Summary of the invention
The objective of the invention is in order to overcome existing olivine structural LiMPO4The class material can not remain the good electron contact during as the positive electrode of serondary lithium battery, and the shortcoming of interface ion transport property difference; Be difficult for the shortcoming of disperseing when simultaneously in positive electrode, directly adding conductive carbon nanotube or nanofiber, thereby provide that a kind of ion transfer character is good, olivine carbon bobbles composite material that carbon nano-tube wherein or nanofiber are difficult for reunion.
The objective of the invention is to realize by the following technical solutions:
The invention provides a kind of olivine carbon bobbles composite material, it comprises an olivine matrix, and thereon carbon nanotubes grown or/and nanofiber.
The average grain diameter of described olivine matrix is 50nm～50um, preferred 50～500nm, and its pattern both can be irregular, also can be for rule, preferred geometric shape be a sphere.
Described olivine matrix promptly has the basis material of olivine structural, and it is the LiMPO of pure phase or doping4, its chemical composition can be represented with following formula:
LixAaMmBbPOzNn
Wherein, A is Na, Mg, Ti, V, Cr, Cu, Mn, Co, Ni, Zn, Ga, In, Ge, Ag, Hg, Au, Zr, Nb, or W;
M is Fe, Co, Mn, Ni, or V;
B is Li, Na, K, Ca, Mg, Ti, V, Cr, Cu, Mn, Co, Ni, Zn, Ga, In, Ge, Ag, Hg, Au, Zr, Nb, or W;
And M and B are not with a kind of element simultaneously;
X, a, m, b, z, n represents molar percentage, 0.9≤x≤1.8; 0≤a≤0.1; 0.5≤m≤1; 0≤b≤0.5; 3≤z≤4; 0≤n≤1;
Preferred olivine matrix is LiFePO4
Described carbon nano-tube or nanofiber diameter are 1～200nm, and length is 50nm～100um, and preferred diameter is 10～100nm, length is 200nm～20um, it both can have straight geometry appearance, also can have the geometry appearance of bending or spiral, both vertical matrix LiMPO4The particle surface oriented growth also can the non-directional growth.
Olivine carbon bobbles composite material provided by the invention also is included in described olivine matrix surface and coats the carbon film that a layer thickness is 2～100nm, the content of carbon accounts for 1～20wt% of olivine matrix weight, the thickness of preferred carbon coating layer is 2～20nm, and the content of carbon accounts for 1～5wt% of olivine matrix weight.
Olivine carbon bobbles composite material provided by the invention is to prepare by following method, specifically comprises the steps:
The preparation of step 1, olivine basis material.
Chemical composition is LixAaMmBbPOzNnPure phase or the LiMPO of doping4Preparation technology with reference to United States Patent (USP) 5,910,382 and 6,514,640, disclosed method among the Chinese patent 200410031151.x, 200410101618.3 and 200410003477.1, use conventional solid phase synthesis process, solvent thermal process, the LiMPO of preparation such as fuse salt growth method pure phase4, use conventional solid phase synthesis process, the LiMPO that preparation such as liquid phase coprecipitation is mixed4
Preparation technology's list of references 1:J.Electrochem.Soc. of the olivine matrix of coated with carbon, 149 (9), A1184-A1189 (2002) is at the LiMPO for preparing pure phase or doping4After, by conventional chemical vapour deposition (CVD), methods such as solid-phase sintering coat carbon-coating, also can be at solid phase synthesis LiFePO on its surface4Process in, add carbon matrix precursor, form carbon coating layer during again by solid-phase sintering.
Consider that from cost and technology controlling and process the present invention prepares all preferred solid phase synthesis process of above-mentioned three kinds of olivine basis materials, but is not limited to this.
Step 2, on the olivine basis material carbon nano-tube or/and nanofiber.
The present invention preferably use the slaine infusion process on the olivine basis material carbon nano-tube or/and nanofiber specifically comprise the steps:
1) preparation is used for carbon nano-tube or/and the catalyst solution of nanofiber.
With the Fe (NO that is selected from as catalyst3)39H2O, FeSO47H2O, FeCl36H2O, Co (NO3)26H2O, Co (CH3COO)24H2O, Ni (NO3)26H2O, (NH4)6Mo7O244H2O, and Cu (NO3)26H2One or more salt among the O add in distilled water, ethanol, methyl alcohol, isopropyl alcohol, ethylene glycol or the glycerol solution one or more, are mixed with the catalyst solution of 0.0001～0.1M.
2) with olivine substrate material surface supported catalyst particles.
The olivine basis material for preparing in the step 1 is added step 2 1) in catalyst solution in, the weight ratio of catalyst in the catalyst solution and olivine matrix is 1: 1～1000, ℃ abundant the stirring 5 minutes～48 hours in room temperature～200, left standstill then 5～72 hours, Separation of Solid and Liquid, isolated solid obtains the olivine basis material of catalyst supported on surface particle 20～200 ℃ of dryings 30 minutes～48 hours.
3) at olivine substrate material surface carbon nano-tube or/and nanofiber.
With step 2 2) in the olivine basis material of the catalyst supported on surface particle that obtains place a heatproof container (as graphite boat, aluminium oxide boat, the iron boat, or stainless steel boat), the tube furnace that the air-tightness of packing into then is good, box type furnace or rotary drum furnace, feed the gaseous mixture of argon gas or argon gas and hydrogen, temperature programming to 450 then～900 ℃ will be reduced to metal as the slaine of catalyst precursor; After being raised to target temperature, furnace gas is converted to carbon-source gas (acetylene, ethene, methane, carbon monoxide, toluene or other carbon-source gas) or is converted to the gaseous mixture of argon gas, nitrogen or hydrogen and above-mentioned carbon-source gas, after constant temperature carried out chemical vapour deposition (CVD) in 20 minutes～48 hours, naturally cool to room temperature, the product that obtains is olivine carbon bobbles composite material of the present invention.
Can be in step 2) in add the load capacity that surfactant comes control catalyst, particle size;
Can be in step 2) in add chemical reducing agent, in liquid phase, directly metallic reducing is deposited on the olivine basis material.
According to existing literature report, the method that load is used for the catalyst granules of carbon nano-tube and nanofiber on other class basis material comprises that also the physical mechanical ball milling mixes several different methods such as vapour deposition.The present invention also can adopt these methods metal supported catalyst on the olivine basis material.But from preparation cost, the complexity of technology controlling and process and technology is considered, preferable alloy salt dipping method of the present invention, but be not limited to this.
Olivine carbon bobbles composite material provided by the invention both can directly use in serondary lithium battery as positive electrode active materials, also can be used as additive, with existing LiCoO2, LiMn2O4, LiNiCoMnO2Mix use Deng positive electrode, its content accounts for 5～98wt% of the total weight of positive electrode.
Olivine carbon bobbles composite material provided by the invention can improve the multiplying power and the security performance of existing positive electrode and battery.It is big that the serondary lithium battery that contains this olivine carbon bobbles composite material has power density, remarkable advantages such as fail safe height.This class serondary lithium battery is applicable to that various mobile electronic devices maybe need the equipment of mobile driven by energy, mobile phone for example, notebook computer, portable video recorder, electronic toy, high power electrokinetic cell particularly, as be used in electric tool, electric automobile, hybrid vehicle, electric topedo, fields such as accumulation power supply, and be not limited to this.
The advantage of olivine carbon bobbles composite material provided by the invention is:
1) the present invention has prepared the LiMPO with the pure phase with olivine structural first4, the LiMPO that mixes4Or the LiMPO of coated with carbon4Be matrix, the olivine carbon bobbles composite material of the carbon nano-tube of having grown on it or nanofiber.
2) because in this olivine carbon bobbles composite material provided by the invention, carbon nano-tube or nanofiber are the LiMPO that is grown directly upon dispersion4On the particle, avoided adopting the uneven shortcoming of dispersion that carbon nano-tube or nanofiber were caused by time in the physical mixed in active material.In addition, because the carbon nano-tube or the nanofiber of conduction are grown directly upon the active particle surface, its length generally surpasses inner LiMPO as basis material4The diameter of particle; like this when the particle of these composite materials contacts; carbon nano-tube or carbon fiber that can be by particle surface overlap mutually with adjacent particle and to form continuous uniform conductive network, therefore can keep good electrical contact by a direct sum active material.
3) according to the transport theory of solid state ionics about ion and electronics, transporting of ion and electronics is to be mutually related.Electron transport fast will help transporting of ion, otherwise slower electron transport will slow down transporting of ion.The particle surface of olivine carbon bobbles composite material provided by the invention is carbon nano-tube or carbon fiber, when this material uses as positive electrode active materials in containing the serondary lithium battery of liquid electrolyte, in nanotube surface, because strong adsorption capacity, electrolyte solution forms thin electrolyte adsorption layer in carbon nano tube surface, in charge and discharge process, under effect of electric field, electronics will transport along carbon nano-tube or electric conduction of carbon fiber network high-speed, this will play pulling function to the ion transport on surface, strengthened surperficial ionic conduction, thereby help the transmission of lithium ion in electrode material surface, promptly be particularly conducive to the high-speed transfer of ion on the electrode active material surface, the fast charging and discharging performance of material is just superior especially like this, so this material is highly suitable in the high power serondary lithium battery and directly uses as positive electrode.
4) composite material provided by the invention, because the inner base material is the active material of storage lithium, the outside can be connected to form the favorable conductive network.Mix use with it or as conductive additive with other positive electrode, can improve the multiplying power of existing positive electrode and battery when being used for serondary lithium battery, have the big remarkable advantage that waits of power density.In addition, since the material of olivine structural, LiFePO when special4The material of class has good fail safe, can also improve the security performance of other positive electrode.
Embodiment
Embodiment 1, pure phase LiFePO4 carbon bobbles composite material 1
Pure phase LiFePO4Can be by following steps by the solid phase synthesis process preparation of two steps.At first, take by weighing LiF, FeC according to mol ratio2O42H2O and NH4H2PO4(mol ratio is 1: 1: 1), after the mechanical mixture (ball milling, rotating speed are 500 rev/mins, 3 hours), with this mixture at high-purity Ar gas/H2Gas gaseous mixture (H2The gas volume ratio accounts for 8%) (heat treated step is: be warming up to 400 ℃ with 1 hour from room temperature to protect heat treatment down; at 400 ℃ of constant temperature after 4 hours; with dropping to room temperature in two hours); (rotating speed is 500 rev/mins to ball milling once more; 1 hour) after; mixture once more sintering (sintering step is: be warming up to 600 ℃ with 2 hours from room temperature, at 600 ℃ of constant temperature after 8 hours, with dropping to room temperature in 3 hours.Obtain pure phase LiFePO4Dusty material, average grain diameter are 200nm.
Being prepared as of catalyst solution: take by weighing 0.01mol Ni (NO3)26H2O puts into beaker, adds 100ml ethylene glycol, and stirring and dissolving obtains 0.1MNi (NO3)26H2In the ethylene glycol solution of O.The method of load is: with the LiFePO of the above-mentioned preparation of 2g4Powder joins the 0.1M Ni (NO of 100ml3)26H2In the O ethylene glycol solution, stirred 10 hours at 60 ℃, by Buchner funnel or other filter plant with Separation of Solid and Liquid, then 80 ℃ of following vacuumizes 10 hours.The method of carbon nano-tube is: the gained material is placed in the aluminium oxide boat, the tube furnace of packing into then charges into argon gas, and flow is 80sccm, after the temperature programming to 600 ℃, gas is converted to the gaseous mixture of acetylene and hydrogen, and its ratio is 3: 2 (v/v), and total flow is 100sccm, after constant temperature carried out chemical vapour deposition (CVD) in 2 hours, gas is converted to argon gas, naturally cools to room temperature, products therefrom is LiFePO4Carbon bobbles composite material 1, wherein the average diameter of carbon nano-tube is 20nm, length is 100 μ m.
Use: with the LiFePO that obtains4Carbon bobbles composite material 1 mixes formation slurry (active material: acetylene black: PVDF=90: 5: 5) at normal temperatures and pressures with the n-formyl sarcolysine base pyrrolidone solution of acetylene black and 10% Kynoar (PVDF), evenly be coated on the aluminum substrates, then 100 ℃ of vacuumizes after 5 hours, the film of gained is compressed under 10MPa pressure, the about 100 μ m of the film thickness of gained are cut into the positive pole of the electrode slice of 1 * 1cm as simulated battery.
The negative pole of simulated battery uses the lithium sheet, and electrolyte is 1mol LiPF6Be dissolved in the mixed solvent of 1L EC and DMC (volume ratio 1: 1).With positive pole, negative pole, electrolyte, barrier film is assembled into simulated battery in the glove box of argon shield.
The electro-chemical test step of simulated battery: at first charge to 4.2V with 30mA/g, the multiplying power current discharge is to 2.0V then, and the capacity of being emitted is with LiFePO4The Mass Calculation of carbon bobbles composite material reaches 120mAh/g, when discharging current increases to 1500mA/g, the discharge capacity of this material is 80mAh/g, this current density, the charge-discharge magnification that is equivalent to 10C, when further raising current density during to 6000mA/g, the discharge capacity of this material is 60mAh/g.This result shows LiFePO4Carbon bobbles composite material 1 has high-multiplying power discharge characteristic preferably.
Embodiment 2, doped iron lithium phosphate carbon bobbles composite material 2
Doped iron lithium phosphate Li0.99Na0.01FePO4Can prepare (with reference to Chinese patent 200410031151.x) by following steps.At first, take by weighing Li according to mol ratio2CO3, Na2CO3, FeC2O42H2O and NH4H2PO4, behind the mechanical ball milling (rotating speed is 500 rev/mins, 3 hours), with this mixture at Ar-H2Gaseous mixture (Ar: H2=92: 8; v/v) (heat treated step is: be warming up to 500 ℃ with 1 hour from room temperature to protect heat treatment down; at 500 ℃ of constant temperature after 8 hours; with dropping to room temperature in two hours); once more behind the ball milling (rotating speed is 500 rev/mins, 1 hour), mixture once more sintering (sintering step is: be warming up to 700 ℃ with 2 hours from room temperature; at 700 ℃ of constant temperature after 24 hours, with dropping to room temperature in 3 hours).Obtain doped iron lithium phosphate Li0.99Na0.01FePO4Dusty material, average grain diameter are 500nm.
Take by weighing 0.001mol Co (NO3)26H2O puts into beaker, adds 100ml ethanol, stirring and dissolving; Then with 10g Li0.99Na0.01FePO4Join in this solution, stirred 10 hours at 25 ℃, by Buchner funnel or other filter plant with Separation of Solid and Liquid, then 80 ℃ of following vacuumizes 10 hours; The gained material is placed in the aluminium oxide boat, the tube furnace of packing into then charges into argon gas, and flow is 80sccm, after the temperature programming to 800 ℃, gas is converted to the gaseous mixture of ethene and hydrogen, and its ratio is 4: 1 (v/v), and total flow is 100sccm, after constant temperature carried out chemical vapour deposition (CVD) in 2 hours, gas is converted to argon gas, naturally cools to room temperature, products therefrom is LiFePO4Carbon bobbles composite material 2, wherein the average diameter of carbon nano-tube is 5nm, length is 10um.
The doped iron lithium phosphate carbon bobbles composite material 2 that obtains is mixed formation slurry (active material: PVDF=98: 2) at normal temperatures and pressures with the n-formyl sarcolysine base pyrrolidone solution of 10% Kynoar (PVDF), evenly be coated on the aluminum substrates, then 100 ℃ of vacuumizes after 5 hours, the film of gained is compressed under 10MPa pressure, the about 60 μ m of the film thickness of gained are cut into the positive pole of the electrode slice of 1 * 1cm as simulated battery.
The negative pole of simulated battery uses the lithium sheet, and electrolyte is 1mol LiPF6Be dissolved in the mixed solvent of 1L EC and DMC (volume ratio 1: 1).With positive pole, negative pole, electrolyte, barrier film is assembled into simulated battery in the glove box of argon shield.
The electro-chemical test step of simulated battery: at first charge to 4.2V with 30mA/g, the multiplying power current discharge is to 2.0V then, the capacity of being emitted reaches 130mAh/g with doped iron lithium phosphate carbon bobbles composite material 2 Mass Calculation, when discharging current increases to 1500mA/g, the discharge capacity of this material is 110mAh/g, and this current density is equivalent to the charge-discharge magnification of 10C, when further raising current density during to 6000mA/g, the discharge capacity of this material is 80mAh/g.This result shows that doped iron lithium phosphate carbon bobbles composite material 2 has high-multiplying power discharge characteristic preferably.Embodiment 3, doped iron lithium phosphate carbon bobbles composite material 3
Doped iron lithium phosphate LiFe0.99Na0.01PO4Can prepare (with reference to Chinese patent 200410031151.x) by following steps.At first, take by weighing Li according to mol ratio2CO3, Na2CO3, FeC2O42H2O and NH4H2PO4, behind the mechanical ball milling (rotating speed is 500 rev/mins, 3 hours), with this mixture at Ar-H2Gaseous mixture (Ar: H2=92: 8; v/v) (heat treated step is: be warming up to 450 ℃ with 1 hour from room temperature to protect heat treatment down; at 450 ℃ of constant temperature after 8 hours; with dropping to room temperature in 5 hours); once more behind the ball milling (rotating speed is 500 rev/mins, 1 hour), mixture once more sintering (sintering step is: be warming up to 800 ℃ with 2 hours from room temperature; at 800 ℃ of constant temperature after 24 hours, with dropping to room temperature in 3 hours).Obtain doped iron lithium phosphate LiFe0.99Na0.01PO4Dusty material, average grain diameter are 300nm.
Take by weighing 0.0001mol Fe (NO3)26H2O puts into beaker, adds the 100ml isopropyl alcohol, stirring and dissolving; Then with 10g LiFe0.99Na0.01PO4Powder (average grain diameter is 200nm) joins in this solution, stirred 1 hour at 25 ℃, by Buchner funnel or other filter plant with Separation of Solid and Liquid, then 100 ℃ of following vacuumizes 10 hours; The gained material is placed in the aluminium oxide boat, the tube furnace of packing into then, charge into argon gas, flow is 80sccm, after the temperature programming to 600 ℃, gas is converted to acetylene gas, total flow is 100sccm, and constant temperature was converted to argon gas with gas after carrying out chemical vapour deposition (CVD) in 2 hours, naturally cool to room temperature, products therefrom is LiFePO4Carbon bobbles composite material, wherein the average diameter of carbon nano-tube is 50nm, length is 0um.
Embodiment 4, doped iron lithium phosphate carbon bobbles composite material 4
Nitrogen doped iron phosphate lithium anode material Li1.8Co0.1FePO3N can prepare by following steps.At first, with Li3N mixes the back in high-purity N with the Co powder2Made Li in 12 hours 700 ℃ of heating down2.4Co0.3N.Take by weighing LiPO then3, Li2.4Co0.3N, Fe3N2(mol ratio is 3: 1: 1) filling high-purity N2In the sealing ball grinder of gas behind the mechanical ball milling (rotating speed is 500 rev/mins, 3 hours), with this mixture in high-purity N2Sample is taken out in heat treatment under the gas shiled (heat treated step is: be warming up to 600 ℃ with 3 hours from room temperature, at 600 ℃ of constant temperature after 8 hours, with dropping to room temperature in two hours).Obtain doped iron lithium phosphate Li1.8Co0.1FePO3N dusty material, average grain diameter are 1um.
Take by weighing 0.0001mol (NH4)6Mo7O244H2O puts into beaker, adds 100ml methyl alcohol, stirring and dissolving; Then with 10g Li1.8Co0.1FePO3N powder (average grain diameter is 500nm) joins in this solution, stirred 10 hours at 25 ℃, by Buchner funnel or other filter plant with Separation of Solid and Liquid, then 100 ℃ of following vacuumizes 10 hours; The gained material is placed in the aluminium oxide boat, the tube furnace of packing into then, charge into argon gas, flow is 80sccm, after the temperature programming to 800 ℃, gas is converted to argon gas stream crosses the toluene bottle, flow is 100sccm, and constant temperature was converted to argon gas with gas after carrying out chemical vapour deposition (CVD) in 20 hours, naturally cool to room temperature, products therefrom is LiFePO4Carbon bobbles composite material, average diameter of carbon fiber is 100nm on it, length is 50um.
The LiFePO4 carbon bobbles composite material of embodiment 5, oxygen-containing vacancy
The LiFePO4 matrix material LiFePO of oxygen-containing vacancy3.998Can prepare by following steps.At first, take by weighing LiF, FeC at 1: 1: 1 according to mol ratio2O42H2O and NH4H2PO4, behind the mechanical ball milling (rotating speed is 500 rev/mins, 3 hours), with this mixture at high-purity Ar gas/H2Gas gaseous mixture (H2The gas volume ratio accounts for 8%) (heat treated step is: be warming up to 400 ℃ with 1 hour from room temperature to protect heat treatment down; at 400 ℃ of constant temperature after 4 hours; with dropping to room temperature in two hours); (rotating speed is 500 rev/mins to ball milling once more; 1 hour) after; mixture once more sintering (sintering step is: be warming up to 600 ℃ with 2 hours from room temperature, at 600 ℃ of constant temperature after 8 hours, with dropping to room temperature in 3 hours.Obtain the LiFePO4 matrix material LiFePO of oxygen-containing vacancy3.998Dusty material, average grain diameter are 100nm.
Take by weighing 0.001mol Ni (NO3)26H2O and 0.000015mol Cu (NO3)26H2O adds the 100ml isopropyl alcohol, stirring and dissolving in beaker.Then with 10g LiFePO3.998Powder joins in this solution, stirred 5 hours at 25 ℃, by Buchner funnel or other filter plant with Separation of Solid and Liquid, then 100 ℃ of following vacuumizes 10 hours; The gained material is placed in the aluminium oxide boat, the tube furnace of packing into then, charge into argon gas, flow is 80sccm, after the temperature programming to 800 ℃, gas is converted to methane gas, total flow is 100sccm, and constant temperature was converted to argon gas with gas after carrying out chemical vapour deposition (CVD) in 20 hours, naturally cool to room temperature, products therefrom is LiFePO4Carbon bobbles composite material, average diameter of carbon fiber is 100nm on it, length is 10um.
Embodiment 6～51, olivine carbon bobbles composite material 6～51
Similar with embodiment 2～5, different is to have prepared the Li doped MPO that contains different doped chemicals and ratio4, basis material, and the LiMPO of oxygen-containing vacancy4Basis material, its expression formula can be written as LixAaMmBbPOzNnWherein, A is Na, Mg, Ti, V, Cr, Cu, Mn, Co, Ni, Zn, Ga, In, Ge, Ag, Hg, Au, Zr, Nb, W; M is Fe, Co, Mn, Ni, V; B is Li, Na, K, Ca, Mg, Ti, V, Cr, Cu, Mn, Co, Ni, Zn, Ga, In, Ge, Ag, Hg, Au, Zr, Nb, W; And M and B are not a kind of element simultaneously; X, a, m, b, z, n represents molar percentage, 0.9≤x≤1.8; 0≤a≤0.1; 0.5≤m≤1; 0≤b≤0.5; 3≤z≤4; 0≤n≤1.
The preparation method of above-mentioned basis material is similar to embodiment 2～5, different is the raw material difference that adopts, the doped chemical difference of adding, about the preparation of these materials, can be with reference to (Wang Deyu, Chen Liquan, Li Hong, yellow-study outstanding person, a kind of positive electrode and purposes that is used for serondary lithium battery, 200410031151.x; Li Hong, yellow-study outstanding person is used for the lithium iron phosphate positive material and uses thereof of the oxygen-containing vacancy of serondary lithium battery, 200410101618.3; Li Hong, yellow-study outstanding person, Wang Deyu, Chen Liquan, positive electrode of a kind of nitrogen phosphate that is used for serondary lithium battery and uses thereof, 200410037502.8).The chemical composition of basis material 6～51 is referring to subordinate list 1.
On above-mentioned different basis material, the method and the embodiment 1～5 of growth carbon nano-fiber and carbon nano-tube are similar, different is the catalyst system therefor kind, content, the carbon-source gas kind, synthesis temperature, the time there are differences, these differences cause the carbon nano-tube that grows out or nanofiber at diameter, there are differences on the length.The feature of these olivine carbon bobbles composite materials is listed in table 1.
Embodiment 52, carbon coat olivine carbon bobbles composite material 52
Carbon coats olivine LiMPO4Can prepare by following steps.At first, take by weighing Li according to mol ratio2CO3, FeC2O42H2O and NH4H2PO4, behind the mechanical ball milling (rotating speed is 500 rev/mins, 3 hours), with this mixture at Ar-H2Gaseous mixture (Ar: H2=92: 8; v/v) (heat treated step is: be warming up to 400 ℃ with 1 hour from room temperature to protect heat treatment down; at 400 ℃ of constant temperature after 8 hours; with dropping to room temperature in two hours); add the carbon black of 10% weight ratio then; the water soluble starch of 10% weight ratio; and the ethanol of 20ml (volume of a container is 100ml) once more ball milling (rotating speed is 500 rev/mins; 1 hour) after; mixture once more sintering (sintering step is: be warming up to 600 ℃ with 2 hours from room temperature; at 600 ℃ of constant temperature after 24 hours, with dropping to room temperature in 3 hours).The basis material that obtains is the LiFePO of coated with carbon particle4, LiFePO wherein4Average grain diameter is 100nm, and the mass percent of carbon is 12% in the product, LiFePO4Mass percent be 88%, the thickness of carbon-coating is 20-30nm.
With the basis material that obtains, adopt similar and method embodiment 1～51, catalyst in the load, according to the condition of table 1, the carbon that obtains superficial growth carbon nano-tube or nanofiber coats olivine carbon bobbles composite material 52.The diameter of epontic carbon nano-tube is 50nm, and length is about 20um.
Embodiment 53～57, carbon coat olivine carbon bobbles composite material 53～57
Be similar to embodiment 52, obtain carbon and coat olivine LiMPO4The olivine LiMPO that different coated4The material difference, its preparation method is identical with embodiment 6～51.Carbon coats the final content difference of back carbon in basis material, not being both because due to the part by weight difference of carbon black that adds and water soluble starch of content.The amount of carbon black is adding fashionable 0～20% weight ratio that generally is controlled at, and the carbon residue rate of water soluble starch generally about 25%, generally is controlled at about 0～40% during interpolation.Water soluble starch and carbon black can not add when synthetic carbon coats the olivine material simultaneously, but must add one of them.Final carbon is no more than 20% in the mass percent that carbon coats in the olivine basis material, is not less than 1%.All these test difference, referring to table 2.
With the basis material that obtains, adopt similar and method embodiment 1～52, catalyst in the load is then by chemical vapor deposition growth carbon nano-tube or carbon fiber.It is irrelevant that the diameter of carbon nano-tube and carbon fiber and length and carbon coat the olivine basis material, only relevant with the load and the growth conditions of catalyst, and the carbon that finally obtains coats the principal character of olivine carbon bobbles composite material and lists in table 2.
Embodiment 58, olivine carbon bobbles composite material are as the purposes 1 of anode of secondary lithium battery additive
With the pure phase LiFePO4 carbon bobbles composite material of embodiment 1 preparation, with cobalt acid lithium (LiCoO2, commercial product, diameter are 20 microns, bulk density is 3g/cm3) and the n-formyl sarcolysine base pyrrolidone solution of 10% Kynoar (PVDF) mix at normal temperatures and pressures and form slurry (pure phase LiFePO4 carbon bobbles composite material 1: LiCoO wherein2: PVDF=10: 85: 5), evenly be coated on the aluminum substrates,, the film of gained compressed under 10MPa pressure then 100 ℃ of vacuumizes after 5 hours, the about 100 μ m of the film thickness of gained are cut into the positive pole of the electrode slice of 1 * 1cm as simulated battery.
The negative pole of simulated battery uses the lithium sheet, and electrolyte is 1mol LiPF6Be dissolved in the mixed solvent of 1L EC and DMC (volume ratio 1: 1).With positive pole, negative pole, electrolyte, barrier film is assembled into simulated battery in the glove box of argon shield.
The electro-chemical test step of simulated battery: at first charge to 4.2V with 30mA/g, the multiplying power current discharge is to 2.0V then, and the capacity of being emitted is with LiFePO4The Mass Calculation that carbon bobbles composite material adds cobalt acid lithium reaches 130mAh/g, when discharging current increases to 1500mA/g, the discharge capacity of this material is 90mAh/g, this current density, the charge-discharge magnification that is equivalent to 10C, when further raising current density during to 6000mA/g, the discharge capacity of this material is 60mAh/g, this current density is equivalent to the charge-discharge magnification of 40C.This result shows LiFePO4Carbon bobbles composite material 1 has significantly improved the high-multiplying power discharge characteristic of cobalt acid lithium as functional additive.
Embodiment 59, olivine carbon bobbles composite material are as the purposes 2 of anode of secondary lithium battery additive
With the doped iron lithium phosphate carbon bobbles composite material 2 of embodiment 2 preparations, with LiMn2O4 (LiMn2O4, commercial product, diameter are 15 microns, bulk density is 2.8g/cm3) and the n-formyl sarcolysine base pyrrolidone solution of 10% Kynoar (PVDF) mix at normal temperatures and pressures and form slurry (wherein the doped iron lithium phosphate carbon bobbles composite material 2: LiMn2O4: PVDF=20: 75: 5), evenly be coated on the aluminum substrates,, the film of gained compressed under 10MPa pressure then 100 ℃ of vacuumizes after 5 hours, the about 100 μ m of the film thickness of gained are cut into the positive pole of the electrode slice of 1 * 1cm as simulated battery.
The negative pole of simulated battery uses the lithium sheet, and electrolyte is 1mol LiPF6Be dissolved in the mixed solvent of 1L EC and DMC (volume ratio 1: 1).With positive pole, negative pole, electrolyte, barrier film is assembled into simulated battery in the glove box of argon shield.
The electro-chemical test step of simulated battery: at first charge to 4.2V with 30mA/g, the multiplying power current discharge is to 2.0V then, and the capacity of being emitted is with LiFePO4The Mass Calculation that carbon bobbles composite material adds LiMn2O4 reaches 110mAh/g, when discharging current increases to 1500mA/g, the discharge capacity of this material is 80mAh/g, this current density, the charge-discharge magnification that is equivalent to 10C, when further raising current density during to 6000mA/g, the discharge capacity of this material is 70mAh/g, this current density is equivalent to the charge-discharge magnification of 40C.This result shows that doped iron lithium phosphate carbon bobbles composite material 2 has significantly improved the high-multiplying power discharge characteristic of LiMn2O4 as functional additive.
Embodiment 60, olivine carbon bobbles composite material are as the purposes 3 of anode of secondary lithium battery additive
According to embodiment 59, with the doped iron lithium phosphate carbon bobbles composite material 2 and lithium nickel cobalt manganese oxygen (LiNi of embodiment 2 preparations0.4Co0.2Mn0.4O2, commercial product, diameter are 5 microns, bulk density is 2.4g/cm3) and the n-formyl sarcolysine base pyrrolidone solution of 10% Kynoar (PVDF) mix at normal temperatures and pressures and form slurry (wherein the doped iron lithium phosphate carbon bobbles composite material 2: LiNi0.4Co0.2Mn0.4O2: PVDF=30: 60: 5), evenly be coated on the aluminum substrates,, the film of gained compressed under 10MPa pressure then 100 ℃ of vacuumizes after 5 hours, the about 100 μ m of the film thickness of gained are cut into the positive pole of the electrode slice of 1 * 1cm as simulated battery.
The negative pole of simulated battery uses the lithium sheet, and electrolyte is 1mol LiPF6Be dissolved in the mixed solvent of 1L EC and DMC (volume ratio 1: 1).With positive pole, negative pole, electrolyte, barrier film is assembled into simulated battery in the glove box of argon shield.
The electro-chemical test step of simulated battery: at first charge to 4.2V with 30mA/g, the multiplying power current discharge is to 2.0V then, and the capacity of being emitted is with LiFePO4The Mass Calculation that carbon bobbles composite material adds lithium nickel cobalt manganese oxygen reaches 130mAh/g, when discharging current increases to 1500mA/g, the discharge capacity of this material is 100mAh/g, this current density, the charge-discharge magnification that is equivalent to 10C, when further raising current density during to 6000mA/g, the discharge capacity of this material is 90mAh/g, this current density is equivalent to the charge-discharge magnification of 40C.This result shows that doped iron lithium phosphate carbon bobbles composite material 2 has significantly improved the high-multiplying power discharge characteristic of lithium nickel cobalt manganese oxygen as functional additive.
Embodiment 61, olivine carbon bobbles composite material are as the purposes 4 of anode of secondary lithium battery additive
According to embodiment 59, with the doped iron lithium phosphate carbon bobbles composite material 2 and lithium nickel cobalt manganese oxygen (LiNi of embodiment 2 preparations0.33Co0.33Mn0.33O2, commercial product, diameter are 8 microns, bulk density is 2.6g/cm3) and the n-formyl sarcolysine base pyrrolidone solution of 10% Kynoar (PVDF) mix at normal temperatures and pressures and form slurry (wherein the doped iron lithium phosphate carbon bobbles composite material 2: LiNi0.4Co0.2Mn0.4O2: PVDF=5: 90: 5), evenly be coated on the aluminum substrates, then 100 ℃ of vacuumizes after 5 hours, the film of gained compressed under 10MPa pressure, the about 100 μ m of the film thickness of gained are cut into the positive pole of the electrode slice of 1 * 1cm as simulated battery.
The negative pole of simulated battery uses the lithium sheet, and electrolyte is 1mol LiPF6Be dissolved in the mixed solvent of 1L EC and DMC (volume ratio 1: 1).With positive pole, negative pole, electrolyte, barrier film is assembled into simulated battery in the glove box of argon shield.
The electro-chemical test step of simulated battery: at first charge to 4.2V with 30mA/g, the multiplying power current discharge is to 2.0V then, and the capacity of being emitted is with LiFePO4The Mass Calculation that carbon bobbles composite material adds lithium nickel cobalt manganese oxygen reaches 150mAh/g, when discharging current increases to 1500mA/g, the discharge capacity of this material is 120mAh/g, this current density, the charge-discharge magnification that is equivalent to 10C, when further raising current density during to 6000mA/g, the discharge capacity of this material is 100mAh/g, this current density is equivalent to the charge-discharge magnification of 40C.This result shows that doped iron lithium phosphate carbon bobbles composite material 2 has significantly improved the high-multiplying power discharge characteristic of lithium nickel cobalt manganese oxygen as functional additive.
Embodiment 62, olivine carbon bobbles composite material are as the purposes 5 of active material of anode of secondary lithium battery
According to embodiment 59, with the doped iron lithium phosphate carbon bobbles composite material 2 and Li-Ni-Mn-O (LiNi of embodiment 2 preparations0.8Mn0.2O2, commercial product, diameter are 10 microns, bulk density is 2.9g/cm3) and the n-formyl sarcolysine base pyrrolidone solution of 10% Kynoar (PVDF) mix at normal temperatures and pressures and form slurry (wherein the doped iron lithium phosphate carbon bobbles composite material 2: LiNi0.8Mn0O2: PVDF=90: 5: 5), evenly be coated on the aluminum substrates, then 100 ℃ of vacuumizes after 5 hours, the film of gained compressed under 10MPa pressure, the about 100 μ m of the film thickness of gained are cut into the positive pole of the electrode slice of 1 * 1cm as simulated battery.
The negative pole of simulated battery uses the lithium sheet, and electrolyte is 1mol LiPF6Be dissolved in the mixed solvent of 1L EC and DMC (volume ratio 1: 1).With positive pole, negative pole, electrolyte, barrier film is assembled into simulated battery in the glove box of argon shield.
The electro-chemical test step of simulated battery: at first charge to 4.2V with 30mA/g, the multiplying power current discharge is to 2.0V then, and the capacity of being emitted is with LiFePO4The Mass Calculation that carbon bobbles composite material adds Li-Ni-Mn-O reaches 150mAh/g, when discharging current increases to 1500mA/g, the discharge capacity of this material is 110mAh/g, this current density, the charge-discharge magnification that is equivalent to 10C, when further raising current density during to 6000mA/g, the discharge capacity of this material is 95mAh/g, this current density is equivalent to the charge-discharge magnification of 40C.This result shows that the anode composite that doped iron lithium phosphate carbon bobbles composite material 2 and Li-Ni-Mn-O are formed has shown good high-multiplying power discharge characteristic.
The principal character of table 1, olivine carbon bobbles composite material provided by the invention
| Embodiment | The olivine basis material | Carbon nano-tube or nanofiber |
| Chemical formula | Average grain diameter | Diameter | Length |
| 1 | LiFePO4 | 200nm | 20nm | 100um |
| 2 | Li0.99Na0.01FePO4 | 500nm | 5nm | 10um |
| 3 | LiFe0.99Na0.01PO4 | 300nm | 50nm | 10um |
| 4 | Li1.8Co0.1FePO3N | 1um | 200nm | 20um |
| 5 | LiFePO3.998 | 100nm | 100nm | 10um |
| 6 | Li1.2FePO3.8N0.2 | 200nm | 4nm | 1um |
| 7 | Li0.9Zr0.1Fe0.9Mg0.1PO3.9N0.17 | 400nm | 40nm | 10um |
| 8 | Li0.95Na0.05Fe0.9Cr0.067PO3.99N0.01 | 300nm | 20nm | 5um |
| 9 | Li0.95Nb0.01Fe0.9Cu0.1PO3.99N0.1 | 350nm | 30nm | 10um |
| 10 | Li0.95W0.01Fe0.9Ni0.1PO3.99N0.01 | 260nm | 10nm | 1um |
| 11 | LiMg0.05Fe0.9Zn0.1PO3.9N0.1 | 200nm | 30nm | 10um |
| 12 | Li0.92Ge0.06Fe0.9Na0.2PO3.9N0.12 | 100nm | 10nm | 5um |
| 13 | Li0.95V0.02Fe0.9Ag0.2PO3.9N0.1 | 200nm | 60nm | 10um |
| 14 | Li0.95Co0.02Fe0.9Cu0.1PO3.9N0.1 | 300nm | 20nm | 15um |
| 15 | Li0.95Ga0.02Fe0.7V0.2PO3.9N0.1 | 300nm | 40nm | 6um |
| 16 | LiCu0.1Co0.7In0.2PO3.4N0.43 | 250nm | 10nm | 1um |
| 17 | Li1.1Mn0.8Zr0.1PO3.9N0.1 | 270nm | 30nm | 50um |
| 18 | Li1.1Ni0.75Nb0.1PO3.9N0.1 | 180nm | 10nm | 5um |
| 19 | Li4FePO4N | 1um | 200nm | 20um |
| 20 | Li0.95Na0.05Fe0.9Co0.1PO3.99N0.01 | 200nm | 10nm | 12um |
| 21 | Li1.8Co0.1FePO3N | 150nm | 60nm | 1um |
| 22 | Li1.04Cr0.02Fe0.5Mn0.5PO3.9N0.1 | 300nm | 20nm | 10um |
| 23 | Li0.96Ti0.05Fe0.9Ca0.1PO3.9N0.12 | 200nm | 30nm | 6um |
| 24 | Li0.94Hg0.08Fe0.9Li0.2PO3.98N0.02 | 180nm | 10nm | 1um |
| 25 | Li0.94Au0.08Fe0.9K0.2PO3.98N0.02 | 100nm | 1nm | 50nm |
| 26 | Li0.95Mn0.02Fe0.9Hg0.2PO3.9N0.1 | 200nm | 10nm | 5um |
| 27 | Li0.95Ni0.02Fe0.9Au0.2PO3.9N0.1 | 400nm | 60nm | 5um |
| 28 | Li0.95In0.02Fe0.7Ga0.2PO3.9N0.1 | 300nm | 30nm | 10um |
| 29 | LiZn0.05Fe0.8Ti0.1PO3.9N0.1 | 100nm | 10nm | 20um |
| 30 | Li1.1Fe0.8Ge0.1PO3.9N0.1 | 200nm | 3nm | 6um |
| 31 | Li1.1V0.5W0.1PO3.9N0.1 | 10um | 100nm | 100um |
| 32 | LiFePO3.998 | 50um | 30nm | 50um |
| 33 | LiFePO3.7 | 20um | 10nm | 5um |
| 34 | LiFePO3.5 | 15um | 200nm | 70um |
| 35 | LiFePO3.97N0.02 | 1um | 10nm | 12um |
| 36 | LiFePO3.25N0.5 | 500nm | 60nm | 10um |
| 37 | LiFePO3N0.5 | 800nm | 20nm | 20um |
| 38 | LiFe0.9Na0.1PO3.95 | 300nm | 3nm | 6um |
| 39 | LiFe0.97Li0.03PO3.98 | 400nm | 50nm | 100um |
| 40 | LiFe0.95K0.05PO3.97 | 500nm | 30nm | 10um |
| 41 | LiFe0.9Cu0.1PO3.95 | 300nm | 10nm | 5um |
| 42 | LiFe0.95Na0.05PO3.925N0.1 | 180nm | 20nm | 100nm |
| 43 | LiFe0.9Cu0.1PO3.1N0.5 | 200nm | 10nm | 12um |
| 44 | LiFe0.9Ag0.1PO3.6N0.2 | 300nm | 60nm | 10um |
| 45 | LiFe0.97Na0.03PO3.8N0.1 | 200nm | 20nm | 20um |
| 46 | LiMnPO4 | 1um | 100nm | 20um |
| 47 | LiCoPO4 | 5um | 50nm | 30um |
| 48 | LiFe0.5Mn0.5PO4 | 30um | 100nm | 100um |
| 49 | LiFe0.8Co0.2PO4 | 20um | 200nm | 40um |
| 50 | LiFe0.8Mn0.2PO4 | 10um | 10nm | 10um |
| 51 | LiMn0.5Co0.5PO4 | 15um | 20nm | 15um |
Table 2, carbon provided by the invention coat the feature of olivine carbon bobbles composite material
| Embodiment | The olivine basis material that carbon coats | Carbon nano-tube or nanofiber |
| The olivine basis material | The carbon-coating that coats | Diameter | Length |
| Chemical formula | Average grain diameter | Content % | Thickness |
| 52 | LiFePO4 | 100nm | 12 | 20nm | 50nm | 20um |
| 53 | LiMnPO4 | 200nm | 1 | 2nm | 1nm | 50nm |
| 54 | LiFePO3.998 | 50nm | 5 | 10nm | 10nm | 1um |
| 55 | Li0.95Na0.05Fe0.9 Co0.1PO3.99N0.01 | 500nm | 10 | 50nm | 80nm | 10um |
| 56 | LiFe0.5Mn0.5PO4 | 50um | 20 | 100nm | 200nm | 50um |
| 57 | LiFe0.9Na0.1PO3.95 | 1um | 3 | 40nm | 100nm | 40um |