Electron / ion double-conductor paste additive and preparation method and application thereof
By grafting polymers with high ion conductivity onto carbon materials, a mixed electronic and ion conductivity is formed, which solves the problems of poor electronic conductivity and difficulty in lithium-ion conduction in layered oxide cathode materials, thereby improving the rate performance of lithium-ion batteries.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHANDONG CHUANGNENG NEW MATERIALS CO LTD
- Filing Date
- 2026-03-05
- Publication Date
- 2026-05-08
AI Technical Summary
Layered oxide cathode materials have poor electronic conductivity, resulting in insufficient rate performance of lithium-ion batteries during high-power charge and discharge. Furthermore, as the electrode thickness increases, lithium-ion conduction becomes more difficult, affecting the rate performance of the battery cell.
By employing an electronic/ionic dual-conductor paste additive, a polymer with high ionic conductivity is grafted onto carbon materials to form a mixed electronic and ionic conductivity, thereby improving the rate performance of the battery cell.
It enhances the transport capacity of ions and electrons in the thick electrode, thereby improving the rate performance of the cell. The specific capacity of the first charge and the specific capacity of the discharge are 318.4~334.6 mAh/g and 288.1~301.8 mAh/g, respectively.
Smart Images
Figure CN122000356A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of lithium battery technology, specifically relating to an electronic / ionic dual conductor slurry additive, its preparation method, and its application. Background Technology
[0002] With the rapid development of the consumer electronics market and new energy vehicles, the demand for high-energy-density lithium-ion batteries is increasing daily. Layered oxide cathode materials have been widely used due to their high discharge specific capacity and energy density. However, due to the poor electronic conductivity of layered oxides, relying solely on their own electronic conductivity is insufficient to meet the requirements of high-power charging and discharging, and there is still room for improvement in rate performance.
[0003] As the energy density of battery cells gradually increases, the areal capacity of the positive electrode plate further increases. However, with the increase in electrode thickness, it becomes more difficult for the electrolyte to fully wet the electrode near the current collector, leading to difficulties in lithium-ion conduction and severely limiting the rate performance of the battery cell. Therefore, how to improve the rate performance of battery cells has become an urgent technical problem to be solved in this field. Summary of the Invention
[0004] The purpose of this invention is to provide an electron / ion dual-conductor paste additive, its preparation method, and its application. The electron / ion dual-conductor paste additive provided by this invention can improve the rate performance of battery cells.
[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides an electronic / ionic dual conductor paste additive, comprising a carbon material and a polymer grafted onto the carbon material; The carbon material is at least one of carbon nanotubes, graphene, graphene oxide, and reduced graphene oxide. The monomers used to prepare the polymer are glycerol diglycidyl ether, benzyl glycidyl ether, furanyl glycidyl ether, diglycidyl ether, 1,3-bis(ethylene oxide-2-ylmethoxy)benzene, 2,2-bis(trifluoromethyl)ethylene oxide, 1,4-bis(ethylene oxide-2-ylmethoxy)butane, bis(4-(ethylene oxide-2-ylmethoxy)phenyl)methane, and 1,4-bis((ethylene oxide-2-yl... At least one of the following: methoxy)methyl)cyclohexane, 2,2'-(((((9H-fluorene-9,9-diyl)bis(4,1-phenylene))bis(oxy))bis(methylene))bis(ethylene oxide), 2,2'-(2,2,3,3,4,4,5,5-octafluorohexane-1,6-diyl)bis(ethylene oxide), resorcinol diglycidyl ether, and 1,4-butanediol diglycidyl ether.
[0006] The present invention also provides a method for preparing the electron / ion dual conductor paste additive described in the above technical solution, comprising the following steps: (1) Mix carbon materials and organic solvents to obtain a carbon material dispersion; (2) The carbon material dispersion obtained in step (1) is mixed with monomer and initiator and polymerized in situ to obtain an electronic / ionic dual conductor slurry additive.
[0007] Preferably, the organic solvent in step (1) is at least one of dimethyl sulfoxide, N-methylpyrrolidone, N,N-dimethylformamide, sulfolane and anhydrous ethanol.
[0008] Preferably, the initiator in step (2) is at least one of aluminum trifluoromethanesulfonate, scandium trifluoromethanesulfonate, triethylborane, phosphazene base, lithium difluorooxalate borate, lithium hexafluorophosphate, and lithium tetrafluoroborate.
[0009] Preferably, in step (2), the mass of the initiator is 0.01 to 50% of the monomer mass.
[0010] Preferably, the mass ratio of carbon material in step (1) to monomer in step (2) is 1:10 to 10:1.
[0011] Preferably, in step (2), the in-situ polymerization temperature is 40~150℃, the in-situ polymerization time is 0.5~72h, and the rate of heating to the in-situ polymerization temperature is 0.5~10℃ / min.
[0012] The present invention also provides the application of the electron / ion dual conductor slurry additive described in the above technical solution or the electron / ion dual conductor slurry additive prepared by the preparation method described in the above technical solution in the positive electrode sheet.
[0013] Preferably, the positive electrode sheet is prepared by mixing an electron / ion dual conductor paste additive, a solvent, a positive electrode material, and a binder, and then drying the mixture to obtain the positive electrode sheet.
[0014] Preferably, the positive electrode material has a mass content of 20-98% in the positive electrode sheet, the electron / ion dual conductor paste additive has a mass content of 0.1-25% in the positive electrode sheet, and the binder has a mass content of 0.1-30% in the positive electrode sheet.
[0015] This invention provides an electronic / ionic dual conductor paste additive, comprising a carbon material and a polymer grafted onto the carbon material; the carbon material is at least one selected from carbon nanotubes, graphene, graphene oxide, and reduced graphene oxide; the monomers for preparing the polymer are glycerol diglycidyl ether, benzyl glycidyl ether, furanyl glycidyl ether, diglycidyl ether, 1,3-bis(ethylene oxide-2-ylmethoxy)benzene, 2,2-bis(trifluoromethyl)ethylene oxide, 1,4-bis(ethylene oxide-2-ylmethoxy)butane, bis(4-(ethylene oxide-2-ylmethoxy)phenyl)methane, 1,4-bis((ethylene oxide-2-ylmethoxy)methyl)cyclohexane, 2,2'-((((9H-fluorene-9,9-dimethyl) The invention utilizes at least one of the following: bis(4,1-phenylene)bis(oxy)bis(methylene)bis(ethylene oxide), 2,2'-(2,2,3,3,4,4,5,5-octafluorohexane-1,6-diyl)bis(ethylene oxide), resorcinol diglycidyl ether, and 1,4-butanediol diglycidyl ether. This invention grafts a polymer with high ionic conductivity onto a carbon material with high electronic conductivity, achieving mixed electronic and ionic conductivity, thereby improving the rate performance of the battery cell. Experimental results show that the battery assembled using the electronic / ionic dual-conductor slurry additive of this invention has a first-cycle charge specific capacity of 318.4~334.6 mAh / g and a first-cycle discharge specific capacity of 288.1~301.8 mAh / g. Attached Figure Description
[0016] Figure 1 The electrochemical performance comparison curves are shown for the batteries assembled using the positive electrode sheets of Example 4 and the comparative example. Figure 2 This is a scanning electron microscope image of the positive electrode sheet prepared using the electron / ion dual conductor paste additive of Example 3. Detailed Implementation
[0017] This invention provides an electronic / ionic dual conductor paste additive, comprising a carbon material and a polymer grafted onto the carbon material; The carbon material is at least one of carbon nanotubes, graphene, graphene oxide, and reduced graphene oxide. The monomers used to prepare the polymer are glycerol diglycidyl ether, benzyl glycidyl ether, furanyl glycidyl ether, diglycidyl ether, 1,3-bis(ethylene oxide-2-ylmethoxy)benzene, 2,2-bis(trifluoromethyl)ethylene oxide, 1,4-bis(ethylene oxide-2-ylmethoxy)butane, bis(4-(ethylene oxide-2-ylmethoxy)phenyl)methane, and 1,4-bis((ethylene oxide-2-yl... At least one of the following: methoxy)methyl)cyclohexane, 2,2'-(((((9H-fluorene-9,9-diyl)bis(4,1-phenylene))bis(oxy))bis(methylene))bis(ethylene oxide), 2,2'-(2,2,3,3,4,4,5,5-octafluorohexane-1,6-diyl)bis(ethylene oxide), resorcinol diglycidyl ether, and 1,4-butanediol diglycidyl ether.
[0018] The present invention does not have any special limitation on the source of the raw materials, and commercially available products known to those skilled in the art can be used.
[0019] In this invention, the electron / ion dual-conductor paste additive provided by this invention includes a carbon material; the carbon material is at least one selected from carbon nanotubes, graphene, graphene oxide, and reduced graphene oxide. In this invention, the carbon material exhibits high electronic conductivity.
[0020] In this invention, the particle size of the carbon material is preferably 3 nm to 50 μm.
[0021] In one embodiment, the graphene can be a single layer with a sheet diameter of 1~5μm, and the manufacturer can be Aladdin.
[0022] In this invention, the carbon nanotube is preferably at least one of single-arm carbon nanotubes, multi-walled carbon nanotubes, carboxylated single-arm carbon nanotubes, carboxylated multi-walled carbon nanotubes, aminated single-arm carbon nanotubes, aminated multi-walled carbon nanotubes, amide-modified single-arm carbon nanotubes, and amide-modified multi-arm carbon nanotubes.
[0023] In one embodiment, the diameter of the multi-arm carbon nanotube can be 100 nm and the length can be 2 μm.
[0024] In this invention, when the carbon nanotubes are carboxylated multi-arm carbon nanotubes and aminated multi-arm carbon nanotubes, the mass ratio of the carboxylated multi-arm carbon nanotubes to the aminated multi-arm carbon nanotubes is preferably 1:1.
[0025] In one embodiment, the carboxylated multi-walled carbon nanotubes can be manufactured by Xianfeng Nano, with a carboxylation degree of 5%, a diameter of 20 nm, and a length of 1 μm; the aminated multi-walled carbon nanotubes can have a diameter of 5-15 nm, a length of 50 μm, an amination degree of 3%, and can be manufactured by Aladdin.
[0026] In this invention, the graphene oxide is preferably carboxylated graphene oxide; the reduced graphene oxide is preferably at least one of carboxylated reduced graphene oxide and aminated reduced graphene oxide.
[0027] In one embodiment, the reduced graphene oxide can be a single layer with a sheet diameter of 1~5μm, and the manufacturer can be Aladdin; the carboxylated graphene oxide can be a single layer with a sheet diameter of 1~5μm and a carboxylation degree of 5%, and the manufacturer can be Xianfeng Nano.
[0028] In this invention, when the carbon material is carbon nanotubes and reduced graphene oxide, the preferred mass ratio of the carbon nanotubes to the reduced graphene oxide is (2~3):(7~8), more preferably 3:7; when the carbon material is carbon nanotubes and graphene oxide, the preferred mass ratio of the carbon nanotubes to the graphene oxide is (45~49):(10~11), more preferably 49:11; when the carbon material is carbon nanotubes, reduced graphene oxide, and graphene oxide, the preferred mass ratio of the carbon nanotubes, reduced graphene oxide, and graphene oxide is (3~4):(1~2):(1~2), more preferably 4:1:1.
[0029] The electronic / ionic dual conductor paste additive provided by this invention comprises a polymer grafted onto the carbon material; the monomers for preparing the polymer are glycerol diglycidyl ether, benzyl glycidyl ether, furanyl glycidyl ether, diglycidyl ether, 1,3-bis(ethylene oxide-2-ylmethoxy)benzene, 2,2-bis(trifluoromethyl)ethylene oxide, 1,4-bis(ethylene oxide-2-ylmethoxy)butane, bis(4-(ethylene oxide-2-ylmethoxy)phenyl)methane, 1,4-bis((ethylene oxide-2-ylmethoxy)butane, bis(4-(ethylene oxide-2-ylmethoxy)phenyl)methane, and 1,4-bis((ethylene oxide-2-ylmethoxy)butane). At least one of the following monomers: 2,2'-(9H-fluorene-9,9-diyl)bis(4,1-phenylene))bis(oxy))bis(methylene))bis(ethylene oxide), 2,2'-(2,2,3,3,4,4,5,5-octafluorohexane-1,6-diyl)bis(ethylene oxide), resorcinol diglycidyl ether, and 1,4-butanediol diglycidyl ether. By limiting the types of the above monomers, the present invention enables the polymer to possess high ionic conductivity.
[0030] In this invention, when the monomer is 1,4-butanediol diglycidyl ether and 1,3-bis(ethylene oxide-2-ylmethoxy)benzene, the preferred mass ratio of 1,4-butanediol diglycidyl ether to 1,3-bis(ethylene oxide-2-ylmethoxy)benzene is 1:(2~3); when the monomer is 1,4-butanediol diglycidyl ether and 1,4-bis((ethylene oxide-2-ylmethoxy)methyl)cyclohexane, the preferred mass ratio of 1,4-butanediol diglycidyl ether to 1,4-bis((ethylene oxide-2-ylmethoxy)methyl)cyclohexane is (7~8):2; when the monomer is 1,4-butanediol diglycidyl ether, 2,2'-(2,2,3,3,4,4,5,5-octafluorohexane-1,6-diyl)bis(ethylene oxide) and 1 When 1,4-butanediol diglycidyl ether, 2,2'-(2,2,3,3,4,4,5,5-octafluorohexane-1,6-diyl)bis(ethylene oxide) and 1,3-bis(ethylene oxide-2-ylmethoxy)benzene are used, the preferred mass ratio is 1:1:1; when the monomer is 1,4-butanediol diglycidyl ether, 2,2' ... When using '-(2,2,3,3,4,4,5,5-octafluorohexane-1,6-diyl)bis(ethylene oxide) and resorcinol diglycidyl ether, the preferred mass ratio of 1,4-butanediol diglycidyl ether, 2,2'-(2,2,3,3,4,4,5,5-octafluorohexane-1,6-diyl)bis(ethylene oxide) and resorcinol diglycidyl ether is 13:6:5. This invention enables the polymer to possess high ionic conductivity by limiting the proportions of the above monomers.
[0031] This invention grafts a polymer with high ion conductivity onto a carbon material with high electronic conductivity, achieving mixed electronic and ion conductivity, thereby improving the rate performance of the battery cell.
[0032] The electron / ion dual conductor paste additive provided by this invention can enhance the transport capacity of ions and electrons in thick electrodes, giving them excellent rate performance.
[0033] The present invention also provides a method for preparing the electron / ion dual conductor paste additive described in the above technical solution, comprising the following steps: (1) Mix carbon materials and organic solvents to obtain a carbon material dispersion; (2) The carbon material dispersion obtained in step (1) is mixed with monomer and initiator and polymerized in situ to obtain an electronic / ionic dual conductor slurry additive.
[0034] This invention mixes carbon materials and organic solvents to obtain a carbon material dispersion.
[0035] In this invention, the organic solvent is preferably at least one selected from dimethyl sulfoxide, N-methylpyrrolidone, N,N-dimethylformamide, sulfolane, and anhydrous ethanol. This invention does not impose a particular limitation on the amount of the organic solvent used, as long as it is sufficient to disperse the carbon material.
[0036] In this invention, the mixing of the carbon material and the organic solvent is preferably carried out under ultrasonic conditions; the ultrasonic duration is preferably 0.5 to 24 hours, more preferably 2 hours. This invention does not impose any particular limitation on the power of the ultrasonic treatment, as long as it ensures that the carbon material is uniformly dispersed in the organic solvent.
[0037] After obtaining the carbon material dispersion, the present invention mixes the carbon material dispersion with monomers and initiators and performs in-situ polymerization to obtain an electronic / ionic dual conductor slurry additive.
[0038] In this invention, the initiator is preferably at least one selected from aluminum trifluoromethanesulfonate, scandium trifluoromethanesulfonate, triethylborane, phosphazene base, lithium difluorooxalate borate, lithium hexafluorophosphate, and lithium tetrafluoroborate; the mass of the initiator is preferably 0.01-50% of the monomer mass. As one embodiment, the mass of the initiator can be 0.5%, 1%, 2.5%, 5%, 7.5%, 10%, 20%, 30%, or 40% of the monomer mass.
[0039] In this invention, when the initiator is triethylborane and phosphazene base, the mass ratio of triethylborane to phosphazene base is preferably 3:1.
[0040] In this invention, the preferred mass ratio of carbon material to monomer is 1:10 to 10:1. As one embodiment, the mass ratio of carbon material to monomer can be 3:4, 1:4, 2:10, 3:10, 4:10, 5:10, 6:10, 7:10, 8:10, 9:10, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, or 9:1. Limiting the mass ratio of carbon material to monomer within the above range further improves the rate performance of the battery cell.
[0041] In this invention, the mixing of the carbon material dispersion with the monomer and the initiator is preferably carried out by adding the carbon material dispersion to a reaction vessel, followed by argon purging, then ultrasonication and stirring, then adding the monomer and the initiator, and then argon purging again.
[0042] The present invention does not have a specific limitation on the model of the reaction vessel; any instrument or equipment familiar to those skilled in the art can be used.
[0043] This invention does not impose a specific limit on the number of argon gas purging operations, as long as the purging is complete. As one embodiment, the number of argon gas purging operations can independently be three times.
[0044] The present invention does not impose any special limitations on the operation of ultrasound and stirring; operations well known in the art can be used.
[0045] In this invention, the in-situ polymerization temperature is preferably 40~150℃; the in-situ polymerization time is preferably 0.5~72h; and the rate of heating to the in-situ polymerization temperature is preferably 0.5~10℃ / min. As one embodiment, the in-situ polymerization temperature can be 50℃, 55℃, 60℃, 70℃, 80℃, 90℃, 100℃, 110℃, 120℃, 130℃, or 140℃; the in-situ polymerization time can be 1h, 5h, 8h, 10h, 12h, 20h, 24h, 30h, 40h, 50h, 60h, or 70h; and the rate of heating to the in-situ polymerization temperature can be 1℃ / min, 2℃ / min, 3℃ / min, 4℃ / min, 5℃ / min, 6℃ / min, 7℃ / min, 8℃ / min, or 9℃ / min.
[0046] As one implementation method, the in-situ polymerization can be segmented polymerization; the segmented polymerization can be carried out by holding at 60°C for 4 hours, and then raising the temperature to 80°C and holding for 12 hours.
[0047] In this invention, the in-situ polymerization is preferably carried out in an argon atmosphere.
[0048] After the in-situ polymerization is completed, the present invention preferably filters, washes and dries the product obtained by the in-situ polymerization reaction in sequence to obtain an electronic / ionic dual conductor slurry additive.
[0049] The present invention does not impose any special limitations on the filtration operation; any operation known to those skilled in the art can be used to obtain the filter residue.
[0050] In this invention, the detergent used for washing is preferably at least one selected from anhydrous ethanol, tetrahydrofuran, acetone, n-hexane, and petroleum ether. This invention does not impose a specific limit on the amount of detergent used; as long as the product cleans effectively, it is sufficient.
[0051] In this invention, the drying temperature is preferably 45~120℃, more preferably 60℃; the drying time is preferably 0.5~24h, more preferably 12h.
[0052] This invention synthesizes an electron / ion dual-conductor slurry additive by fully mixing carbon materials and monomers in a solvent in a specific ratio. Under heating conditions, the monomers are polymerized by an initiator to graft high-conductivity carbon materials onto high-ion-conductivity polymers. After washing and drying, the electron / ion dual-conductor slurry additive is obtained. Subsequently, the electron / ion dual-conductor slurry additive is fully mixed with positive electrode materials, binders, and solvents to obtain a high-area-capacity positive electrode sheet, which improves the transport dynamics of electrons and lithium ions in the electrode sheet and is beneficial to improving the rate performance of the battery cell.
[0053] The present invention also provides the application of the electron / ion dual conductor slurry additive described in the above technical solution or the electron / ion dual conductor slurry additive prepared by the preparation method described in the above technical solution in the positive electrode sheet.
[0054] In this invention, the preferred method for preparing the positive electrode sheet is to mix an electron / ion dual conductor paste additive, a solvent, a positive electrode material, and a binder, and then dry the mixture to obtain the positive electrode sheet.
[0055] The present invention does not specifically limit the type of solvent; any solvent well known to those skilled in the art can be used. As one embodiment, the solvent may be N-methylpyrrolidone.
[0056] In this invention, the positive electrode material can be a layered positive electrode material; the layered positive electrode material is preferably a lithium-rich manganese-based positive electrode material; the structural formula of the lithium-rich manganese-based positive electrode material is preferably xLi2MnO3·(1-x)LiTMO2, wherein TM is at least one of Ni, Mn, Co, Ti, Al, Ir, Ru and Zr, and 0≤x≤1; the binder is preferably polyvinylidene fluoride.
[0057] The present invention does not have a special limitation on the amount of solvent used, as long as the raw materials are completely dissolved.
[0058] In this invention, the mass content of the positive electrode material in the positive electrode sheet is preferably 20-98%; the mass content of the electron / ion dual conductor slurry additive in the positive electrode sheet is preferably 0.1-25%; and the mass content of the binder in the positive electrode sheet is preferably 0.1-30%. As one embodiment, the mass content of the positive electrode material in the positive electrode sheet can be 25%, 50%, 75%, 90%, 92%, 94%, 95%, or 97%; the mass content of the electron / ion dual conductor slurry additive in the positive electrode sheet can be 1%, 1.5%, 3%, 4%, 5%, 10%, 15%, or 20%; and the mass content of the binder in the positive electrode sheet can be 1%, 1.5%, 3%, 4%, 5%, 10%, 20%, or 25%.
[0059] In one embodiment, the mass ratio of the positive electrode material, binder, electron / ion dual conductor slurry additive, and solvent can be 92:3:5:60.
[0060] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.
[0061] Example 1 An electronic / ionic dual conductor paste additive is composed of a carbon material and a polymer grafted onto the carbon material; The carbon material is a multi-arm carbon nanotube with a diameter of 100 nm and a length of 2 μm; The monomer of the polymer is 1,4-butanediol diglycidyl ether; The preparation method of the electron / ion dual conductor paste additive is as follows: 50 mL of dry, anhydrous N-methylpyrrolidone was placed in a reaction vessel, and 100 mg of multi-arm carbon nanotubes were added to obtain a carbon material dispersion. The reaction vessel was then purged with argon three times, followed by ultrasonic dispersion for 2 h, and then stirring for 3 h. Next, 100 mg of 1,4-butanediol diglycidyl ether and 10 mg of lithium difluorooxalate borate were added, and the reaction vessel was purged with argon three times with continuous argon gas flow. Subsequently, the reaction vessel was heated under stirring at a heating rate of 2 °C / min to 60 °C and held at that temperature for 12 h. After the reaction was completed, the mixture was filtered, and the product was washed three times with anhydrous ethanol and dried in a vacuum oven at 60 °C for 12 h to obtain an electron / ion dual conductor slurry additive.
[0062] Li-rich manganese-based cathode material Li 1.2 Mn 0.6 Ni 0.2 O2, polyvinylidene fluoride, and the electron / ion dual conductor slurry additive prepared in Example 1 were mixed evenly in N-methylpyrrolidone at a mass ratio of 90:5:5, and then dried in a vacuum oven at 120°C for 12 hours to form a positive electrode sheet with a diameter of 10 mm.
[0063] Example 2 An electronic / ionic dual conductor paste additive is composed of a carbon material and a polymer grafted onto the carbon material; The carbon material is a carboxylated multi-arm carbon nanotube manufactured by Xianfeng Nano, with a carboxylation degree of 5%, a diameter of 20 nm, and a length of 1 μm. The monomers of the polymer are 1,4-butanediol diglycidyl ether and 1,3-bis(ethylene oxide-2-ylmethoxy)benzene in a mass ratio of 1:3. The preparation method of the electron / ion dual conductor paste additive is as follows: 50 mL of dry, anhydrous N-methylpyrrolidone was placed in a reaction vessel, and 300 mg of carboxylated multi-arm carbon nanotubes were added to obtain a carbon material dispersion. The reaction vessel was then purged with argon three times, followed by ultrasonic dispersion for 2 h, and then stirring for 3 h. Next, 100 mg of 1,4-butanediol diglycidyl ether, 300 mg of 1,3-bis(ethylene oxide-2-ylmethoxy)benzene, and 30 mg of lithium hexafluorophosphate were added. The reaction vessel was then purged with argon three times and argon was continuously introduced. Subsequently, the reaction vessel was heated under stirring at a heating rate of 2 °C / min to 55 °C and held at that temperature for 8 h. After the reaction was completed, the mixture was filtered, and the product was washed three times with anhydrous ethanol and dried in a vacuum oven at 60 °C for 12 h to obtain an electronic / ionic dual conductor slurry additive.
[0064] Li-rich manganese-based cathode material Li 1.2 Mn 0.6 Ni 0.2 O2, polyvinylidene fluoride, and the electron / ion dual conductor slurry additive prepared in Example 2 were mixed evenly in N-methylpyrrolidone at a mass ratio of 92:4:4, and then dried in a vacuum oven at 120°C for 12 hours to form a positive electrode sheet with a diameter of 10 mm.
[0065] Example 3 An electronic / ionic dual conductor paste additive is composed of a carbon material and a polymer grafted onto the carbon material; The carbon material is aminated multi-arm carbon nanotubes and reduced graphene oxide in a mass ratio of 3:7. The aminated multi-walled carbon nanotubes have a diameter of 5-15 nm, a length of 50 μm, an amination degree of 3%, and are manufactured by Aladdin. The reduced graphene oxide is a single layer with a sheet diameter of 1~5μm, and the manufacturer is Aladdin; The monomers of the polymer are 1,4-butanediol diglycidyl ether and 1,4-bis((ethylene oxide-2-ylmethoxy)methyl)cyclohexane in a mass ratio of 8:2. The preparation method of the electron / ion dual conductor paste additive is as follows: 50 mL of dry, anhydrous N-methylpyrrolidone was placed in a reaction vessel, along with 30 mg of aminated multi-arm carbon nanotubes and 70 mg of reduced graphene oxide to obtain a carbon material dispersion. The reaction vessel was then purged with argon three times, followed by ultrasonic dispersion for 2 h, and then stirring for another 3 h. Next, 80 mg of 1,4-butanediol diglycidyl ether, 20 mg of 1,4-bis((ethylene oxide-2-ylmethoxy)methyl)cyclohexane, 5 mg of lithium hexafluorophosphate, and 5 mg of lithium difluorooxalate borate were added. The reaction vessel was then purged with argon three times and argon was continuously introduced. Subsequently, the reaction vessel was heated under stirring at a rate of 2 °C / min to 60 °C and held at that temperature for 10 h. After the reaction was completed, the mixture was filtered, and the product was washed three times with anhydrous ethanol. The product was then dried in a vacuum oven at 60 °C for 12 h to obtain an electronic / ionic dual conductor slurry additive.
[0066] Li-rich manganese-based cathode material Li 1.2 Mn 0.6 Ni 0.2 O2, polyvinylidene fluoride, and the electron / ion dual conductor slurry additive prepared in Example 3 were mixed evenly in N-methylpyrrolidone at a mass ratio of 94:3:3, and then dried in a vacuum oven at 120°C for 12 hours to form a positive electrode sheet with a diameter of 10 mm.
[0067] Example 4 An electronic / ionic dual conductor paste additive is composed of a carbon material and a polymer grafted onto the carbon material; The carbon material is carboxylated multi-arm carbon nanotubes and carboxylated graphene oxide in a mass ratio of 49:11. The manufacturer of the carboxylated multi-arm carbon nanotubes is Xianfeng Nano, with a carboxylation degree of 5%, a diameter of 20nm, and a length of 1μm; The carboxylated graphene oxide is a single layer with a sheet diameter of 1~5μm and a carboxylation degree of 5%. The manufacturer is Xianfeng Nano. The monomers of the polymer are 1,4-butanediol diglycidyl ether, 2,2'-(2,2,3,3,4,4,5,5-octafluorohexane-1,6-diyl)bis(ethylene oxide) and 1,3-bis(ethylene oxide-2-ylmethoxy)benzene in a mass ratio of 1:1:1. The preparation method of the electron / ion dual conductor paste additive is as follows: 50 mL of dry, anhydrous N-methylpyrrolidone was placed in a reaction vessel, along with 245 mg of carboxylated multi-arm carbon nanotubes and 55 mg of carboxylated graphene oxide to obtain a carbon material dispersion. The reaction vessel was then purged with argon three times, followed by ultrasonic dispersion for 5 h, and then stirring for another 3 h. Next, 100 mg of 1,4-butanediol diglycidyl ether and 100 mg of 2,2'-(2,2,3,3,4,4,5,5-octafluorohexane-1,6-diyl)bis(ethylene oxide) were added. The reaction mixture consisted of 100 mg of 1,3-bis(ethylene oxide-2-ylmethoxy)benzene and 30 mg of triethylborane, followed by three argon purgings in the reactor and continuous argon flow. The reactor was then heated under stirring at a rate of 2 °C / min to 60 °C, held at that temperature for 4 h, then heated to 80 °C and held at that temperature for 12 h. After the reaction was completed, the mixture was filtered, and the product was washed three times with anhydrous ethanol and dried in a vacuum oven at 60 °C for 12 h to obtain an electronic / ionic dual conductor slurry additive.
[0068] Li-rich manganese-based cathode material Li 1.2 Mn 0.6 Ni 0.2 O2, polyvinylidene fluoride, and the electron / ion dual conductor slurry additive prepared in Example 4 were mixed evenly in N-methylpyrrolidone at a mass ratio of 92:4:4, and then dried in a vacuum oven at 120°C for 12 hours to form a positive electrode sheet with a diameter of 10 mm.
[0069] Example 5 An electronic / ionic dual conductor paste additive is composed of a carbon material and a polymer grafted onto the carbon material; The carbon material is graphene, which is a single layer with a sheet diameter of 1~5μm, and is manufactured by Aladdin. The monomer of the polymer is 1,4-butanediol diglycidyl ether; The preparation method of the electron / ion dual conductor paste additive is as follows: 50 mL of dry, anhydrous N-methylpyrrolidone was placed in a reaction vessel, and 100 mg of graphene was added to obtain a carbon material dispersion. The reaction vessel was then purged with argon three times, followed by ultrasonic dispersion for 2 h, and then stirring for 3 h. Next, 400 mg of 1,4-butanediol diglycidyl ether and 10 mg of lithium tetrafluoroborate were added, and the reaction vessel was purged with argon three times with continuous argon gas flow. Subsequently, the reaction vessel was heated under stirring at a heating rate of 2 °C / min to 80 °C and held at that temperature for 24 h. After the reaction was completed, the mixture was filtered, and the product was washed three times with anhydrous ethanol and dried in a vacuum oven at 60 °C for 12 h to obtain an electronic / ionic dual conductor slurry additive.
[0070] Li-rich manganese-based cathode material Li 1.2 Mn 0.6 Ni0.2 O2, polyvinylidene fluoride, and the electron / ion dual conductor slurry additive prepared in Example 5 were mixed evenly in N-methylpyrrolidone at a mass ratio of 97:1.5:1.5, and then dried in a vacuum oven at 120°C for 12 hours to form a positive electrode sheet with a diameter of 10 mm.
[0071] Example 6 An electronic / ionic dual conductor paste additive is composed of a carbon material and a polymer grafted onto the carbon material; The carbon material is composed of carboxylated multi-arm carbon nanotubes, aminated multi-arm carbon nanotubes, reduced graphene oxide, and carboxylated graphene oxide in a mass ratio of 2:2:1:1. The manufacturer of the carboxylated multi-arm carbon nanotubes is Xianfeng Nano, with a carboxylation degree of 5%, a diameter of 20nm, and a length of 1μm; The aminated multi-walled carbon nanotubes have a diameter of 5-15 nm, a length of 50 μm, an amination degree of 3%, and are manufactured by Aladdin. The reduced graphene oxide is a single layer with a sheet diameter of 1~5μm, and the manufacturer is Aladdin; The carboxylated graphene oxide is a single layer with a sheet diameter of 1~5μm and a carboxylation degree of 5%. The manufacturer is Xianfeng Nano. The monomers of the polymer are 1,4-butanediol diglycidyl ether, 2,2'-(2,2,3,3,4,4,5,5-octafluorohexane-1,6-diyl)bis(ethylene oxide) and resorcinol diglycidyl ether in a mass ratio of 13:6:5. The preparation method of the electron / ion dual conductor paste additive is as follows: 50 mL of dry, anhydrous N-methylpyrrolidone was placed in a reaction vessel, and 100 mg of carboxylated multi-arm carbon nanotubes, 100 mg of aminated multi-arm carbon nanotubes, 50 mg of reduced graphene oxide, and 50 mg of carboxylated graphene oxide were added to obtain a carbon material dispersion. The reaction vessel was then purged with argon three times, followed by ultrasonic dispersion for 4 h, and then stirring for another 6 h. Next, 650 mg of 1,4-butanediol diglycidyl ether and 300 mg of 2,2'-(2,2,3,3,4,4,5,...) were added. 5-Octafluorohexane-1,6-diyl)bis(ethylene oxide), 250 mg resorcinol diglycidyl ether, 90 mg triethylborane, and 30 mg phosphazene base were used to purge the reactor with argon three times while continuously introducing argon. Subsequently, the reactor was heated under stirring at a rate of 2 °C / min to 80 °C and held at that temperature for 24 h. After the reaction was completed, the mixture was filtered, and the product was washed three times with anhydrous ethanol and dried in a vacuum oven at 60 °C for 12 h to obtain an electron / ion dual conductor paste additive.
[0072] Li-rich manganese-based cathode material Li 1.2Mn 0.6 Ni 0.2 O2, polyvinylidene fluoride, and the electronic / ionic dual conductor slurry additive prepared in Example 6 were mixed evenly in N-methylpyrrolidone at a mass ratio of 94:3:3, and then dried in a vacuum oven at 120°C for 12 hours to form a positive electrode sheet with a diameter of 10 mm.
[0073] Comparative Example Super P Li-rich manganese-based cathode material Li 1.2 Mn 0.6 Ni 0.2 O2, polyvinylidene fluoride, and Super P (comparative example) were mixed uniformly in N-methylpyrrolidone at a mass ratio of 92:4:4, and then dried in a vacuum oven at 120°C for 12 hours to form a positive electrode sheet with a diameter of 10 mm.
[0074] In an argon glove box (water content less than 0.1 ppm; oxygen content less than 0.1 ppm), CR 2032 button-type half-cells were assembled using positive electrode sheets (Examples 1-6 and Comparative Examples) as the working electrode, lithium metal sheets as the counter electrode, and polypropylene microporous membranes as the separator. Charge-discharge tests were performed on the assembled cells using a Blue Battery Tester. The voltage range for the first cycle was 4.8–2 V, and the current density was 20 mA / g. After the second cycle began, the current density was 200 mA / g. The results are shown in Table 1 and [Table data missing]. Figure 1 As shown.
[0075] Table 1. Performance data of batteries assembled from the positive electrode sheets prepared in Examples 1-6.
[0076] As can be seen from Table 1, the electronic / ionic dual conductor slurry additive provided by the present invention can improve the specific capacity of the battery.
[0077] Figure 1 To compare the electrochemical performance curves of the batteries assembled using the positive electrode sheets of Example 4 and the comparative example, the test method was to charge and discharge the batteries in the first cycle at a current density of 20 mA / g in the voltage range of 2 to 4.8 V, and then cycle them in the second cycle at a current density of 200 mAh / g in the voltage range of 2 to 4.6 V.
[0078] from Figure 1 It can be seen that the battery prepared using the electron / ion dual conductor slurry additive of the present invention has excellent cycle stability.
[0079] Figure 2 This is a scanning electron microscope image of the positive electrode sheet prepared using the electron / ion dual conductor paste additive of Example 3.
[0080] from Figure 2 It can be seen that the lithium-rich manganese-based cathode material is tightly bonded to conductive carbon and has a filamentous ion-conducting network on its surface, which facilitates the conduction of electrons and lithium ions.
[0081] As can be seen from the above embodiments, the electronic / ionic dual conductor paste additive provided by the present invention can improve the rate performance of the battery cell.
[0082] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. An electronic / ionic dual conductor paste additive, comprising a carbon material and a polymer grafted onto the carbon material; The carbon material is at least one of carbon nanotubes, graphene, graphene oxide, and reduced graphene oxide. The monomers used to prepare the polymer are glycerol diglycidyl ether, benzyl glycidyl ether, furanyl glycidyl ether, diglycidyl ether, 1,3-bis(ethylene oxide-2-ylmethoxy)benzene, 2,2-bis(trifluoromethyl)ethylene oxide, 1,4-bis(ethylene oxide-2-ylmethoxy)butane, bis(4-(ethylene oxide-2-ylmethoxy)phenyl)methane, and 1,4-bis((ethylene oxide-2-yl... At least one of the following: methoxy)methyl)cyclohexane, 2,2'-(((((9H-fluorene-9,9-diyl)bis(4,1-phenylene))bis(oxy))bis(methylene))bis(ethylene oxide), 2,2'-(2,2,3,3,4,4,5,5-octafluorohexane-1,6-diyl)bis(ethylene oxide), resorcinol diglycidyl ether, and 1,4-butanediol diglycidyl ether.
2. The method for preparing the electron / ion dual conductor paste additive according to claim 1, characterized in that, Includes the following steps: (1) Mix carbon materials and organic solvents to obtain a carbon material dispersion; (2) The carbon material dispersion obtained in step (1) is mixed with monomer and initiator and polymerized in situ to obtain an electronic / ionic dual conductor slurry additive.
3. The preparation method according to claim 2, characterized in that, The organic solvent in step (1) is at least one of dimethyl sulfoxide, N-methylpyrrolidone, N,N-dimethylformamide, sulfolane and anhydrous ethanol.
4. The preparation method according to claim 2, characterized in that, The initiator in step (2) is at least one of aluminum trifluoromethanesulfonate, scandium trifluoromethanesulfonate, triethylborane, phosphazene base, lithium difluorooxalate borate, lithium hexafluorophosphate, and lithium tetrafluoroborate.
5. The preparation method according to claim 2, characterized in that, In step (2), the mass of the initiator is 0.01 to 50% of the monomer mass.
6. The preparation method according to claim 2, characterized in that, The mass ratio of carbon material in step (1) to monomer in step (2) is 1:10 to 10:
1.
7. The preparation method according to claim 2, characterized in that, In step (2), the in-situ polymerization temperature is 40~150℃, the in-situ polymerization time is 0.5~72h, and the rate of heating to the in-situ polymerization temperature is 0.5~10℃ / min.
8. The application of the electron / ion dual conductor slurry additive of claim 1 or the electron / ion dual conductor slurry additive prepared by any one of claims 2 to 7 in the positive electrode sheet.
9. The application according to claim 8, characterized in that, The positive electrode sheet is prepared by mixing an electron / ion dual conductor paste additive, a solvent, a positive electrode material, and a binder, and then drying the mixture to obtain the positive electrode sheet.
10. The application according to claim 9, characterized in that, The positive electrode material has a mass content of 20-98% in the positive electrode sheet, the electron / ion dual conductor paste additive has a mass content of 0.1-25% in the positive electrode sheet, and the binder has a mass content of 0.1-30% in the positive electrode sheet.