Summary of the invention
The object of the invention is to overcome the power density, the energy density that exist in prior art lower, the defect that range of application is narrower and problem, there is provided a kind of power density, energy density higher, hybrid super capacitor anode pole piece of the carbon nano-tube compound that range of application is wider and preparation method thereof.
For realizing above object, technical solution of the present invention is: the hybrid super capacitor anode pole piece of carbon nano-tube compound, comprise the positive pole of collector and upper compacting thereof, the component of described positive pole comprises positive electrode, conductive agent, glue, and described positive electrode is LiMn2O4, nickle cobalt lithium manganate or cobalt acid lithium;
The component of described positive pole also comprises carbon nano-tube;
The component of described positive pole and weight ratio thereof are: positive electrode 70 – 89.5, carbon nano-tube 0.5 – 20, conductive agent 5, glue 5.
The component of described positive pole and weight ratio thereof are: positive electrode 80, carbon nano-tube 10, conductive agent 5, glue 5.
Described carbon nano-tube is single wall, double-walled or multi-walled carbon nano-tubes.
Described conductive agent is acetylene black, conductive black or carbon black conductive agent.
Described glue comprises water-base cement or oily gum, and described water-base cement comprises polytetrafluoroethylene or anionic polymer dispersion, and described oily gum comprises Kynoar.
The manufacture method of the hybrid super capacitor anode pole piece of above-mentioned carbon nano-tube compound, described manufacture method comprises the following steps successively:
The first step: first glue is added in solvent and be uniformly mixed, to be mixed evenly after, add conductive agent, scattered carbon nanotube dispersed slurries more wherein, proceed to be uniformly mixed, to be mixed evenly after, then add positive electrode wherein, proceed to be uniformly mixed, to be mixed evenly after, positive electrode slurries can be obtained;
In described carbon nanotube dispersed slurries, the content of carbon nano-tube is 1 – 20 wt.%; In described positive electrode slurries, the weight ratio of positive electrode, carbon nano-tube, conductive agent, glue is: positive electrode 70 – 89.5, carbon nano-tube 0.5 – 20, conductive agent 5, glue 5;
Second step: first by the above-mentioned positive electrode slurries mixed on stainless steel, with stainless steel bar, positive electrode slurries are rolled uniformly thin slice again, then the consistent pole piece blank of multiple shape is shaped to tablet press machine, again pole piece blank is put into vacuum drying oven and carry out drying, after drying, described positive pole can be obtained;
3rd step: with hydraulic press above-mentioned positive pole is formed on collector at the pressure of 10 – 25Mpa and can obtains described hybrid super capacitor anode pole piece.
In the described first step, described solvent is water or N – methyl pyrrolidone.
In described second step, the pressure head diameter of described tablet press machine is 2cm, the circle of the shape of described pole piece blank to be diameter be 9mm.
In described second step, the temperature of described drying is 120 DEG C, and drying time is 8h.
In described 3rd step, the pressure of described hydraulic press is 12 – 15Mpa.
Compared with prior art, beneficial effect of the present invention is:
1, carbon nano-tube is added in the component of the middle positive pole of hybrid super capacitor anode pole piece of carbon nano-tube compound of the present invention and preparation method thereof, in positive pole, this carbon nano-tube can set up the passage of electronics and lithium ion on the one hand, improve the efficiency of transmission of electric charge and ion, strengthen the activity of positive electrode, on the other hand, carbon nano-tube self also can adsorption/desorption electric charge, storage power, thus improve the performance of supercapacitor positive electrode, the hybrid super capacitor applying this positive pole is made to have higher energy density and power density, its energy density is up to 30 – 40 Wh/kg, power density is up to 1500 – 4000 W/kg, and then expand its range of application, be applicable to developing into high-performance energy storage device.Therefore, the present invention not only power density, energy density is higher, and range of application is wider.
In the hybrid super capacitor anode pole piece and preparation method thereof of 2, carbon nano-tube compound of the present invention, the component of positive pole and weight ratio thereof are: positive electrode 70 – 89.5, carbon nano-tube 0.5 – 20, conductive agent 5, glue 5, wherein, the consumption of carbon nano-tube has strict requirement, its reason is: along with carbon nano-tube content in positive pole increases, positive conductive rate can increase gradually, but positive electrode content can decline simultaneously, although the adsorbable charge storage electricity of carbon nano tube surface, but the charge density of its absorption is far below the density storing electric charge in positive electrode body, therefore, the capacity of capacitor and energy density can be caused to decline when carbon nano-tube exceedes certain content, thus the chemical property not being the more capacitors of amount that carbon nano-tube adds is better, for this reason, since the content of carbon nanotubes that the present invention selects is guaranteed to obtain higher energy density and capacity, higher power density can be obtained again.Therefore, the present invention not only capacity, energy density is better, and power density is higher.
In the hybrid super capacitor anode pole piece and preparation method thereof of 3, carbon nano-tube compound of the present invention when making positive pole, carry out particular design and make effect to improve, be specially: first, first add glue, add conductive agent, carbon nanotube dispersed slurries again, it is uneven in order to prevent slurry to mix for then adding positive electrode; Secondly, baking temperature is 120 DEG C, and the time is that 8h can guarantee to remove moisture content all in pole piece blank, to improve the quality of positive pole; Again, first drying is carried out to pole piece, then suppressed and positive electrode can be prevented to be separated with collector on collector, be conducive to reducing internal resistance, thus improve anode pole piece quality, strengthen the chemical property of capacitor.Therefore, the present invention is conducive to the quality improving anode pole piece, and strengthens the chemical property of ultracapacitor.
Positive pole in the hybrid super capacitor anode pole piece and preparation method thereof of 4, carbon nano-tube compound of the present invention is formed on collector at the pressure of 10 – 25Mpa to produce supercapacitor positive electrode pole piece, its optimal pressure range is 12 – 15Mpa, this pressure limit can guarantee that electrolyte easily penetrates in positive pole, do not affect the performance of active material performance, thus improve energy density and the power density of ultracapacitor further, simultaneously, active material Contact resistance can not be caused again excessive, avoid internal resistance larger to affect capacitor performance.Therefore, the present invention not only power density, energy density is higher, and internal resistance is less.
Embodiment
Illustrate that the present invention is further detailed explanation with embodiment below in conjunction with accompanying drawing.
See figure 1 – Fig. 2, the hybrid super capacitor anode pole piece of carbon nano-tube compound, comprise the positive pole of collector and upper compacting thereof, the component of described positive pole comprises positive electrode, conductive agent, glue, and described positive electrode is LiMn2O4, nickle cobalt lithium manganate or cobalt acid lithium;
The component of described positive pole also comprises carbon nano-tube;
The component of described positive pole and weight ratio thereof are: positive electrode 70 – 89.5, carbon nano-tube 0.5 – 20, conductive agent 5, glue 5.
The component of described positive pole and weight ratio thereof are: positive electrode 80, carbon nano-tube 10, conductive agent 5, glue 5.
Described carbon nano-tube is single wall, double-walled or multi-walled carbon nano-tubes.
Described conductive agent is acetylene black, conductive black or carbon black conductive agent.
Described glue comprises water-base cement or oily gum, and described water-base cement comprises polytetrafluoroethylene or anionic polymer dispersion, and described oily gum comprises Kynoar.
The manufacture method of the hybrid super capacitor anode pole piece of above-mentioned carbon nano-tube compound, described manufacture method comprises the following steps successively:
The first step: first glue is added in solvent and be uniformly mixed, to be mixed evenly after, add conductive agent, scattered carbon nanotube dispersed slurries more wherein, proceed to be uniformly mixed, to be mixed evenly after, then add positive electrode wherein, proceed to be uniformly mixed, to be mixed evenly after, positive electrode slurries can be obtained;
In described carbon nanotube dispersed slurries, the content of carbon nano-tube is 1 – 20 wt.%; In described positive electrode slurries, the weight ratio of positive electrode, carbon nano-tube, conductive agent, glue is: positive electrode 70 – 89.5, carbon nano-tube 0.5 – 20, conductive agent 5, glue 5;
Second step: first by the above-mentioned positive electrode slurries mixed on stainless steel, with stainless steel bar, positive electrode slurries are rolled uniformly thin slice again, then the consistent pole piece blank of multiple shape is shaped to tablet press machine, again pole piece blank is put into vacuum drying oven and carry out drying, after drying, described positive pole can be obtained;
3rd step: with hydraulic press above-mentioned positive pole is formed on collector at the pressure of 10 – 25Mpa and can obtains described hybrid super capacitor anode pole piece.
In the described first step, described solvent is water or N – methyl pyrrolidone.
In described second step, the pressure head diameter of described tablet press machine is 2cm, the circle of the shape of described pole piece blank to be diameter be 9mm.
In described second step, the temperature of described drying is 120 DEG C, and drying time is 8h.
In described 3rd step, the pressure of described hydraulic press is 12 – 15Mpa.
Principle of the present invention is described as follows:
1, carbon nano-tube:
The present invention adds carbon nano-tube in the component of positive pole.In positive pole, this carbon nano-tube can set up the passage of electronics and lithium ion on the one hand, be built into conductive network (see Fig. 1, Fig. 1 is the electron scanning micrograph of positive pole in the present invention, can know in this figure and find out that carbon nano-tube is wrapped between positive electrode particle, and positive electrode particle is communicated with, construct conductive network), thus improve the efficiency of transmission of electric charge and ion, strengthen the activity of positive electrode, on the other hand, carbon nano-tube self also can adsorption/desorption electric charge, storage power, thus improve the performance of supercapacitor positive electrode, the hybrid super capacitor applying this positive pole is made to have higher energy density and power density, its energy density is up to 30 – 40 Wh/kg, power density is up to 1500 – 4000 W/kg, and then expand its range of application, be applicable to developing into high-performance energy storage device.
Meanwhile, the consumption of the present invention to carbon nano-tube has strict demand, and namely the component of described positive pole and weight ratio thereof are: positive electrode 70 – 89.5, carbon nano-tube 0.5 – 20, conductive agent 5, glue 5.Carbon nano-tube adopts the reason of this consumption to be: along with carbon nano-tube content in positive pole increases, positive conductive rate can increase gradually, but positive electrode content can decline simultaneously, although the adsorbable charge storage electricity of carbon nano tube surface, but the charge density of its absorption is far below the density storing electric charge in positive electrode body, therefore, the capacity of capacitor and energy density can be caused to decline when carbon nano-tube exceedes certain content, be not thus that the chemical property of the more capacitors of amount that carbon nano-tube adds is better.In the process making pole piece, generally speaking, positive pole is under certain pressure, and content of carbon nanotubes is that 10 capacitor electrode chemical properties are more excellent.Meanwhile, content of carbon nanotubes is lower than 0.5, then positive pole resistance is higher, improves chemical property not obvious; Higher than 20, then carbon nano-tube is difficult to dispersion, and can reduce chemical property.
Content as positive electrode then decides according to final chemical property effect; The consumption of glue and conductive agent then determines according to the experiment making ultracapacitor, experiment display, and glue 5, conductive agent 5 are preferably ratios.
In addition, the present invention have employed carbon nanotube dispersed slurries when making positive pole, in these carbon nanotube dispersed slurries, the content of carbon nano-tube is 1 – 20 wt.%, take to disperse the reason of slurries to be: use carbon nanotube dispersed slurries instead of direct carbon nanotube powders to join in positive electrode slurries, object is that carbon nano-tube is more easily disperseed in positive electrode slurries.
2, the order of addition of material in making:
In the present invention, the order of addition of material is followed successively by: first added in solvent by glue and be uniformly mixed, to be mixed evenly after, add conductive agent, scattered carbon nanotube dispersed slurries more wherein, proceed to be uniformly mixed, to be mixed evenly after, then add positive electrode wherein, proceed to be uniformly mixed, to be mixed evenly after, positive electrode slurries can be obtained.
The present invention adopts the reason of glue, conductive agent, carbon nanotube dispersed slurries, this order of addition of positive electrode to be: first add glue and be also called dozen glue, glue joins in liquid, and liquid viscosity increases greatly, need first glue to be disperseed, otherwise glue there will be cluster, therefore, first glue need be played.The order that conductive agent and carbon nanotube dispersed slurries add then does not limit, and finally adds lithium ion anode material.This order can not be upset, otherwise easily causes slurry uneven.
3, the oven dry of positive pole:
What dry positive pole in the present invention is operating as: pole piece blank is put into vacuum drying oven and carries out drying, after drying, can obtain described positive pole, and preferably dry temperature is 120 DEG C, and drying time is 8h.Wherein, have requirement to baking temperature, time, its reason is: adopt this baking temperature and time can guarantee to remove moisture content all in pole piece blank, to improve the quality of positive pole, guarantee the result of use of capacitor.Other temperature and time otherwise do not reach the effect removing all moisture content, otherwise be exactly the too high or overlong time of temperature, causes temperature, time coordination does not agree with, waste resource.
In addition, the present invention first carries out drying to pole piece, suppressed again on collector, instead of first suppress and dry again in collector, its reason is: if dry after first compacting, then easily cause positive electrode to be separated with collector, be unfavorable for the combination of positive electrode and collector, be unfavorable for reducing internal resistance.
4, the pressing pressure of positive pole:
Described positive pole is formed on obtained described hybrid super capacitor anode pole piece on collector at the pressure of 10 – 25Mpa by application claims, and preferred pressure range is 12 – 15Mpa.
Select the reason of this pressure limit to be: if pressure is excessive, then easily cause electrolyte to be difficult to penetrate in positive pole, thus affect active material performance, reduce energy density and the power density of capacitor; If pressure is too small, then active material Contact resistance can be caused excessive, easily cause internal resistance excessive, affect capacitor performance.
5, positive pole is made with positive electrode slurries:
In the present invention first by positive electrode slurries on stainless steel, then with stainless steel bar, positive electrode slurries are rolled uniformly thin slice, be then shaped to the consistent pole piece blank of multiple shape with tablet press machine, drier to obtain positive pole to pole piece blank.This is the operating process doing small capacitor, if will do corresponding large capacitor, it makes slurry process and does the identical of small capacitor, and difference is, is to slurry coating, obtains positive pole after having made slurry.
Embodiment 1:
The hybrid super capacitor anode pole piece of carbon nano-tube compound, comprises the positive pole of collector and upper compacting thereof, and the component of described positive pole comprises positive electrode, conductive agent, glue, and described positive electrode is LiMn2O4, nickle cobalt lithium manganate or cobalt acid lithium; The component of described positive pole and weight ratio thereof are: positive electrode 85, carbon nano-tube 5, conductive agent 5, glue 5;
Described carbon nano-tube is single wall, double-walled or multi-walled carbon nano-tubes, described conductive agent is acetylene black, conductive black or carbon black conductive agent, described glue comprises water-base cement or oily gum, and described water-base cement comprises polytetrafluoroethylene or anionic polymer dispersion, and described oily gum comprises Kynoar.
The manufacture method of the hybrid super capacitor anode pole piece of above-mentioned carbon nano-tube compound, described manufacture method comprises the following steps successively:
The first step: first glue is added in solvent and be uniformly mixed, to be mixed evenly after, add conductive agent, scattered carbon nanotube dispersed slurries more wherein, proceed to be uniformly mixed, to be mixed evenly after, then add positive electrode wherein, proceed to be uniformly mixed, to be mixed evenly after, positive electrode slurries can be obtained; Described solvent is water or N – methyl pyrrolidone;
In described carbon nanotube dispersed slurries, the content of carbon nano-tube is 1 – 20 wt.%; In described positive electrode slurries, the weight ratio of positive electrode, carbon nano-tube, conductive agent, glue is: positive electrode 85, carbon nano-tube 5, conductive agent 5, glue 5;
Second step: first by the above-mentioned positive electrode slurries mixed on stainless steel, with stainless steel bar, positive electrode slurries are rolled uniformly thin slice again, then the consistent pole piece blank of multiple shape is shaped to tablet press machine, again pole piece blank is put into vacuum drying oven and carry out drying, baking temperature is 120 DEG C, drying time is 8h, after drying, can obtain described positive pole; The pressure head diameter of described tablet press machine is 2cm, the circle of the shape of described pole piece blank to be diameter be 9mm;
3rd step: with hydraulic press above-mentioned positive pole is formed on collector at the pressure of 25Mpa and can obtains described hybrid super capacitor anode pole piece.
Take the present invention as anode pole piece, active carbon is cathode pole piece, and the lithium sulfate solution of 1Mol/L is electrolyte, is assembled into hybrid super capacitor.Anode pole piece, cathode pole piece are inserted in electrolyte, and with electrochemical workstation connecting test hybrid super capacitor chemical property (see Fig. 2).In 0 – 1.8 V voltage range under room temperature, to be 200 mA/g(calculate with both positive and negative polarity active material gross mass current density) constant current charge-discharge test and ac impedance measurement, the specific capacity recording this hybrid super capacitor is 73.4F/g, energy density is 33.0Wh/kg, and power density is 1.5 KW/kg.
Embodiment 2:
Substance is with embodiment 1, and difference is:
The component of described positive pole and weight ratio thereof are: positive electrode 80, carbon nano-tube 10, conductive agent 5, glue 5; The pressure of described hydraulic press is 12Mpa;
The specific capacity of described hybrid super capacitor is 82.5F/g, and energy density is 37.1 Wh/kg, and power density is 2.0KW/kg.
Embodiment 3:
Substance is with embodiment 1, and difference is:
The component of described positive pole and weight ratio thereof are: positive electrode 75, carbon nano-tube 15, conductive agent 5, glue 5; The pressure of described hydraulic press is 15Mpa;
The specific capacity of described hybrid super capacitor is 68.9F/g, and energy density is 31.0 Wh/kg, and power density is 4.0KW/kg.
Embodiment 4:
Substance is with embodiment 1, and difference is:
The component of described positive pole and weight ratio thereof are: positive electrode 89, carbon nano-tube 1, conductive agent 5, glue 5; The pressure of described hydraulic press is 15Mpa;
The specific capacity of described hybrid super capacitor is 85.9F/g, and energy density is 38.2 Wh/kg, and power density is 2.6KW/kg.
Embodiment 5:
Substance is with embodiment 1, and difference is:
The component of described positive pole and weight ratio thereof are: positive electrode 89.5, carbon nano-tube 0.5, conductive agent 5, glue 5; The pressure of described hydraulic press is 10Mpa;
The specific capacity of described hybrid super capacitor is 80F/g, and energy density is 32 Wh/kg, and power density is 2.0 KW/kg.)
Embodiment 6:
Substance is with embodiment 1, and difference is:
The component of described positive pole and weight ratio thereof are: positive electrode 70, carbon nano-tube 20, conductive agent 5, glue 5; The pressure of described hydraulic press is 20Mpa;
The specific capacity of described hybrid super capacitor is 70F/g, and energy density is 32 Wh/kg, and power density is 3.8 KW/kg.