Secondary cell current-collector, secondary cell negative electrode, secondary cell anode, secondary cell and manufacturing approach thereof
Related application
The application is dividing an application of the International Application PCT/JP2006/302791 one Chinese patent application 200680004362.1 that gets into the China national stage; Wherein above-mentioned international application requires Japanese patent application No.2005-34639 that submitted on February 10th, 2005 and the U.S. Provisional Application S.N.60/653 that submitted on February 17th, 2005,529 priority.
The application incorporates above-mentioned open text in first to file as a reference at this, and requirement and patent application 200680004362.1 corresponding benefit of priority.
Technical field
The present invention relates to lithium rechargeable battery current-collector, secondary cell negative electrode, secondary cell anode, secondary cell and manufacturing approach thereof, also relate to and make lithium rechargeable battery have the superior high performance material that recharges characteristic fast.
Background technology
Lithium rechargeable battery is the high-performance secondary cell, is applied to a plurality of fields because of it has high-energy-density, for example mobile phone, notebook and camcorder, and application prospect is very extensive.Cobalt acid lithium or LiMn2O4 are usually as the cathodic electricity active material, and graphite is as the anode of small-scale lithium ion cell.This lithium ion battery also comprises slider and the electrolytic solution of being processed by the porous plate of for example polypropylene, polyethylene etc., for example comprises the organic solution of lithium salts, such as lithium hexafluoro phosphate (LiPF
6) the ethylene carbonate based sols.
More specifically; The negative electrode of common lithium rechargeable battery prepares through cathodic electricity active material and electronic conductivity carbon particulate are fixed on the tinsel; Wherein the cathodic electricity active material for example is cobalt acid lithium or LiMn2O4, and electronic conductivity carbon particulate has the current collection effect that transmits electronics.The tinsel that is adopted is generally aluminium foil, and for example gathers inclined to one side vinylidene fluoride (PVDF) or polytetrafluoroethylene (PTFE) as fixed negative pole electroactive material and the carbon particulate adhesive on it.
Recently, this high-performance secondary cell has and constantly is applied to the high field of the power requirement trend of automotive field for example, and this has just proposed the problem that conventional compact battery was not run into.
One of them problem is repid discharge/charge characteristic.Generation is more high-power to obtain bigger electric current owing to needing, so battery electric quantity should be full of battery after exhausting fast once more.Should make battery charging process shorten through adopting bigger charging current, can elongate the time of waiting for that battery recovery uses because charging process is long.Discharge under the bigger electric current and charge characteristic are referred to as the fast charging and discharging characteristic, and it is the important indicator of secondary cell practicality.
As stated, adopt bigger charging current for repid discharge and charging, to be absolutely necessary.Yet; Conventional lithium rechargeable battery can produce because of repeating to discharge and recharge the problem of rapid deterioration capacity characteristic (conservation rate of initial cells capacity) when adopting bigger electric current to discharge and recharge; Just, under big electric current, repeating to discharge and recharge can the deterioration power output.More specifically; Even can be to battery charging and discharging under 1C (electric current that can in 1 hour, discharge and recharge) electric current to battery; Current also hardly maybe be to battery charging and discharging under 20C (just, this electric current is in 1 hour, battery to be discharged and recharged 20 times of required electric current) electric current; Therefore, carry out the multiple effort of for example following content of text in said and improve this problem.
The open No.2001-266850 of japanese unexamined patent
Japan is the open No.7-123053 of unexamined patent
Japanese publication No.1989293
The 45th battery seminar (2004) 3C18
Yet the described method of above-mentioned each content of text also be not very effective aspect the reparation unconformability.
Here the description to the merits and demerits of disclosed various features, embodiment, method and apparatus in other publication never is used to limit the present invention.In fact, some characteristic of the present invention can overcome wherein some shortcoming, also still remains with perhaps all characteristics, embodiment, method and apparatus more disclosed herein simultaneously.
Through following preferred embodiment, it is obviously clear that other purpose of the present invention and advantage will become.
Summary of the invention
The present invention considers the problems referred to above of the prior art and/or other problem and makes.The present invention can improve existing method and/or device greatly.
In other possible advantage; Some embodiment can provide a kind of current-collector that is used for lithium secondary battery; It can carry out fast charging and discharging and have higher initial cells capability retention with higher rate (with higher electric current), and a kind of secondary cell that utilizes this current-collector is provided.
After further investigation realizes the means of this purpose; The inventor finds, can solve the problems referred to above through a kind of lithium rechargeable battery below preparing, in the structure of this lithium rechargeable battery; Especially in cathode construction; The ion permeability compound is realized lithium ion conductive, and electronic conductivity carbon particulate is realized electronic conductivity, thereby realizes the present invention.Therefore, the present invention relates to:
(1) a kind of secondary cell current-collector comprises aluminium or copper foil and the film that on said paillon foil, forms, and said film comprises iontophoretic injection compound and carbon particulate.
(2) a kind of secondary cell current-collector comprises aluminium or copper foil and the film that on said paillon foil, forms, and said film is included in non-bloating compound and carbon particulate in the organic solvent.
(3) a kind of secondary cell current-collector comprises aluminium or copper foil and the film that on said paillon foil, forms, and said film is included in compound and the carbon particulate that utilizes organic solvent to peel off antistripping in the test process.
(4) a kind of secondary cell current-collector comprises aluminium or copper foil and the film that on said paillon foil, forms, and said film is included in compound and the carbon particulate that band shape is peeled off antistripping in test (JIS D0202-1988) process.
(5) a kind of secondary cell negative electrode, comprise aluminium foil, form above that as the film that comprises iontophoretic injection compound and carbon particulate of lower floor and the film that comprises adhesive, carbon particulate and cathodic electricity active material that forms above that as the upper strata.
(6) a kind of secondary cell negative electrode comprises aluminium foil, non-bloating compound and the film of carbon particulate and the film that comprises adhesive, carbon particulate and cathodic electricity active material as the upper strata that forms in the organic solvent of being included in as lower floor that forms above that above that.
(7) a kind of secondary cell negative electrode, what comprise aluminium foil, formation above that utilizes organic solvent to peel off compound and the film of carbon particulate and the film that comprises adhesive, carbon particulate and cathodic electricity active material as the upper strata that forms of antistripping in the test process above that as being included in of lower floor.
(8) a kind of secondary cell negative electrode comprises aluminium foil, compound and the film of carbon particulate and the film that comprises adhesive, carbon particulate and cathodic electricity active material as the upper strata that forms that band shape is peeled off antistripping in test (JIS D0202-1988) process that be included in as lower floor that forms above that above that.
(9) a kind of secondary cell anode, comprise copper foil, form above that as the film that comprises iontophoretic injection compound and carbon particulate of lower floor and the film that comprises adhesive, carbon particulate and anode electroactive material that forms above that as the upper strata.
(10) a kind of secondary cell anode comprises copper foil, non-bloating compound and the film of carbon particulate and the film that comprises adhesive, carbon particulate and anode electroactive material as the upper strata that forms in the organic solvent of being included in as lower floor that forms above that above that.
(11) a kind of secondary cell anode, what comprise copper foil, formation above that utilizes organic solvent to peel off compound and the film of carbon particulate and the film that comprises adhesive, carbon particulate and anode electroactive material as the upper strata that forms of antistripping in the test process above that as being included in of lower floor.
(12) a kind of secondary cell anode comprises copper foil, compound and the film of carbon particulate and the film that comprises adhesive, carbon particulate and anode electroactive material as the upper strata that forms that band shape is peeled off antistripping in test (JIS D0202-1988) process that be included in as lower floor that forms above that above that.
(13) a kind of secondary cell negative electrode comprises aluminium foil and the film that comprises iontophoretic injection compound, carbon particulate and cathodic electricity active material that forms above that.
(14) a kind of secondary cell negative electrode comprises aluminium foil and the film that is included in non-bloating compound in the organic solvent, carbon particulate and cathodic electricity active material that forms above that.
(15) a kind of secondary cell negative electrode comprises aluminium foil and the film that is included in the compound, carbon particulate and the cathodic electricity active material that utilize organic solvent to peel off antistripping in the test process that forms above that.
(16) a kind of secondary cell negative electrode, comprise aluminium foil and form above that be included in the film that band shape is peeled off compound, carbon particulate and the cathodic electricity active material of antistripping in test (JIS D0202-1988) process.
(17) a kind of secondary cell anode comprises copper foil and the film that comprises iontophoretic injection compound, carbon particulate and anode electroactive material that forms above that.
(18) a kind of secondary cell anode comprises copper foil and the film that is included in non-bloating compound in the organic solvent, carbon particulate and anode electroactive material that forms above that.
(19) a kind of secondary cell anode comprises copper foil and the film that is included in the compound, carbon particulate and the anode electroactive material that utilize organic solvent to peel off antistripping in the test process that forms above that.
(20) a kind of secondary cell anode comprises copper foil and is included in the film that band shape is peeled off compound, carbon particulate and the anode electroactive material of antistripping in test (JISD0202-1988) process.
(21) a kind of according to above-mentioned (1) in (4) each described secondary cell current-collector, wherein this carbon particulate is needle-like or staff-like shape.
(22) a kind of according to above-mentioned (5) to (8) and (13) to (16) each described secondary cell negative electrode, wherein this carbon particulate is needle-like or staff-like shape.
(23) a kind of according to above-mentioned (9) to (12) and (17) to (20) each described secondary cell anode, wherein this carbon particulate is needle-like or staff-like shape.
(24) a kind of method of making the secondary cell current-collector comprises through applying the step that on aluminium or copper foil, forms the film that comprises iontophoretic injection compound and carbon particulate.
(25) a kind of method of making the secondary cell current-collector comprises through applying on aluminium or copper foil forming the step that is included in the film of non-bloating compound and carbon particulate in the organic solvent.
(26) a kind of method of making the secondary cell current-collector comprises through applying on aluminium or copper foil the step that forms the film that is included in the compound that utilizes organic solvent to peel off antistripping in the test process and carbon particulate.
(27) a kind of method of making the secondary cell current-collector comprises through applying on aluminium or copper foil forming being included in the step of film that band shape is peeled off compound and the carbon particulate of antistripping in test (JIS D0202-1988) process.
(28) a kind of method of making the secondary cell negative electrode; Comprise; Through the dispersion that on aluminium foil, applies the film that comprises iontophoretic injection compound and carbon particulate and also be coated in adhesive, carbon particulate and cathodic electricity active material in the solvent above that, and on said aluminium foil, form film.
(29) a kind of method of making the secondary cell negative electrode; Comprise; Be included in non-bloating compound and the film of carbon particulate and the dispersion that also is coated in adhesive, carbon particulate and cathodic electricity active material in the solvent above that in the organic solvent through on aluminium foil, applying, and on said aluminium foil, form film.
(30) a kind of method of making the secondary cell negative electrode; Comprise; Be included in compound and the film of carbon particulate and the dispersion that also is coated in adhesive, carbon particulate and cathodic electricity active material in the solvent above that of utilizing organic solvent to peel off antistripping in the test process through applying on the aluminium foil, and on said aluminium foil, form film.
(31) a kind of method of making the secondary cell negative electrode; Comprise; Be included in compound and the film of carbon particulate and the dispersion that also is coated in adhesive, carbon particulate and cathodic electricity active material in the solvent above that band shape is peeled off antistripping in test (JIS D0202-1988) process through on aluminium foil, applying, and on said aluminium foil, form film.
(32) a kind of method of making the secondary cell anode; Comprise; Through the dispersion that on copper foil, applies the film that comprises iontophoretic injection compound and carbon particulate and also be coated in adhesive, carbon particulate and anode electroactive material in the solvent above that, and on said copper foil, form film.
(33) a kind of method of making the secondary cell anode; Comprise; Be included in non-bloating compound and the film of carbon particulate and the dispersion that also is coated in adhesive, carbon particulate and anode electroactive material in the solvent above that in the organic solvent through on copper foil, applying, and on said copper foil, form film.
(34) a kind of method of making the secondary cell anode; Comprise; Be included in compound and the film of carbon particulate and the dispersion that also is coated in adhesive, carbon particulate and anode electroactive material in the solvent above that of utilizing organic solvent to peel off antistripping in the test process through on copper foil, applying, and on said copper foil, form film.
(35) a kind of method of making the secondary cell anode; Comprise; Be included in compound and the film of carbon particulate and the dispersion that also is coated in adhesive, carbon particulate and anode electroactive material in the solvent above that band shape is peeled off antistripping in test (JIS D0202-1988) process through on copper foil, applying, and on said copper foil, form film.
(36) a kind of method of making the secondary cell negative electrode comprises, in the dispersion of coating on the aluminium foil and dry iontophoretic injection compound, carbon particulate and cathodic electricity active material in solvent, thereby on said aluminium foil, forms film.
(37) a kind of method of making the secondary cell negative electrode is included on the aluminium foil and applies and the dry dispersion of non-bloating compound, carbon particulate and cathodic electricity active material in organic solvent in solvent, thereby on said aluminium foil, forms film.
(38) a kind of method of making the secondary cell negative electrode; Comprise; Peel off the dispersion of the compound of antistripping in the test process, carbon particulate and cathodic electricity active material in coating on the aluminium foil and the organic solvent that utilizing of drying in solvent, thereby on said aluminium foil, form film.
(39) a kind of method of making the secondary cell negative electrode; Comprise; Applying on the aluminium foil and dryly in solvent, peeling off the dispersion of compound, carbon particulate and the cathodic electricity active material of antistripping in test (JIS D0202-1988) process, thereby on said aluminium foil, forming film in band shape.
(40) a kind of method of making the secondary cell anode comprises, in the dispersion of coating on the copper foil and dry iontophoretic injection compound, carbon particulate and anode electroactive material in solvent, thereby on said copper foil, forms film.
(41) a kind of method of making the secondary cell anode comprises, is applying on the copper foil and the dry dispersion of non-bloating compound, carbon particulate and anode electroactive material in organic solvent in solvent, thereby on said copper foil, is forming film.
(42) a kind of method of making the secondary cell anode; Comprise; Peel off the dispersion of the compound of antistripping in the test process, carbon particulate and anode electroactive material in coating on the copper foil and the organic solvent that utilizing of drying in solvent, thereby on said copper foil, form film.
(43) a kind of method of making the secondary cell anode; Comprise; Applying on the copper foil and dryly in solvent, peeling off the dispersion of compound, carbon particulate and the anode electroactive material of antistripping in test (JIS D0202-1988) process, thereby on said copper foil, forming film in band shape.
(44) a kind of method of making secondary cell; Comprise and utilize organic electrolyte solution dipping to comprise step according to the layer structure of the sequential cascade of negative electrode, slider and anode, the negative electrode that wherein adopts be according to above-mentioned (5) to the item of (8) and (13) to (16) each described negative electrode.
(45) a kind of secondary cell; Comprise layer structure according to the sequential cascade of negative electrode, slider and anode; Said layer structure be through the organic electrolyte solution dipping, the negative electrode that wherein adopts be according to above-mentioned (5) to (8) and (13) to (16) each described negative electrode.
(46) a kind of method of making secondary cell; Comprise and utilize organic electrolyte solution dipping to comprise step according to the layer structure of the sequential cascade of negative electrode, slider and anode, the anode that wherein adopts be above-mentioned (9) to the item of (12) and (17) to (20) each described anode.
(47) a kind of secondary cell; Comprise layer structure according to the sequential cascade of negative electrode, slider and anode; This layer structure be through organic electrolyte solution dipping, the anode that wherein adopts be above-mentioned (9) to (12) and (17) to (20) each described anode.
(48) a kind of as above-mentioned (5) to (8) and (13) to (16) each described secondary cell negative electrode, wherein said cathodic electricity active material comprises following any one or multiple material: cobalt acid lithium (LiCoO
2), LiMn2O4 (LiMn
2O
4), lithium nickelate (LiNiO
2), the ternary lithium compound [Li (Co of Co, Mn and Ni
xMn
yNi
z) O
2], sulphur compound (TiS
2), olivinization compound (LiFePO
4, LiMnPO
4).
(49) as above-mentioned (28) to (31) and (36) to (39) the method for each described manufacturing secondary cell negative electrode, wherein said cathodic electricity active material comprises following any one or multiple material: cobalt acid lithium (LiCoO
2), LiMn2O4 (LiMn
2O
4), lithium nickelate (LiNiO
2), the ternary lithium compound [Li (Co of Co, Mn and Ni
xMn
yNi
z) O
2], sulphur compound (TiS
2), olivinization compound (LiFePO
4, LiMnPO
4).
(50) as above-mentioned (45) or (47) described secondary cell, wherein said cathodic electricity active material comprises following any one or multiple material: cobalt acid lithium (LiCoO
2), LiMn2O4 (LiMn
2O
4), lithium nickelate (LiNiO
2), the ternary lithium compound [Li (Co of Co, Mn and Ni
xMn
yNi
z) O
2], sulphur compound (TiS
2), olivinization compound (LiFePO
4, LiMnPO
4).
(51) as above-mentioned (45) or (47) described secondary cell, wherein said anode electroactive material comprises graphite.
(52) as above-mentioned (1) in (4) each described secondary cell current-collector, wherein said compound is the cross-linked polysaccharides polymer.
(53) as above-mentioned (24) in (27) the method for each described manufacturing secondary cell current-collector, wherein said compound is the cross-linked polysaccharides polymer.
(54) as above-mentioned (45) or (47) described secondary cell, wherein said compound is the cross-linked polysaccharides polymer.
(55) like above-mentioned (54) described secondary cell; Wherein said compound is polysaccharide polymer and the crosslinked cross-linking compounds of following arbitrary material: third rare acid amides, third rare nitrile, Kytamer PC, hydroxypropyl chitosan and acid anhydrides, said acid anhydrides for example are phthalic anhydride, maleic anhydride, 1,2; 4-benzenetricarboxylic anhydride and 1; 2,4, the 5-pyromellitic anhydride.
(56) as above-mentioned (45) or (47) described secondary cell, the lithium ion of wherein said compound or the conductivity of fluorine ion are 1 * 10
-2More than the S/cm.
(57) as above-mentioned (1) in (4) each described secondary cell current-collector, the number-average molecular weight of wherein said compound is below 50,000.
(58) as above-mentioned (45) or (47) described secondary cell, the number-average molecular weight of wherein said compound is below 50,000.
(59) a kind of motor vehicle unit and electric tool, it is equipped with like each described secondary cell in above-mentioned (45), (47), (50), (51), (54) to (56) and (58).
The invention effect
According to secondary cell current-collector of the present invention, negative electrode, anode and secondary cell; And improved under the two-forty conservation rate greatly, and can be advantageously used in or as fast charging and discharging performance superior secondary cell with respect to initial capacity through secondary cell current-collector, negative electrode, anode and secondary cell that manufacturing method according to the invention makes.
Description of drawings
Set forth the preferred embodiments of the present invention in the accompanying drawings without limitation through exemplary approach,
Fig. 1 is the sketch map of cross-sectional structure that the lower floor of the current-collector in the instance 1 of the present invention is shown; And
Fig. 2 is the sketch map that the cross-sectional structure of the negative electrode in the instance 2 of the present invention is shown.
Embodiment
In the paragraph below, will set forth some preferred embodiments of the present invention by non-limiting way through exemplary approach.Should be appreciated that based on disclosure of the present invention through reading these said embodiment, those skilled in the art can make multiple other modification.In this manual, aluminium is meant aluminium or aluminium alloy, and copper is meant fine copper or copper alloy.
Restriction is not used for aluminium foil of the present invention especially, can also adopt multiple aluminium, comprises the for example fine aluminium of A1085 and A3003.Its thickness is preferably about 5 to 100 microns.Copper foil also is similarly, preferably adopts rolled copper foil sheet or cathode copper paillon foil.In the present invention, aluminium foil is as the part of negative electrode, and copper foil is as the part of anode.
The thickness of not hoping aluminium or copper foil is less than 5 microns; This is because this can cause in the applying step that forms current collection layer, because of insufficient strength the paillon foil fracture taking place; Do not hope simultaneously that its thickness surpasses 100 microns, can cause the battery capacity variation because paillon foil accounts for the concrete volume ratio increase of battery like this.
Restriction is not used for cathodic electricity active material of the present invention especially, as long as it is the material that absorbs and discharge lithium (ion).Its representative instance comprises cobalt acid lithium (LiCoO
2), LiMn2O4 (LiMn
2O
4), lithium nickelate (LiNiO
2), the ternary lithium compound [Li (Co of Co, Mn and Ni
xMn
yNi
z) O
2], sulphur compound (TiS
2), olivinization compound (LiFePO
4, LiMnPO
4) or the like.
The particle diameter of these cathodic electricity active materials is preferably 1 to 50 micron.Do not hope particle diameter greater than 50 microns, because can cause between granule interior and the outside lithium to absorb like this and discharge inconsistent.On the other hand, do not hope this diameter smaller or equal to 1 micron yet, because can cause degree of crystallinity variation and grain structure irregular like this, thus degrade performance.
Any one well known materials can be as the anode electroactive material of anode.Do not limit anode material especially, the example comprises the material based on graphite, for example graphite, amorphous graphite material and oxide material.
Being used for iontophoretic injection examples for compounds of the present invention comprises: at the non-bloating compound of organic solvent, utilizing organic solvent to peel off the compound of antistripping in the test process, the compound of peeling off antistripping in the test process in band shape (hereinafter; All these compounds all are called as film and form compound), with and representative instance be described below:
Do not limit this iontophoretic injection compound especially; As long as it is the material (comprising compound) that can permeate ion, the example comprises cross-linked polymer of cellulose and acrylamide and cross-linked polymer, cellulose and Kytamer PC or the like.Other instance comprises the cross-linked polymer of polysaccharide polymer, for example with the crosslinked chitosan of crosslinking agent or chitin or the like.The instance of the crosslinking agent that adopts comprises third rare acid amides, third rare nitrile, Kytamer PC, hydroxypropyl chitosan and acid anhydrides or the like, and said acid anhydrides for example is phthalic anhydride, maleic anhydride, 1,2; 4-benzenetricarboxylic anhydride and 1; 2,4,5-pyromellitic anhydride or the like.
Its ionic conductance is preferably higher, and this considers from the battery performance angle.Lithium ion conductivity is preferably higher, and the preferred, lithium ionic conductance is 1 * 10
-2The compound that S/cm is above.Also preferred fluorine ion conductivity is 1 * 10
-2The compound that S/cm is above.
Film forms compound and is preferably and above-mentionedly can resists organic solvent and can closely adhere to one of compound of tinsel; This is because formed film is dissolved in the organic electrolyte solution, and this organic electrolyte solution is usually as the electrolyte solution in the lithium ion battery.
Polyamide, polyamide-imides etc. all are the known compound of opposing organic solvent, and they are very expensive and impracticable usually.In addition, the number-average molecular weight of these polymer is less, is approximately 50,000, is not enough to adhere on the tinsel.On the other hand, the number-average molecular weight of some polymer being arranged is more than 50,000; For example PVDF, PTFE and above-mentioned some other polymer; These polymer are enough to adhere on the tinsel, but can not resist organic solvent, and for example they can expand in organic solvent.Therefore, the number-average molecular weight of hoping polymer has enough adhesivenesses to adhere to tinsel and especially can have the higher resistance to organic solvent less than 50,000.
Peel off test (abrasion test) and the band shape of can be through the expansion in solvent test, immersing that cloth in the solvent carries out before utilizing be peeled off test (JIS D0202-1988) and are measured these characteristics.
The instance that the material of above-mentioned characteristic is shown comprises material of deriving with the derivative of the crosslinked polysaccharide polymer of acrylic acid additive or acid anhydrides, from chitosan derivative or the like.
Restriction is not used for electrical conductivity carbon particulate of the present invention especially, preferred following material particulate: acetylene black and Ketjen deceive, gas-phase carbon fiber, graphite fine particle or the like.Especially, preferably resistivity is 1 * 10 in 100% former base
-1Carbon particulate below the Ω cm can be used in combination above-mentioned particle when needed.
Do not limit the particle size of electrical conductivity carbon particulate especially, this is preferably dimensioned to be 10 to 100 nanometers.Its shape is preferably non-sphere, more preferably has the carbon particulate of anisotropy shape, needle-like or staff-like shape.Reason is described below: an electrical conductivity carbon particulate part is used for the electronics of conductive lithium ion secondary battery.Contact area between aluminium foil and the cathodic electricity active material is preferably bigger between charge period, and this is because the electronics that provides from the outside should be transmitted to the cathodic electricity active material through aluminium foil.Therefore, preferably adopt every weight to have particulate than high surface area.In addition, in order to preserve battery capacity, need to adopt a small amount of as far as possible particulate.For this reason, hope to adopt electrical conductivity carbon particulate with anisotropy shape.
In the present invention, the restriction preparation does not comprise the method that film forms the film of compound and carbon particulate especially, can adopt any one known method.Representative instance comprises casting, metering bar coater coating, dip coating, printing or the like.Wherein, for better controlling diaphragm thickness, preferred metering bar coater coating, casting or the like method.Prepare current-collector (being used for negative electrode or anode) through on aluminium or copper foil, forming the film that comprises the carbon particulate.Its thickness is preferably 0.1 micron to 10 microns.0.1 the thickness below the micron can stop the acquisition desired effects, therefore, does not hope to adopt.On the other hand, do not hope that thickness is more than 10 microns, because this can cause electroactive material relative reduction of ratio in the concrete volume in secondary cell yet.
Can also in similar procedure, prepare the film that comprises anode or cathodic electricity active material.Film thickness is preferably more than and equals 10 microns and smaller or equal to 500 microns.Film thickness below 10 microns can cause the ratio of electroactive material in the concrete volume of battery to reduce and make the battery capacity variation, therefore, does not hope to adopt.On the other hand, do not hope that thickness is more than 500 microns, because this internal resistance that can cause film to peel off and to increase battery from paillon foil yet.
Below, more detailed description is formed the method for the film that comprises the cathodic electricity active material.Also can be similar to above-mentioned film that kind and prepare the film that comprises the anode electroactive material, replace aluminium foil and cathodic electricity active material with copper foil and anode electroactive material respectively below difference is.
In the step of the slurry that is formed for film, regulate the component of film.Especially, form other material in compound, carbon compound, cathodic electricity active material and the kneading machine through hybrid films and also add then and be used to regulate the solvent of viscosity, thereby prepare this slurry.Because this solvent is removed through evaporation in the step below, so residual solids material (film forms compound, carbon particulate and cathodic electricity active material) in film only.These components, i.e. the content of film formation compound, carbon particulate and cathodic electricity active material preferably is respectively 1 to 30wt%, 1 to 30wt% and more than the 65wt%.
Film thickness is preferably more than and equals 0.1 micron and smaller or equal to 500 microns.0.1 the thickness below the micron can stop the acquisition desired effects.On the other hand, the thickness more than 500 microns can cause the film crack and peel off from aluminium foil, does not therefore hope to adopt.
Current-collector according to the present invention has two films, i.e. the upper and lower on the aluminium foil.To comprise the film that film forms compound and carbon particulate then and form lower floor, and the film that will comprise adhesive, carbon particulate and cathodic electricity active material forms the upper strata.Restriction is not included in the adhesive in the upper strata especially, as long as it can stable particle, and it can also comprise: film formation compound; For example with the crosslinked polysaccharide polymer of acrylic acid additive; Or the sharing compound, for example gather inclined to one side vinylidene fluoride (PVDF) or polytetrafluoroethylene (PTFE).
Through utilizing current-collector to prepare electrode and utilize known slider and organic electrolyte solution to form secondary cell together, thereby can carry out Performance Evaluation according to secondary cell current-collector of the present invention as battery.
In addition, when secondary cell according to the present invention is installed in motor vehicle (for example automobile or bicycle) or the electric tool (for example, electric drill, impact wrench or the like), can assess performance according to secondary cell of the present invention.
Instance
Below, will specifically describe the present invention with reference to instance and comparison example, still should be appreciated that to the invention is not restricted to following instance.
(instance 1)
Can obtain thickness and be 30 microns A1085 aluminium foil.Then, will be prepared as the iontophoretic injection compound with the crosslinked polysaccharide polymer chitosan of pyromellitic anhydride.Its molecular weight is determined as 35,000 through GPC.40 nanometers), above-mentioned chitosan and solvent preparation mixed type slurry comprises electrical conductivity carbon particulate (acetylene black, particle diameter:.The solvent that adopts is a water, and the weight ratio of iontophoretic injection compound, carbon particulate and water is 35: 15: 50.Then; Through adopting medicine applying apparatus (opening: 10 microns) slurry to be applied on the aluminium foil through casting; Then, under 180 degrees centigrade, reach 3 minutes and carry out the thermmohardening processing, so that aluminium foil has the film that comprises iontophoretic injection compound and carbon particulate at air drying.
The film thickness of after drying, measuring is 5 microns, and the content of electrical conductivity carbon particulate is 30wt% in the film.
Be 200 microns electrode layer through utilizing cathode slurry to form thickness then, wherein this cathode slurry is by cathodic electricity active material, electrical conductivity carbon particulate, adhesive and solvent, thereby forms the lithium rechargeable battery negative electrode.The cathodic electricity active material that adopts is a cobalt acid lithium; Conductibility carbon particulate is an acetylene black; Adhesive is to gather inclined to one side vinylidene fluoride (PVDF); And solvent is the N-N-methyl-2-2-pyrrolidone N-.Each constituent content, i.e. cathodic electricity active material: carbon particulate: the ratio of adhesive is 95: 2: 3 (weight ratio), and the weight ratio that the consumption of solvent accounts for the cathodic electricity active material is 10wt%.
And, the anode that connects slider and on copper foil, form, and this compound is impregnated in the organic electrolyte solution, to form lithium rechargeable battery.
Measure the cycle characteristics of the lithium rechargeable battery that obtains below.In result shown in the table 1.The analyzer that adopts is the battery charging and discharging device HJ-2010 of Hokuto Denko manufactured, and the conservation rate with respect to initial capacity after under the current changing rate of 0.1C, 2C and 20C, carrying out circulating for 100 times illustrates through percentage.See from showing to know; Utilization is according to current-collector of the present invention; Though the conservation rate with respect to initial capacity under the low current rate of change changes not obvious; But especially the conservation rate with respect to initial capacity is significantly improved under high current changing rate, the quick charge excellent of this expression current-collector.
Also measure the internal resistance of secondary cell.Measure through AC impedance method, wherein utilize the cell tester HIOKI3551 under the 1kHz test frequency.In result shown in the table 2.Littler measured value is represented more excellent quick charge characteristic.
(instance 2)
Can obtain thickness and be 30 microns A1085 aluminium foil.In addition, will be prepared as the iontophoretic injection compound with the crosslinked polysaccharide polymer chitin of maleic anhydride.Measuring its molecular weight through GPC is 30,000.40 nanometers), above-mentioned crosslinked chitin, cathodic electricity active material LiMn2O4 (LiMn preparation mixed type slurry comprises electrical conductivity carbon particulate (acetylene black, particle diameter:
2O
4) and solvent (NMP).The content of the infiltration of slurry intermediate ion compound, carbon particulate and cathodic electricity active material is respectively 2wt%, 3wt%, 95wt%; The content that the solvent that adopts accounts for the cathodic electricity active material is 10wt%.Then; Through utilizing medicine applying apparatus (opening: 250 microns) slurry is applied on the aluminium foil with instance 1 similar mode; Then, under 180 degrees centigrade, reach 3 minutes, carry out thermmohardening then at air drying; Thereby form the aluminium foil with film, this film comprises iontophoretic injection compound and carbon particulate and cathodic electricity active material.
The thickness that after drying, records this film is 200 microns; The content of electrical conductivity carbon particulate and cathodic electricity active material is respectively 3wt% and 95wt% in the film.
Then with instance 1 similar step, through the anode collector that connects slider and on copper foil, form, and this compound is impregnated in the organic electrolyte solution, thereby prepares lithium rechargeable battery.
Measure conservation rate and internal resistance similarly, in result shown in the table 1 and 2 with respect to initial capacity.
(instance 3)
In instance 3; Utilize aluminium foil A3003 to replace the aluminium foil materials A of using in the instance 2 1085; And will utilize organic solvent to peel off the compound of antistripping in the test process, promptly with the crosslinked polysaccharide polymer chitosan of acrylonitrile, as the iontophoretic injection compound.When this compound film forming be 0.5 micron thickness and utilize organic solvent for example alcohol this film is peeled off when test, do not have peeling off phenomenon.The molecular weight of measuring through GPC is 31,000.The carbon particulate that adopts is gas-phase carbon fiber (registered trade name: VGCF is made by Showa Denko).In addition, utilize olivinization compound (LiFePO
4) alternative cathodic electricity active material.The amount of the carbon particulate that adds also changes; In the slurry, be respectively 2wt% at the content that utilizes organic solvent to peel off the compound of antistripping in the test process, carbon particulate and cathodic electricity active material, 1wt% and 97wt%.
To prepare lithium rechargeable battery with instance 2 similar modes, difference only is above-mentioned variation.Measure conservation rate and internal resistance similarly, in result shown in the table 1 with respect to initial capacity.
(instance 4)
In instance 4, be utilized in not dilatable compound among the NMP, promptly with 1,2, the crosslinked polysaccharide polymer chitosan of 4-benzenetricarboxylic anhydride comes the iontophoretic injection compound in the alternate example 1, and adopts NMP as solvent.The molecular weight of the compound of measuring through GPC is 22,000.
To prepare lithium rechargeable battery with instance 1 similar mode, difference only is above-mentioned variation.Measure conservation rate and internal resistance similarly, in result shown in the table 1 and 2 with respect to initial capacity.
(instance 5)
Can obtain thickness and be 9 microns electrolyte copper foil.Then, will be the iontophoretic injection compound with the crosslinked polysaccharide polymer preparation of cellulose of Kytamer PC.Measuring its molecular weight through GPC is 40,000.Preparation mixed type slurry comprises cellulose and electrical conductivity carbon particulate (acetylene black, particle diameter: 40 nanometers).The solvent that adopts is NMP, and iontophoretic injection compound: carbon particulate: the weight ratio of solvent is 35: 15: 50.Then; Through utilizing intaglio printing running roller (#200) this slurry to be applied on the copper foil through the recess printing process; Under 180 degrees centigrade, reach 3 minutes then at air drying; Carry out thermmohardening then, thereby form the copper foil (current-collector) with film, this film comprises iontophoretic injection compound and carbon particulate.
The thickness that after drying, records this film is 0.2 micron, and the content of electrical conductivity carbon particulate is 30wt% in the film.
Then, the anode slurry formation thickness that comprises anode electroactive material, electrical conductivity carbon particulate, adhesive and solvent through utilization is 250 microns electrode layer, thereby forms the lithium rechargeable battery anode.The anode electroactive material that adopts is a graphite; Conductibility carbon particulate is an acetylene black; Adhesive is to gather inclined to one side vinylidene fluoride (PVDF); And solvent is the N-N-methyl-2-2-pyrrolidone N-.Each component, i.e. anode electroactive material: carbon particulate: the ratio between the adhesive is 92: 5: 3 (weight ratio), and the solvent of employing is 10wt% with respect to the content of anode electroactive material.
Then with instance 1 similar step, through the negative electrode that forms on the aluminium foil that connects slider and in instance 1, adopt, and this compound is impregnated in the organic electrolyte solution, thereby prepares lithium rechargeable battery.Measure conservation rate and internal resistance similarly, in result shown in the table 1 and 2 with respect to initial capacity.
(instance 6)
Prepare the compound of peeling off antistripping in the test process in band shape, with the crosslinked polysaccharide polymer chitosan of acrylonitrile, with the iontophoretic injection compound that uses in its alternate example 5.This compound film forming is 0.5 micron thickness, and stands this band shape and peel off test, in 100 situation that 100 tests obtain, does not have peeling off phenomenon.The molecular weight that records through GPC is 26,000.The carbon particulate that adopts is gas-phase carbon fiber (registered trade name: VGCF is made by Showa Denko).To prepare lithium rechargeable battery with instance 5 similar modes, difference only is above-mentioned variation.Measure conservation rate and internal resistance similarly, in result shown in the table 1 and 2 with respect to initial capacity.
(comparison example 1)
To prepare cathode collector with instance 1 similar mode; Difference is, utilize comprise the cathodic electricity active material shown in the instance 1 (cobalt acid lithium), electrical conductivity carbon particulate (acetylene black), adhesive (PVDF) and solvent (NMP), thickness is that 200 microns current collection layer substitutes and is formed on complexes membrane on the A1085 aluminium foil, that comprise iontophoretic injection compound and electrical conductivity carbon particulate.Prepare lithium rechargeable battery then similarly, with instance 1 similar condition under measure conservation rate and internal resistance with respect to initial capacity, in result shown in the table 1 and 2.
(comparison example 2)
To prepare lithium rechargeable battery with instance 1 similar mode; Difference is; Utilize above-mentioned PVDF adhesive (peeling off the compound of antistripping in the test) to come the iontophoretic injection compound that adopts in the alternate example 5 at organic solvent; And with instance 1 similar condition under measure conservation rate and internal resistance with respect to initial capacity, in result shown in the table 1 and 2.Though can prepare secondary cell; But when the surface of current-collector and NMP dipping cloth carry out repeated friction; The current-collector with the film that comprises the carbon particulate of preparation can take place to peel off in a large number, this means that secondary cell can not bear long-time use, even it has gratifying initial characteristic.
(comparison example 3)
To prepare lithium rechargeable battery with instance 1 similar mode; Difference is; Utilize PVA (polyvinyl alcohol) adhesive (peel off be prone to the compound peeled off in the test at band) to come the iontophoretic injection compound that adopts in the alternate example 1; And with instance 1 similar condition under measure conservation rate and internal resistance with respect to initial capacity, in result shown in the table 1 and 2.Though can prepare secondary cell; But peel off when test when standing band shape; Peeling off in a large number of current-collector surface can take place in the current-collector with the film that comprises the carbon particulate of preparation, this means that secondary cell can not bear long-time use, even it has gratifying initial characteristic.
Table 1 shows; Compare with those instances of the instance according to the present invention; Secondary cell in comparison example conservation rate with respect to initial capacity under the reduced-current rate of change is not low; But the conservation rate with respect to initial capacity under the high current rate of change reduces greatly, this means that secondary cell is difficult to fast charging and discharging more.
Table 2 shows that also the internal resistance of the secondary cell in the instance is lower, is applicable to fast charging and discharging.
Fast charging and discharging characteristic according to secondary cell of the present invention looks it is tinsel, comprise bonding result more closely between film and the electrode film of carbon particulate, and this is because iontophoretic injection adhesive and the conduction of realization ion and electronics separately respectively of electrical conductivity carbon particulate.
Table 1
Instance/comparison example |
0.1C |
2C | 20C |
Instance |
1 |
98% |
80% |
60% |
Instance |
2 |
98% |
85% |
70% |
Instance |
3 |
98% |
80% |
65% |
Instance |
4 |
98% |
85% |
70% |
Instance |
5 |
98% |
85% |
70% |
Instance 6 |
98% |
80% |
65% |
Comparison example 1 |
98% |
70% |
30% |
Comparison example 2 |
97% |
60% |
20% |
Comparison example 3 |
96% |
50% |
10% |
Table 2
Instance/comparison example |
Internal resistance |
Instance |
1 |
5mΩ |
Instance |
2 |
8mΩ |
Instance |
3 |
6mΩ |
Instance |
4 |
4mΩ |
Instance |
5 |
4mΩ |
Instance 6 |
7mΩ |
Comparison example 1 |
15mΩ |
Comparison example 2 |
25mΩ |
Comparison example 3 |
20mΩ |
Industrial applicability
The present invention provides a kind of secondary cell current-collector, a kind of method of making the secondary cell current-collector, and a kind of secondary cell with this current-collector.Particularly; This secondary cell current-collector comprises aluminium foil and the iontophoretic injection compound that comprises formation above that and the film of carbon particulate; The secondary cell that forms can improve under the high current changing rate conservation rate with respect to initial capacity significantly; And its fast charging and discharging excellent, this secondary cell current-collector and related invention can be preferred for being equipped with in the device of secondary cell, for example communicator and digital electronic device.The application of having widened the device that secondary cell is housed according to these characteristics of secondary cell current-collector of the present invention and other characteristic with and industrial applicability.
Though the present invention can be implemented as many multi-form; But many exemplary embodiments have been described here; Should be appreciated that present disclosure is to be used to provide instance to set forth principle of the present invention, these instances are not used in and limit the invention to preferred embodiment described here and/or that set forth here.
Though described exemplary embodiment of the present invention at this; But the invention is not restricted to a plurality of preferred embodiments described here; But comprise any and all embodiment that those skilled in the art understand the equivalent element that, modification, omission, combination (for example, the each side of a plurality of embodiment makes up), are suitable for and/or change based on present disclosure.The technical scheme that limits in the claim should be carried out wide in range understanding based on the language that adopts in the claim, and the instance that is not restricted in this specification or between the application's implementation period, describes, these instances all are nonexcludabilities.For example, in this disclosure, term " preferably " is a nonexcludability, mean " preferred, and be not limited to ".In this disclosure and between the application's implementation period, device adds limiting mode that function or step add function just to be adopted during all following conditions below only in concrete right requires to limit, occurring: a) know and narrated " be used for ... device " perhaps " and be used for ... step "; B) the clear corresponding function of having narrated; And c) there are not narrative structure, the material of supporting this structure or effect.In this disclosure and between the application's implementation period, term " the present invention " perhaps " invention " is used for an above aspect with reference to present disclosure.The present invention of this language or invention should not be interpreted as the expression of boundary inadequately; Should not be interpreted as all aspects of application or embodiment inadequately (just; It is to be understood that to the present invention to have many aspects and embodiment), and the scope that should not be interpreted as restriction the application or claim inadequately.In this disclosure and between the application's implementation period, term " embodiment " can be used in describes any aspect, characteristic, process or step and any combination and/or its any part, or the like.In some instance, a plurality of embodiment can comprise overlapping characteristic.In this disclosure and between the application's implementation period, can adopt following abbreviation term: " e.g. " means " for example ", and " NB " means " attention ".