A kind of lithium battery electrode material and preparation method thereofTechnical field
The invention belongs to energy battery technical fields, and in particular to a kind of lithium battery electrode material and preparation method thereof.
Background technology
Current main energy storage device includes electrochmical power source energy storage, mechanical energy storage.Compared to mechanical energy storage to environment compared withHigh request, chemical energy storage such as lithium ion battery, lead-acid battery, flow battery etc. is because it is with higher energy density and powerDensity and portability are widely used in consumer electronics and electric vehicle field.
Lithium metal have minimum reduction potential (- 3.04V is to standard hydrogen electrode), highest specific capacity 3860mAh/g, becauseThis makees cathode using lithium metal, and battery will have high-energy density advantage.Lithium metal is a non-embedded structure as cathode, storageDeposit the process that lithium metal is exactly an electrochemical deposition.Metallic lithium surface chemical composition it is uneven, influence whether the unevenness of lithiumEven deposition, the high local lithium metal deposition of lithium ion conductivity is most, and the low place deposition of conductivity is few, lithium metal deposition processIt is that process of the lithium metal from having nothing is compared with carbon materials such as graphite, volume change is very big, is easy to cause negative terminal surfaceSEI layers of rupture, form Li dendrite.In addition, under high current, dendrite can also interact with inside battery electric field, accelerate its lifeIt is long.The growth of Li dendrite can react with electrolyte, cause the consumption of electrolyte, to reduce the cycle life of battery, togetherWhen Li dendrite growth be possible to pierce through diaphragm cause positive and negative anodes connect occur internal short-circuit and discharge heat, cause electrolyteConsumption is decomposed, and the burning and explosion of battery are even resulted in.
Invention content
One embodiment of the invention provides a kind of lithium battery electrode material, can effectively inhibit the growth of Li dendrite, shouldLithium battery includes with electrode material：
The porous carbon for being constituted cell structure by more carbon nano-tube fibres and being attached on the carbon nano-tube fibreGrain, wherein in the cell structure and/or the porous carbon particle at least partly in be filled with lithium metal.
In one embodiment, the porous carbon particle be carbon fiber wound at carbon fiber microballoon or acetylene black.
In one embodiment, the average pore size of the porous carbon particle is 20~70nm, preferably 30~50nm.
In one embodiment, the average grain diameter of the porous carbon particle is 2 μm~150 μm；And/or the porous carbon particleConductivity is 1.5*103~10Scm-1；And/or the specific surface area of the porous carbon particle is 300~1000m2/g；And/orLoading of the lithium metal in the electrode material is 20~70wt.%.
Further include between the carbon nano-tube fibre and lithium metal to improve the activity of interfacial reaction in one embodimentState material.
In one embodiment, the activated state material is selected from Al, Al2O3, In, ceramics in one or more combinations.
One embodiment of the invention also provides a kind of preparation method of lithium battery electrode material, and this method includes：
Cell structure including more carbon nano-tube fibres is immersed in the solution for being dispersed with porous carbon particle, so thatPorous carbon particle is uniformly adhered on carbon nano-tube fibre, obtains material intermediate；
Deposit lithium metal on mesosome in the material, so that lithium metal is filled in cell structure and porous carbon particleIn.
In one embodiment, further include：
Activated state material is coated on the carbon nano-tube fibre, and the activated state material is made to be located at carbon nanotube fibreTo improve interfacial reaction between peacekeeping lithium metal.
In one embodiment, the porous structure including carbon nano-tube fibre is made by floating catalyst method.
In one embodiment, specifically include：
Reacting furnace is warming up to 1100 DEG C~1600 DEG C, and is passed through carrier gas thereto；
It after phase carbon source is gasified, is brought into using carrier gas in the high-temperature region of the reacting furnace, generating has more carbon nanometersThe aggregation of pipe fiber；
The aggregation is deposited on receiver board, obtain include more carbon nano-tube fibres cell structure.
Compared with prior art, technical scheme of the present invention has the advantages that：
It, can be with by the cell structure for combining more carbon nano-tube fibres to constitute and porous carbon particle attached theretoLithium metal more uniformly divides in multiple cavernous structures, in the charge and discharge process of lithium battery, helps to maintain lithium metalTopographical property, inhibit the generation of Li dendrite, to improve the safety of lithium battery, and provide higher specific heat capacity and preferableCycle performance.
Description of the drawings
Fig. 1 is the TEM photos of cell structure in lithium battery electrode material in one embodiment of the application；
Fig. 2 be in the embodiment of the present application 1~5 using the electrode obtained material as cathode, LiFePO4 be anode assembling buttonThe cycle performance test chart of battery.
Specific implementation mode
The application is described in detail below with reference to specific implementation mode shown in the drawings.But these embodiments are simultaneouslyThe application is not limited, structure that those skilled in the art are made according to these embodiments, method or functionallyTransformation is all contained in the protection domain of the application.
Join Fig. 1, one embodiment of the invention provides a kind of lithium battery electrode material, including by more carbon nano-tube fibre structuresAt cell structure and the porous carbon particle being attached on the carbon nano-tube fibre, wherein the cell structure and/or instituteState in porous carbon particle at least partly in be filled with lithium metal.
The cell structure being made of more carbon nano-tube fibres can be rendered as receiving with the carbon of setting thicknessThe carbon nano-tube film of mitron layer or self-supporting.Preferably, more carbon nano-tube fibres are in unordered intertexture shape, such as unordered intertexture shapeAt three-dimensional flat plate shape structure.Cell structure can be that the method for example by compacting is made as the porosity with settingStructural material.
In one embodiment, the porous carbon particle be carbon fiber wound at carbon fiber microballoon or acetylene black.
In one embodiment, the average pore size of the porous carbon particle is 20~70nm, preferably 30~50nm.
In one embodiment, the average grain diameter of the porous carbon particle is 2 μm~150 μm；And/or the porous carbon particleConductivity is 1.5*103~10Scm-1；And/or the specific surface area of the porous carbon particle is 300~1000m2/g；And/orLoading of the lithium metal in the electrode material is 20~70wt.%.
Further include between the carbon nano-tube fibre and lithium metal to improve the activity of interfacial reaction in one embodimentState material.
In one embodiment, the activated state material is selected from Al, Al2O3, In, ceramics in one or more combinations.
Activated state material is (for example, Al, Al2O3, In, ceramic material etc.) can be for example coated in the form of ultrathin membraneInterface.
One embodiment of the invention also provides a kind of preparation method of lithium battery electrode material, and this method includes：
Cell structure including more carbon nano-tube fibres is immersed in the solution for being dispersed with porous carbon particle, so thatPorous carbon particle is uniformly adhered on carbon nano-tube fibre, obtains material intermediate；
Deposit lithium metal on mesosome in the material, so that lithium metal is filled in cell structure and porous carbon particleIn.
In one embodiment, further include：
Activated state material is coated on the carbon nano-tube fibre, and the activated state material is made to be located at carbon nanotube fibreTo improve interfacial reaction between peacekeeping lithium metal.
In one embodiment, the porous structure including carbon nano-tube fibre is made by floating catalyst method.
In one embodiment, specifically include：
S1, reacting furnace is warming up to 1100 DEG C~1600 DEG C, and is passed through carrier gas thereto.
S2, it after phase carbon source gasifies, is brought into using carrier gas in the high-temperature region of the reacting furnace, generating, there are more carbon to receiveThe aggregation of mitron fiber.
Wherein, the phase carbon source can be the mixed solution etc. of ethyl alcohol, ferrocene, thiophene.For example, the quality hundred of ethyl alcoholDivide than being 90~99.9%, the mass percent of ferrocene is 0.1~5%, the mass percent of thiophene is 0.1~5%.ItsIn, the carrier gas is the mixed gas of hydrogen and nitrogen or hydrogen and inert gas, for example, the percent by volume of hydrogen can be withIt is 1~100%, inert gas is argon gas or helium, and gas of carrier gas flow is 1~15L/min.
S3, the aggregation is deposited on receiver board, obtain include more carbon nano-tube fibres cell structure.
Cooperation is with reference to Fig. 2, and hereinafter, following embodiment is intended to the description present invention and does not limit its scope.
Embodiment 1
1) van der Waals interaction between carbon nanotube is relied on, the hollow carbon nanotube of the tubular grown from high temperature furnace is gatheredCollective's (reference《science》, 2004,304 phases, p276), under the buoyancy of air, constantly it is wrapped in cylindrical sleepingOn formula roller, roller can prolong axial reciprocating movement while rotation, and displacement distance is the length of roller, adds up continuous collectAfter a certain period of time, the carbon nano-tube fibre porous material of self-supporting, thickness about 0.5mm are formed.
2) Al is coated in the form of ultrathin membrane on carbon nano-tube fibre by way of PVD, the thickness of the ultrathin Al filmDegree is 5nm.
3) it is 35nm, specific surface area 384m obtained carbon nano-tube fibre porous material to be immersed average pore size2/ g'sIn the dispersion liquid of carbon fiber microballoon, take out afterwards for 24 hours dry to get to material intermediate.
4) deposit lithium metal on mesosome in the material by way of PVD so that lithium metal be filled in cell structure andIn porous carbon particle.Wherein, the load capacity of lithium metal is 42% in obtained electrode material.
It is cathode by obtained electrode material, take LiFePO4 as anode assembling button cell, after circulating battery 250 timesCapacity retention ratio is 85%.
Embodiment 2
1) with reference to the mode of embodiment 1, by the van der Waals interaction between carbon nanotube, by what is grown from high temperature furnaceThe hollow carbon nanotube agglomerate of tubular is constantly wrapped on cylindrical horizontal drum, roller exists under the buoyancy of airWhile rotation, axial reciprocating movement can be prolonged, displacement distance is the length of roller, adds up continuous collection after a certain period of time,To carbon nanotube agglomerate on apply ethanol solution, and coordinate the roll shaft of certain pressure, the carbon nanotube for forming self-supporting is fineTie up porous material, thickness about 0.3mm.
2) by Al by way of PVD2O3It is coated on carbon nano-tube fibre in the form of ultrathin membrane, the ultra-thin Al2O3FilmThickness be 5nm.
3) it is 35nm, specific surface area 384m obtained carbon nano-tube fibre porous material to be immersed average pore size2/ g'sIn the dispersion liquid of carbon fiber microballoon, take out afterwards for 24 hours dry to get to material intermediate.
4) deposit lithium metal on mesosome in the material by way of PVD so that lithium metal be filled in cell structure andIn porous carbon particle.Wherein, the load capacity of lithium metal is 48% in obtained electrode material.
It is cathode by obtained electrode material, take LiFePO4 as anode assembling button cell, after circulating battery 250 timesCapacity retention ratio is 92%.
Embodiment 3
1) with reference to the mode of embodiment 1, by the van der Waals interaction between carbon nanotube, by what is grown from high temperature furnaceThe hollow carbon nanotube agglomerate of tubular is constantly wrapped on cylindrical horizontal drum, roller exists under the buoyancy of airWhile rotation, axial reciprocating movement can be prolonged, displacement distance is the length of roller, adds up continuous collection after a certain period of time,To carbon nanotube agglomerate on apply ethylene glycol solution, and coordinate the roll shaft of certain pressure, form the carbon nanotube of self-supportingTextile porous materials, thickness about 0.3mm.
2) In is coated in the form of ultrathin membrane on carbon nano-tube fibre by way of PVD, the thickness of the ultra-thin In filmsDegree is 4nm.
3) it is 28nm, specific surface area 352m obtained carbon nano-tube fibre porous material to be immersed average pore size2/ g'sIn the dispersion liquid of acetylene black, take out afterwards for 24 hours dry to get to material intermediate.
4) deposit lithium metal on mesosome in the material by way of PVD so that lithium metal be filled in cell structure andIn porous carbon particle.Wherein, the load capacity of lithium metal is 37% in obtained electrode material.
It is cathode by obtained electrode material, take LiFePO4 as anode assembling button cell, after circulating battery 250 timesCapacity retention ratio is 82%.
Embodiment 4
1) with reference to the mode of embodiment 1, by the van der Waals interaction between carbon nanotube, by what is grown from high temperature furnaceThe hollow carbon nanotube agglomerate of tubular is constantly wrapped on cylindrical horizontal drum, roller exists under the buoyancy of airWhile rotation, axial reciprocating movement can be prolonged, displacement distance is the length of roller, adds up continuous collection after a certain period of time,To carbon nanotube agglomerate on apply ethylene glycol solution, and coordinate the roll shaft of certain pressure, form the carbon nanotube of self-supportingTextile porous materials, thickness about 0.3mm.
2) by Al by way of PVD2O3It is coated on carbon nano-tube fibre in the form of ultrathin membrane, the ultra-thin Al2O3FilmThickness be 2nm.
3) it is 35nm, specific surface area 384m obtained carbon nano-tube fibre porous material to be immersed average pore size2/ g'sIn the dispersion liquid of carbon fiber microballoon, take out afterwards for 24 hours dry to get to material intermediate.
4) deposit lithium metal on mesosome in the material by way of PVD so that lithium metal be filled in cell structure andIn porous carbon particle.Wherein, the load capacity of lithium metal is 40% in obtained electrode material.
It is cathode by obtained electrode material, take LiFePO4 as anode assembling button cell, after circulating battery 250 timesCapacity retention ratio is 84%.
Embodiment 5
1) with reference to the mode of embodiment 1, by the van der Waals interaction between carbon nanotube, by what is grown from high temperature furnaceThe hollow carbon nanotube agglomerate of tubular is constantly wrapped on cylindrical horizontal drum, roller exists under the buoyancy of airWhile rotation, axial reciprocating movement can be prolonged, displacement distance is the length of roller, adds up continuous collection after a certain period of time,To carbon nanotube agglomerate on apply ethylene glycol solution, and coordinate the roll shaft of certain pressure, form the carbon nanotube of self-supportingTextile porous materials, thickness about 0.5mm.
2) by Al by way of PVD2O3It is coated on carbon nano-tube fibre in the form of ultrathin membrane, the ultra-thin Al2O3FilmThickness be 3nm.
3) it is 35nm, specific surface area 384m obtained carbon nano-tube fibre porous material to be immersed average pore size2/ g'sIn the dispersion liquid of carbon fiber microballoon, take out afterwards for 24 hours dry to get to material intermediate.
4) deposit lithium metal on mesosome in the material by way of PVD so that lithium metal be filled in cell structure andIn porous carbon particle.Wherein, the load capacity of lithium metal is 38% in obtained electrode material.
It is cathode by obtained electrode material, take LiFePO4 as anode assembling button cell, after circulating battery 250 timesCapacity retention ratio is 80%.
As can be seen from the above embodiments, make the cathode of lithium battery, battery by using electrode material provided by the inventionCapacity retention ratio be greatly improved, especially in embodiment 2 by make 0.3mm thickness carbon nano-tube fibre it is morePorous materials, and attachment aperture is coordinated to be 35nm, specific surface area 384m2The carbon fiber microballoon of/g, can be by the load of lithium metalAmount is promoted to 48%, and the capacity retention ratio after circulating battery 250 times is 92%, has obtained great promotion.
The application is had the advantages that by the above embodiment/embodiment：
It, can be with by the cell structure for combining more carbon nano-tube fibres to constitute and porous carbon particle attached theretoLithium metal more uniformly divides in multiple cavernous structures, in the charge and discharge process of lithium battery, helps to maintain lithium metalTopographical property, inhibit the generation of Li dendrite, to improve the safety of lithium battery, and provide higher specific heat capacity and preferableCycle performance.
It should be appreciated that although this specification is described in terms of embodiments, but not each embodiment only includes oneA independent technical solution, this description of the specification is merely for the sake of clarity, and those skilled in the art should will sayAs a whole, the technical solution in each embodiment may also be suitably combined to form those skilled in the art can for bright bookWith the other embodiment of understanding.
The series of detailed descriptions listed above only for the application feasible embodiment specificallyBright, they are all without departing from equivalent implementations made by the application skill spirit not to limit the protection domain of the applicationOr change should be included within the protection domain of the application.