CN109941990A - A kind of preparation method of LiFePO 4 material surface coated graphite alkene - Google Patents
A kind of preparation method of LiFePO 4 material surface coated graphite alkene Download PDFInfo
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- CN109941990A CN109941990A CN201711396897.4A CN201711396897A CN109941990A CN 109941990 A CN109941990 A CN 109941990A CN 201711396897 A CN201711396897 A CN 201711396897A CN 109941990 A CN109941990 A CN 109941990A
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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
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- 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 relates to a kind of preparation methods of LiFePO 4 material surface coated graphite alkene, using LiFePO 4 powder as growth substrate and are passed through carbon source, using plasma enhances chemical vapour deposition technique and grows graphene on growth substrate surface；The parameter of the plasma enhanced chemical vapor deposition method includes: that the reaction temperature of growth substrate is 300~500 DEG C；1~10 sccm of flow of carbon source；Vacuum degree is lower than 40 pa；100~300 W of power；Growth time 5~20 minutes.
Description
Technical field
The present invention relates to a kind of preparation methods of LiFePO 4 material surface coated graphite alkene, and in particular to utilizes graphene
Surface cladding and modification are carried out to LiFePO 4 material, material property is promoted, belongs to field of composite material preparation.
Background technique
Ion battery LiFePO 4 of anode material has higher specific capacity, excellent cycle performance, high-temperature behavior and safety
Performance is current power type lithium ion battery first choice positive electrode.The major defect of LiFePO4 be it electronic conductivity compared with
Low (10-9S·cm-2), this makes rate charge-discharge performance poor.Improve conductivity of lithium iron phosphate material most effective approach be
Coated modified carbon is carried out to material.Currently, it is to pass through chemical vapor deposition that LiFePO 4 material, which carries out carbon-coated common method,
Technology deposits upper one layer of agraphitic carbon on LiFePO4 surface, to promote the electric conductivity of material.
This new carbon of recent graphene just causes widely to pay close attention to once appearance.With Chang Chuantong carbon coating material
Material is compared, and graphene has superior electronic conduction characteristic, big specific surface area and excellent chemical resistance properties.Therefore close
Graphene-coated lithium iron phosphate is prepared over year to promote the research of LiFePO 4 material performance and receive extensive concern.But early period is reported
Graphene/LiFePO 4 material aluminium foil mostly use graphene oxide as graphene presoma, be blended and coated by liquid phase, after
The mode of continuous thermal reduction, prepares graphene coated/LiFePO 4 material.However this method is using the graphene oxide conduct of reduction
Covering material, this type graphene self-defect is more to cause electric conductivity poor, and material surface graphene coated is uniform
Property is also difficult to control.
Summary of the invention
In view of the above-mentioned problems, the present invention provides a kind of preparation method of LiFePO 4 material surface coated graphite alkene, with
LiFePO 4 powder is as growth substrate and is passed through carbon source, and using plasma enhances chemical vapour deposition technique in growth substrate table
It looks unfamiliar long graphene；The parameter of the plasma enhanced chemical vapor deposition method includes: that the reaction temperature of growth substrate is 300
~500 DEG C；1~10sccm of flow of carbon source；Vacuum degree is lower than 40pa；100~300W of power；5~20 points of growth time
Clock.
The present invention is using LiFePO 4 powder as growth substrate and is passed through carbon source, and using plasma enhances chemical vapor deposition
Long-pending method starts the growth of graphene.Under plasma conditions, LiFePO4 surface can generate for our creative discoveries
Micro Fe 2P can be used as catalyst, catalytic growth of the catalytic graphite alkene on LiFePO4 surface, reality under 300-500 DEG C of low temperature
Growth in situ of the existing graphene on LiFePO4 surface coats, to prepare the lithium iron phosphate positive material of graphene coated.
Preferably, the carbon source is at least one of methane, ethylene and difluoromethane.
Preferably, the partial size of the LiFePO 4 powder is 200nm~10 μm.
Preferably, the heating rate of the growth substrate reaction temperature is 1~6 DEG C/min.
On the other hand, the present invention also provides it is a kind of according to above-mentioned preparation method prepare graphene/LiFePO 4 material,
Including LiFePO 4 powder and it is coated on the graphene on LiFePO 4 powder surface, the graphene number of plies is 2~10 layers.
The present invention is mainly to realize that graphene is coated and is modified to the surface of LiFePO4, with the conductive characteristic of reinforcing material.
In another aspect, the present invention also provides a kind of graphene/LiFePO 4 materials prepared according to above-mentioned preparation method
Application in lithium ion battery.The present invention is by enhancing chemical vapor deposition method using plasmon, in LiFePO4 table
Face directly grows graphene coated layer, is prepared for high performance graphene/iron phosphate compound anode material of lithium.The preparation method is first
It is secondary to realize under chemical vapor deposition conditions, the growth in situ cladding of LiFePO4 surface graphene.Prepared composite material
In, LiFePO4 surface has coated the controllable graphene layer of the number of plies, and the internal resistance of lithium battery, capacitor can be significantly reduced, and is promoted
The high power performance of battery.The used technique of the present invention is plasma enhanced chemical vapor deposition, is realized at a lower temperature
The preparation of graphene is grown.
Detailed description of the invention
Fig. 1 is graphene/LiFePO 4 material transmission electron microscope picture prepared by embodiment 1；
Fig. 2 is graphene/LiFePO 4 material transmission electron microscope picture prepared by embodiment 1；
Fig. 3 is graphene/LiFePO 4 material transmission electron microscope picture prepared by embodiment 1；
Fig. 4 is graphene/LiFePO 4 material transmission electron microscope picture prepared by embodiment 3；
Fig. 5 is the half-cell AC impedance figure of graphene-coated lithium iron phosphate material prepared by embodiment 1.
Specific embodiment
The present invention is further illustrated below by way of following embodiments, it should be appreciated that following embodiments are merely to illustrate this
Invention, is not intended to limit the present invention.
The present invention is in the way of plasma enhanced chemical vapor deposition, under lower temperature conditions, realizes graphene
Growth on LiFePO 4 powder surface.
The present invention enhances the method work of preparing graphene through chemical vapor deposition coated LiFePO 4 for lithium ion batteries material using plasmon
Skill is simple, and process is easy to control, and prepared graphene/lithium iron phosphate positive material is had excellent performance.Illustrate this hair to following exemplary
The preparation method of the LiFePO 4 material surface coated graphite alkene of bright offer.
Using plasma of the present invention enhances chemical vapour deposition technique, 300-500 DEG C under vacuum and low temperature growth conditions,
With carbon source (for example, methane etc.) for raw material, grow to obtain one layer of continuous highly conductive graphene in LiFePO 4 material surface in situ
Clad.The partial size of the LiFePO 4 powder can be 200nm~10 μm.Wherein, the plasma enhanced chemical vapor is heavy
The parameter of area method includes: that the reaction temperature of growth substrate is 300~500 DEG C；1~10sccm of flow of carbon source；Vacuum degree is lower than
40pa；100~300W of power；Growth time 5~20 minutes.The heating rate of the growth substrate reaction temperature can be 1
~6 DEG C/min.Carbon source used in growth graphene can be methane, ethylene or difluoromethane.
As an example, LiFePO 4 powder is placed in ceramic boat first and be put in tube furnace road, vacuumized.Then
Tube furnace is with the heating of 3 DEG C/min heating rate, until being passed through CH after 300-500 DEG C of predetermined reaction temperature4(1-10sccm) is kept
Vacuum degree is lower than 40 Pascals, opens RF power supply, and power is adjusted to 100-300W, generates hydrogen plasma in quartz ampoule.
The thick grapheme material at 2-10 layers from level to level is grown on lithium iron phosphate particles surface after following reaction 5-20min.
Enumerate embodiment further below with the present invention will be described in detail.It will similarly be understood that following embodiment is served only for this
Invention is further described, and should not be understood as limiting the scope of the invention, those skilled in the art is according to this hair
Some nonessential modifications and adaptations that bright above content is made all belong to the scope of protection of the present invention.Following examples are specific
Technological parameter etc. is also only an example in OK range, i.e. those skilled in the art can be done properly by the explanation of this paper
In the range of select, and do not really want to be defined in hereafter exemplary specific value.The partial size of LiFePO 4 powder in following embodiments
It is 200nm-10 microns.
Embodiment 1
(1) LiFePO 4 powder is placed in ceramic boat first and be put in tube furnace road, vacuumized.Subsequent tube furnace with 3 DEG C/
Min heating rate heating, until being passed through CH after 300 DEG C of predetermined reaction temperature4(10sccm) keeps vacuum degree to be lower than 40 Pascals,
RF power supply is opened, power is adjusted to 100W, generates hydrogen plasma in quartz ampoule.In ferric phosphate after following reaction 20min
Lithium particle surface grows the thick grapheme material at 2-5 layers from level to level.
Embodiment 2
LiFePO 4 powder is placed in ceramic boat first and is put in tube furnace road, is vacuumized.Subsequent tube furnace is with 3 DEG C/min liter
Warm rate heating, until being passed through CH after 500 DEG C of predetermined reaction temperature4(1sccm) keeps vacuum degree to be lower than 40 Pascals, opens RF
Power supply, power are adjusted to 100W, generate hydrogen plasma in quartz ampoule.In lithium iron phosphate particles table after following reaction 5min
It looks unfamiliar and grows the thick grapheme material at 2-5 layers from level to level.
Embodiment 3
LiFePO 4 powder is placed in ceramic boat first and is put in tube furnace road, is vacuumized.Subsequent tube furnace is with 3 DEG C/min liter
Warm rate heating, until being passed through CH after 500 DEG C of predetermined reaction temperature4(10sccm) keeps vacuum degree to be lower than 40 Pascals, opens
RF power supply, power are adjusted to 300W, generate hydrogen plasma in quartz ampoule.In LiFePO4 after following reaction 20min
Grain surface grows the thick grapheme material at 5-10 layers from level to level.
Embodiment 4
LiFePO 4 powder is placed in ceramic boat first and is put in tube furnace road, is vacuumized.Subsequent tube furnace is with 3 DEG C/min liter
Warm rate heating, until being passed through CH after 400 DEG C of predetermined reaction temperature4(5sccm) keeps vacuum degree to be lower than 40 Pascals, opens RF
Power supply, power are adjusted to 200W, generate hydrogen plasma in quartz ampoule.In lithium iron phosphate particles after following reaction 10min
Surface grows the thick grapheme material at 2-10 layers from level to level.
Embodiment 5
LiFePO 4 powder is placed in ceramic boat first and is put in tube furnace road, is vacuumized.Subsequent tube furnace is with 3 DEG C/min liter
Warm rate heating, until being passed through CH after 400 DEG C of predetermined reaction temperature4(2sccm) keeps vacuum degree to be lower than 40 Pascals, opens RF
Power supply, power are adjusted to 200W, generate hydrogen plasma in quartz ampoule.In lithium iron phosphate particles after following reaction 10min
Surface grows the thick grapheme material at 2-5 layers from level to level.
Embodiment 6
LiFePO 4 powder is placed in ceramic boat first and is put in tube furnace road, is vacuumized.Subsequent tube furnace is with 3 DEG C/min liter
Warm rate heating, until being passed through CH after 500 DEG C of predetermined reaction temperature4(5sccm) keeps vacuum degree to be lower than 40 Pascals, opens RF
Power supply, power are adjusted to 300W, generate hydrogen plasma in quartz ampoule.In lithium iron phosphate particles after following reaction 10min
Surface grows the thick grapheme material at 2-10 layers from level to level.
Embodiment 7
LiFePO 4 powder is placed in ceramic boat first and is put in tube furnace road, is vacuumized.Subsequent tube furnace is with 3 DEG C/min liter
Warm rate heating, until being passed through CH after 300 DEG C of predetermined reaction temperature4(1sccm) keeps vacuum degree to be lower than 40 Pascals, opens RF
Power supply, power are adjusted to 100W, generate hydrogen plasma in quartz ampoule.In lithium iron phosphate particles table after following reaction 5min
It looks unfamiliar and grows the thick grapheme material at 2-5 layers from level to level.
Embodiment 8
LiFePO 4 powder is placed in ceramic boat first and is put in tube furnace road, is vacuumized.Subsequent tube furnace is with 3 DEG C/min liter
Warm rate heating, until being passed through CH after 300 DEG C of predetermined reaction temperature4(10sccm) keeps vacuum degree to be lower than 40 Pascals, opens
RF power supply, power are adjusted to 300W, generate hydrogen plasma in quartz ampoule.In LiFePO4 after following reaction 20min
Grain surface grows the thick grapheme material at 5-10 layers from level to level.
Embodiment 9
LiFePO 4 powder is placed in ceramic boat first and is put in tube furnace road, is vacuumized.Subsequent tube furnace is with 3 DEG C/min liter
Warm rate heating, until being passed through CH after 300 DEG C of predetermined reaction temperature4(10sccm) keeps vacuum degree to be lower than 40 Pascals, opens
RF power supply, power are adjusted to 200W, generate hydrogen plasma in quartz ampoule.In LiFePO4 after following reaction 5-20min
Particle surface grows the thick grapheme material at 2-10 layers from level to level.
Embodiment 10
LiFePO 4 powder is placed in ceramic boat first and is put in tube furnace road, is vacuumized.Subsequent tube furnace is with 3 DEG C/min liter
Warm rate heating, until being passed through CH after 500 DEG C of predetermined reaction temperature4(5sccm) keeps vacuum degree to be lower than 40 Pascals, opens RF
Power supply, power are adjusted to 300W, generate hydrogen plasma in quartz ampoule.In lithium iron phosphate particles after following reaction 20min
Surface grows thick mostly 5-10 layers of grapheme material from level to level.
Fig. 1 is graphene/LiFePO 4 material transmission electron microscope picture prepared by embodiment 1, is used as we know from the figure
LiFePO4 material powder is the rod-shpaed particle of 200 rans；
Fig. 2 is graphene/LiFePO 4 material transmission electron microscope picture prepared by embodiment 1, as we know from the figure LiFePO4 table
Face grown graphene；
Fig. 3 is graphene/LiFePO 4 material transmission electron microscope picture prepared by embodiment 1, as we know from the figure LiFePO4 table
2 layers of face graphene thickness；
Fig. 4 is graphene/LiFePO 4 material transmission electron microscope picture prepared by embodiment 3, as we know from the figure LiFePO4 table
8 layers of face graphene thickness；
Fig. 5 is the half-cell AC impedance of graphene-coated lithium iron phosphate material prepared by embodiment 1, from graphene packet known to figure
The internal resistance for covering LiFePO4 is significantly reduced compared to pure ferric phosphate lithium.
Claims (6)
1. a kind of preparation method of LiFePO 4 material surface coated graphite alkene, which is characterized in that using LiFePO 4 powder as
Growth substrate is simultaneously passed through carbon source, and using plasma enhances chemical vapour deposition technique and grows graphene on growth substrate surface；
The parameter of the plasma enhanced chemical vapor deposition method includes: that the reaction temperature of growth substrate is 300~500 DEG C；
1~10 sccm of flow of carbon source；Vacuum degree is lower than 40 pa；100~300 W of power；Growth time 5~20 minutes.
2. preparation method according to claim 1, which is characterized in that the carbon source is in methane, ethylene and difluoromethane
At least one.
3. preparation method according to claim 1 or 2, which is characterized in that the partial size of the LiFePO 4 powder is 200
Nm~10 μm.
4. preparation method according to any one of claim 1-3, which is characterized in that the growth substrate reaction temperature
Heating rate is 1~6 DEG C/min.
5. a kind of graphene/LiFePO 4 material of the preparation of preparation method described in any one of -4 according to claim 1, feature
It is, including LiFePO 4 powder and is coated on the graphene on LiFePO 4 powder surface, the graphene number of plies is 2~
10 layers.
6. a kind of graphene/LiFePO 4 material of the preparation of preparation method described in any one of -4 according to claim 1 lithium from
Application in sub- battery.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN111048784A (en) * | 2019-12-27 | 2020-04-21 | 中国科学院化学研究所 | Method for coating electrode material with carbon |
| WO2021156196A1 (en) * | 2020-02-03 | 2021-08-12 | Cealtech As | Process and device for large-scale production of graphene |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN111048784A (en) * | 2019-12-27 | 2020-04-21 | 中国科学院化学研究所 | Method for coating electrode material with carbon |
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Application publication date: 20190628 |