A kind of ultralight complex lithium band of high intensity and preparation method thereof
Technical field
The invention belongs to lithium cell cathode material preparation technical fields, and in particular to a kind of ultralight complex lithium band of high intensity and
Preparation method.
Background technique
Lithium metal theoretical specific capacity is up to 3860 mAh/g and electrode potential is down to -3.04V(relative standard hydrogen electrode), it uses
Lithium battery energy density is remarkably improved as cathode.With the system that matches at present containing lithium anode material, cathode of lithium is inevitable
It is significantly excessive, therefore reduce the dosage of cathode of lithium, it is possible to reduce the invalid quality of cathode, to further promote lithium metal battery
Mass energy density, therefore lithium band ultrathin have become trend.However since lithium metal matter is soft and specific strength is low, in lithium electricity
The problem of cathode faces processing difficulties is done using the ultra-thin lithium band of self-supporting in pond, either by ultra-thin lithium band together with positive plate
It is wound into the process of battery, or ultra-thin lithium band is cut into small pieces lamination can all be very easy to cause at the process of battery again
Lithium band deformation, fold even rupture, for by ultra-thin lithium band connection tab and complete encapsulation process, be easier to lead to tab
With the rupture at ultra-thin lithium band connection.The scheme of one solution is to be attached to ultra-thin lithium in copper foil current collector by mechanical press
Lithium copper composite insulating foil is formed, Tianjin China Energy Lithium Co., Ltd. can produce the lithium of 50 μm of+10 μm of lithium+50 μm of copper foil lithiums with small lot
Copper composite insulating foil.Copper foil is sandwiched between lithium metal paillon by the Chinese invention patent application of publication number CN107819104A, forms lithium
Foil/copper foil/lithium foil sandwich of layers;Using common rolling equipment, starts trailer system, lithium foil/copper foil/lithium foil sandwich of layers is made to pass through stone roller
Pressure roller forms compartment local pressure to it, and pressure limit is 0.05MPa ~ 5MPa, forms pre-composite lithium foil/copper foil/lithium foil
Sandwich;By pre-composite lithium foil/copper foil/sandwich of lithium foil again by milling roller, and applies pressure and carry out shaping, pressure model
It encloses for 0.02MPa ~ 5MPa to get to lithium copper composite negative pole paillon.The Chinese invention patent application of publication number CN106702441A
Using electric plating method on the substrates such as copper foil one layer of lithium of electro-deposition, obtain lithium copper composite negative pole.Publication number CN107425175A
Chinese invention patent application using melting lithium ingot by being cast on extra thin copper foil substrate, and be aided with double roller cold pressing, to make
Standby lithium metal battery ultra-thin lithium copper composite insulating foil.The utility model patent of publication number CN207265160U discloses a kind of by true
Sky vapor deposition continuously prepares the device of ultra-thin lithium copper composite insulating foil.The Chinese invention patent application of publication number CN105489845A uses object
Physical vapor deposition (PVD) method is prepared in negative current collector copper foil surface stringer metallic lithium base negative electrode material, in thin au
Belong to lithium base negative electrode material surface stringer coat of metal.In addition to lithium to be attached in copper foil current collector, there are also a kind of improvement
Method be that fibre framework materials are mixed in cathode of lithium.The Chinese invention patent of publication number CN104466095A by lithium metal with
It is ground after the fiber-heated melting mixings such as carbon nano-fiber pipe, vapor deposition carbon fiber, ultrafine carbon fiber or superfine graphite fiber
It is molded to obtain strengthened lithium band.
First thinking is that lithium is attached on copper current collector in the above method, can thoroughly solve self-supporting ultra-thin lithium band
The low unmanageable problem of intensity and tab the problem of connecting, but due to the density of copper height, introduce copper foil or copper mesh and do
Collector will lead to entire battery weight energy density and substantially reduce.Second thinking is by some carbon fibers in the above method
In equal materials incorporation lithium, intensity can be improved really, but it is very limited to the improvement of tab connectivity problem, tab junction can
It is low by property.
Summary of the invention
That the purpose of the present invention is to solve existing battery weight energy densities is low, tab junction reliability is low asks
Topic, provides a kind of ultralight complex lithium band of high intensity and preparation method thereof, and the intensity of ultra-thin lithium band, improvement lithium band can be improved in the present invention
Processing performance and tab connection reliability, while to greatest extent keep lithium metal extremely-low density brought by the high weight of battery
The advantage of energy density.
To achieve the above object, the technical solution adopted by the present invention is as follows:
A kind of ultralight complex lithium band of high intensity, the complex lithium band include conducting matrix grain and the metal being attached on conducting matrix grain
Lithium or lithium alloy;The conducting matrix grain is the evenly dispersed perforated membrane formed in the polymer of conductive powder material.
A kind of preparation method of the above-mentioned ultralight complex lithium band of high intensity, specific step is as follows for the method:
It is first that polymer and conductive powder material melting mixing is uniform, wherein the mass fraction of conductive powder material be 0.01 ~
50%, perforated membrane is prepared using the double daraf(reciprocals of farad) of dry method in lithium battery diaphragm production equipment, then use vacuum evaporation, plating or machine
Tool rolling process adheres to the super thin metal lithium or lithium alloy that a layer thickness is 0.01 ~ 50 μm in porous film surface or hole, obtains height
The ultralight complex lithium band of intensity.
The beneficial effect of the present invention compared with the existing technology is: the present invention is poly- using conductive powder material to be dispersed in
It closes in object, then perforated membrane is formed by biaxial tension, using this perforated membrane is as framework material and lithium is compound obtains complex lithium band.By
In the perforated membrane is high with intensity, density is low, the good characteristic of electric conductivity, finally obtained complex lithium band has high-intensitive super
Light characteristic, mechanical strength are 5 ~ 1000 MPa, and surface density is 0.1 ~ 8 mg/cm2.It is once electric that the complex lithium band is used for lithium
Pond and lithium secondary battery can improve lithium band processing performance while improve battery energy density.It is worth noting that lithium metal in addition to
It can be attached to porous film outer surface, can also be entered in the hole of perforated membrane, this construction can greatly enhance the viscous of lithium and perforated membrane
Power is tied, prevents lithium from falling off from perforated membrane.
Detailed description of the invention
Fig. 1 is the structural schematic diagram of the high-intensitive ultralight complex lithium band of the present invention, wherein 1 is conductive powder material, and 2 be poly-
Object is closed, 3 be perforated membrane, and 4 be lithium metal or lithium alloy.The hole of perforated membrane in figure is straight hole, but the shape of actual conditions lower opening
Shape is simultaneously irregular.
Specific embodiment
Further description of the technical solution of the present invention with reference to the accompanying drawings and examples, and however, it is not limited to this,
All to be modified to technical solution of the present invention or equivalent replacement, range without departing from the spirit of the technical scheme of the invention should all
Cover within the protection scope of the present invention.The material and instrument arrived used in the present invention such as not special explanation, be
Conventional material and conventional instrument, it is commercially available.
Specific embodiment 1: present embodiment record is a kind of ultralight complex lithium band of high intensity, the complex lithium
Band includes conducting matrix grain and the lithium metal or lithium alloy 4 that are attached on conducting matrix grain;The conducting matrix grain is conductive powder body material
Material 1 is dispersed in the perforated membrane 3 formed in polymer 2.
Specific embodiment 2: a kind of ultralight complex lithium band of high intensity, the conduction described in specific embodiment one
For skeleton with a thickness of 1 ~ 100 μm, porosity is 0.01 ~ 80%.
Specific embodiment 3: a kind of ultralight complex lithium band of high intensity, the conduction described in specific embodiment one
Powder body material is carbon black, carbon nanotube, graphene, carbon fiber, copper nanoparticle, nanometer aluminium powder, nano-nickel powder, nano-silver powder, phthalein
Cyanines indigo plant, zinc oxide or the stannic oxide for adulterating Sb element.
Specific embodiment 4: a kind of ultralight complex lithium band of high intensity, the doping described in specific embodiment three
The stannic oxide of Sb element, wherein the content of Sb element is 0.1 ~ 50wt%.
Specific embodiment 5: a kind of ultralight complex lithium band of high intensity, the polymer described in specific embodiment one are
Polyethylene, polypropylene, polystyrene, polyethylene terephthalate or polycarbonate.
Specific embodiment 6: a kind of ultralight complex lithium band of high intensity described in specific embodiment one, the lithium is closed
Gold is lithium-aluminium alloy, lithium boron alloy, lithium magnesium alloy, lithium indium alloy, lithium gallium alloy or lithium-tin alloy.
Specific embodiment 7: a kind of high intensity described in any claim is ultralight multiple in specific embodiment one to six
Close lithium band, the lithium metal or lithium alloy with a thickness of 0.01 ~ 50 μm.
Specific embodiment 8: a kind of preparation method of the ultralight complex lithium band of high intensity described in specific embodiment seven,
Specific step is as follows for the method:
As shown in Figure 1, first that polymer 2 and 1 melting mixing of conductive powder material is uniform, wherein the quality of conductive powder material 1
Score is 0.01 ~ 50%, prepares perforated membrane 3 using the double daraf(reciprocals of farad) of well known dry method in lithium battery diaphragm production equipment, then use
Vacuum evaporation, plating or mechanical rolling process adhere to the super thin metal that a layer thickness is 0.01 ~ 50 μm in 3 surface of perforated membrane or hole
Lithium or lithium alloy 4 obtain high-intensitive ultralight complex lithium band.Into the lithium metal or lithium alloy in porous fenestra, can increase
The cohesive force of strong lithium and perforated membrane, prevents lithium from falling off from perforated membrane.
Embodiment 1:
It is first that polyethylene and carbon black (carbon black mass percentage composition is 1%) melting mixing is uniform, in lithium battery diaphragm production equipment
The perforated membrane of 5 μm of porositys 35% of thickness is prepared using the double daraf(reciprocals of farad) of well known dry method.Again using vacuum vapour deposition in perforated membrane table
The lithium metal (perforated membrane upper and lower surface is coated with 5 μm of lithium metals respectively) that a layer thickness is 5 μm is plated in face, obtains high-intensitive ultralight compound
Lithium band.
Embodiment 2:
It is first that polyethylene and graphene (graphene mass percentage is 0.1%) melting mixing is uniform, it is produced in lithium battery diaphragm
The perforated membrane of 1 μm of porosity 0.1% of thickness is prepared in equipment using the double daraf(reciprocals of farad) of well known dry method.Again using galvanoplastic porous
Film surface plates the lithium metal (perforated membrane upper and lower surface is plated with 10 μm of lithium metals) that a layer thickness is 10 μm, obtains high-intensitive ultralight
Complex lithium band.
Embodiment 3:
It is first that polypropylene and carbon nanotube (carbon nanotube mass percentage composition is 10%) melting mixing is uniform, in lithium battery diaphragm
The double daraf(reciprocals of farad) of well known dry method are used to prepare 50 μm of porositys of thickness as 80% perforated membrane in production equipment.Galvanoplastic are used again
The lithium metal (perforated membrane upper and lower surface is plated with 0.1 μm of lithium metal) that a layer thickness is 0.1 μm is plated in porous film surface, obtains height
The ultralight complex lithium band of intensity.
Embodiment 4:
It is first that PET and carbon black (carbon black mass percentage composition is 50%) melting mixing is uniform, it is adopted in lithium battery diaphragm production equipment
The perforated membrane that 10 μm of porositys of thickness are 20% is prepared with the double daraf(reciprocals of farad) of well known dry method.Again using mechanical rolling process in perforated membrane
The lithium-tin alloy (perforated membrane upper and lower surface is all attached with 30 μm of lithium-tin alloys) that a layer thickness is 30 μm is adhered on surface, obtains high-strength
Spend ultralight complex lithium band.
Embodiment 5:
It is first that polystyrene and carbon fiber (carbon fiber mass percentage is 20%) melting mixing is uniform, it is raw in lithium battery diaphragm
It produces and the double daraf(reciprocals of farad) of well known dry method is used to prepare 15 μm of porositys of thickness as 25% perforated membrane in equipment.Again using mechanical calendering
Method in porous film surface adheres to the lithium-aluminium alloy that a layer thickness is 50 μm, and (perforated membrane upper and lower surface is all attached with 50 μm of lithium aluminium and closes
Gold), obtain high-intensitive ultralight complex lithium band.
Embodiment 6:
It is first that polycarbonate and carbon black (carbon black mass percentage composition is 30%) melting mixing is uniform, it is set in lithium battery diaphragm production
The double daraf(reciprocals of farad) of well known dry method are used to prepare 8 μm of porositys of thickness as 15% perforated membrane on standby.Again using vacuum vapour deposition more
Hole film surface plates the lithium indium alloy (perforated membrane upper and lower surface is coated with 2 μm of lithium indium alloys respectively) that a layer thickness is 2 μm, obtains high-strength
Spend ultralight complex lithium band.
Comparative example 1:
Commercially available 50 μm of self-supportings ultra-thin lithium band.
Comparative example 2:
Commercially available lithium copper composite insulating foil (50 μm of+50 μm of copper foil of+10 μm of lithium lithiums).
Comparative example 3:
Using ultra-thin lithium-carbon fiber composite insulating foil of 50 μ m-thicks of the method preparation in patent CN104466095A.
Lithium tape test tensile strength and surface density in complex lithium band and comparative example 1 ~ 3 prepared by embodiment 1 ~ 6, as a result
As shown in table 1.
Table 1
As can be known from the results of Table 1, using the ultralight complex lithium band of high intensity of the method for the present invention preparation, compared to the lithium band of comparative example,
Tensile strength significantly improves, and maintains lower surface density.The ultralight complex lithium band of the high intensity is used for lithium primary battery
Lithium band processing performance can be improved with lithium secondary battery while improving battery energy density.