Summary of the invention
The objective of the invention is provides a kind of incorporation time weak point and can make the well-mixed electrode slurry mixed method of electrode slurry in order to overcome electrode slurry incorporation time length of the prior art and can not to make the well-mixed shortcoming of electrode slurry.
The inventor discovers, adopts the mixing arrangement of prior art, even the electrode slurry of battery was mixed more than 20 hours, the heavy-current discharge performance of battery, capacity and cycle performance and incorporation time are the tangible raising of 6 hours there is no.Tracing it to its cause, may be because mixed method of the prior art is a kind of simple mechanical mixture, can only make electrode slurry mix more evenly to a certain extent.
The inventor is surprised to find that, mixed 30 minutes by the anode sizing agent of battery being put into a kind of high-shearing dispersion emulsifying machine, can improve heavy-current discharge performance, capacity and the cycle performance of battery effectively, and incorporation time shortens greatly than 6 hours of prior art also.
This high-shearing dispersion emulsifying machine is used for industries such as papermaking, printing and dyeing, food, mainly comprise rotor, Stator and electrical machine, stator is positioned at the periphery of rotor, rotor is electrically connected with motor, under the driving of motor, rotor can rotate, and described rotor comprises a plurality of paddles, and described stator comprises a plurality of columns that along the circumferential direction are provided with at interval.
The invention provides a kind of mixed method of electrode slurry, this method comprises that the material that will form electrode slurry mixes in blender, wherein, described blender is a high-shearing dispersion emulsifying machine, described high-shearing dispersion emulsifying machine comprises rotor, Stator and electrical machine, described stator is positioned at the periphery of rotor, and described rotor is electrically connected with motor, and rotor rotates under driven by motor.
Electrode slurry mixed method provided by the invention successfully will only be used for papermaking at present, printing and dyeing, the high-shearing dispersion emulsifying machine of industries such as food is applied to field of batteries, make material immiscible in the electrode slurry in moment uniform, fine ground dispersion, emulsification, homogeneous, dissolving, obtaining can be at the stable mixed system that is not separated for a long time, effectively improved the heavy-current discharge performance of battery, capacity and cycle performance, thereby overcome the bad shortcoming of lithium ion battery high-rate performance in the prior art, and greatly shortened the incorporation time of electrode slurry, improved efficiency greatly.
The specific embodiment
The invention provides a kind of mixed method of electrode slurry, this method comprises that the material of forming electrode slurry is put into blender to be mixed, wherein, described blender is a high-shearing dispersion emulsifying machine, described high-shearing dispersion emulsifying machine comprises rotor, Stator and electrical machine, described stator is positioned at the periphery of rotor, and described rotor is electrically connected with motor, and rotor rotates under driven by motor.
Described high-shearing dispersion emulsifying machine can be various mulsers with shearing, emulsification.Described high-shearing dispersion emulsifying machine can in all sorts of ways and obtain, and for example can be commercially available, for example can be available from Shanghai Fu Luke mechanical ﹠ electronic equipment corporation, Ltd.Select high-shearing dispersion emulsifying machine in the specific embodiment of the invention for use available from the Shanghai Fu Luke FC-140 of mechanical ﹠ electronic equipment corporation, Ltd model.The structure of described mulser such as Fig. 1 or shown in Figure 2 comprise rotor 1, stator 2 and motor (not shown), and stator 2 is positioned at the periphery of rotor 1, and rotor 1 is electrically connected with motor, and under the driving of motor, rotor 1 can rotate.
There is no particular limitation to the distance between rotor 1 and the stator 2 in the present invention, as long as can effectively produce shearing force, under the preferable case, the spacing between rotor 1 and the stator 2 is the 2-10 millimeter, is preferably the 2-5 millimeter.The present invention does not have special requirement to the shape of rotor 1 and stator 2, as long as rotor 1 can rotate, can produce shearing force and gets final product with cooperating between the stator 2.For example, described rotor 1 can be cylinder, comprise a plurality of radially outside sector structures of the blades of radiation.Preferred rotor 1 of the present invention is a plurality of blades that radially outwards radiate that comprise shown in Figure 1, and the quantity of described blade is decided on actual needs, and preferred rotor 1 of the present invention comprises 2-10 blade.The present invention is to the thickness of blade and have no special requirements, as long as can bear the high shear that produces when mixing.More preferably under the situation, described blade has the opening of penetrating blade width near a side of stator.The present invention there is no special qualification to the size of opening, all can than the virtually any size that blade height is little.Described opening preferably is not the circumference continuous distributed on blade, but described opening is spaced apart in a circumferential direction, can and there be the blade of opening to distribute successively for the blade that is distributed with opening, also can be a plurality of openings that distribute on each blade, the opening on the different blades be on the sustained height position of blade.
Described stator 2 comprises a plurality of columns that along the circumferential direction are provided with at interval.Rotor 1 is positioned at the central authorities of column.Described column is preferably 3-15.Spacing between the column of the present invention there is no special requirement, helps making the uniform any spacing of mixing of materials all can.Spacing between the preferred described column of the present invention is the 5-20 millimeter, more preferably the 9-10 millimeter.
Among the present invention, described width is meant arc length along the circumferential direction.Described thickness is meant the distance of pointing to rotor 2 center of circle directions.Described height is meant the distance of rotor 1 and stator 2 parallel directions.The present invention is also without particular limitation to the material of rotor 1 and stator 2, as long as can satisfy intensity required under the velocity of rotation of the present invention.Obviously, those skilled in the art can expect that described material also should or can not produce harmful effect to material not with the mixed material reaction under stirring condition.For the mixing of battery electrode paste, preferred rotor 1 and stator 2 adopt materials such as stainless steel, polytetrafluoroethylene (PTFE).
Described motor can be various motors, and those skilled in the art are easy to select suitable motor according to required purpose.Electric connection mode between motor and the rotor and concrete operations have been conventionally known to one of skill in the art, do not repeat them here.
The operation principle of high-shearing dispersion emulsifying machine of the present invention is: under the high-speed driving of motor, slurry 4 in the turning handle container 3 of rotor 1 is drawn in the space of rotor 1 and stator 2, because rotor 1 rotates high linear speed and the next powerful kinetic energy of high frequency machinery effect belt that is produced at a high speed, make in the accurate gap of slurry 4 between rotor 1 and stator 2 and be subjected to strong shearing, centrifugal extruding, the liquid layer friction, high-speed impact is torn and comprehensive functions such as turbulent flow, and make slurry bear the inferior this shear action of hundreds of thousands at short notice, slurry divides under above-mentioned effect, broken, disperse, thereby in the fully dispersion of moment uniform, fine ground, emulsification, homogeneous, dissolving.And slurry forms three-dimensional up and down turbulent flow in container after rotor stator combination high speed is fallen out.Through moving in circles of high frequency, finally obtain stable mixed slurry system 4 '.The rotating speed of described rotor is preferably 1000-3000 rev/min, and more preferably 1900-2100 rev/min, the mixing time under this rotating speed is preferably 10-50 minute, more preferably 20-30 minute.
Under the preferable case, method of the present invention also comprises the step that the electrode slurry behind the dispersion and emulsion is outgased.Can in all sorts of ways described slurry is outgased.The degassing of the present invention comprises stirs slurry in de-airing mixer, the speed of stirring is preferably 150-500 rev/min, more preferably 190-210 rev/min; The time of stirring is 40-100 minute, more preferably 70-90 minute.The degassing is in order to eliminate the bubble that slurry produces when the high cut disperse emulsification.Therefore the preferred 15-45 of temperature ℃ of the degassing, more preferably 20-30 ℃.Can be controlled at 15-45 ℃ by the variety of way temperature that will outgas, for example can be by water-bath cooling or the water-cooled mode of condensation.
Each composition of forming electrode slurry directly can be mixed with high-shearing dispersion emulsifying machine according to required proportioning, also can by premixed in advance with after the mixing of materials again with high-shearing dispersion emulsifying machine stir, emulsification, dispersion.Under the preferable case, the method for the invention comprises and will form the premixed step of material of electrode slurry.Described premixed condition is preferably: the speed of stirring is 200-450 rev/min, mixing time 40-90 minute; More preferably the speed of Jiao Baning is 390-410 rev/min, and the time of stirring is 55-65 minute.Described premixed can be carried out in conventional agitating device, also can carry out in high-shearing dispersion emulsifying machine of the present invention.Preferred pre-blend step is carried out in conventional mixer in the specific embodiment of the invention.
Electrode slurry mixed method provided by the present invention is applicable to the battery electrode paste that all needs mix, as the anode sizing agent of lithium ion battery, the cathode size of lithium ion battery, and the anode sizing agent of MH secondary battery or the cathode size of MH secondary battery.
The required material of described composition electrode slurry has been conventionally known to one of skill in the art, can comprise electrode active material, adhesive, solvent and various additive, and described additive for example comprises conductive agent, depolarizing agent.The proportioning of above-mentioned material has been conventionally known to one of skill in the art, does not repeat them here.
Particularly, electrode slurry mixed method provided by the invention comprises and will form the required material of electrode slurry earlier with conventional mixer premixed, using high-shearing dispersion emulsifying machine then instead mixes, refinement, disperse, adjust the position of high-shearing dispersion emulsifying machine in container, the rotor of high-shearing dispersion emulsifying machine is farthest contacted with material with stator, open motor then, make rotor rotation, rotor was stirred 5-10 minute down at 1000-1200 rev/min earlier, the rotating speed of adjusting rotor then is 1900-2100 rev/min, stirred 5-40 minute, the electrode slurry that obtains mixing, then electrode slurry is transferred in the de-airing mixer and outgased, obtain final electrode slurry product.
Described container 3 can be the various materials that are used for the splendid attire electrode slurry, and the present invention there is no special qualification to this, as long as can effectively cooperate with high-shearing dispersion emulsifying machine.
Among the present invention, the homogeneity of described slurry is evaluated by the homogeneity of solid content.The assay method of the homogeneity of described solid content is as follows: the upper, middle and lower in slurry is respectively got 3 samples (A, B, C) for three layers respectively, takes by weighing the weight m of each sample with electronic balance
0, the sample after will weighing is then put into 200 ℃ constant temperature roaster and was heavily toasted 30 minutes, the baking of the weighing afterwards remaining solid masses m in back
1, and according to solid content ρ=m
1/ m
0Calculate the solid content of each sample.
The following examples will the invention will be further described.Used high-shearing dispersion emulsifying machine is the high-shearing dispersion emulsifying machine available from the Shanghai Fu Luke FC-140 of mechanical ﹠ electronic equipment corporation, Ltd model in the embodiments of the invention, spacing between rotor and the stator is 3 millimeters, rotor comprises 6 blades to becoming to distribute, stator comprises 10 columns, and the spacing between the column is 10 millimeters.
Embodiment 1
Present embodiment is used to illustrate electrode slurry mixed method provided by the invention.
Use high-shearing dispersion emulsifying machine as shown in Figure 1 that 10 kilograms of lithium cobalt oxygen, 0.5 kilogram of acetylene black, 4.0 kilograms of N-methyl pyrrolidones (NMP), 0.5 kilogram of polytetrafluoroethylene (PTFE) (PVDF) are mixed, obtain lithium ion battery anode glue size, the rotating speed of the rotor of high-shearing dispersion emulsifying machine is 2000 rev/mins, and the time of stirring is 30 minutes.
Embodiment 2
Present embodiment is used to illustrate electrode slurry mixed method provided by the invention.
With 10 kilograms of lithium cobalt oxygen, 0.5 kilogram acetylene black, 4.0 kilogram N-methyl pyrrolidone (NMP), 0.5 kilogram polytetrafluoroethylene (PTFE) (PVDF) speed with 250 rev/mins in conventional mixer mixed 60 minutes, obtain the electrode slurry 4 after the premixed, then slurry 4 is transferred in the high-shearing dispersion emulsifying machine as shown in Figure 1 and mixed, disperse and refinement, obtain disperseing, the lithium ion battery anode glue size 4 ' of refinement, it is 10 minutes that the rotor of high-shearing dispersion emulsifying machine at first stirs under rotating speed is 1000 rev/mins, stirs 30 minutes down at 2000 rev/mins then.
Embodiment 3
Present embodiment is used to illustrate electrode slurry mixed method provided by the invention.
With 10 kilograms of lithium cobalt oxygen, 0.5 kilogram acetylene black, 4.0 kilogram N-methyl pyrrolidone (NMP), 0.5 kilogram polytetrafluoroethylene (PTFE) (PVDF) speed with 450 rev/mins in conventional mixer mixed 40 minutes, obtain the electrode slurry 4 after the premixed, the high-shearing dispersion emulsifying machine that slurry 4 is transferred to as shown in Figure 1 mixes then, disperse, refinement, obtain disperseing, the lithium ion battery anode glue size 4 ' of refinement, high-shearing dispersion emulsifying machine at first stirred 10 minutes under the rotor speed of mulser is 1000 rev/mins, stirred 30 minutes down at 2000 rev/mins then, afterwards slurry is changed in the de-airing mixer, under 200 rev/mins of rotating speeds, stirred 70 minutes, with recirculated cooling water system temperature is reduced to 30 ℃ simultaneously, the lithium ion battery anode glue size after obtaining outgasing.
Embodiment 4
Present embodiment is used to illustrate electrode slurry mixed method provided by the invention.
The step that repeats embodiment 3 prepares lithium ion battery anode glue size, different is that high-shearing dispersion emulsifying machine at first stirred 5 minutes under the rotor speed of mulser is 1100 rev/mins, stirred 25 minutes down at 2500 rev/mins then, afterwards slurry is changed in the de-airing mixer, under 250 rev/mins of rotating speeds, stirred 50 minutes, with recirculated cooling water system temperature is reduced to 25 ℃ simultaneously, the lithium ion battery anode glue size after obtaining outgasing.
Comparative Examples 1
This Comparative Examples is used for illustrating the mixed method of prior art electrode slurry.
The composition that will be identical with embodiment 1 and the electrode material of proportioning join in the mixer successively and mix, mixer elder generation obtains slurry with 350 rev/mins speed stirring after 5 hours, and then, obtain lithium ion battery anode glue size with 250 rev/mins of stirrings 2 hours.
Performance test
The lithium ion battery anode glue size that the foregoing description 1-4 and Comparative Examples 1 are made carries out the solid content test respectively, and measurement result is as shown in table 1 below.
The lithium ion battery anode glue size that the foregoing description 1-4 and Comparative Examples 1 make is made corresponding battery S1-4 and D1 with conventional method, measure capacity, cycle performance and the heavy-current discharge performance of each battery then, measurement result is shown in following table 2, table 3.
From the result of last table 1 as can be seen, the solid content homogeneity of the electrode slurry that makes with method provided by the invention obviously is better than the homogeneity of the electrode slurry that prior art makes.
From last table 2 and table 3 as can be seen, the electrode slurry that makes with method provided by the invention can make battery have excellent heavy-current discharge performance, cyclical stability and higher capacity.