The preparation method of high density lithium cell positive material lithium manganate having spinel structure
Technical field
The invention belongs to the anode material of lithium battery technical field, be specifically related to a kind of lithium manganate having spinel structure LiMn
2O
4The preparation method.
Background technology
Along with the increasingly exhaustion of petroleum resources and increasingly sharpening of environmental pollution, the hybrid electric automobile take battery as power and pure electric automobile have become global much-talked-about topic.In the recent period, countries in the world have all given great support to the development of electric automobile, and have formulated corresponding development plan, and expectation is alleviated more and more serious energy crisis and air environmental pollution problem with this.At present, large-scale lithium ion battery is considered to the potential automobile power cell of tool.Domestic and international many automobile production producer is getting down to the research of vehicle lithium ion battery, and has realized the part commercialization.Lithium manganate having spinel structure has that Heat stability is good, overcharging resisting electricity, high rate during charging-discharging are superior, aboundresources and the advantage such as environmentally friendly, and therefore it become the desirable positive electrode of automobile-used large-scale lithium ion battery.In recent years, lithium manganate having spinel structure is generally accepted in the electric automobile field, and enters the industrialization stage.For example, the electric automobile produced of the motor corporations such as Toyota, Honda, daily output has all used take lithium manganate having spinel structure as anodal lithium ion battery." i-MiEV " electric automobile that Mitsubishi Motors released in July, 2009 also adopts LiMn2O4 as the positive electrode of lithium ion battery.
Along with the progressively development of electric automobile, to the also progressively raising of performance requirement of lithium manganate having spinel structure.For the energy density per unit volume metric density that further improves battery and the coating quality that improves electrode slice, need further to improve the tap density of lithium manganate having spinel structure.The pattern of sphere or class sphere then is the important channel of increasing the lithium manganate having spinel structure tap density.The particle of this outer spherical or class sphere is conducive to the coating of electrode slice, can be fully and conductive additive mix, and therefore promote the power characteristic of battery.Yet it is relatively more difficult synthesizing the lithium manganate having spinel structure with sphere or class sphere with conventional method.Existing lithium manganate having spinel structure Li
xMn
2O
4The preparation method of positive electrode mainly is the high temperature solid-phase sintering method.The method synthesis technique is simple, only behind the lithium source and the abundant mixing of manganese source material (chemical manganese bioxide or electrolytic manganese dioxide) of need with the chemical formula proportioning, at 700-1000
oCalcining got final product to get product in 12-48 hour in the C scope.But the standby material granule of this legal system all has typical octahedral structure (being spinel structure), and corner angle are clearly demarcated and sharp.This particle packing is difficult to realize high tap density together the time, in addition electrode slice apply and rolling process in, sharp grain corner damages collector easily.
Summary of the invention
The object of the invention is to: developed a kind of sphere or class spherical spinel type LiMn2O4 LiMn of preparing
2O
4New method.This method can be prepared by simple synthesis technique sphere or the class spherical lithium manganate LiMn of high-tap density
2O
4
For achieving the above object, the present invention has adopted following technical scheme.
The preparation method of described high density lithium cell positive material lithium manganate having spinel structure, it is characterized in that: comprise the steps: one, at first prepare MnOOH by chemical method: the aqueous solution that will contain manganese ion, in the situation of strong stirring, be added drop-wise in the alkaline solution; Precipitation reaction occurs in this course, its precipitated product MnOOH; Subsequently, with precipitated product MnOOH separation, washing, drying; Two, the MnOOH that makes and lithium salts or lithium salts and other metal oxides are mixed together, prepare again the lithium manganate having spinel structure of sphere or class sphere through high-temperature calcination; And the particle diameter of resulting lithium manganate having spinel structure particle is in the scope of 1-10 um.
Further, the preparation method of aforesaid high density lithium cell positive material lithium manganate having spinel structure, wherein: the described salt that comprises in the aqueous solution of manganese ion that contains is: one or more mixtures in manganese acetate, manganese nitrate, nitrate trihydrate manganese, manganese sulfate, the manganese sulfate monohydrate.
Further, the preparation method of aforesaid high density lithium cell positive material lithium manganate having spinel structure, wherein: described lithium salts is: one or several mixtures in lithium nitrate, lithium carbonate, lithium acetate, the lithium hydroxide.
Further, the preparation method of aforesaid high density lithium cell positive material lithium manganate having spinel structure, wherein: described lithium manganate having spinel structure LiMn
2O
4Also can carry out monobasic or polynary other doped with metal elements, form doped compound LiM
xMn
2-xO
4Here doped chemical (M) comprises first, second host element and transition metal and the rare earth element in the periodic table of elements, for example Na, K, Zn
2+, Mg
2+, Al
3+, Cu
2+, Co
3+, Cr
3+, Fe
3+, V
4+, La
3+Deng.In concrete the application, can use following metal oxide ZnO, Al
2O
3, MgO, CoO, Co
3O
4, Fe
2O
3, V
2O
5, La
2O
3In one or several mixture.
The invention has the beneficial effects as follows: sphere or the class spherical spinel type LiMn of said method preparation
2O
4Or the compound L iM of monobasic or polynary other doped with metal elements
xMn
2-xO
4If be applied to ion battery, can promote battery electrode density, increase the energy density per unit volume metric density of battery, and promote the power characteristic of battery, thereby improve significantly the overall performance of battery.
Embodiment
The invention will be further described below by specific embodiment.
Embodiment 1.
One, at first prepares MnOOH by chemical method: will contain the aqueous solution of manganese ion, and in the situation of strong stirring, be added drop-wise in the alkaline solution; Precipitation reaction occurs in this course, its precipitated product MnOOH; Subsequently, with precipitated product MnOOH separation, washing, drying; Two, MnOOH and the lithium salts that makes is mixed together, prepares again the lithium manganate having spinel structure particle of sphere or class sphere through high-temperature calcination.Obtaining the product granular size is 5 um, and tap density is 2.3g/cm
3With the LiMn that makes
2O
4Particle, conductive agent and binding agent are then controlled conventional thickness and are coated on the aluminum foil current collector according to the mass ratio mixed slurry of 85:5:10.LiPF with 1.0 mol/L
6/ EC+DEC+DMC (volume ratio 1:1:1) is electrolyte, and the Li sheet is negative pole, and it is barrier film that the U.S. produces Cellgard-2400 type polypropylene screen, is assembled into button cell in being full of the glove box of argon gas.Then on the LandCT2001A type battery test system that Jin Nuo Electronics Co., Ltd. in Wuhan produces, synthetic material is carried out multiplying power test and cycle life test.When 1/3C charged and discharged, the capacity of this material was 120mAh/g; When 1C charged and discharged, its capacity was 116mAh/g; When 20C charges and discharge, the capacity of this material be 84mAh/g. under the 1C condition, charge and discharge the circulation 100 weeks, the capacity dimension holdup is 85%.
Comparative example 1.
The MnO that makes with chemical method
2Be raw material, adopt conventional solid phase synthesis process to prepare LiMn
2O
4Material: after chemical manganese bioxide and lithium salts grinding evenly, at 800-1000
oCalcining is 6-48 hour under the C, gets final product to get product.The particle that obtains product is sharp-featured octahedron, and size is about 1-2 um, and the particle tap density is 1.7g/cm
3With the LiMn that makes
2O
4Particle, conductive agent and binding agent are then controlled conventional thickness and are coated on the aluminum foil current collector according to the mass ratio mixed slurry of 85:5:10.LiPF with 1.0 mol/L
6/ EC+DEC+DMC (volume ratio 1:1:1) is electrolyte, and the Li sheet is negative pole, and it is barrier film that the U.S. produces Cellgard-2400 type polypropylene screen, is assembled into button cell in being full of the glove box of argon gas.Then on the LandCT2001A type battery test system that Jin Nuo Electronics Co., Ltd. in Wuhan produces, synthetic material is carried out multiplying power test and cycle life test.When 1/3C charged and discharged, the capacity of this material was 118mAh/g; When 1C charged and discharged, its capacity was 104mAh/g; When 20C charges and discharge, the capacity of this material be 60mAh/g. under the 1C condition, charge and discharge the circulation 100 weeks, the capacity dimension holdup is 73%.
Comparative example 2.
Adopt conventional solid phase synthesis process to prepare LiMn
2O
4Material: after electrolytic manganese dioxide and lithium salts grinding evenly, at 800-1000
oCalcining is 6-48 hour under the C, gets final product to get product.The particle that obtains product is the sharp octahedrons of corner angle, and size is about 2-5 um, and the particle tap density is 1.8g/cm
3With the LiMn that makes
2O
4Micron particles, conductive agent and binding agent are then controlled conventional thickness and are coated on the aluminum foil current collector according to the mass ratio mixed slurry of 85:5:10.LiPF with 1.0 mol/L
6/ EC+DEC+DMC (volume ratio 1:1:1) is electrolyte, and the Li sheet is negative pole, and it is barrier film that the U.S. produces Cellgard-2400 type polypropylene screen, is assembled into button cell in being full of the glove box of argon gas.Then on the LandCT2001A type battery test system that Jin Nuo Electronics Co., Ltd. in Wuhan produces, synthetic material is carried out multiplying power test and cycle life test.When 1/3C charged and discharged, the capacity of this material was 119mAh/g; When 1C charged and discharged, its capacity was 103mAh/g; When 20C charges and discharge, the capacity of this material be 57mAh/g. under the 1C condition, charge and discharge the circulation 100 weeks, the capacity dimension holdup is 70%.
Embodiment 2.
One, at first prepares MnOOH by chemical method: will contain the aqueous solution of manganese ion, and in the situation of strong stirring, be added drop-wise in the alkaline solution; Precipitation reaction occurs in this course, its precipitated product MnOOH; Subsequently, with precipitated product MnOOH separation, washing, drying; Two, MnOOH and the lithium salts that makes is mixed together, prepares again the Li of sphere or class sphere through high-temperature calcination
1.05Mn
1.95O
4Particle.Obtaining the product granular size is 5-10um, and tap density is 2.3g/cm
3With the Li that makes
1.05Mn
1.95O
4Particle, conductive agent and binding agent are then controlled conventional thickness and are coated on the aluminum foil current collector according to the mass ratio mixed slurry of 85:5:10.LiPF with 1.0 mol/L
6/ EC+DEC+DMC (volume ratio 1:1:1) is electrolyte, and the Li sheet is negative pole, and it is barrier film that the U.S. produces Cellgard-2400 type polypropylene screen, is assembled into button cell in being full of the glove box of argon gas.Then on the LandCT2001A type battery test system that Jin Nuo Electronics Co., Ltd. in Wuhan produces, synthetic material is carried out multiplying power test and cycle life test.When 1/3C charged and discharged, the capacity of this material was 110mAh/g; When 1C charged and discharged, its capacity was 107mAh/g; When 20C charges and discharge, the capacity of this material be 87mAh/g. under the 1C condition, charge and discharge the circulation 100 weeks, the capacity dimension holdup is 95%.
Embodiment 3.
One, at first prepares MnOOH by chemical method: will contain the aqueous solution of manganese ion, and in the situation of strong stirring, be added drop-wise in the alkaline solution; Precipitation reaction occurs in this course, its precipitated product MnOOH; Subsequently, with precipitated product MnOOH separation, washing, drying; Two, the MnOOH that makes and lithium salts and MgO are mixed together, prepare again the LiMg of sphere or class sphere through high-temperature calcination
0.05Mn
1.95O
4Particle.Obtaining the product granular size is 5-10 um, and tap density is 2.4g/cm
3With the LiMg that makes
0.05Mn
1.95O
4, conductive agent and binding agent be according to the mass ratio mixed slurry of 85:5:10, then control conventional thickness and coat on the aluminum foil current collector.LiPF with 1.0 mol/L
6/ EC+DEC+DMC (volume ratio 1:1:1) is electrolyte, and the Li sheet is negative pole, and it is barrier film that the U.S. produces Cellgard-2400 type polypropylene screen, is assembled into button cell in being full of the glove box of argon gas.Then on the LandCT2001A type battery test system that Jin Nuo Electronics Co., Ltd. in Wuhan produces, synthetic material is carried out multiplying power test and cycle life test.When 1/3C charged and discharged, the capacity of this material was 119mAh/g; When 1C charged and discharged, capacity was 106mAh/g; When 20C charges and discharge, the capacity of this material be 88mAh/g. under the 1C condition, charge and discharge the circulation 100 weeks, the capacity dimension holdup is 95%.