CN100377395C - Nano composite lithium ion cell cathode material and its preparing method - Google Patents

Nano composite lithium ion cell cathode material and its preparing method Download PDF

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Publication number
CN100377395C
CN100377395C CNB2006100234832A CN200610023483A CN100377395C CN 100377395 C CN100377395 C CN 100377395C CN B2006100234832 A CNB2006100234832 A CN B2006100234832A CN 200610023483 A CN200610023483 A CN 200610023483A CN 100377395 C CN100377395 C CN 100377395C
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lithium ion
preparation
sol
obtains
cathode material
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CN1822415A (en
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吴广明
肖锟
陈世文
沈军
周斌
倪星元
张志华
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Tongji University
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Tongji University
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    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Abstract

The present invention belongs to the technical field of a lithium ion battery, particularly to cathode materials of a nano compound lithium ion battery and a preparing method thereof. V2 O5 powder is adopted to prepare V2 O5 sol by using a sol-gel method, the V2 O5 sol is compounded with a carbon nano-pipe treated by purification, V2 O5 aerogel compounded from the carbon nano-pipe is prepared by a solvent substitution method, the specific surface area of the V2 O5 aerogel is 120 to 280m<2>/g, and a hole rate is 60 to 90 percent. The present invention adopts the sol-gel method, combines with solvent substitution technology, and prepares the V2 O5 aerogel compounded from the carbon nano-pipe under a normal pressure condition. The vanadium pentoxide aerogel compounded from the carbon nano-pipe of the present invention is used as the cathode materials of the lithium ion battery and has advantages of high specific surface area, high specific capacity and good electric conductivity and circulation reversibility.

Description

A kind of preparation method of nano composite lithium ion cell cathode material
Technical field
The invention belongs to technical field of lithium ion, be specifically related to a kind of preparation method of nano composite lithium ion cell cathode material.
Background technology
Since the nineties, along with the day by day intensification of people to the energy shortage problem, it is strong that the demand of lithium rechargeable battery is also said benefit.Especially in recent years, along with the develop rapidly in fields such as microelectronics industry, engineering in medicine, electric automobile, space technology, war industry, the range of application of lithium ion battery is more and more wider, and is also more and more higher to the lithium ion battery performance demands.The characteristic of lithium ion battery is strong depends on its electrode material, particularly cathode material, V 2O 5Material is because its special layer structure, become one of good cathode material for lithium ion battery, but its traditional structure and characteristic since low surface area be difficult in lithium ion battery electric charge capacity, energy density, discharge and recharge and realize aspect the performance raisings such as invertibity, ion transfer speed breaking through.V 2O 5The birth of aeroge has broken through traditional V 2O 5The structure and characteristics of material, an a new direction has been opened up in the development of injecting fast cathode material for lithium ion battery.
V 2O 5Aeroge is a kind of novel nano porous material, and its porosity height, specific area are big, have the characteristics such as porosity is adjustable, nano-porous structure is controlled.Because its special nano-porous structure has many unusual character, thereby is containing very big application potential.5th, in 6 international aeroge meetings, various countries scholar's research report has shown this material and application prospects thereof fully.The nano-porous structure of this material, not only can make electrolyte osmosis among the aeroge network, and in the nano aperture solid phase skeleton size only in tens nanometer range, can reduce the characteristic length of lithium ion diffusion significantly, improve the ionic diffusion coefficient of material, increase the ion injection capacity and improve battery charging and discharging cycle life.This novel nano porous material can greatly improve the performance of lithium ion battery, thereby is expected to promote the development and the exploitation of high-performance, big capacity, the durable quick charge lithium ion battery that circulates.
With the wet gel that sol-gal process prepares under normal condition, the surface tension that produces often causes caving in of gel network structure because solvent volatilizees rapidly, causes nano-porous structure imperfect, and porosity is low.If introduce the supercritical drying drying process, although can prepare the complete V of nano-porous structure 2O 5Aeroge, and the material porosity is significantly improved, but this complex process, cost height, and critical gas is dangerous, and this has just limited its practical application.Utilize the method for exchange of solvent under normal temperature, normal pressure, to prepare nanoporous V 2O 5Aeroge has reduced cost, obtains the material of similar nano-porous structure.
Because V 2O 5The electric conductivity of aerogel material self is poor, can't fast charging and discharging.CNT mix the electrical conductivity that will improve aeroge, improve battery capacity, improve V 2O 5The performance of aeroge is for the application of lithium ion battery provides more wide space.
At present, external existing employing vanadium source is the patent that raw material prepares cathode material for lithium ion battery, mainly is with V 2O 5, V 2O 3Or the vanadium oxidate for lithium that generates as additive and lithium salts or the reaction of other transition metal oxides of vanadic salts or other compounds are as cathode material for lithium ion battery.Such as European patent (EP0397608) with V 2O 5With Li 2CO 3React the Li that makes through high-temperature fusion 1+xV 3O 8As cathode material for lithium ion battery; United States Patent (USP) (US5486346) is with M (NO 3) 2.6H 2O and LiOH, Li 2O, Li 2CO 3Or Li (CH 3COO) Li of reactant aqueous solution preparation xMO 2(wherein M is Ni or Co) particle is with V 2O 3, V 2O 5Or NH 4VO 3Reaction at high temperature obtains LiMVO 4As cathode material for lithium ion battery.
Domestic about V 2O 5And composite to do the patent of cathode material for lithium ion battery few in number.Chinese patent (0081943) uses vanadate to adopt the method for ion-exchange to prepare vanadium oxide water and compositions as lithium ion cathode materials as raw material.Chinese patent (97196288) is prepared chemical formula and is respectively Li xM yV zO ( X+5z+ny)/2And M yV zO (5z+ny) / 2The vanadium metal oxide of amorphous state ternary thionate and the metal oxide of amorphous state binary nonthionate as lithium ion cathode materials.
Also do not find with V at present 2O 5Powder is raw material, by the compound V of the compound preparation CNT of CNT 2O 5Aeroge is as the patent report of cathode material for lithium ion battery.
Summary of the invention
The object of the present invention is to provide a kind of with low cost, easy and simple to handle, can satisfy have high-performance, the preparation method of the nano composite lithium ion cell cathode material of big capacity, the durable quick charge lithium ion battery demand of circulation.
The nano composite lithium ion cell cathode material that the present invention proposes is by V 2O 5The V that powder adopts sol-gel process to prepare 2O 5Colloidal sol, compound with the CNT of crossing through purification process, prepare the compound V of CNT through the solvent Shift Method again 2O 5Aeroge, its specific area are 120～280m 2/ g, hole ratio are 60～90%, and wherein, CNT accounts for V 2O 5The mass percent of powder is 1%-20%.
The preparation method of the nano composite lithium ion cell cathode material that the present invention proposes, its concrete steps are as follows:
(1) V 2O 5The preparation of colloidal sol
Adopt sol-gel process, with V 2O 5Powder, phenmethylol and isopropyl alcohol are with 1: (1～10): the mixed in molar ratio of (1～100), 85 ℃～120 ℃ lower backflows 1～10 hour, adopt then centrifugal action with 100-10000 rev/min of rotation 10-60 minute, remove unreacted residual substance, obtain bottle-green V 2O 5Colloidal sol;
(2) purifying of carbon nano-tube
It is the HNO of 2.0-3.2M that carbon nano-tube is placed molar concentration 3In the solution, at 30-60 ℃ of following backflow 18-36 hour, cooling adopts centrifugal action to separate in 1-30 minute with 100-5000 rev/min of rotation, abandons supernatant, use deionized water wash then, adopt centrifugal action to separate in 1-30 minute, use deionized water wash, centrifugation repeatedly, be neutral to sediment with 100-5000 rev/min of rotation, the product that obtains places isopropyl alcohol or isobutanol, and this moment, the carbon nano-tube dispersive property was greatly improved; Wherein, disperse the 0.01-1g carbon nano-tube in every 10ml isopropyl alcohol or the isobutanol;
(3) preparation of gel
With the V that obtains in the purified CNT that obtains in the step (2) and the step (1) 2O 5Colloidal sol mixes, and vibration is stirred, and obtains complex sol, and complex sol is placed 20-50 ℃ of lower wearing out 3-5 days, obtains gel; The quality of CNT is V 2O 5The 1-20% of colloidal sol solid content;
(4) V 2O 5The preparation of aeroge
Adopt solvent replacement, atmosphere pressure desiccation, the gel that obtains in the step (3) is immersed in acetone, cyclohexane or the n-heptane solution successively, soaked 0.5～5 day in every kind of solvent, clean, to remove water, ethanol, the isopropyl alcohol equal solvent in the block hole, at last with gel at normal temperatures drying obtain composite aerogel.
Among the present invention, with the composite aerogel made in the oxygen protective atmosphere heat treatment 0.5-5 hour, the oxygen protective atmosphere was in order to prevent that pentavalent vanadium ion from degenerating, and heat treatment temperature is 50 ℃～200 ℃.
Among the present invention, described carbon nano-tube is a kind of of single wall or multi-walled carbon nano-tubes.
Among the present invention, acetone, cyclohexane or n-heptane solution all adopt the analysis alcoholic solution.
The nano composite aerogel that the present invention obtains by the solvent Shift Method, cost is low, and process conditions require simple.
The present invention is with V 2O 5Powder, CNT, phenmethylol, isopropyl alcohol or isobutanol are raw material, prepare a kind of composite aerogel as cathode material for lithium ion battery.Have simple to operately, with low cost, be convenient to the advantage of large-scale production, stable performance.V 2O 5Aeroge is as cathode materials for lithium battery, and lithium ion injects and withdraws from/good reversibility, and charging capacity is big, and the circulation durability is good; After mixing multi-walled carbon nano-tubes, improved the specific area of material (from 120-140m 2/ g brings up to 160-200m2/g), increased its specific capacity, the remarkable electric conductivity that must improve material makes fast charging and discharging become possibility, can be used for making high power, high capacity lithium ion battery.
Description of drawings
Fig. 1 is the SEM surface topography map of V2O5 aeroge of about 12% carbon nano-tube of doping of embodiment 1 preparation.
Fig. 2 is the discharge curve of SEM of V2O5 aeroge of about 12% carbon nano-tube of doping of embodiment 1 preparation.
Embodiment
Further specify the present invention and beneficial effect thereof below by embodiment and accompanying drawing.
Embodiment 1:
One, V 2O 5The preparation of colloidal sol
Adopt sol-gel process to prepare V 2O 5Colloidal sol is with V 2O 5Powder, phenmethylol and isopropyl alcohol 110 ℃ of lower backflows 5 hours, adopt centrifugal action with 3000 rev/mins of rotations 30 minutes with 1: 4: 40 mixed in molar ratio then, remove unreacted residual substance, obtain bottle-green V 2O 5Colloidal sol.Residual substance is dried weighing, calculate V in the colloidal sol 2O 5Content.
Two, the purification process of carbon nano-tube
Getting original carbon nano-tube 0.2g adding 40mL concentration is the HNO of 2.6M 3In the solution, 40 ℃ were refluxed 24 hours.Separate with 1000 rev/mins of rotating centrifugals after cooling off, pour the deionized water washing after the upper strata stillness of night is outwelled into, and then separate with 1000 rev/mins of rotating centrifugals, be repeated several times until neutrality will precipitate and collect rear 90 ℃ of oven dry.
Three, the preparation of plural gel
Take by weighing V in the colloidal sol 2O 5The CNT of quality about 12% is put into a small amount of isopropyl alcohol, sonic oscillation 30 minutes.Isopropyl alcohol and the V that will contain CNT 2O 5Colloidal sol mixes, and stirs sonic oscillation one hour one hour.Place 30 ℃ baking oven gel also to wear out 5 days complex sol.
Four, constant pressure and dry prepares V 2O 5Aeroge
Solvent is replaced atmosphere pressure desiccation and is prepared the compound V of CNT 2O 5Aeroge is put into acetone with gel, in the cyclohexane solution, soaked respectively 1 day, and 5 times repeatedly, to remove the organic solvents such as water in the block hole, ethanol, isopropyl alcohol, at last heat treatment 3 hours in 150 ℃ of oxygen protective atmospheres.
Five, the compound V of CNT 2O 5The aeroge performance test
Through the XL-30 of Philips company environmental scanning microscope and standard three-electrode method, adopt lithium metal as auxiliary electrode and reference electrode, to contain 1M/LLiPF 6Ethylene carbonate (EC) and methyl ethyl carbonate (EMC) mixed solution (Korea S Samsung provides) be electrolyte, wherein EC: EMC=1: 1, carry out electro-chemical test at the gloves that are full of argon gas in mutually.
Being prepared as follows of work electrode:
Sample with claying into power, is added 10%PVDF (as binder).After mixing, slowly add 1-methyl-2-again than pyrrolidone, until sample is diluted to pasty state.Again it is applied on Copper Foil uniformly.The oven dry Copper Foil of slowly heating, 40 ℃ of heating earlier 8 hours, 70 ℃ of heating are 4 hours again, at last wherein 120 ℃ of bakings 2 hours.Naturally cool to room temperature then.
The compound V of the CNT that makes 2O 5The surface topography of aeroge as shown in Figure 1, its discharge curve as shown in Figure 2, the V of the inventive method preparation as can be known 2O 5Aerogel block body has very high hole ratio and specific area, and specific capacity is big, and charge/discharge capacity is 250～450mAh/g.
Above-described embodiment is only in order to illustrate technological thought of the present invention and characteristics; its purpose is to make those of ordinary skill in the art can understand content of the present invention and implements according to this; scope of the present invention also not only is confined to above-mentioned specific embodiment; be all equal variation or modifications of doing according to disclosed spirit, still be encompassed in protection scope of the present invention.

Claims (4)

1. the preparation method of a nano composite lithium ion cell cathode material is characterized in that concrete steps are as follows:
(1) V 2O 5The preparation of colloidal sol
Adopt sol-gel process, with V 2O 5Powder, phenmethylol and isopropyl alcohol are with 1: (1～10): the mixed in molar ratio of (1～100), 85 ℃～120 ℃ lower backflows 1～10 hour, adopt then centrifugal action with 100-10000 rev/min of rotation 10-60 minute, remove unreacted residual substance, obtain bottle-green V 2O 5Colloidal sol;
(2) purifying of carbon nano-tube
It is the HNO of 2.0-3.2M that CNT is placed molar concentration 3In the solution, at 30-60 ℃ of lower backflow 18-36 hour, cooling, adopt centrifugal action to separate in 1-30 minute with 100-5000 rev/min of rotation, abandon supernatant, wash with deionized water then, adopt centrifugal action to separate in 1-30 minute with 100-5000 rev/min of rotation, the washing of Reusability deionized water, centrifugation are neutral to sediment, and the product that obtains places isopropyl alcohol or isobutanol; Disperse the 0.01-1g CNT in every 10ml isopropyl alcohol or the isobutanol;
(3) preparation of gel
With the V that obtains in the purified CNT that obtains in the step (2) and the step (1) 2O 5Colloidal sol mixes, and vibration is stirred, and obtains complex sol, and complex sol is placed 20-50 ℃ of lower wearing out 3-5 days, obtains gel; The quality of CNT is V 2O 5The 1-20% of colloidal sol solid content;
(4) V 2O 5The preparation of aeroge
Adopt that solvent is replaced, atmosphere pressure desiccation, the gel that obtains in the step (3) immersed in acetone, cyclohexane or the n-heptane solution successively, soaked 0.5～5 day, cleaning, at last with gel at normal temperatures drying obtain composite aerogel.
2. the preparation method of nano composite lithium ion cell cathode material according to claim 1 is characterized in that the composite aerogel that obtains in the step (4) in the oxygen protective atmosphere heat treatment 0.5-5 hour, and heat treatment temperature is 50 ℃～200 ℃.
3. the preparation method of described nano composite lithium ion cell cathode material according to claim 1 is characterized in that described carbon nano-tube is a kind of of single wall or multi-walled carbon nano-tubes.
4. the preparation method of nano composite lithium ion cell cathode material according to claim 1 is characterized in that acetone, cyclohexane or n-heptane solution all adopt the analysis alcoholic solution.
CNB2006100234832A 2006-01-19 2006-01-19 Nano composite lithium ion cell cathode material and its preparing method Expired - Fee Related CN100377395C (en)

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CN101900607B (en) * 2010-06-24 2012-07-25 电子科技大学 Vanadium oxide film for infrared detector and manufacturing method thereof
CN102364728B (en) * 2011-11-02 2013-05-29 上海交通大学 Positive electrode material for lithium ion cells and preparation method thereof
CN102978992B (en) * 2012-11-20 2015-10-21 江苏科捷锂电池有限公司 The preparation method of silicon conductive nano-paper electrode material of lithium ion battery
CN103022457B (en) * 2012-12-19 2014-12-10 同济大学 High-performance nano granular vanadium pentoxide lithium ion battery cathode material and preparation method thereof
CN103208619B (en) * 2013-03-13 2015-02-04 武汉理工大学 Potassium ion embedded type vanadium pentoxide nanowire and preparation method thereof and application thereof
CN103708545B (en) * 2013-12-26 2016-01-13 天津大学 A kind of preparation method of lithium ion battery negative material
CN105384191B (en) * 2015-10-08 2016-11-30 同济大学 A kind of vanadium pentoxide nanometer material of hexagonal plate and its preparation method and application
CN105244486B (en) * 2015-11-11 2017-12-15 攀钢集团攀枝花钢铁研究院有限公司 Carbon coating composite containing vanadium and preparation method thereof
CN106984062B (en) * 2017-03-28 2019-02-01 桂林电子科技大学 A kind of efficient complex compound wet gel solvent method of replacing

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