CN115011897B - Method for surface modification of metallic lithium by exciting supercritical fluid plasma - Google Patents
Method for surface modification of metallic lithium by exciting supercritical fluid plasma Download PDFInfo
- Publication number
- CN115011897B CN115011897B CN202210439470.2A CN202210439470A CN115011897B CN 115011897 B CN115011897 B CN 115011897B CN 202210439470 A CN202210439470 A CN 202210439470A CN 115011897 B CN115011897 B CN 115011897B
- Authority
- CN
- China
- Prior art keywords
- lithium
- supercritical fluid
- plasma
- supercritical
- exciting
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 229910052744 lithium Inorganic materials 0.000 title claims abstract description 127
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 title claims abstract description 118
- 239000012530 fluid Substances 0.000 title claims abstract description 44
- 238000000034 method Methods 0.000 title claims abstract description 26
- 230000004048 modification Effects 0.000 title claims description 9
- 238000012986 modification Methods 0.000 title claims description 9
- 229910052751 metal Inorganic materials 0.000 claims abstract description 49
- 239000002184 metal Substances 0.000 claims abstract description 49
- 239000011241 protective layer Substances 0.000 claims abstract description 12
- 239000007789 gas Substances 0.000 claims description 47
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims description 28
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 18
- RAHZWNYVWXNFOC-UHFFFAOYSA-N Sulphur dioxide Chemical compound O=S=O RAHZWNYVWXNFOC-UHFFFAOYSA-N 0.000 claims description 18
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims description 16
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical group [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 16
- 229910002092 carbon dioxide Inorganic materials 0.000 claims description 14
- 239000001569 carbon dioxide Substances 0.000 claims description 14
- PQXKHYXIUOZZFA-UHFFFAOYSA-M lithium fluoride Chemical compound [Li+].[F-] PQXKHYXIUOZZFA-UHFFFAOYSA-M 0.000 claims description 10
- 238000001035 drying Methods 0.000 claims description 9
- 238000011049 filling Methods 0.000 claims description 9
- 229910052786 argon Inorganic materials 0.000 claims description 8
- 229910052757 nitrogen Inorganic materials 0.000 claims description 8
- 229910021529 ammonia Inorganic materials 0.000 claims description 7
- XGZVUEUWXADBQD-UHFFFAOYSA-L lithium carbonate Chemical compound [Li+].[Li+].[O-]C([O-])=O XGZVUEUWXADBQD-UHFFFAOYSA-L 0.000 claims description 7
- 229910052808 lithium carbonate Inorganic materials 0.000 claims description 7
- FUJCRWPEOMXPAD-UHFFFAOYSA-N lithium oxide Chemical compound [Li+].[Li+].[O-2] FUJCRWPEOMXPAD-UHFFFAOYSA-N 0.000 claims description 7
- 229910001947 lithium oxide Inorganic materials 0.000 claims description 7
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 6
- 229910052799 carbon Inorganic materials 0.000 claims description 6
- IDBFBDSKYCUNPW-UHFFFAOYSA-N lithium nitride Chemical compound [Li]N([Li])[Li] IDBFBDSKYCUNPW-UHFFFAOYSA-N 0.000 claims description 4
- INHCSSUBVCNVSK-UHFFFAOYSA-L lithium sulfate Inorganic materials [Li+].[Li+].[O-]S([O-])(=O)=O INHCSSUBVCNVSK-UHFFFAOYSA-L 0.000 claims description 3
- GLNWILHOFOBOFD-UHFFFAOYSA-N lithium sulfide Chemical compound [Li+].[Li+].[S-2] GLNWILHOFOBOFD-UHFFFAOYSA-N 0.000 claims description 3
- 239000000843 powder Substances 0.000 claims description 3
- RBTVSNLYYIMMKS-UHFFFAOYSA-N tert-butyl 3-aminoazetidine-1-carboxylate;hydrochloride Chemical compound Cl.CC(C)(C)OC(=O)N1CC(N)C1 RBTVSNLYYIMMKS-UHFFFAOYSA-N 0.000 claims description 3
- -1 freon R134a Chemical compound 0.000 claims description 2
- JCXJVPUVTGWSNB-UHFFFAOYSA-N nitrogen dioxide Inorganic materials O=[N]=O JCXJVPUVTGWSNB-UHFFFAOYSA-N 0.000 claims 1
- 238000006243 chemical reaction Methods 0.000 abstract description 7
- 230000008901 benefit Effects 0.000 abstract description 5
- 230000009286 beneficial effect Effects 0.000 abstract description 3
- 239000000463 material Substances 0.000 abstract description 2
- 238000009776 industrial production Methods 0.000 abstract 1
- 238000002715 modification method Methods 0.000 abstract 1
- 238000007789 sealing Methods 0.000 description 21
- 238000002360 preparation method Methods 0.000 description 13
- 230000000052 comparative effect Effects 0.000 description 12
- 150000002641 lithium Chemical class 0.000 description 8
- 239000000126 substance Substances 0.000 description 5
- 238000000026 X-ray photoelectron spectrum Methods 0.000 description 4
- GELKBWJHTRAYNV-UHFFFAOYSA-K lithium iron phosphate Chemical compound [Li+].[Fe+2].[O-]P([O-])([O-])=O GELKBWJHTRAYNV-UHFFFAOYSA-K 0.000 description 4
- 239000002245 particle Substances 0.000 description 4
- 239000011261 inert gas Substances 0.000 description 3
- 239000002932 luster Substances 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 238000001228 spectrum Methods 0.000 description 3
- 238000003860 storage Methods 0.000 description 3
- 239000011247 coating layer Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000005684 electric field Effects 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 239000007791 liquid phase Substances 0.000 description 2
- 230000007935 neutral effect Effects 0.000 description 2
- LVGUZGTVOIAKKC-UHFFFAOYSA-N 1,1,1,2-tetrafluoroethane Chemical compound FCC(F)(F)F LVGUZGTVOIAKKC-UHFFFAOYSA-N 0.000 description 1
- 229910013870 LiPF 6 Inorganic materials 0.000 description 1
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- YNQRWVCLAIUHHI-UHFFFAOYSA-L dilithium;oxalate Chemical compound [Li+].[Li+].[O-]C(=O)C([O-])=O YNQRWVCLAIUHHI-UHFFFAOYSA-L 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 239000003792 electrolyte Substances 0.000 description 1
- 230000005281 excited state Effects 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000011031 large-scale manufacturing process Methods 0.000 description 1
- 239000010410 layer Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 229910001416 lithium ion Inorganic materials 0.000 description 1
- 239000007773 negative electrode material Substances 0.000 description 1
- 238000004806 packaging method and process Methods 0.000 description 1
- 239000012071 phase Substances 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 239000000376 reactant Substances 0.000 description 1
- 230000035484 reaction time Effects 0.000 description 1
- 238000001878 scanning electron micrograph Methods 0.000 description 1
- 238000007614 solvation Methods 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
- C22F3/00—Changing the physical structure of non-ferrous metals or alloys by special physical methods, e.g. treatment with neutrons
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
- C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
- C22F1/02—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working in inert or controlled atmosphere or vacuum
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
- C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
- C22F1/16—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of other metals or alloys based thereon
-
- 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
Landscapes
- Chemical & Material Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
The invention belongs to the technical field of metal lithium material processing, and relates to a method for exciting supercritical fluid plasma to surface modify metal lithium. The invention provides a method for modifying the surface of metal lithium, which aims to solve the problems of poor air stability and poor interface stability of the metal lithium. The atmosphere in the reactor is replaced by the supercritical fluid, and the plasma formed between the metal electrodes at two sides of the supercritical fluid provides energy for the reaction between the metal lithium and the supercritical fluid, so that the reaction is promoted to occur rapidly, a uniform and compact protective layer is formed on the surface of the metal lithium, the air stability of the metal lithium is improved, and meanwhile, the electrochemical performance of the metal lithium can be further improved through the selection of the types of the supercritical fluid. Meanwhile, the metal lithium surface modification method provided by the invention has the advantages of simplicity in operation, low cost and the like, and is beneficial to industrial production.
Description
Technical Field
The invention relates to a method for exciting supercritical fluid plasma surface modification of metallic lithium, and belongs to the technical field of metallic lithium material processing.
Technical Field
Lithium metal has been attracting attention in recent years as an ideal negative electrode material for lithium batteries. However, poor air stability and poor interfacial stability are two important factors impeding its practical development. Because the lithium metal has strong chemical activity and is extremely easy to react with other substances to form impurities on the surface, the production and the storage of the lithium metal often need the protection of inert gas, and the cost is high. If the packaging leaks during production and storage, metallic lithium and air can be oxidized and corroded by contact, and a multi-component and uneven oxidized impurity layer is formed on the surface, so that the practical application of the lithium-ion battery pack is affected.
When the substance is heated or exists in a magnetic field or an electric field, the thermal motion of molecules and atoms constituting the substance starts to accelerate, and various particles are strongly collided with each other to ionize positive ions and negative electrons, at the moment, the molecules and the atoms are in an excited state, the whole is electrically neutral, and the plasma is composed of electrons, ions and non-ionized neutral particles and has certain energy. Compared with gas phase plasma active particles, the liquid phase plasma active particles have stronger permeation effect and can be more uniformly contacted with reactants, thereby being beneficial to uniform occurrence of reaction. Supercritical fluids have many unique properties, with viscosity and diffusion coefficient approaching that of gases, density and solvation capacity approaching that of liquids, and higher energy than general liquid phases, which is more conducive to rapid and uniform reactions.
Aiming at the problems of poor air stability and poor interface stability of metal lithium, the invention provides a method for exciting supercritical fluid plasma surface to modify metal lithium.
Disclosure of Invention
In order to solve the defects in the prior art, the invention provides a method for exciting supercritical fluid plasma to surface modify metallic lithium, which is quick, efficient, low in cost and simple in operation.
The technical scheme adopted for solving the technical problems is as follows:
A method for exciting supercritical fluid plasma surface modified metallic lithium, comprising the following steps:
s1: placing metallic lithium in a plasma reactor under an inert atmosphere;
S2: replacing the atmosphere in the plasma reactor with a supercritical fluid;
s3: and (3) generating plasma in the plasma reactor, and reacting for a certain time at a certain temperature to obtain the surface modified metallic lithium.
Preferably, in the above preparation method step S1, the metal lithium is in the form of powder, block, strip, etc., and more preferably, the metal lithium is at least one of lithium powder, lithium block, lithium strip, and lithium sheet.
Preferably, the above preparation method step S1 places metallic lithium in a glove box filled with an inert atmosphere in a plasma reactor.
Preferably, in the preparation method step S1, the plasma reactor is sealed after the lithium metal is placed in the plasma reactor.
Preferably, the plasma reactor in the step S1 of the preparation method is a high temperature and high pressure resistant plasma reactor.
Preferably, in the step S2 of the preparation method, the supercritical fluid is at least one of supercritical carbon dioxide, supercritical freon, supercritical ammonia, supercritical nitrogen, and supercritical sulfur dioxide, and the purity is not less than 99.9%.
Preferably, in the preparation method step S2, the atmosphere is replaced with a supercritical fluid by:
S2.1: pumping out inert gas in the plasma reactor, and then filling a specific drying gas, wherein the pressure of the filled drying gas is not lower than the critical pressure of the inert gas; by specific drying gas is meant that the drying gas has the property of being capable of being converted into a supercritical fluid under conditions of not lower than a critical pressure and a critical temperature;
s2.2: and heating the plasma reactor to a temperature not lower than the critical temperature of the drying gas, so that the drying gas is converted into supercritical fluid.
Preferably, the dry gas in the step S2.1 of the preparation method is one or more of carbon dioxide, freon, ammonia, nitrogen, sulfur dioxide, etc., and the purity of the gas is not less than 99.9%.
Preferably, the pressure of the injected dry gas and the temperature of the temperature rise in the steps S2.1 and S2.2 of the above preparation method are not lower than the critical pressure and critical temperature of the dry gas; more preferably:
the drying gas is carbon dioxide: the pressure is more than or equal to 7.4M Pa, and the temperature is more than or equal to 31.2 ℃;
The dry gas is ammonia: the pressure is more than or equal to 11.5M Pa, and the temperature is more than or equal to 132.4 ℃;
the dry gas is nitrogen: the pressure is more than or equal to 3.4M Pa, and the temperature is more than or equal to-147 ℃;
the dry gas is freon R134a (tetrafluoroethane): the pressure is more than or equal to 4.07M Pa, and the temperature is more than or equal to 101 ℃;
The dry gas is sulfur dioxide: the pressure is more than or equal to 7.9 MPa, the temperature is more than or equal to 157.8 ℃.
Preferably, in the step S3 of the preparation method, electrons between the anode and the cathode of the plasma reactor are subjected to the action of an electric field force to form plasma by turning on a direct current; more preferably, the DC current power is 40-600W.
Preferably, the reaction time in the step S3 of the preparation method is 1-400min; the temperature is not lower than the critical temperature of the supercritical fluid.
Preferably, in the above preparation method step S3, the surface modification is performed by forming a uniform and dense protective layer on the surface of the metal lithium, where the uniform and dense protective layer is at least one of lithium carbonate, lithium fluoride, lithium sulfide, lithium sulfate, lithium nitride, lithium oxide, carbon, and the like.
Preferably, the inert atmosphere in the present invention is argon.
Preferably, the method specifically comprises the following steps:
s1: placing metallic lithium in a plasma reactor in a glove box filled with inert atmosphere, and sealing;
S2: vacuumizing the interior of the plasma reactor, and then filling dry gas with the pressure not lower than the critical pressure of the gas into the interior of the plasma reactor;
S3: raising the temperature to be not lower than the critical temperature of the gas, and keeping the temperature unchanged, so that the gas in the plasma reactor is converted into supercritical fluid;
s4: and (3) starting a direct current power supply, adjusting power, reacting for a certain time at a certain temperature, closing the direct current power supply, discharging redundant gas in the reactor, and opening a sealing cover to obtain the modified metal lithium.
The invention provides a method for exciting supercritical fluid plasma surface modification metal lithium, which comprises the steps of firstly sealing the metal lithium in a plasma reactor, then injecting gas quantity exceeding the critical pressure of gas into the interior through a vent hole on a sealing cover, keeping the temperature above the critical temperature of the gas, converting the injected gas into the supercritical fluid, starting a direct current power supply, forming plasma between metal electrodes positioned at two sides of the supercritical fluid, providing energy for the reaction between the supercritical fluid and the metal lithium, and constructing a uniform and compact protective layer on the surface of the metal lithium. The method is simple to operate, low in cost, rapid and efficient, and has potential of large-scale production.
Compared with the prior art, the invention has the beneficial effects that:
The invention is characterized in that the gas quantity exceeding the critical pressure of the gas is injected into the reactor, the temperature is raised to be higher than the critical temperature of the gas, the injected gas is converted into the supercritical fluid, and the plasma formed between the metal electrodes at the two sides of the supercritical fluid provides energy for the reaction between the metal lithium and the supercritical fluid, so that the reaction is promoted to occur rapidly, and a uniform and compact protective layer is constructed on the surface of the metal lithium. The uniform and compact protective layer can isolate the metal lithium from air, so that the metal lithium is protected from being corroded by the air, in addition, a protective layer which is favorable for exerting electrochemical performance can be constructed on the surface of the metal lithium through the selection of the types of the supercritical fluid, the air stability is improved, the charge and discharge performance is improved, the production and storage costs are reduced, and meanwhile, the safety problem is avoided. The method has the advantages of simple process, simple and convenient operation, high speed and high efficiency and remarkable economic benefit.
Drawings
FIG. 1 is a graph showing the comparison of unmodified metallic lithium (left), modified metallic lithium (middle) of example 1 and modified metallic lithium (right) of comparative example after 5min (up) and 60min (down) exposure to air.
Fig. 2 is an SEM of the modified metallic lithium of example 1.
FIG. 3 is an XPS spectrum of the modified lithium metal of example 1.
Fig. 4 is a graph showing the cycle performance of lithium iron phosphate batteries respectively assembled using the modified metallic lithium of example 1, the unmodified metallic lithium and the modified metallic lithium of comparative example.
Fig. 5 is a graph showing cycle performance of lithium iron phosphate batteries respectively assembled using the modified metallic lithium of example 1, the unmodified metallic lithium, and the modified metallic lithium of comparative example after exposure to air for 5 minutes.
FIG. 6 is an XPS spectrum of modified metallic lithium of example 2.
Detailed Description
The technical scheme of the present invention is further described below by way of examples with reference to the accompanying drawings, but the scope of the present invention is not limited thereto. The room temperature in the present invention is 15 to 40 ℃, more preferably 25 to 30 ℃.
Example 1:
a method for exciting supercritical fluid plasma surface modified metallic lithium, comprising the steps of:
S1: a metallic lithium sheet with a diameter of 10mm is placed in a plasma reactor in a glove box filled with argon gas and sealed;
S2: vacuumizing the interior of the reactor through a vent on a sealing cover of the plasma reactor, then filling 8 MPa of dry carbon dioxide into the interior of the plasma reactor through the vent and a plunger pump, wherein the gas purity is 99.9%, and closing a valve;
S3: raising the temperature of the plasma reactor to 60 ℃ and keeping the temperature unchanged, so that the carbon dioxide gas in the reactor is converted into supercritical carbon dioxide fluid;
S4: and (3) starting a direct current power supply, adjusting the power to 40W, closing the direct current power supply after reacting for 100min, opening a valve to discharge redundant carbon dioxide in the reactor, and opening a sealing cover to obtain a modified metal lithium sheet with the surface coated with a compact and uniform lithium oxide, lithium carbonate and carbon co-coating layer.
Comparative example:
s1: placing a metal lithium sheet in a reactor in a glove box filled with argon, and sealing;
S2: vacuumizing the inside of the reactor through a vent on a sealing cover of the reactor, then filling 0.1M Pa of dry carbon dioxide into the inside of the reactor through the vent and a plunger pump, wherein the gas purity is 99.9%, and closing a valve;
S3: raising the temperature to 60 ℃ and keeping the temperature unchanged, wherein the inside of the reactor is still carbon dioxide gas;
S4: after the carbon dioxide gas reacts with the lithium metal for 100min, the valve is opened to slowly discharge the redundant carbon dioxide in the reactor, and the sealing cover is opened to obtain the carbon dioxide gas modified lithium metal with carbon, lithium oxide, lithium carbonate and lithium oxalate attached on the surface.
The modified metallic lithium obtained in the above example 1 and comparative example were subjected to correlation performance detection and comparison, and it can be seen from the accompanying drawings that:
FIG. 1 is a graph showing the comparison of unmodified metallic lithium (left), modified metallic lithium (middle) of example 1 and modified metallic lithium (right) of comparative example after 5min (up) and 60min (down) exposure to air. After 5min of air exposure, the unmodified metallic lithium surface had blackened, while the modified metallic lithium surfaces of example 1 and comparative example both maintained metallic luster; the modified metallic lithium of example 1 still maintained metallic luster after exposure to air for 60min, while the unmodified metallic lithium surface became black, was completely oxidized and corroded, and the comparative modified metallic lithium surface also lost metallic luster and was oxidized.
Fig. 2 is an SEM image of the modified metallic lithium of example 1, which shows that the surface of the modified lithium is uniformly and densely distributed with lamellar substances, and shows that a uniform and compact protective layer is formed on the surface of the modified metallic lithium.
FIG. 3 is an XPS spectrum of the modified lithium metal of example 1. Carbon and lithium carbonate are formed on the surface of the modified lithium from the C1s spectrum, and lithium, lithium carbonate and lithium oxide are formed on the surface of the modified lithium from the Li 1s spectrum, wherein the lithium is metallic lithium. Therefore, it was found that the modified lithium of this example had a dense protective layer of carbon, lithium oxide and lithium carbonate attached to the surface.
The modified metallic lithium and the unmodified metallic lithium of example 1 and the modified metallic lithium of comparative example were used as negative electrodes, respectively, and assembled with a lithium iron phosphate positive electrode and an electrolyte (1M LiPF 6/(ec+dmc)) to form a battery, and fig. 4 is a graph showing cycle performance comparison of these three batteries. The modified metal lithium assembled battery of example 1 has a capacity of 156.2mA h g -1 after 50 cycles, the unmodified metal lithium assembled battery has a capacity of 152.1mA h g -1 after 50 cycles, and the modified metal lithium assembled battery of comparative example has a capacity of 148.8mA h g -1 after 50 cycles, and the modified metal lithium battery of example 1 not only overcomes the problem that the capacity is reduced when the prior modified metal lithium is modified, but also further enables the battery to exert a larger capacity, and exceeds the capacity of the unmodified metal lithium assembled battery.
Fig. 5 is a graph showing cycle performance of lithium iron phosphate batteries respectively assembled using the modified metallic lithium of example 1 and the unmodified metallic lithium and the modified metallic lithium of comparative example after exposing to air for 5 minutes. The battery assembled after the modified metallic lithium of example 1 is exposed to air has a capacity of 155.1mA h g -1 after 50 cycles, can still circulate stably, and exerts a larger capacity, the circulation performance and the capacity value of the battery are not changed greatly compared with those of the battery assembled without the modified metallic lithium after the modified metallic lithium is exposed to air, the capacity of the battery assembled after the modified metallic lithium is exposed to air decays quickly, the capacity of the battery assembled after the modified metallic lithium is exposed to air only remains 135.1mA h g -1 after 50 cycles, the electrochemical performance is seriously deteriorated, and in addition, the battery assembled after the modified metallic lithium of comparative example is exposed to air has a capacity of 139.3mA h g -1 after 50 cycles, the circulation stability is poor, and the electrochemical performance is also seriously deteriorated.
Example 2:
a method for exciting supercritical fluid plasma surface modified metallic lithium, comprising the steps of:
S1: winding a metal lithium coil into a metal lithium coil in a glove box filled with argon, placing the metal lithium coil in a plasma reactor, and sealing;
S2: vacuumizing the interior of the reactor through a vent on a sealing cover of the plasma reactor, then filling dry Freon R134a of 4.5M Pa into the interior of the plasma reactor through the vent and a plunger pump, wherein the gas purity is 99.9%, and closing a valve;
S3: raising the temperature to 110 ℃ and keeping the temperature unchanged, so that the Freon R134a in the reactor is converted into supercritical Freon R134a fluid;
s4: and (3) starting a direct current power supply, adjusting the power to 50W, closing the direct current power supply after reacting for 400min, opening a valve to discharge redundant Freon R134a in the reactor, and opening a sealing cover to obtain the modified metal lithium belt with the surface coated with uniform and compact lithium fluoride.
FIG. 6 is an XPS spectrum of modified metallic lithium of example 2. As can be seen from the F1s spectrum, the modified metal lithium of this example produced lithium fluoride on the surface, and therefore it was found that the modified lithium of this example had a lithium fluoride protective layer attached to the surface.
Example 3:
a method for exciting supercritical fluid plasma surface modified metallic lithium, comprising the steps of:
s1: placing a metal lithium sheet in a glove box filled with argon, and sealing;
s2: vacuumizing the interior of the reactor through a vent on a sealing cover of the plasma reactor, then filling 4 MPa dry nitrogen into the interior of the plasma reactor through the vent and a plunger pump, wherein the gas purity is 99.9%, and closing a valve;
s3: raising the temperature to 40 ℃ and keeping the temperature unchanged, so that nitrogen in the reactor is converted into supercritical nitrogen;
S4: and (3) starting a direct current power supply, adjusting the power to 600W, closing the direct current power supply after reacting for 1min, opening a valve to slowly discharge redundant nitrogen in the reactor, and opening a sealing cover to obtain the modified metal lithium sheet with the surface coated with uniform and compact lithium nitride.
Example 4:
a method for exciting supercritical fluid plasma surface modified metallic lithium, comprising the steps of:
s1: placing a metal lithium sheet in a glove box filled with argon, and sealing;
S2: vacuumizing the interior of the reactor through a vent on a sealing cover of the plasma reactor, then filling 15 MPa of dry ammonia gas into the interior of the plasma reactor through the vent and a plunger pump, wherein the gas purity is 99.9%, and closing a valve;
s3: raising the temperature to 140 ℃ and keeping the temperature unchanged, so that ammonia in the reactor is converted into supercritical ammonia;
s4: and (3) starting a direct current power supply, adjusting the power to 200W, closing the direct current power supply after reacting for 20min, opening a valve to slowly discharge redundant ammonia gas in the reactor, and opening a sealing cover to obtain a modified metal lithium sheet with the surface coated with uniform and compact lithium nitride.
Example 5:
a method for exciting supercritical fluid plasma surface modified metallic lithium, comprising the steps of:
s1: placing a metal lithium sheet in a glove box filled with argon, and sealing;
S2: vacuumizing the interior of the reactor through a vent on a sealing cover of the plasma reactor, then filling 9 MPa of dry sulfur dioxide into the interior of the plasma reactor through the vent and a plunger pump, wherein the gas purity is 99.9%, and closing a valve;
s3: raising the temperature to 200 ℃ and keeping the temperature unchanged, so that sulfur dioxide in the reactor is converted into supercritical sulfur dioxide;
s4: and (3) starting a direct current power supply, adjusting the power to 300W, closing the direct current power supply after reacting for 30min, opening a valve to slowly discharge redundant sulfur dioxide in the reactor, and opening a sealing cover to obtain a modified metal lithium sheet with the surface coated with a uniform and compact lithium sulfide, lithium sulfate and lithium oxide co-coating layer.
The preparation parameters and performance results for each example are shown in table 1.
Table 1 preparation parameters and performance results for each example
In conclusion, the modified metal lithium obtained by the method can improve the air stability, improve the electrochemical performance, further improve the capacity of a lithium battery and enhance the stability and the cycle performance; the method has the advantages of simple process, simple and convenient operation, high speed and high efficiency and remarkable economic benefit.
The above-described embodiments are only preferred embodiments of the present invention, and are not intended to limit the present invention in any way, and other variations and modifications may be made without departing from the technical aspects set forth in the claims.
Claims (5)
1. A method for exciting supercritical fluid plasma surface modification of metallic lithium, which is characterized by comprising the following steps:
s1: placing metallic lithium in a plasma reactor under an inert atmosphere;
s2: replacing the atmosphere in the plasma reactor with a supercritical fluid; the supercritical fluid is one of supercritical carbon dioxide, supercritical freon R134a, supercritical ammonia, supercritical nitrogen and supercritical sulfur dioxide, and has purity not lower than 99.9%;
s3: generating plasma in the plasma reactor by starting direct current, and reacting for 1-400min at the temperature not lower than the critical temperature of the supercritical fluid to obtain surface modified metallic lithium; the power of the direct current is 40-600W; the surface modification of the metal lithium is carried out by forming a uniform and compact protective layer on the surface of the metal lithium, wherein the uniform and compact protective layer is at least one of lithium carbonate, lithium fluoride, lithium sulfide, lithium sulfate, lithium nitride, lithium oxide and carbon.
2. The method for surface modification of metallic lithium by exciting supercritical fluid plasma according to claim 1, wherein the metallic lithium in the step S1 is at least one of lithium powder, lithium block, lithium band and lithium sheet.
3. The method for exciting supercritical fluid plasma to surface modify metallic lithium according to claim 1, wherein in the step S2, the atmosphere is replaced by supercritical fluid by the steps of:
S2.1: vacuumizing the plasma reactor, and then filling dry gas, wherein the pressure of the filled dry gas is not lower than the critical pressure;
S2.2: the plasma reactor is heated to a temperature not lower than the critical temperature of the drying gas, so that the drying gas is converted into a supercritical fluid.
4. The method for exciting supercritical fluid plasma to surface modify metallic lithium according to claim 3, wherein the dry gas in step S2.1 is one of carbon dioxide, freon R134a, ammonia, nitrogen and sulfur dioxide, and the gas purity is not lower than 99.9%.
5. The method of exciting supercritical fluid plasma to surface modify lithium metal according to claim 1, wherein the inert atmosphere is argon.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210439470.2A CN115011897B (en) | 2022-04-25 | 2022-04-25 | Method for surface modification of metallic lithium by exciting supercritical fluid plasma |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210439470.2A CN115011897B (en) | 2022-04-25 | 2022-04-25 | Method for surface modification of metallic lithium by exciting supercritical fluid plasma |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115011897A CN115011897A (en) | 2022-09-06 |
| CN115011897B true CN115011897B (en) | 2024-04-23 |
Family
ID=83067387
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210439470.2A Active CN115011897B (en) | 2022-04-25 | 2022-04-25 | Method for surface modification of metallic lithium by exciting supercritical fluid plasma |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115011897B (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20140105811A1 (en) * | 2012-10-12 | 2014-04-17 | Hefei Guoxuan High-Tech Power Energy Co., Ltd. | Supercritical continuous hydrothermal synthesis of lithium titanate anode materials for lithium-ion batteries |
| CN108461714A (en) * | 2017-02-21 | 2018-08-28 | 中国科学院物理研究所 | Lithium anode and preparation method thereof includes the secondary cell of lithium anode |
| CN108987684A (en) * | 2018-06-05 | 2018-12-11 | 燕山大学 | It is a kind of can placement stable in the air lithium metal preparation method |
| CN110714195A (en) * | 2019-08-26 | 2020-01-21 | 浙江工业大学 | Surface modification method for metal lithium |
| CN110846610A (en) * | 2019-08-26 | 2020-02-28 | 浙江工业大学 | Method for improving surface stability of metal lithium |
| CN112490395A (en) * | 2020-12-03 | 2021-03-12 | 惠州亿纬锂能股份有限公司 | Drying method of lithium ion battery pole piece and drying device used by drying method |
-
2022
- 2022-04-25 CN CN202210439470.2A patent/CN115011897B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20140105811A1 (en) * | 2012-10-12 | 2014-04-17 | Hefei Guoxuan High-Tech Power Energy Co., Ltd. | Supercritical continuous hydrothermal synthesis of lithium titanate anode materials for lithium-ion batteries |
| CN108461714A (en) * | 2017-02-21 | 2018-08-28 | 中国科学院物理研究所 | Lithium anode and preparation method thereof includes the secondary cell of lithium anode |
| CN108987684A (en) * | 2018-06-05 | 2018-12-11 | 燕山大学 | It is a kind of can placement stable in the air lithium metal preparation method |
| CN110714195A (en) * | 2019-08-26 | 2020-01-21 | 浙江工业大学 | Surface modification method for metal lithium |
| CN110846610A (en) * | 2019-08-26 | 2020-02-28 | 浙江工业大学 | Method for improving surface stability of metal lithium |
| CN112490395A (en) * | 2020-12-03 | 2021-03-12 | 惠州亿纬锂能股份有限公司 | Drying method of lithium ion battery pole piece and drying device used by drying method |
Non-Patent Citations (3)
| Title |
|---|
| 杨武成.等离子加工.《特种与精密加工》.西安电子科技大学出版社,2018,第200-202页. * |
| 王承阳等.临界参数.《工程热力学》.冶金工业出版社,2016,第231页. * |
| 翟玮玮等.《食品加工原理（第二版）》.中国轻工业出版社,2018,第222页. * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115011897A (en) | 2022-09-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110993908A (en) | Vertical graphene/manganese dioxide composite material and preparation method and application thereof | |
| CN110224182B (en) | Method for pre-lithiation of lithium ion battery | |
| CN107634224B (en) | Preparation method of fluorinated multi-walled carbon nanotube containing outer wall of iron fluoride intercalation substance | |
| CN108134077B (en) | Preparation method of high-voltage lithium ion battery anode material with core-shell structure | |
| CN102623677A (en) | Process for producing high capacity molybdenum dioxide/carbon cathode materials | |
| CN108321436A (en) | A kind of cathode uses the lithium ion battery forming and capacity dividing method of silicon-carbon | |
| CN111916702B (en) | Coated modified cathode material, preparation method thereof and lithium ion battery | |
| WO2010084808A1 (en) | Process for production of iron sulfide/lithium composite | |
| CN109346710A (en) | A kind of nitridation lithium titanate-nitriding and oxidizing aluminium composite material and the preparation method and application thereof | |
| CN109167062A (en) | A kind of method of nitrogen and hydrogen hybrid plasma processing powdered graphite | |
| CN111354932A (en) | Preparation method of lithium-sulfur battery positive electrode material | |
| Jung et al. | Triphenyl phosphate as an efficient electrolyte additive for Ni-rich NCM cathode materials | |
| CN115011897B (en) | Method for surface modification of metallic lithium by exciting supercritical fluid plasma | |
| CN108598417B (en) | Conductive carbon black modified silica aerogel sulfur-loaded composite cathode material and preparation method thereof | |
| CN113066971A (en) | Gas phase coating method of lithium-rich manganese-based positive electrode material | |
| CN108091835A (en) | Lithium-sulfur battery composite cathode material of cobalt ferrite sulfur loaded and preparation method thereof | |
| CN108550844B (en) | Modification method of Prussian blue compound serving as positive electrode material of sodium-ion battery | |
| Qiu et al. | Plasma-induced amorphous N-nano carbon shell for improving structural stability of LiNi0. 8Co0. 1Mn0. 1O2 cathode | |
| CN114094106B (en) | Ammonium polyphosphate modified graphite negative electrode material and preparation method and application thereof | |
| CN103359712A (en) | Graphite oxide/graphene oxide composite material, preparation method thereof, battery anode and capacitor battery | |
| CN115477294A (en) | Defective nano lithium iron phosphate and preparation method and application thereof | |
| CN111224065B (en) | Method for reducing PH value of lithium battery electrode material by HF gas phase neutralization | |
| CN114975907A (en) | Vanadium boride coated nickel cobalt lithium manganate positive electrode material and preparation method thereof | |
| CN111653724B (en) | Surface-modified lithium nickel manganese oxide positive electrode material and preparation method thereof | |
| CN110247035B (en) | Method for modifying high-nickel anode material |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |