular type kiln roasting, firing temperature is 800 DEG C, firing time is 5h;
(3) material through burning till process being carried out sieve, obtaining lithium ion battery aluminum fluoride coated graphite negative material except magnetic, screening process.
The specific area of gained aluminum fluoride coated graphite negative material is 4.11m
2/ g, tap density is 0.890g/cm
3, compacted density is 1.670g/cm
3, crystal layer spacing d
002for 0.33578nm.Gained aluminum fluoride coated graphite negative material describes the specific capacity of doff lithium first, first the discharging efficiency data that record in table 2 by electrochemical property test, and high rate performance data are in table 3.
Comparative example 1
Use embodiment 1,5,9 to prepare the native graphite of aluminum fluoride coated graphite negative material, described graphite is natural spherical, and by described graphite through pitch-coating carbonization treatment, its average grain diameter is 15 ~ 18 μm, specific area is 3.21m
2/ g, tap density is 1.054g/cm
3, compacted density is 1.596g/cm
3, crystal layer spacing d
002for 0.33568nm, the graphite cathode material after the process of pitch-coating carbonization treatment is prepared battery according to the method for embodiment 1.Describe the specific capacity of doff lithium first, first the discharging efficiency data that record in table 2 by electrochemical property test, high rate performance data are as shown in Fig. 3 and table 3.
Comparative example 2
The composite graphite of the native graphite and Delanium that use embodiment 2,6,10 to prepare aluminum fluoride coated graphite negative material prepares battery according to the method for embodiment 1, and the average grain diameter of described composite graphite is 18 ~ 22 μm, specific area is 3.45m
2/ g, tap density is 1.021g/cm
3, compacted density is 1.510g/cm
3, crystal layer spacing d
002for 0.33573nm.Describe the specific capacity of doff lithium first, first the discharging efficiency data that record in table 2 by electrochemical property test, high rate performance data are as shown in table 3.
Comparative example 3
Use embodiment 3,7,11 to prepare the native graphite of aluminum fluoride coated graphite negative material, described graphite is natural spherical plumbago, and by it through pitch-coating carbonization treatment, its average grain diameter is 10 ~ 13 μm, specific area is 3.42m
2/ g, tap density is 0.948g/cm
3, compacted density is 1.263g/cm
3, crystal layer spacing d
002for 0.33567nm, the graphite cathode material after the process of pitch-coating carbonization treatment is prepared battery according to the method for embodiment 1.Describe the specific capacity of doff lithium first, first the discharging efficiency data that record in table 2 by electrochemical property test, high rate performance data are as shown in table 3.
Comparative example 4
The Delanium that the raw material using embodiment 4,8,12 to prepare aluminum fluoride coated graphite negative material is prepared by needle coke prepares battery according to the method for embodiment 1, and the average grain diameter of described Delanium is 17 ~ 20 μm, specific area is 3.73m
2/ g, tap density is 0.887g/cm
3, compacted density is 1.691g/cm
3, crystal layer spacing d
002for 0.33581nm.Describe the specific capacity of doff lithium first, first the discharging efficiency data that record in table 2 by electrochemical property test, high rate performance data are in table 3.
Under embodiment 1-12 in comparison sheet 1-3 and the specific area of comparative example 1-4, tap density, compacted density, crystal layer spacing, first doff lithium specific capacity, first discharging efficiency and different multiplying, de-lithium capacity ratio data can be found out, compared with raw material, the specific area of aluminum fluoride coated graphite increases, the change of tap density, compacted density, crystal layer spacing, first doff lithium specific capacity, first discharging efficiency is little, 0.2C, 0.5C, 1C, 2C, 5C high rate performance promotes, and particularly moderate multiplying factor (0.5C, 1C, 2C) performance significantly promotes.
Adopt the average grain diameter of Britain's Malvern laser particle analyzer MS2000 test material particle size range and feed particles.
Adopt the full-automatic specific area of Tristar3000 of Micromeritics Instrument Corp. U.S.A and the specific area of lacunarity analysis instrument test material.
Adopt the tap density of Quantachrome AutoTap tap density meter test material.
Adopt the compacted density of U.S. Carver tablet press machine test material.
Dutch PANalytical X ' pert PRO X-ray diffraction analysis instrument is adopted to measure crystallogram and the crystal layer spacing of material.According to graphite, the MCMB crystal layer spacing d of XRD test
002the degree of graphitization of the aluminum fluoride coated graphite described in embodiment 1 to embodiment 15 calculated is between 92.4% ~ 96.9%.
Adopt the surface topography, particle size etc. of the KYKY 2800B sem observation sample of BeiJing ZhongKe's tech.The embodiment of the present invention 1 prepare aluminum fluoride coated graphite negative material surface scan electromicroscopic photograph as shown in Figure 1, its surface topography similar " potato " shape.
HIT S4800 scanning electron microscopy and England Oxford company X-Max energy disperse spectroscopy is adopted to characterize the content of aluminum fluoride coated graphite surfaces of aluminum and fluorine.Energy dispersion X-ray spectrum (EDX) figure of aluminum fluoride coated graphite negative material prepared by the embodiment of the present invention 1 as shown in Figure 2.
Japanese TOYO company's T OSCAT-3100 is adopted to test the high rate performance of cabinet sign aluminum fluoride coated graphite negative material.Aluminum fluoride coated graphite negative material different multiplying performance data figure prepared by the embodiment of the present invention 1 as shown in Figure 3.
The result of the average grain diameter of the aluminum fluoride coated graphite that above-described embodiment 1-12 and comparative example 1-4 obtains, specific area, tap density, compacted density, crystal layer spacing performance parameter is as shown in table 1.
The specific capacity of doff lithium first of the aluminum fluoride coated graphite that above-described embodiment 1-12 and comparative example 1-4 obtains, discharging efficiency result is as shown in table 2 first.
The high rate performance result of the aluminum fluoride coated graphite that above-described embodiment 1-12 and comparative example 1-4 obtains is as shown in table 3.
Table 1
Table 2
Table 3
Experimental example |
0.2C/0.1C |
0.5C/0.1C |
1C/0.1C |
2C/0.1C |
5C/0.1C |
Embodiment 1 |
98.3% |
82.2% |
33.5% |
5.5% |
3.2% |
Embodiment 2 |
97.6% |
71.8% |
41.0% |
5.7% |
2.8% |
Embodiment 3 |
99.2% |
91.3% |
56.3% |
11.6% |
4.1% |
Embodiment 4 |
97.5% |
70.9% |
39.7% |
5.4% |
3.2% |
Embodiment 5 |
97.3% |
79.2% |
24.1% |
5.6% |
2.9% |
Embodiment 6 |
97.0% |
68.7% |
37.6% |
5.1% |
2.3% |
Embodiment 7 |
99.5% |
92.3% |
57.4% |
12.9% |
4.3% |
Embodiment 8 |
97.3% |
69.2% |
36.3% |
5.0% |
2.9% |
Embodiment 9 |
98.6% |
79.1% |
29.0% |
4.2% |
1.6% |
Embodiment 10 |
97.7% |
72.0% |
41.6% |
5.8% |
3.0% |
Embodiment 11 |
98.5% |
75.6% |
42.8% |
5.9% |
2.9% |
Embodiment 12 |
99.8% |
91.0% |
56.9% |
12.3% |
3.8% |
Comparative example 1 |
97.7% |
68.6% |
20.8% |
3.9% |
1.2% |
Comparative example 2 |
96.6% |
58.7% |
28.0% |
4.0% |
0.8% |
Comparative example 3 |
99.4% |
88.9% |
52.7% |
10.0% |
3.9% |
Comparative example 4 |
96.3% |
56.7% |
26.8% |
4.0% |
1.1% |
As can be seen from table 1 to table 3, the de-first lithium specific capacity of the surface coated graphite cathode material that the present invention obtains is greater than 360mAh/g, and discharging efficiency is greater than 93% first; 0.2C, 0.5C, 1C, 2C doff lithium high rate performance is excellent.
Applicant states, the present invention illustrates detailed process equipment and process flow process of the present invention by above-described embodiment, but the present invention is not limited to above-mentioned detailed process equipment and process flow process, namely do not mean that the present invention must rely on above-mentioned detailed process equipment and process flow process and could implement.Person of ordinary skill in the field should understand, any improvement in the present invention, to equivalence replacement and the interpolation of auxiliary element, the concrete way choice etc. of each raw material of product of the present invention, all drops within protection scope of the present invention and open scope.