CN117410453A - Lithium powder negative electrode, preparation method thereof and lithium battery - Google Patents
Lithium powder negative electrode, preparation method thereof and lithium battery Download PDFInfo
- Publication number
- CN117410453A CN117410453A CN202311646312.5A CN202311646312A CN117410453A CN 117410453 A CN117410453 A CN 117410453A CN 202311646312 A CN202311646312 A CN 202311646312A CN 117410453 A CN117410453 A CN 117410453A
- Authority
- CN
- China
- Prior art keywords
- lithium
- negative electrode
- lithium powder
- polymer
- conductor
- 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.)
- Pending
Links
- 229910052744 lithium Inorganic materials 0.000 title claims abstract description 159
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 title claims abstract description 157
- 239000000843 powder Substances 0.000 title claims abstract description 107
- 238000002360 preparation method Methods 0.000 title claims abstract description 19
- 229920000642 polymer Polymers 0.000 claims abstract description 70
- 239000011533 mixed conductor Substances 0.000 claims abstract description 40
- 239000000463 material Substances 0.000 claims abstract description 38
- 239000010416 ion conductor Substances 0.000 claims abstract description 37
- 239000004020 conductor Substances 0.000 claims abstract description 31
- 238000001035 drying Methods 0.000 claims abstract description 21
- 239000003960 organic solvent Substances 0.000 claims abstract description 20
- 239000011248 coating agent Substances 0.000 claims abstract description 18
- 238000000576 coating method Methods 0.000 claims abstract description 18
- 229910003002 lithium salt Inorganic materials 0.000 claims abstract description 14
- 159000000002 lithium salts Chemical class 0.000 claims abstract description 14
- 239000011268 mixed slurry Substances 0.000 claims abstract description 13
- 239000007788 liquid Substances 0.000 claims abstract description 11
- 239000011261 inert gas Substances 0.000 claims abstract description 7
- -1 polyethylene succinate Polymers 0.000 claims description 23
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical group [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 20
- 239000010949 copper Substances 0.000 claims description 15
- 239000011889 copper foil Substances 0.000 claims description 14
- 238000000034 method Methods 0.000 claims description 14
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 12
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 claims description 11
- 238000003756 stirring Methods 0.000 claims description 10
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 claims description 9
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 claims description 9
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 9
- RAXXELZNTBOGNW-UHFFFAOYSA-N imidazole Natural products C1=CNC=N1 RAXXELZNTBOGNW-UHFFFAOYSA-N 0.000 claims description 9
- 239000001301 oxygen Substances 0.000 claims description 9
- 229910052760 oxygen Inorganic materials 0.000 claims description 9
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 9
- 239000002033 PVDF binder Substances 0.000 claims description 7
- 229920000123 polythiophene Polymers 0.000 claims description 7
- 229920002981 polyvinylidene fluoride Polymers 0.000 claims description 7
- BTBUEUYNUDRHOZ-UHFFFAOYSA-N Borate Chemical compound [O-]B([O-])[O-] BTBUEUYNUDRHOZ-UHFFFAOYSA-N 0.000 claims description 6
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 6
- XTHFKEDIFFGKHM-UHFFFAOYSA-N Dimethoxyethane Chemical compound COCCOC XTHFKEDIFFGKHM-UHFFFAOYSA-N 0.000 claims description 6
- IAZDPXIOMUYVGZ-UHFFFAOYSA-N Dimethylsulphoxide Chemical compound CS(C)=O IAZDPXIOMUYVGZ-UHFFFAOYSA-N 0.000 claims description 6
- FXHOOIRPVKKKFG-UHFFFAOYSA-N N,N-Dimethylacetamide Chemical compound CN(C)C(C)=O FXHOOIRPVKKKFG-UHFFFAOYSA-N 0.000 claims description 6
- 229920003171 Poly (ethylene oxide) Polymers 0.000 claims description 6
- 229910052802 copper Inorganic materials 0.000 claims description 6
- 239000006260 foam Substances 0.000 claims description 6
- 229910052759 nickel Inorganic materials 0.000 claims description 6
- 229920000128 polypyrrole Polymers 0.000 claims description 6
- 229910001496 lithium tetrafluoroborate Inorganic materials 0.000 claims description 5
- 229910052799 carbon Inorganic materials 0.000 claims description 4
- 229920000049 Carbon (fiber) Polymers 0.000 claims description 3
- OIFBSDVPJOWBCH-UHFFFAOYSA-N Diethyl carbonate Chemical compound CCOC(=O)OCC OIFBSDVPJOWBCH-UHFFFAOYSA-N 0.000 claims description 3
- KMTRUDSVKNLOMY-UHFFFAOYSA-N Ethylene carbonate Chemical compound O=C1OCCO1 KMTRUDSVKNLOMY-UHFFFAOYSA-N 0.000 claims description 3
- VOEUMFXKYRCDKK-UHFFFAOYSA-N FS(=N)F.FS(=N)F.[Li] Chemical compound FS(=N)F.FS(=N)F.[Li] VOEUMFXKYRCDKK-UHFFFAOYSA-N 0.000 claims description 3
- 239000004696 Poly ether ether ketone Substances 0.000 claims description 3
- 229920002873 Polyethylenimine Polymers 0.000 claims description 3
- 239000004793 Polystyrene Substances 0.000 claims description 3
- HSFWRNGVRCDJHI-UHFFFAOYSA-N alpha-acetylene Natural products C#C HSFWRNGVRCDJHI-UHFFFAOYSA-N 0.000 claims description 3
- 239000004917 carbon fiber Substances 0.000 claims description 3
- IEJIGPNLZYLLBP-UHFFFAOYSA-N dimethyl carbonate Chemical compound COC(=O)OC IEJIGPNLZYLLBP-UHFFFAOYSA-N 0.000 claims description 3
- 239000006185 dispersion Substances 0.000 claims description 3
- JBTWLSYIZRCDFO-UHFFFAOYSA-N ethyl methyl carbonate Chemical compound CCOC(=O)OC JBTWLSYIZRCDFO-UHFFFAOYSA-N 0.000 claims description 3
- 239000004744 fabric Substances 0.000 claims description 3
- MHCFAGZWMAWTNR-UHFFFAOYSA-M lithium perchlorate Chemical compound [Li+].[O-]Cl(=O)(=O)=O MHCFAGZWMAWTNR-UHFFFAOYSA-M 0.000 claims description 3
- 229910001486 lithium perchlorate Inorganic materials 0.000 claims description 3
- 238000004519 manufacturing process Methods 0.000 claims description 3
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims description 3
- 229920002492 poly(sulfone) Polymers 0.000 claims description 3
- 229920001197 polyacetylene Polymers 0.000 claims description 3
- 229920000767 polyaniline Polymers 0.000 claims description 3
- 229920002530 polyetherether ketone Polymers 0.000 claims description 3
- 229920006389 polyphenyl polymer Polymers 0.000 claims description 3
- 229920001451 polypropylene glycol Polymers 0.000 claims description 3
- 229920002223 polystyrene Polymers 0.000 claims description 3
- RUOJZAUFBMNUDX-UHFFFAOYSA-N propylene carbonate Chemical compound CC1COC(=O)O1 RUOJZAUFBMNUDX-UHFFFAOYSA-N 0.000 claims description 3
- 150000003460 sulfonic acids Chemical class 0.000 claims description 3
- 238000002604 ultrasonography Methods 0.000 claims description 2
- 239000011532 electronic conductor Substances 0.000 abstract description 19
- 230000006911 nucleation Effects 0.000 abstract description 15
- 238000010899 nucleation Methods 0.000 abstract description 15
- 150000002500 ions Chemical class 0.000 abstract description 12
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 abstract description 11
- 229910001416 lithium ion Inorganic materials 0.000 abstract description 11
- 230000001105 regulatory effect Effects 0.000 abstract description 9
- 210000001787 dendrite Anatomy 0.000 abstract description 8
- 238000002156 mixing Methods 0.000 abstract description 7
- 230000005540 biological transmission Effects 0.000 abstract description 6
- 239000011888 foil Substances 0.000 abstract description 5
- 238000004090 dissolution Methods 0.000 abstract description 3
- 238000012546 transfer Methods 0.000 abstract description 3
- 239000011230 binding agent Substances 0.000 abstract description 2
- 230000015572 biosynthetic process Effects 0.000 abstract description 2
- 238000003487 electrochemical reaction Methods 0.000 abstract description 2
- 239000010408 film Substances 0.000 description 20
- 239000002002 slurry Substances 0.000 description 12
- 230000000694 effects Effects 0.000 description 10
- 239000003792 electrolyte Substances 0.000 description 9
- 230000000052 comparative effect Effects 0.000 description 7
- 239000003292 glue Substances 0.000 description 7
- 239000000203 mixture Substances 0.000 description 7
- 239000007773 negative electrode material Substances 0.000 description 7
- 238000001878 scanning electron micrograph Methods 0.000 description 7
- 239000002904 solvent Substances 0.000 description 7
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 6
- 230000001276 controlling effect Effects 0.000 description 6
- 229910052751 metal Inorganic materials 0.000 description 6
- 239000002184 metal Substances 0.000 description 6
- 210000004027 cell Anatomy 0.000 description 5
- 238000000151 deposition Methods 0.000 description 5
- 230000008021 deposition Effects 0.000 description 5
- 230000002401 inhibitory effect Effects 0.000 description 5
- 238000009472 formulation Methods 0.000 description 4
- 230000008569 process Effects 0.000 description 4
- 229910052786 argon Inorganic materials 0.000 description 3
- 239000002131 composite material Substances 0.000 description 3
- 230000002829 reductive effect Effects 0.000 description 3
- 238000007086 side reaction Methods 0.000 description 3
- 229920001940 conductive polymer Polymers 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 229910002804 graphite Inorganic materials 0.000 description 2
- 239000010439 graphite Substances 0.000 description 2
- 230000000670 limiting effect Effects 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 238000009210 therapy by ultrasound Methods 0.000 description 2
- 239000010409 thin film Substances 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 230000006978 adaptation Effects 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000007767 bonding agent Substances 0.000 description 1
- 239000003575 carbonaceous material Substances 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 239000002322 conducting polymer Substances 0.000 description 1
- 239000006258 conductive agent Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 230000001351 cycling effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000005137 deposition process Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000004146 energy storage Methods 0.000 description 1
- 238000000724 energy-dispersive X-ray spectrum Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- 230000002427 irreversible effect Effects 0.000 description 1
- 238000011031 large-scale manufacturing process Methods 0.000 description 1
- 238000001465 metallisation Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000010287 polarization Effects 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 239000011232 storage material Substances 0.000 description 1
Classifications
-
- 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
- Battery Electrode And Active Subsutance (AREA)
Abstract
The invention provides a preparation method of a lithium powder negative electrode, which comprises the following steps: fully dissolving a mixed conductor material of lithium salt, an ion conductor polymer and an electronic conductor polymer in an organic solvent to obtain viscous liquid; dispersing lithium powder into the viscous liquid under the protection of inert gas to obtain mixed slurry; and coating the mixed slurry on a current collector, and drying to obtain the lithium powder cathode. According to the preparation method, lithium powder is uniformly adhered in a simple dissolution mixing mode, a binder is not needed, energy density can be improved, a mixed ion and electron conducting network can be formed, a continuous ion and electron transmission channel is provided for electrochemical reaction, the conductivity of ions/electrons is controlled through mixing of an ion conductor polymer and an electron conductor polymer, the transmission dynamics of lithium ions is controlled, further lithium nucleation sites are regulated and controlled, lithium dendrite formation is inhibited, and accordingly, a negative electrode with higher active surface area than that of a lithium foil, higher charge transfer rate and lower impedance is obtained, and the multiplying power performance of the negative electrode can be improved.
Description
Technical Field
The invention belongs to the technical field of lithium secondary battery negative electrode materials, and particularly relates to a lithium powder negative electrode, a preparation method and application thereof.
Background
Along with the rapid development of electronic products and electric automobiles, lithium ion batteries become more and more important, and currently, the lithium ion batteries mainly use carbon materials as cathodes, but the theoretical specific capacity of graphite cathodes is only 372 mAh g -1 It is difficult to meet the high energy density requirements of lithium ion batteries.
The metallic lithium has a mAh g of up to 3860 mAh -1 Is a negative electrode material of a next-generation lithium secondary battery with development prospect, and has the theoretical specific capacity and the lowest electrode potential (-3.04V). In recent years, a great deal of research has focused on sheet-like lithium negative electrodes. However, the available contact area of the active surface of the lithium sheet is limited, so that the actual power of the lithium metal anode is reduced, limiting the application thereof.
Studies have shown that after powdering metallic lithium, it can provide a higher active surface area, inhibit polarization of lithium ions, increase the charge transfer rate of the lithium anode, and further slow down the increase of the interface impedance of the anode, which indicates that metallic lithium powder has better cycle performance (see Kwon C W, cheon S E, song J M. et. al, J.Power Sources, 2001, 93:145-150).
At present, the preparation of the metal lithium powder negative electrode is mainly to disperse metal lithium powder, a conductive agent and other components into a glue solution composed of a solvent and an adhesive, such as a high-capacity metal lithium powder composite negative electrode and a preparation method thereof and a multilayer composite electrode (application number: CN 102201565A) disclosed by Hangzhou Wanjiao power battery limited company.
The irreversible capacity loss of materials such as a carbon negative electrode, a silicon negative electrode and the like in the first charge and discharge process can be effectively compensated by using the metal lithium powder, and the first efficiency of the materials is improved. However, the prepared lithium powder negative electrode needs to be combined with electrode layers such as a graphite layer to form a composite negative electrode layer, so that the effect of inhibiting the growth of lithium dendrites can be achieved.
There are studies showing that lithium deposition starts at randomly distributed lithium nucleation sites and grows in an uncontrolled manner (see Yangyang Liu, shizhao Xiong, jialin Wang, et. Energy Storage Materials, 2019, 19:24-30), so nucleation sites that induce lithium metal deposition will be effective in inhibiting lithium dendrite growth.
Disclosure of Invention
In order to overcome the defects in the prior art, one of the purposes of the invention is to provide a lithium powder negative electrode, a preparation method thereof and a lithium battery.
In order to achieve the above object, the present invention provides the following technical solutions:
the invention provides a preparation method of a lithium powder negative electrode, which comprises the following steps:
(1) Fully dissolving lithium salt and a mixed conductor material in an organic solvent to obtain viscous liquid; the mixed conductor material comprises an ion conductor polymer and an electron conductor polymer;
(2) Dispersing lithium powder into the viscous liquid under the protection of inert gas to obtain mixed slurry; and coating the mixed slurry on a current collector, and drying to obtain the lithium powder cathode.
Preferably, the mass ratio of the ionic conductor polymer to the electronic conductor polymer in the mixed conductor material is 0.1-10.
Preferably, the ionic conductor polymer is one or more than two of polyethylene oxide, polypropylene oxide, polyethylene succinate, polyethylene sebacate, polyethylene imine, polyvinylidene fluoride, perfluorinated sulfonic acid polymer, sulfonated polyether ether ketone, quaternized polysulfone and polystyrene imidazole.
Preferably, the electron conductive polymer is one or more of polyacetylene, polyphenyl, polypyrrole, polythiophene, polyaniline and polyphenylacetylene.
Preferably, the organic solvent is one or more selected from N-methylpyrrolidone, dimethylacetamide, dimethylsulfoxide, acetone, diethyl ether, propylene carbonate, ethylene carbonate, diethyl carbonate, dimethyl carbonate, methylethyl carbonate and ethylene glycol dimethyl ether.
Preferably, the lithium salt is one or more selected from lithium perchlorate, lithium tetrafluoroborate, lithium hexafluoroarsenate, lithium hexafluorophosphate, lithium bisoxalato borate, lithium difluorooxalato borate, lithium bisdifluorosulfimide and lithium bistrifluoromethylsulfonimide.
Preferably, the mixed slurry comprises, by mass, 15% -50% of lithium powder, 20% -70% of an organic solvent, 5% -10% of lithium salt and 10% -20% of a mixed conductor material.
Optionally, in step (2), the current collector is selected from copper foil, copper foam, copper mesh, carbon fiber cloth, carbon mesh, nickel foam, or nickel mesh.
Preferably, in the step (2), the coating thickness of the mixed slurry is 0.2mm to 1mm.
Preferably, in the step (2), the drying temperature is 25-80 ℃, and the water content is controlled to be less than or equal to 0.1ppm and the oxygen content is controlled to be less than or equal to 0.1ppm during drying.
Preferably, step (2) is performed in a dry environment; the water content is controlled to be less than or equal to 0.1ppm and the oxygen content is controlled to be less than or equal to 0.1ppm in the drying environment.
Preferably, step (1) is performed in a dry environment.
Preferably, in step (2), the dispersing is performed under stirring and/or ultrasound.
The invention also provides a lithium powder negative electrode which is prepared by adopting the preparation method.
The present invention also provides a lithium battery including the above-described lithium powder negative electrode or the lithium powder negative electrode manufactured by the above-described manufacturing method, as one general inventive concept.
Compared with the prior art, the invention has the following beneficial effects:
(1) According to the preparation method of the lithium powder negative electrode, the lithium powder is uniformly bonded in a simple dissolution mixing mode, the mixed conductor material has the bonding effect, and the electrode can tightly and uniformly bond the metal lithium powder without adding an additional bonding agent, so that the problems of loose contact and large contact resistance among lithium powder particles are solved, the mass ratio of the lithium powder can be increased, and the energy density is further improved; the ion conductor polymer and the electron conductor polymer can be uniformly dissolved in the solvent, and the electrode can form a mixed ion and electron conductive network after being dried, so that continuous ion and electron transmission channels are provided for electrochemical reaction; and the conductivity of ions/electrons is controlled by mixing the ion conductor polymer and the electron conductor polymer to control the transmission dynamics of lithium ions, so that lithium nucleation sites are regulated and controlled, and lithium dendrite formation is inhibited, thereby obtaining the negative electrode with higher active surface area than that of a lithium foil, faster charge transfer rate and lower impedance, and improving the rate capability of the negative electrode. The preparation of the conventional lithium powder negative electrode needs a tabletting process, and the invention uses a simple natural film forming method to keep the original characteristics of the lithium powder, and simultaneously can accurately control the quality of the lithium powder negative electrode in the preparation process so as to achieve the purpose of balancing the quality of the positive electrode and the negative electrode.
(2) The invention can adjust the ionic conductivity and the electronic conductivity of the material by controlling the proportion of the ionic conductor polymer and the electronic conductor polymer which form the mixed conductor. The lithium ion reduction nucleation occurs at the junction of the ions and the electrons in the lithium deposition process, and the lithium nucleation site of the negative electrode can be controlled by regulating and controlling the transmission rate of the ions and the electrons, so that the lithium ions can be uniformly nucleated in the thin film formed by the polymer ion conductor and the polymer electron conductor, the tip effect of the lithium ion nucleation is avoided, and the purposes of inhibiting the growth of lithium dendrites and the interface side reaction are achieved.
(3) The preparation method of the lithium powder negative electrode provided by the invention has the advantages of simple process and simple operation condition, and the prepared lithium powder negative electrode is a colloidal film, is suitable for most solid batteries and liquid batteries in the market, has the advantages of industrialization and large scale, and is suitable for large-scale production and practical application.
Drawings
Fig. 1 is an SEM image of the lithium powder negative electrode material prepared in example 1.
Fig. 2 is an EDS spectrum of the lithium powder negative electrode material prepared in example 1.
Fig. 3 is a voltage time graph of a symmetrical battery assembled by lithium powder negative electrode tabs prepared in example 1, comparative example 1 and comparative example 2.
Fig. 4 is an SEM image of both sides of the peeled conductor film after charge-discharge cycles of three sets of Li Cu batteries; (a) and (d) correspond to the conductor films of the first group of Li Cu cells; (b) (e) a conductor film corresponding to a second group of Li Cu cells, and (c) a conductor film corresponding to a third group of Li Cu cells.
Fig. 5 is a graph of voltage versus time for the lithium powder negative electrode fabricated symmetrical batteries of examples 2-5.
Detailed Description
Some embodiments of the present invention provide a method for preparing a lithium powder negative electrode, including:
(1) Fully dissolving lithium salt and a mixed conductor material in an organic solvent to obtain viscous liquid; the mixed conductor material comprises an ion conductor polymer and an electron conductor polymer;
(2) Under the protection of inert gas, dispersing lithium powder in the viscous liquid to obtain mixed slurry, coating the mixed slurry on a current collector, and drying to obtain the lithium powder cathode.
In the method, the ion conductor polymer and the electronic conductor polymer can form a continuous and uniform mixed conductive network in the negative electrode, so that the electrochemical performance is improved, the polymer can also serve as a binder, the problems of loose contact among lithium powder particles and large contact resistance are solved, the lithium powder content of a negative electrode active material in the negative electrode material can also be improved, and the activity of the negative electrode material is improved; and the research shows that the lithium nucleation site can be regulated and controlled by controlling the proportion of the ion conductor polymer and the electron conductor polymer, so that lithium ions can be uniformly nucleated in the thin film formed by the polymer ion conductor and the polymer electron conductor, the tip effect of lithium ion nucleation is avoided, and the effect of inhibiting the growth of lithium dendrite and interface side reaction is achieved.
According to the preparation method of the lithium powder negative electrode, the problem of lithium dendrite is solved by adjusting the nucleation site of lithium deposition, and the problem of unstable structure of the metal lithium sheet due to serious volume expansion is solved by using the lithium powder. The metallic lithium powder anode with good flexibility is prepared by mixing metallic lithium powder with lithium salt, mixed conductor material, organic solvent and other materials, coating and drying, and is widely applicable to liquid batteries and solid batteries.
In some preferred embodiments, the mass ratio of the ionic conductor polymer to the electronic conductor polymer in the mixed conductor material is 0.1-10, more preferably 0.2-5, for example 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.8, 3, 3.2, 3.5, 3.7, 4, 4.2, 4.5, 4.8, 5, etc., and the lithium nucleation sites are better regulated and controlled by optimizing the ionic conductor polymer and the electronic conductor polymer, so that better effects of inhibiting lithium dendrite growth and interfacial side reactions are obtained, and electrochemical performance and cycle stability are improved.
In some preferred embodiments, the ionic conductor polymer is one or more than two of polyethylene oxide, polypropylene oxide, polyethylene succinate, polyethylene sebacate, polyethylene imine, polyvinylidene fluoride, perfluorinated sulfonic acid polymer, sulfonated polyether ether ketone, quaternized polysulfone, and polystyrene imidazole.
In some preferred embodiments, the electron conducting polymer is one or more of polyacetylene, polyphenyl, polypyrrole, polythiophene, polyaniline, and polyphenylacetylene.
The solvent is evaporated in the subsequent process, and has no substantial influence on the product, so that the use amount of the solvent is not strictly limited, but good mixing and dispersion of the mixed conductor material and other raw materials are ensured, and optionally, the mass ratio of the solvent is 20-70%.
In the actual preparation process, the mixed conductor material is dissolved in an organic solvent and can also play a role in bonding.
In some embodiments, the organic solvent is selected from one or more of N-methylpyrrolidone, dimethylacetamide, dimethylsulfoxide, acetone, diethyl ether, propylene carbonate, ethylene carbonate, diethyl carbonate, dimethyl carbonate, methylethyl carbonate, and ethylene glycol dimethyl ether.
In some preferred embodiments, the lithium salt is selected from one or more of lithium perchlorate, lithium tetrafluoroborate, lithium hexafluoroarsenate, lithium hexafluorophosphate, lithium bisoxalato borate, lithium difluorooxalato borate, lithium bisdifluorosulfimide, and lithium bistrifluoromethylsulfonimide.
In the invention, the mixed conductor material can also be composed of other general ionic conductor polymers and electronic conductor polymers, and the organic solvent can also be of other general varieties, but at least the mixed conductor material and the solvent can not react with lithium powder.
In some preferred embodiments, the mixed slurry comprises 15% -50% by mass of lithium powder, for example 15%, 18%, 20%, 23%, 25%, 28%, 30%, 32%, 35%, 38%, 40%, 43%, 45%, 48%, 50% and the like, 20% -70% by mass of organic solvent, for example 20%, 23%, 25%, 28%, 30%, 33%, 35%, 38%, 40%, 43%, 45%, 48%, 50%, 52%, 55%, 58%, 60%, 62%, 65%, 67%, 70% and the like, 5% -10% by mass of lithium salt, for example 5%, 6%, 7%, 8%, 9%, 10% and the like, and 10% -20% by mass of mixed conductor material, for example 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20% and the like.
In some embodiments, in step (2), the current collector is selected from copper foil, copper foam, copper mesh, carbon fiber cloth, carbon mesh, nickel foam, or nickel mesh.
In some embodiments, in the step (2), the lithium powder slurry is coated to a thickness of 0.2mm to 1mm, for example, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, etc.
In some preferred embodiments, the drying temperature is 25-80 ℃, and the water content is controlled to be less than or equal to 0.1ppm and the oxygen content is controlled to be less than or equal to 0.1ppm during drying.
In a partially preferred embodiment, step (2) is performed in a dry environment; the water content is controlled to be less than or equal to 0.1ppm and the oxygen content is controlled to be less than or equal to 0.1ppm in the drying environment. For example, laboratory operations can be performed in a glove box, and industrial applications can select appropriate operation scenes according to practical situations.
In some alternative embodiments, step (1) is performed in a dry environment. For example, laboratory operations can be performed in a glove box, and industrial applications can select appropriate operation scenes according to practical situations.
In a partially preferred embodiment, step (1) may be performed under stirring conditions to facilitate faster dissolution of the lithium salt and mixed conductor material in the solvent.
In a partially preferred embodiment, in step (2), the dispersion may be carried out under conventional mechanical forces; for example, the stirring and/or ultrasonic treatment is performed by stirring and/or ultrasonic treatment to uniformly disperse the lithium powder in the viscous liquid, and the lithium powder has high activity and cannot be too severe to ensure safety, so that the stirring and/or ultrasonic parameters can achieve the above-mentioned purposes.
The invention also provides a lithium powder negative electrode which is prepared by adopting the preparation method.
The present invention also provides a lithium battery including the above-described lithium powder negative electrode or the lithium powder negative electrode manufactured by the above-described manufacturing method, as one general inventive concept.
The present invention will be further described with reference to specific examples and drawings, but the present invention is not limited to the following examples. Unless defined otherwise, all technical and scientific terms used hereinafter have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the scope of the present invention.
The experimental methods described in the following examples are all conventional methods unless otherwise specified; the reagents and materials, unless otherwise specified, are commercially available.
Example 1
The formula of the lithium powder negative electrode with the performance of the ion/electron mixed conductor is as follows:
the mass ratio of the lithium powder to the lithium salt to the mixed conductor material to the organic solvent is 50:5:10:35. the mass ratio of the ion conductor polymer to the electron conductor polymer in the mixed conductor material is 1:1.
mixing ion conductor polyvinylidene fluoride and electronic conductor polythiophene according to a proportion at the dew point of-20 ℃ to prepare a mixed conductor polymer, dissolving lithium tetrafluoroborate salt and the mixed conductor polymer into an organic solvent N-methylpyrrolidone according to the proportion, and stirring and dispersing until the glue solution is red and transparent;
under the protection of inert gas argon (operating in a glove box), controlling the water content to be less than or equal to 0.1ppm and the oxygen content to be less than or equal to 0.1ppm, adding lithium powder into the stably dispersed glue solution, stirring at a low speed of 5m/s for 70min to obtain dispersed and uniform lithium powder slurry, coating the slurry on copper foil with the coating thickness of 0.2mm, and drying at the temperature of 60 ℃ to obtain the lithium powder negative plate.
The SEM diagram of the obtained lithium powder negative plate is shown in fig. 1, the EDS energy spectrum is shown in fig. 2, and the N element, the F element and the S element are uniformly distributed near the lithium powder, which shows that the ion conductor polyvinylidene fluoride containing the F element and the electron conductor polythiophene containing the N element and the S element are uniformly added into a lithium powder gap, and the mixed conductor and the lithium powder are successfully prepared into the lithium powder negative electrode.
And cutting the lithium powder negative electrode plate into a circular plate with the diameter of 15 mm, and sequentially using the positive electrode shell, the lithium powder negative electrode plate, the electrolyte, the diaphragm, the electrolyte, the lithium powder negative electrode plate, the gasket, the elastic sheet and the negative electrode shell to form the CR 2032 symmetrical battery.
Comparative example 1
The formula of the lithium powder negative electrode comprises the following components:
the mass ratio of the lithium powder to the lithium salt lithium tetrafluoroborate to the electron conductor polymer polythiophene to the organic solvent N-methyl pyrrolidone is 50:5:10:35.
At the dew point of-20 ℃, dissolving lithium tetrafluoroborate and polythiophene in an organic solvent N-methyl pyrrolidone, and dispersing at high speed until the glue solution is red and transparent;
under the protection of inert gas argon (operating in a glove box), controlling the water content to be less than or equal to 0.1ppm and the oxygen content to be less than or equal to 0.1ppm, adding lithium powder into the stably dispersed glue solution, stirring at a low speed of 5m/s for 70min to obtain dispersed and uniform lithium powder slurry, coating the slurry on copper foil with the coating thickness of 0.2mm, and drying at the temperature of 60 ℃ to obtain the lithium powder negative plate.
A symmetrical battery of CR 2032 was assembled in the same manner as in example 1.
Comparative example 2
The formula of the lithium powder negative electrode comprises the following components:
the mass ratio of the lithium powder to the lithium salt lithium tetrafluoroborate to the ion conductor polymer polyvinylidene fluoride to the organic solvent N-methyl pyrrolidone is 50:5:10:35.
Dissolving lithium tetrafluoroborate and polyvinylidene fluoride in an organic solvent N-methyl pyrrolidone at the dew point of-20 ℃ and dispersing at high speed until the glue solution is transparent;
under the protection of inert gas argon (operating in a glove box), controlling the water content to be less than or equal to 0.1ppm and the oxygen content to be less than or equal to 0.1ppm, adding lithium powder into the stably dispersed glue solution, stirring at a low speed of 5m/s for 70min to obtain dispersed and uniform lithium powder slurry, coating the slurry on copper foil with the coating thickness of 0.2mm, and drying at the temperature of 60 ℃ to obtain the lithium powder negative plate.
A symmetrical battery of CR 2032 was assembled in the same manner as in example 1.
Fig. 3 is a graph of voltage versus time for the lithium powder negative electrode assembled symmetrical batteries made in example 1, comparative example 1, and comparative example 2. As can be seen from the figure, comparative example 1 was due to Li during cycling + The slow transmission speed and high diffusion barrier make the overpotential increase rapidly at 520 and h, and the comparison example 2 accelerates Li during circulation + But the current density is high, the phenomenon of rapid increase of overpotential occurs at 800 h. In contrast, the assembled symmetrical cell of example 1 has excellent ionic/electronic conductivity, at accelerated Li + The transportation speed is reduced, and meanwhile, the current density is reduced, and the low-potential stable long-cycle performance is shown.
To explore the effect of conductivity on lithium nucleation sites, three sets of li||cu cells were assembled:
a first group: and dissolving the polymer electronic conductor in N-methyl pyrrolidone, coating the obtained slurry on a copper foil, drying to obtain a Cu pole piece, and assembling the Li-Cu battery by using the Cu pole piece, the Li foil, the diaphragm and the electrolyte.
Second group: and dissolving the polymer ion conductor in N-methyl pyrrolidone, coating the obtained slurry on a copper foil, drying to obtain a Cu pole piece, and assembling the Li-Cu battery by using the Cu pole piece, the Li foil, the diaphragm and the electrolyte.
Third group: the polymer electronic conductor and the polymer ion conductor are mixed according to the mass ratio of 1:1, dissolving in N-methyl pyrrolidone, coating the obtained slurry on a copper foil, drying to obtain a Cu pole piece, and assembling the Li-Cu battery by the Cu pole piece, the Li foil, the diaphragm and the electrolyte.
Wherein the mass of the first group of polymeric electronic conductors, the second group of polymeric ionic conductors, and the third group of mixed polymeric conductors are the same.
All three groups of batteries are arranged at the current density of 0.1 mA cm -2 Deposition capacity of 1 mAh cm -1 Under the condition of (1) charge-discharge cycle, and the position of lithium deposition is explored. And disassembling the recycled battery, and stripping the conductor film on the copper foil. Fig. 4 is an SEM image of both sides of the conductor film. Wherein a, d corresponds to SEM images of both sides of the first group of stripped conductor films, wherein a is the electrolyte side and d is the copper foil side; b, e is an SEM image of both sides of the second set of stripped conductor films, where b is the electrolyte side and e is the copper foil side; c, f is SEM images of both sides of the third set of stripped conductor films, where c is the electrolyte side and f is the copper foil side.
Comparing SEM images of the three groups of battery peeled conductor films, it can be found that lithium is mainly deposited on the electrolyte side, i.e., the conductor film surface, when a pure electronic conductor film is used; when using a pure ion conductor film, lithium is mainly deposited on the copper foil side, i.e., the bottom of the conductor film; when the mixed ion/electron conductor film is used, lithium deposition is less on the surface and the bottom of the film, the film is supposed to be deposited in the conductor film, the obvious control effect of ion conductivity and electron conductivity on lithium nucleation sites is proved, the lithium nucleation sites in the battery can be regulated and controlled by adopting the mixed conductor of the polymer ion conductor and the polymer electron conductor, the lithium nucleation sites in the battery can be regulated and controlled by regulating the ratio of the polymer ion conductor to the polymer electron conductor, and the electrochemical performance of the battery can be further regulated and controlled.
Example 2
This example differs from example 1 only in that the mass ratio of the ionic conductor polymer to the electronic conductor polymer in the mixed conductor material in the formulation is 1:8.
example 3
This example differs from example 1 only in that the mass ratio of the ionic conductor polymer to the electronic conductor polymer in the mixed conductor material in the formulation is 8:1.
example 4
This example differs from example 1 only in that the mass ratio of the ionic conductor polymer to the electronic conductor polymer in the mixed conductor material in the formulation is 1:5.
example 5
This example differs from example 1 only in that the mass ratio of the ionic conductor polymer to the electronic conductor polymer in the mixed conductor material in the formulation is 5:1.
the lithium powder negative electrode tabs obtained in examples 2 to 5 were assembled into a symmetrical battery of CR 2032 in the same manner as in example 1.
Fig. 5 is a graph of voltage versus time for the lithium powder negative electrode fabricated symmetrical batteries of examples 2-5. It can be seen from the figure that examples 4-5 exhibited lower overpotential stability performance, and better performance.
Example 6
A lithium powder negative electrode sheet was prepared according to the method of example 1, except that the coating thickness of the lithium powder slurry was 0.5mm.
Example 7
A lithium powder negative electrode sheet was prepared as in example 1, except that the mass ratio of lithium powder, lithium salt, mixed conductor material and organic solvent was 20:5:10:60.
example 8
The components and proportions of the lithium powder negative electrode with the ion/electron mixed conductor performance are the same as those of example 7, except that the coating thickness of the lithium powder slurry is 1mm, and the lithium powder negative electrode sheet is obtained after drying.
Example 9
The negative electrode lithium powder of this example is different from the negative electrode lithium powder of example 1 in composition, and specifically includes:
the mass ratio of the lithium powder to the lithium hexafluorophosphate to the mixed conductor material to the dimethylacetamide is 40:8:20:32. the mass ratio of the ionic conductor polymer polyethylene oxide to the electronic conductor polymer polypyrrole in the mixed conductor material is 1:1.
example 10
The negative electrode lithium powder of this example is different from the negative electrode lithium powder of example 1 in composition, and specifically includes:
the mass ratio of the lithium powder to the lithium hexafluorophosphate to the mixed conductor material to the dimethylacetamide is 40:5:10:45. the mass ratio of the ionic conductor polymer polyethylene oxide to the electronic conductor polymer polypyrrole in the mixed conductor material is 1:1.
example 11
The negative electrode lithium powder of this example is different from the negative electrode lithium powder of example 1 in composition, and specifically includes:
the mass ratio of the lithium powder to the lithium hexafluorophosphate to the mixed conductor material to the dimethylacetamide is 30:8:15:47. the mass ratio of the ionic conductor polymer polyethylene oxide to the electronic conductor polymer polypyrrole in the mixed conductor material is 1:1.
the foregoing is merely a preferred embodiment of the present invention and it should be noted that modifications and adaptations to those skilled in the art may be made without departing from the principles of the present invention, which are intended to be comprehended within the scope of the present invention.
Claims (10)
1. The preparation method of the lithium powder cathode is characterized by comprising the following steps:
(1) Fully dissolving lithium salt and a mixed conductor material in an organic solvent to obtain viscous liquid; the mixed conductor material comprises an ion conductor polymer and an electron conductor polymer;
(2) Dispersing lithium powder into the viscous liquid under the protection of inert gas to obtain mixed slurry; and coating the mixed slurry on a current collector, and drying to obtain the lithium powder cathode.
2. The method for preparing a lithium powder negative electrode according to claim 1, wherein the mass ratio of the ion conductor polymer to the electron conductor polymer in the mixed conductor material is 0.1-10.
3. The method for preparing a lithium powder negative electrode according to claim 2, wherein the ion conductor polymer is one or more than two of polyethylene oxide, polypropylene oxide, polyethylene succinate, polyethylene sebacate, polyethylene imine, polyvinylidene fluoride, perfluorinated sulfonic acid polymer, sulfonated polyether ether ketone, quaternized polysulfone and polystyrene imidazole; the electron conductor polymer is one or more than two of polyacetylene, polyphenyl, polypyrrole, polythiophene, polyaniline and polyphenylacetylene.
4. The method for producing a negative electrode for lithium powder according to claim 1, wherein the lithium salt is one or more selected from the group consisting of lithium perchlorate, lithium tetrafluoroborate, lithium hexafluoroarsenate, lithium hexafluorophosphate, lithium bisoxalato borate, lithium difluorooxalato borate, lithium bisdifluorosulfimide and lithium bistrifluoromethylsulfonimide;
the organic solvent is one or more than two selected from N-methylpyrrolidone, dimethylacetamide, dimethyl sulfoxide, acetone, diethyl ether, propylene carbonate, ethylene carbonate, diethyl carbonate, dimethyl carbonate, methyl ethyl carbonate and ethylene glycol dimethyl ether.
5. The method for preparing a lithium powder negative electrode according to any one of claims 1 to 4, wherein the mixed slurry comprises, by mass, 15% -50% of lithium powder, 20% -70% of an organic solvent, 5% -10% of lithium salt and 10% -20% of a mixed conductor material.
6. The method for preparing a lithium powder negative electrode according to any one of claims 1 to 4, wherein in the step (2), the current collector is selected from copper foil, copper foam, copper mesh, carbon fiber cloth, carbon mesh, nickel foam or nickel mesh;
the coating thickness of the mixed slurry is 0.2 mm-1.0 mm.
7. The method for preparing a lithium powder negative electrode according to any one of claims 1 to 4, wherein the step (2) is performed in a dry environment; the water content is controlled to be less than or equal to 0.1ppm, and the oxygen content is controlled to be less than or equal to 0.1ppm in the drying environment;
step (1) is carried out in a dry environment;
in step (2), the dispersion is carried out under stirring and/or ultrasound.
8. The method for preparing a lithium powder negative electrode according to any one of claims 1 to 4, wherein in the step (2), the drying temperature is 25 to 80 ℃; the water content of the environment is less than or equal to 0.1ppm and the oxygen content is less than or equal to 0.1ppm during drying.
9. A lithium powder negative electrode characterized by being prepared by the preparation method according to any one of claims 1 to 8.
10. A lithium battery comprising the lithium powder negative electrode of claim 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311646312.5A CN117410453A (en) | 2023-12-04 | 2023-12-04 | Lithium powder negative electrode, preparation method thereof and lithium battery |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311646312.5A CN117410453A (en) | 2023-12-04 | 2023-12-04 | Lithium powder negative electrode, preparation method thereof and lithium battery |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117410453A true CN117410453A (en) | 2024-01-16 |
Family
ID=89487298
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311646312.5A Pending CN117410453A (en) | 2023-12-04 | 2023-12-04 | Lithium powder negative electrode, preparation method thereof and lithium battery |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117410453A (en) |
-
2023
- 2023-12-04 CN CN202311646312.5A patent/CN117410453A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110137485B (en) | Preparation method of silicon negative electrode material containing surface modification film | |
| CN108417777B (en) | Porous ternary composite positive plate and preparation method and application thereof | |
| CN110707287B (en) | Metal lithium negative electrode, preparation method thereof and lithium battery | |
| JP2005310795A (en) | Lithium single-ion conducting inorganic filler-containing composite polymer electrolyte for lithium secondary battery and method of manufacturing the same | |
| CN110676433B (en) | Composite lithium cathode, preparation method thereof and lithium battery | |
| KR20040092189A (en) | Composite polymer electrolytes including single-ion conductor for lithium rechargeable battery and method for preparing the same | |
| CN111073184B (en) | Gel electrolyte film for secondary battery, preparation and application thereof | |
| CN112736245B (en) | Lithium ion battery negative electrode material, and preparation method and application thereof | |
| CN111987278A (en) | Composite diaphragm for lithium metal secondary battery and preparation method and application thereof | |
| CN114373982B (en) | Liquid ether organic electrolyte-based low-negative electrode secondary sodium battery and preparation method thereof | |
| CN111933940B (en) | Lithium battery composite electrode piece and preparation method and application thereof | |
| CN111933945B (en) | High-capacity lithium ion battery pole piece and lithium ion secondary battery containing same | |
| CN115440987A (en) | Current collector and preparation method thereof, negative electrode and electrochemical energy storage device | |
| CN116314774A (en) | Negative electrode plate, preparation method thereof and sodium ion battery | |
| CN111969242B (en) | Lithium metal battery and preparation method thereof | |
| CN115084562A (en) | Carbon fluoride based metal lithium battery and manufacturing method thereof | |
| CN114122395B (en) | Preparation and application of negative electrode plate for sodium ion battery | |
| CN114883749A (en) | Fluorine-containing diaphragm, negative electrode interface modification material, method for performing interface modification on negative electrode material and battery | |
| CN117410453A (en) | Lithium powder negative electrode, preparation method thereof and lithium battery | |
| CN108807916B (en) | Application of carbon nanotube film in lithium ion battery cathode, symmetric battery, half battery and preparation method | |
| CN114649502A (en) | Liquid metal coating, preparation method thereof and application thereof in lithium-free metal lithium battery | |
| CN112259787A (en) | Composite polymer all-solid-state electrolyte, preparation method thereof and lithium battery | |
| CN112117438A (en) | Negative plate, preparation method thereof and solid-state battery | |
| JP2023513815A (en) | Anode piece, battery and electronic device employing said electrode piece | |
| CN113793936B (en) | Composite binder for solid lithium battery and preparation method and application thereof |
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 |