CN114937759A - Sodium-based composite positive electrode material, electrode and electrochemical device - Google Patents

Sodium-based composite positive electrode material, electrode and electrochemical device Download PDF

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CN114937759A
CN114937759A CN202210367577.0A CN202210367577A CN114937759A CN 114937759 A CN114937759 A CN 114937759A CN 202210367577 A CN202210367577 A CN 202210367577A CN 114937759 A CN114937759 A CN 114937759A
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composite positive
sodium
stirring
layered oxide
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蔡伟华
赵建明
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Shenzhen Huaxin Material Co ltd
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    • H—ELECTRICITY
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    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
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    • H—ELECTRICITY
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    • H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
    • H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
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    • H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
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    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
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    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
    • H01M2004/028—Positive electrodes
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Abstract

The invention relates to a sodium-based composite cathode material, an electrode and an electrochemical device. The electrochemical device containing the sodium-based layered oxide composite cathode material prepared by the invention effectively solves the potential hidden dangers of easy thermal runaway and natural spontaneous explosion under the high-temperature condition, simultaneously solves the problem of poor performance of the traditional lithium ion battery under the low-temperature condition, and remarkably improves the safety. The electrochemical device is higher in energy density, the problem that the capacity retention rate of the traditional lithium ion battery is greatly reduced in a low-temperature environment is effectively solved, meanwhile, the capacity retention rate of the battery is not obviously reduced after the battery is charged and discharged for many times, the service efficiency of the electrochemical device in an extreme environment can be obviously improved, and the service life and the effect of the battery are improved; the electrochemical device has the advantages of simpler preparation process, lower survival and preparation cost and wide market application prospect.

Description

Sodium-based composite positive electrode material, electrode and electrochemical device
Technical Field
The invention relates to the technical field of nano materials, in particular to a sodium-based composite cathode material, an electrode and an electrochemical device.
Background
Lithium-based layered oxide material LiNi x Co y Mn z O 2 Has higher gram capacity, is widely applied to the anode active materials of power lithium ion batteries and is widely used in hybrid electric vehicles and pure electric vehicles. However, the lithium-based layered oxide material has insufficient stability of crystal structure, releases oxygen during high temperature thermal runaway, has poor thermal stability, has a low runaway temperature point, and is liable to cause spontaneous combustion explosion of electric vehicles during driving or standing.
Moreover, the temperature in winter in high latitude areas is generally below zero, the KyogJi economic circle has a long time of 3 to 4 months at minus ten degrees in winter, the pure electric automobile with the lithium ion battery only continues to run for about 240 kilometers in winter after 600 kilometers in summer, and the low-temperature endurance capacity is greatly reduced.
Disclosure of Invention
The invention aims to solve the technical problems of high temperature easy thermal runaway, low temperature endurance decay and the like of a lithium ion battery in the prior art, so that a composite anode material is provided, a sodium-based layered oxide material with high thermal stability, low cost and good heat temperature capacity is selected to form the composite anode material with a conventional lithium-based oxide material, a composite electrode is prepared by using the composite anode material, and a sodium-lithium electrochemical device is produced, so that the comprehensive effects of high safety, low temperature resistance and low cost are achieved.
In order to solve the above-mentioned technical problems, the present invention is achieved by the following technical means.
The invention provides a composite cathode material, which comprises the following components in percentage by mass: 50-99% of lithium-based ternary layered oxide and 1-50% of sodium-based layered oxide.
Preferably, the composite cathode material comprises the following components in percentage by mass: 80% of lithium-based ternary layered oxide and 20% of sodium-based layered oxide.
Preferably, the lithium-based ternary layered oxide has a formula selected from the group consisting of LiNi x Co y Mn z O 2 Or LiNi a Co b AlO 2 One or more of (a).
Preferably, for the lithium-based ternary layered oxide, wherein x + y + z =100%, x: y: z is selected from one or more of 1:1:1 or 5:2:3 or 8:1: 1.
Preferably, for the lithium-based ternary layered oxide, wherein a + b =100% and a > 90%.
Preferably, the lithium-based ternary layered oxide has an R-3m space structure.
Preferably, the sodium-based layered oxide has the formula of NaA x B y C z D w E t O 2 Wherein the element A, B, C, D, E is selected from one of Ni, Al, Mn, Fe and Cu.
Preferably, for the sodium-based layered oxide, wherein x + y + z + w + t = 100%.
Preferably, the sodium-based layered oxide has a molecular formula of NaNi 0.2 Fe 0.3 Mn 0.1 Cu 0.1 Al 0.3 O 2 。
Preferably, the sodium-based layered oxide is P2 or O3 in a steric structure.
Preferably, the sodium-based layered oxide is prepared by the following method:
(a) respectively dissolving metal salts of element A, B, C, D, E in deionized water to prepare solution A;
(b) preparing NaOH and ammonia water solution as solution B;
(c) mixing the solution A and the solution B in an empty container, filtering to obtain a precursor, and mixing the precursor with Na 2 CO 3 Mixing and calcining at 600 ℃.
Preferably, the lithium-based ternary layered oxide and the sodium-based layered oxide are prepared by mixing one or more of a mechanical mixing method, a liquid mixing method and a chemical coating method.
The invention provides a composite positive plate, which comprises the composite positive material, Carbon Nano Tubes (CNT), conductive carbon black (Super P), polyvinylidene fluoride (PVDF) and N-methylpyrrolidone (NMP).
Preferably, the composite positive plate comprises the following components in parts by weight: 100 parts of composite positive electrode material, 13.63 parts of carbon nano tube, 0.5 part of conductive carbon black, 2.5 parts of polyvinylidene fluoride and 55 parts of N-methylpyrrolidone.
The third aspect of the invention provides a preparation method of a composite positive plate, which comprises the following steps:
(1) adding N-methyl pyrrolidone and polyvinylidene fluoride into a stirrer, and stirring and dispersing to prepare binder slurry;
(2) adding carbon nano tubes into the binder slurry, stirring and dispersing, then adding conductive carbon black, stopping the machine after stirring and dispersing, and scraping edges to prepare conductive slurry;
(3) adding a lithium-based ternary layered oxide into the conductive plasma, uniformly stirring under a vacuum condition, then adding a sodium-based layered oxide, stirring under the vacuum condition, uniformly mixing, then stirring at a high speed under the vacuum condition, and then stirring at a low speed to obtain a main material;
(4) and (4) sieving the main material obtained in the step (3) by a 200-mesh sieve, coating the main material on a current collector, and drying to obtain the composite positive plate.
Preferably, the stirring speed in step (1) is 700rpm, and the stirring time is 30 min.
Preferably, the stirring speed of the CNT in the step (2) is 700rpm, and the stirring time is 30 min; the Super P stirring speed was 700rpm and the stirring time was 10 min.
Preferably, the stirring speed of the lithium-based ternary layered oxide in the step (3) is 1900rpm, and the stirring time is 2 h; the stirring time of the sodium-based layered oxide is 1900rpm and 2 h; the high-speed stirring speed is 1900rpm, and the stirring time is 1-2.5 h; the low-speed stirring speed is 600rpm, and the stirring time is 15 min. Air bubbles were removed by stirring under vacuum.
Preferably, the current collector in step (4) is selected from aluminum foil.
The invention provides an electrochemical device, which comprises a pole core and electrolyte, wherein the pole core comprises the composite positive plate, the diaphragm and the negative plate.
Preferably, the electrochemical device is selected from one or more of a soft package of an aluminum plastic film, a square aluminum shell or a cylindrical steel shell.
Preferably, the negative electrode sheet includes hard carbon, Styrene Butadiene Rubber (SBR), sodium carboxymethyl cellulose (CMC), and a current collector.
Preferably, the current collector in the negative electrode sheet is selected from copper current collectors.
It is to be understood that TMO is common general knowledge in the art 6 /Na + The layers are classified into P-type and O-type (P is a prism, O is an octahedron) according to the surrounding environment of Na ions. In addition, the particular number (usually 2 or 3) following the letter P or O is used to describe the number of unique TMO6 octahedral layers within each unit, so the phase names can be described as P2, P3, O2, and O3. Thus, unless otherwise specified, references in the context of the present invention such as "R-3 m space structure", "P2 space structure", "O3 space structure", etc., are all terms of ordinary skill in the art, and those skilled in the art will be able to clearly understand the metal layered oxide space groups that they actually represent; in the lithium-based ternary layered oxide and the sodium-based layered oxide, a, b, c, x, y, z, w, t, etc. each represent the atomic mole percentage ratio of each element.
Compared with the prior art, the invention has the following technical effects:
(1) the electrochemical device containing the sodium-based layered oxide composite cathode material prepared by the invention effectively solves the potential hidden dangers of easy thermal runaway and natural spontaneous explosion under the high-temperature condition, simultaneously solves the problems of poor performance and unmatched anode charging and discharging windows of the traditional lithium ion battery under the low-temperature condition, does not generate overcharge even if the charging voltage exceeds 3.8V, and obviously improves the safety.
(2) The electrochemical device containing the sodium-based layered oxide composite cathode material prepared by the invention has higher energy density, effectively solves the problem that the capacity retention rate of the traditional lithium ion battery is greatly reduced in a low-temperature environment, does not obviously reduce the capacity retention rate after being charged and discharged for many times, can obviously improve the service efficiency of the electrochemical device in an extreme environment, and improves the service life and the effect of the battery; the electrochemical device is simpler in preparation process, lower in survival and preparation cost and wide in market application prospect.
Drawings
FIG. 1 is a scanning electron microscope photograph of a lithium-based layered ternary oxide of example 1.
FIG. 2 is a scanning electron microscope photograph of the sodium-based layered oxide of example 1.
Fig. 3 is a 0.3C charging and discharging curve diagram of the button cell battery of example 1, wherein two curves represent a charging curve and a discharging curve, respectively.
FIG. 4 comparative graph of the discharge capacity at 25 ℃ and-10 ℃ for coin cells of example 1 and comparative example 1, respectively.
Fig. 5 is a graph of the cycle performance of the pouch cell of example 2.
Detailed Description
In order to make the objects, technical solutions and effects of the present invention clearer and clearer, the present invention is further described in detail below with reference to examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the invention.
Example 1
The preparation method of the composite positive plate comprises the following steps of circulating water in the whole process.
(1) Baking polyvinylidene fluoride (PVDF) with the molecular weight of 80-100 ten thousand for 10 hours at 80 ℃ under a vacuum condition, respectively baking conductive carbon black (Super P), lithium-based layered ternary oxide and sodium-based layered oxide for 12 hours at 120 ℃ under the vacuum condition, completely cooling, and cooling to room temperature for later use; the molecular formula of the lithium-based layered oxide is LiNi 0.8 Co 0.1 Mn 0.1 O 2 The molecular formula of the sodium-based layered oxide is NaNi 0.2 Fe 0.3 Mn 0.1 Cu 0.1 Al 0.3 O 2 (ii) a The sodium-based layered oxide is prepared by the following method:
(a) 0.2mol of NiSO 4 、0.3mol FeSO 4 、0.1mol MnSO 4 、0.1molCuCl 2 、0.3mol AlCl 3 Dissolving in 2000mL deionized water to obtain solution A;
(b) preparing 1000mL of NaOH with the concentration of 1M and 800mL of ammonia water solution with the concentration of 0.5M as solution B;
(c) mixing the solution A and the solution B in an empty container, filtering to obtain a precursor, and mixing the precursor with Na 2 CO 3 Mixing and calcining at 600 ℃ to obtain the catalyst;
wherein a scanning electron micrograph of the lithium-based layered ternary oxide is shown in FIG. 1, and a scanning electron micrograph of the sodium-based layered oxide is shown in FIG. 2;
(2) slowly adding 125g of PVDF into 2750g N-methyl pyrrolidone, stirring in vacuum at 700rpm for 30min, and standing to obtain 5% binder slurry;
(3) adding 681.5g of CNT into the bonding paste, stirring for 30min at 700rpm in vacuum, adding 25g of Super P, continuing stirring for 10min at 700rpm in vacuum, after uniform dispersion, stopping the machine and scraping edges to obtain conductive paste;
(4) 4000g of lithium-based layered ternary oxide and 2500g of NMP were added to the conductive plasma, and stirred at 1900rpm for 2 hours under vacuum; then 1000g of sodium-based layered oxide is added, and the mixture is stirred for 2 hours at 1900rpm under vacuum; uniformly mixing, increasing the rotating speed to 2000rpm, stirring for 1h to remove bubbles, then adding a proper amount of NMP to adjust the viscosity to 5000mPa & s, continuously stirring at 1900rpm for 1.5h under vacuum, and finally stirring at 600rpm for 15min under vacuum to obtain a main material;
(5) and coating the obtained main material on an aluminum foil with the thickness of 12 mu m, drying at high temperature to remove NMP, and rolling and slitting to obtain the composite positive plate.
Further, dissolving the negative active material hard carbon, Styrene Butadiene Rubber (SBR) and sodium carboxymethyl cellulose (CMC) in deionized water according to the mass ratio of 100:3.375:1.6, uniformly stirring to prepare slurry, coating the slurry on a copper current collector, drying, rolling and cutting to prepare a negative plate; and then cutting the prepared composite positive plate, the diaphragm and the negative plate into original plates in a glove box, and assembling the original plates into the CR2032 type button battery.
Example 2
A preparation method of the composite positive plate comprises the following steps:
（1）baking polyvinylidene fluoride (PVDF) with the molecular weight of 80-100 ten thousand for 10 hours at 80 ℃ under a vacuum condition, respectively baking conductive carbon black (Super P), lithium-based layered ternary oxide and sodium-based layered oxide for 12 hours at 120 ℃ under the vacuum condition, completely cooling, and cooling to room temperature for later use; the molecular formula of the lithium-based layered oxide is LiNi 0.8 Co 0.1 Mn 0.1 O 2 The molecular formula of the sodium-based layered oxide is NaNi 1/3 Fe 1/3 Mn 1/3 O 2 (ii) a The sodium-based layered oxide is prepared by the following method:
(a) 0.2mol of NiSO 4 、0.3mol FeSO 4 、0.1mol MnSO 4 、0.1molCuCl 2 、0.3mol AlCl 3 Dissolving in 2000mL deionized water to obtain solution A;
(b) preparing 1000mL of NaOH with the concentration of 1M and 800mL of ammonia water solution with the concentration of 0.5M as solution B;
(c) mixing the solution A and the solution B in an empty container, filtering to obtain a precursor, and mixing the precursor with Na 2 CO 3 Mixing and calcining at 600 ℃ to obtain the catalyst;
(2) slowly adding 125g of PVDF into 2750g N-methyl pyrrolidone, stirring in vacuum at 700rpm for 30min, and standing to obtain 5% binder slurry;
(3) adding 681.5g of CNT into the bonding paste, stirring for 30min at 700rpm in vacuum, adding 25g of Super P, continuing stirring for 10min at 700rpm in vacuum, after uniform dispersion, stopping the machine and scraping edges to obtain conductive paste;
(4) 4000g of lithium-based layered ternary oxide and 2500g of NMP are added into the conductive plasma, and the mixture is stirred for 2 hours at 1900rpm under vacuum; then 1000g of sodium-based layered oxide is added, and the mixture is stirred for 2 hours at 1900rpm under vacuum; uniformly mixing, increasing the rotating speed to 2000rpm, stirring for 1h to remove bubbles, then adding a proper amount of NMP to adjust the viscosity to 5000mPa & s, continuously stirring for 1.5h at 2000rpm under vacuum, and finally stirring for 15min at 600rpm under vacuum to obtain a main material;
(5) and coating the obtained main material on an aluminum foil with the thickness of 12 mu m, drying at high temperature to remove NMP, and rolling and slitting to obtain the composite positive plate.
Further, dissolving the negative active material hard carbon, Styrene Butadiene Rubber (SBR) and sodium carboxymethyl cellulose (CMC) in deionized water according to the mass ratio of 100:3.375:1.6, uniformly stirring to prepare slurry, coating the slurry on a copper current collector, drying, rolling and cutting to prepare a negative plate; and then, preparing the positive plate, the negative plate and the diaphragm into a pole core by adopting a lamination process, and obtaining the 15Ah aluminum plastic film soft package battery through packaging, liquid injection, formation, air exhaust and sealing.
Comparative example 1
A preparation method of the composite positive plate comprises the following steps:
(1) baking polyvinylidene fluoride (PVDF) with the molecular weight of 80-100 ten thousand for 10 hours at 80 ℃ under a vacuum condition, baking conductive carbon black (Super P) and lithium-based layered ternary oxide for 12 hours at 120 ℃ respectively, completely cooling, and cooling to room temperature for later use; the molecular formula of the lithium-based layered oxide is LiNi 0.8 Co 0.1 Mn 0.1 O 2 ；
(2) Slowly adding 125g of PVDF into 2750g N-methyl pyrrolidone, stirring in vacuum at 700rpm for 30min, and standing to obtain 5% binder slurry;
(3) adding 681.5g of CNT into the adhesive slurry, stirring for 30min at 700rpm in vacuum, adding 25g of Super P, continuing stirring for 10min at 700rpm in vacuum, dispersing uniformly, stopping the machine, and scraping edges to obtain conductive slurry;
(4) 4000g of lithium-based layered ternary oxide and 2500g of NMP were added to the conductive plasma, and stirred at 1900rpm for 2 hours under vacuum; uniformly mixing, increasing the rotating speed to 2000rpm, stirring for 1h to remove bubbles, then adding a proper amount of NMP to adjust the viscosity to 5000mPa & s, continuously stirring for 1.5h at 2000rpm under vacuum, and finally stirring for 15min at 600rpm under vacuum to obtain a main material;
(5) and coating the obtained main material on an aluminum foil with the thickness of 12 mu m, drying at high temperature to remove NMP, and rolling and slitting to obtain the composite positive plate.
Further, dissolving the negative active material hard carbon, Styrene Butadiene Rubber (SBR) and sodium carboxymethyl cellulose (CMC) in deionized water according to the mass ratio of 100:3.375:1.6, uniformly stirring to prepare slurry, coating the slurry on a copper current collector, drying, rolling and cutting to prepare a negative plate; and then cutting the prepared composite positive plate, the diaphragm and the negative plate into original plates in a glove box, and assembling the original plates into the CR2032 type button battery.
Comparative example 2
A preparation method of the composite positive plate comprises the following steps:
(1) baking polyvinylidene fluoride (PVDF) with the molecular weight of 80-100 ten thousand for 10 hours at 80 ℃ under a vacuum condition, baking conductive carbon black (Super P) and lithium-based layered ternary oxide for 12 hours at 120 ℃ respectively, completely cooling, and cooling to room temperature for later use; the molecular formula of the lithium-based layered oxide is LiNi 0.8 Co 0.1 Mn 0.1 O 2 ；
(2) Slowly adding 125g of PVDF into 2750g N-methyl pyrrolidone, stirring in vacuum at 700rpm for 30min, and standing to obtain 5% binder slurry;
(3) adding 681.5g of CNT into the bonding paste, stirring for 30min at 700rpm in vacuum, adding 25g of Super P, continuing stirring for 10min at 700rpm in vacuum, after uniform dispersion, stopping the machine and scraping edges to obtain conductive paste;
(4) 4000g of lithium-based layered ternary oxide and 2500g of NMP were added to the conductive plasma, and stirred at 1900rpm for 2 hours under vacuum; uniformly mixing, increasing the rotating speed to 2000rpm, stirring for 1h to remove bubbles, then adding a proper amount of NMP to adjust the viscosity to 5000mPa & s, continuously stirring for 1.5h at 2000rpm under vacuum, and finally stirring for 15min at 600rpm under vacuum to obtain a main material;
(5) and coating the obtained main material on an aluminum foil with the thickness of 12 mu m, drying at high temperature to remove NMP, and rolling and slitting to obtain the composite positive plate.
Further, dissolving the negative active material hard carbon, Styrene Butadiene Rubber (SBR) and sodium carboxymethyl cellulose (CMC) in deionized water according to the mass ratio of 100:3.375:1.6, uniformly stirring to prepare slurry, coating the slurry on a copper current collector, drying, rolling and cutting to prepare a negative plate; and then, preparing the positive plate, the negative plate and the diaphragm into a pole core by adopting a lamination process, and obtaining the 15Ah aluminum plastic film soft package battery by packaging, injecting, forming, exhausting and sealing.
Verification example 1
The button cell prepared in example 1 and comparative example 1 is taken for charge and discharge test, and the test method and the result evaluation standard are shown in GB/T-31485-. The results are shown in FIGS. 3-4. The result shows that the discharge capacity of the button cell in the comparative example 1 is 170mAh/g and the discharge capacity of the button cell in the example 1 is 158mAh/g under the condition of 25 ℃; under the condition of minus 10 ℃, the discharge capacity of the button cell in the comparative example 1 is 68mAh/g, and the discharge capacity of the button cell in the example 1 is 126.4 mAh/g. Therefore, the discharge capacity retention rate of the conventional lithium-based ternary layered oxide at-10 ℃ is 40%, while the discharge capacity retention rate of the button battery added with the sodium-based layered oxide composite material in example 1 at-10 ℃ is 80%, and the latter is 2 times of that of the former, so that the composite electrode has relatively strong low-temperature decay resistance.
Verification example 2
The soft package batteries prepared in the example 2 and the comparative example 2 are taken for testing, and the test method and the result evaluation standard are shown in GB/T-31485-2015. The results show that the pouch cell prepared in example 2 had a capacity retention of 94% and a mass energy density of 180Wh/Kg (as shown in fig. 5) after 500 cycles, whereas the pouch cell prepared in comparative example 2 had a capacity retention of only 63% and a mass energy density of 119Wh/Kg, which is much lower than that of example 2, after 500 cycles.
Further, according to the test requirements of national standard GB/T-31485-2015, the soft package batteries prepared in example 2 and comparative example 2 are respectively penetrated by tungsten steel needles with the diameter of 3-5mm for carrying out a needling test, and the results show that the soft package battery in comparative example 2 burns on fire, while the soft package battery in example 2 only smokes and does not ignite, which shows that the safety of the soft package battery formed after the sodium-based layered oxide composite material is added is obviously improved.
The above detailed description section specifically describes the analysis method according to the present invention. It should be noted that the above description is only for the purpose of helping those skilled in the art better understand the method and idea of the present invention, and not for the limitation of the related contents. The present invention may be appropriately adjusted or modified by those skilled in the art without departing from the principle of the present invention, and the adjustment and modification also fall within the scope of the present invention.

Claims (10)

1. The composite cathode material is characterized by comprising the following components in percentage by mass: 50-99% of lithium-based ternary layered oxide and 1-50% of sodium-based layered oxide.
2. The composite positive electrode material according to claim 1, wherein the lithium-based ternary layered oxide has a formula selected from the group consisting of LiNi x Co y Mn z O 2 Or LiNi a Co b AlO 2 Wherein x + y + z =100%, a + b = 100%.
3. The composite positive electrode material of claim 1, wherein the sodium-based layered oxide has a molecular formula of NaA x B y C z D w E t O 2 Wherein the elements A, B, C, D, E are respectively selected from one of Ni, Al, Mn, Fe and Cu, and x + y + z + w + t = 100%.
4. The composite positive electrode material according to claim 1, wherein the lithium-based ternary layered oxide and the sodium-based layered oxide are prepared by mixing one or more of a mechanical mixing method, a liquid mixing method, and a chemical coating method.
5. A composite positive electrode sheet comprising the composite positive electrode material according to any one of claims 1 to 4, carbon nanotubes, conductive carbon black, polyvinylidene fluoride, and N-methylpyrrolidone.
6. The composite positive plate according to claim 5, wherein the composite positive plate comprises the following components in parts by weight: the composite positive electrode material according to any one of claims 1 to 4, comprising 100 parts of the composite positive electrode material, 13.63 parts of the carbon nanotubes, 0.5 part of the conductive carbon black, 2.5 parts of the polyvinylidene fluoride, and 55 parts of the N-methylpyrrolidone.
7. The composite positive electrode sheet according to claim 5, characterized in that it is prepared by the following method:
(1) adding N-methyl pyrrolidone and polyvinylidene fluoride into a stirrer, and stirring and dispersing to prepare binder slurry;
(2) adding carbon nano tubes into the binder slurry, stirring and dispersing, then adding conductive carbon black, stopping the machine after stirring and dispersing, and scraping edges to prepare conductive slurry;
(3) adding a lithium-based ternary layered oxide into the conductive plasma, uniformly stirring under a vacuum condition, then adding a sodium-based layered oxide, stirring under the vacuum condition, uniformly mixing, then stirring at a high speed under the vacuum condition, and then stirring at a low speed to obtain a main material;
(4) and (4) sieving the main material obtained in the step (3) by a 200-mesh sieve, coating the main material on a current collector, and drying to obtain the composite positive plate.
8. An electrochemical device comprising a core and an electrolyte, the core comprising the composite positive electrode sheet according to any one of claims 5 to 7, a separator, and a negative electrode sheet.
9. The preparation method according to claim 8, wherein the electrochemical device is selected from one or more of a soft package of an aluminum plastic film, a square aluminum case or a cylindrical steel case.
10. The preparation method according to claim 8, wherein the negative electrode sheet comprises hard carbon, styrene-butadiene rubber, sodium carboxymethylcellulose, and a current collector.
CN202210367577.0A 2022-04-08 2022-04-08 Sodium-based composite positive electrode material, electrode and electrochemical device Pending CN114937759A (en)

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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113193166A (en) * 2021-04-28 2021-07-30 珠海冠宇电池股份有限公司 Positive plate, battery core and battery
CN114142003A (en) * 2021-11-05 2022-03-04 成都佰思格科技有限公司 Composite positive electrode slurry, lithium ion secondary battery and preparation method thereof

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113193166A (en) * 2021-04-28 2021-07-30 珠海冠宇电池股份有限公司 Positive plate, battery core and battery
CN114142003A (en) * 2021-11-05 2022-03-04 成都佰思格科技有限公司 Composite positive electrode slurry, lithium ion secondary battery and preparation method thereof

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
MUHAMMAD MOMINUR RAHMAN ET AL.: "An Ordered P2/P3 Composite Layered Oxide Cathode with Long Cycle Life in Sodium-Ion Batteries", ACS MATERIALS LETT., 16 October 2019 (2019-10-16), pages 573 - 581 *

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