CN115172747A - Positive electrode slurry, positive electrode plate and lithium ion battery - Google Patents

Positive electrode slurry, positive electrode plate and lithium ion battery Download PDF

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CN115172747A
CN115172747A CN202210526812.4A CN202210526812A CN115172747A CN 115172747 A CN115172747 A CN 115172747A CN 202210526812 A CN202210526812 A CN 202210526812A CN 115172747 A CN115172747 A CN 115172747A
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positive electrode
slurry
based additive
electrode slurry
lithium ion
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陈民
王文杰
吴华斌
田冰冰
李真堂
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Guangdong Carriage Power Technology Co ltd
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    • 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
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/628—Inhibitors, e.g. gassing inhibitors, corrosion inhibitors
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • 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
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/131—Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
    • 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
    • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
    • H01M2004/028—Positive electrodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2220/00—Batteries for particular applications
    • H01M2220/20—Batteries in motive systems, e.g. vehicle, ship, plane
    • 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

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Abstract

The invention discloses anode slurry, an anode plate and a lithium ion battery, wherein the anode slurry comprises an anode active substance, a conductive agent and a binder, and is characterized by further comprising a phosphate silicon-based additive, wherein the chemical structural general formula of the phosphate silicon-based additive is as follows:

Description

Positive electrode slurry, positive electrode plate and lithium ion battery
Technical Field
The invention relates to the technical field of anode materials, in particular to anode slurry, an anode plate and a lithium ion battery.
Background
The lithium ion battery is energy-saving and environment-friendly and is widely applied to the field of electric automobiles. However, with the popularization of electric vehicles, the problem of exposure of lithium ion batteries is increasing. Wherein, in order to meet the requirements of power performance and energy density of the electric vehicle, the current battery voltage is generally 4.3-4.4V. Under high voltage, the side reaction of the electrode, particularly the positive electrode, and the electrolyte is increased, which directly causes the structural degradation of the positive electrode, and further influences the electrical property and the safety performance of the battery.
Accordingly, the prior art is yet to be improved and developed.
Disclosure of Invention
In view of the defects of the prior art, the invention aims to provide a positive electrode slurry, a positive electrode plate and a lithium ion battery, and aims to solve the problem that the cycle performance of the lithium ion battery is affected due to the degradation of the positive electrode structure caused by the easy side reaction of the positive electrode and an electrolyte in the use process of the conventional lithium ion battery.
The technical scheme of the invention is as follows:
the positive electrode slurry comprises a positive electrode active material, a conductive agent and a binder, and further comprises a phosphate silicon-based additive, wherein the chemical structural general formula of the phosphate silicon-based additive is as follows:
Figure BDA0003644849540000021
wherein, R1-R8 are respectively and independently one of H, halogen atom, phenyl, carboxyl, C1-C4 alkyl, C1-C4 haloalkyl, C1-C4 alkoxy and C1-C4 haloalkoxy.
The positive electrode slurry is characterized in that R1-R5 are respectively and independently selected from H or halogen atoms; R6-R7 are each independently selected from phenyl or carboxyl; r8 is selected from C1-C4 alkyl or C1-C4 haloalkyl.
The positive electrode slurry is characterized in that the phosphate silicon-based additive isOne of the following chemical structural formulas:
Figure BDA0003644849540000022
Figure BDA0003644849540000023
the positive electrode slurry is characterized in that the phosphate silicon-based additive accounts for 0.2-2% of the weight of the positive electrode active material.
The positive electrode slurry is characterized in that the conductive agent is one or more selected from conductive carbon black, conductive graphite, carbon nanotubes, carbon fibers and graphene.
The positive electrode slurry is characterized in that the binder is one or more selected from polyvinylidene fluoride, polytetrafluoroethylene, polyvinyl alcohol, carboxymethyl cellulose and polyolefin.
The positive pole piece comprises a current collector and an active layer arranged on the current collector, wherein the active layer is formed by coating the positive pole slurry on the surface of the current collector and curing.
A lithium ion battery comprises the positive pole piece.
Has the beneficial effects that: the invention provides positive electrode slurry, which comprises a positive electrode active substance, a conductive agent, a binder and a phosphate silicon-based additive, wherein the chemical structural general formula of the phosphate silicon-based additive is as follows:
Figure BDA0003644849540000031
in the invention, after the anode slurry forms the anode electrode, because the phosphate silicon-based additive has higher highest occupied molecular energy level (HOMO), electrons are easy to lose, and oxidation reaction is preferentially generated, and a film forming reaction can be preferentially generated when the battery is charged and discharged for the first time, so that the side reaction of the anode active substance and the electrolyte is prevented, and the cycle performance of the lithium ion battery is improved.
Detailed Description
The invention provides a positive electrode slurry, a positive electrode plate and a lithium ion battery, and the invention is further described in detail below in order to make the purpose, technical scheme and effect of the invention clearer and more clear. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
In order to solve the problem that the positive pole piece is easy to generate side reaction with the electrolyte in the lithium ion battery, so that the structure of the positive pole piece is degraded, and the electrical property and the safety performance of the battery are affected, film forming additives such as phosphate or fluoro organic matters and the like can be added into the electrolyte. However, this method of adding these additives to the electrolyte has the following disadvantages: first, the additive is in the electrolyte solution, and thus cannot preferentially form a film to protect the positive electrode, but is accompanied by other side reactions during film formation, which causes unstable film formation and easy decomposition at the later stage. Second, too much electrolyte additive can cause too much battery impedance, thereby affecting battery performance.
Based on the above, the invention provides a positive electrode slurry, which comprises a positive electrode active material, a conductive agent, a binder and a phosphate silicon-based additive, wherein the chemical structural general formula of the phosphate silicon-based additive is as follows:
Figure BDA0003644849540000041
wherein, R1-R8 are independently selected from one of H, halogen atom, phenyl, carboxyl, C1-C4 alkyl, C1-C4 halogenated alkyl, C1-C4 alkoxy and C1-C4 halogenated alkoxy.
In the invention, after the anode slurry forms the anode electrode, because the phosphate silicon-based additive has higher highest occupied molecular energy level (HOMO), electrons are easy to lose, and oxidation reaction is preferentially generated, and film forming reaction can be preferentially generated when the battery is charged and discharged for the first time, so that side reaction between the anode active substance and electrolyte is prevented, and the cycle performance of the lithium ion battery is improved.
In some embodiments, the chemical structure of the phosphate silicon-based additive is that R1-R5 are each independently selected from H or a halogen atom; R6-R7 are each independently selected from phenyl or carboxyl; r8 is selected from C1-C4 alkyl or C1-C4 haloalkyl. The R1-R8 functional groups can enable the formed electrolyte membrane to have good conductivity, so that the direct current internal resistance of the battery is reduced, and the electrochemical performance of the battery is improved.
In some embodiments, the phosphate silicone-based additive is one of the following chemical structures:
Figure BDA0003644849540000051
Figure BDA0003644849540000052
but is not limited thereto.
In some embodiments, the phosphate silicon-based additive accounts for 0.2% to 2% by weight of the positive electrode active material, and may be, for example, 0.2%, 0.5%, 1%, 1.5%, 2%, or the like.
In some embodiments, the conductive agent is selected from one or more of conductive carbon black, conductive graphite, carbon nanotubes, carbon fibers, and graphene, but is not limited thereto.
In some embodiments, the binder is selected from one or more of polyvinylidene fluoride, polytetrafluoroethylene, polyvinyl alcohol, carboxymethyl cellulose, and polyolefins, but is not limited thereto.
In some embodiments, a positive electrode sheet is further provided, which includes a current collector and an active layer disposed on the current collector, wherein the active layer is formed by coating the positive electrode slurry of the present invention on the surface of the current collector and curing the positive electrode slurry.
In some embodiments, a lithium ion battery is also provided, which comprises the positive electrode plate of the invention.
The invention is further illustrated by the following specific examples:
example 1
Step 1, adding LiNi serving as a positive electrode active material 6 Co 1 Mn 3 O 2 The weight ratio of the conductive agent super P, the Carbon Nanotubes (CNTs) and the adhesive PVDF is 97.5%:0.8%:0.4%:1.3 percent of the slurry is added into NMP solvent together for slurry mixing, and then phosphate silicon-based additives are added into the mixture during high-speed stirring to prepare the anode slurry. Wherein the amount of the phosphate ester additive is 0.5 wt% of the positive active materialPercent, the chemical formula of the phosphate silicon-based additive is shown as formula 1, and is as follows:
Figure BDA0003644849540000061
step 2, uniformly coating the slurry prepared in the step 1 on a 10-micron aluminum foil current collector, drying, rolling, and performing die cutting to obtain a positive pole piece;
and 3, matching the positive pole piece prepared in the step 2 with a proper negative pole piece, a diaphragm and electrolyte to assemble the battery. The negative pole piece is manufactured by uniformly coating negative pole slurry on a 6um copper foil, and is formed by baking, rolling and die cutting. The negative electrode slurry is prepared from artificial graphite, a conductive agent super P, a thickening agent carboxymethylcellulose sodium (CMC) and a binder Styrene Butadiene Rubber (SBR) in a mass ratio of 96.2%:0.8%:1.2%:1.8 percent of the total weight is stirred at high speed to prepare the product. The diaphragm is a PP/PE diaphragm, and the electrolyte is lithium salt LiPF 6 Is 1mol/L of organic solvent.
And 4, carrying out a normal-temperature and 45-DEG C high-temperature cycle test on the battery prepared in the step 3, wherein the cycle charge-discharge current is 1C.
Example 2
Step 1, adding LiNi serving as a positive electrode active material 6 Co 1 Mn 3 O 2 The weight ratio of the conductive agent super P, the Carbon Nanotubes (CNTs) and the binder PVDF is 97.5%:0.8%:0.4%:1.3 percent of the slurry is added into NMP solvent together for slurry mixing, and then phosphate silicon-based additives are added into the mixture during high-speed stirring to prepare the anode slurry. Wherein, the amount of the phosphate ester additive is 0.8wt% of the positive active material, and the chemical formula of the phosphate ester silicon-based additive is shown as formula 1, and is as follows:
Figure BDA0003644849540000071
step 2, uniformly coating the slurry prepared in the step 1 on a 10-micron aluminum foil current collector, drying, rolling and performing die cutting to obtain a positive pole piece;
and 3, matching the positive pole piece prepared in the step 2 with a proper negative pole piece, a diaphragm and electrolyte to assemble the battery. WhereinThe negative pole piece is manufactured by uniformly coating negative pole slurry on a 6um copper foil, and is formed by baking, rolling and die cutting. The negative electrode slurry is prepared from artificial graphite, a conductive agent super P, a thickening agent carboxymethylcellulose sodium (CMC) and a binder Styrene Butadiene Rubber (SBR) in a mass ratio of 96.2%:0.8%:1.2%:1.8 percent of the total saponin is obtained by high-speed stirring. The diaphragm is a PP/PE diaphragm, and the electrolyte is lithium salt LiPF 6 Is 1mol/L of organic solvent.
And 4, carrying out a normal-temperature and 45-DEG C high-temperature cycle test on the battery prepared in the step 3, wherein the cycle charge-discharge current is 1C.
Example 3
Step 1, adding LiNi serving as a positive electrode active material 6 Co 1 Mn 3 O 2 The weight ratio of the conductive agent super P, the Carbon Nanotubes (CNTs) and the binder PVDF is 97.5%:0.8%:0.4%:1.3 percent of the slurry is added into NMP solvent together for slurry mixing, and then phosphate silicon-based additives are added into the mixture during high-speed stirring to prepare the anode slurry. Wherein, the amount of the phosphate ester additive is 1.0wt% of the positive active material, and the chemical formula of the phosphate ester silicon-based additive is shown as formula 1, and is as follows:
Figure BDA0003644849540000072
step 2, uniformly coating the slurry prepared in the step 1 on a 10-micron aluminum foil current collector, drying, rolling and performing die cutting to obtain a positive pole piece;
and 3, matching the positive pole piece prepared in the step 2 with a proper negative pole piece, a diaphragm and electrolyte to assemble the battery. Wherein, the negative pole piece is made on 6um copper foil by the even coating of negative pole thick liquids, through toasting, the roll-in, the cross cutting forms. The negative electrode slurry is prepared from artificial graphite, a conductive agent super P, a thickening agent carboxymethylcellulose sodium (CMC) and a binder Styrene Butadiene Rubber (SBR) in a mass ratio of 96.2%:0.8%:1.2%:1.8 percent of the total saponin is obtained by high-speed stirring. The diaphragm is a PP/PE diaphragm, and the electrolyte is lithium salt LiPF 6 Is 1mol/L of organic solvent.
And 4, carrying out a normal-temperature and 45-DEG C high-temperature cycle test on the battery prepared in the step 3, wherein the cycle charge-discharge current is 1C.
Example 4
Step 1, adding LiNi serving as a positive electrode active material 6 Co 1 Mn 3 O 2 The weight ratio of the conductive agent super P, the Carbon Nanotubes (CNTs) and the adhesive PVDF is 97.5%:0.8%:0.4%:1.3 percent of the slurry is added into NMP solvent together for slurry mixing, and then phosphate silicon-based additives are added into the mixture during high-speed stirring to prepare the anode slurry. Wherein, the amount of the phosphate ester additive is 1.0wt% of the positive active material, and the chemical formula of the phosphate ester silicon-based additive is shown as formula 2, and is as follows:
Figure BDA0003644849540000081
step 2, uniformly coating the slurry prepared in the step 1 on a 10-micron aluminum foil current collector, drying, rolling and performing die cutting to obtain a positive pole piece;
and 3, matching the positive pole piece prepared in the step 2 with a proper negative pole piece, a diaphragm and electrolyte to assemble the battery. The negative pole piece is manufactured by uniformly coating negative pole slurry on a 6um copper foil, and is formed by baking, rolling and die cutting. The negative electrode slurry is prepared from artificial graphite, a conductive agent super P, a thickening agent carboxymethylcellulose sodium (CMC) and a binder Styrene Butadiene Rubber (SBR) in a mass ratio of 96.2%:0.8%:1.2%:1.8 percent of the total saponin is obtained by high-speed stirring. The diaphragm is a PP/PE diaphragm, and the electrolyte is lithium salt LiPF 6 Is 1mol/L of organic solvent.
And 4, carrying out a normal-temperature and 45-DEG C high-temperature cycle test on the battery prepared in the step 3, wherein the cycle charge-discharge current is 1C.
Example 5
Step 1, adding LiNi serving as a positive electrode active material 6 Co 1 Mn 3 O 2 The weight ratio of the conductive agent super P, the Carbon Nanotubes (CNTs) and the adhesive PVDF is 97.5%:0.8%:0.4%:1.3 percent of the solution is added into NMP solvent for slurry mixing, and then phosphate silicon-based additives are added into the solution during high-speed stirring to prepare the anode slurry. Wherein the amount of the phosphate ester additive is 1.0wt% of the positive active material, and the chemical formula of the phosphate ester silicon-based additive is shown in the specificationFormula 3, is:
Figure BDA0003644849540000091
step 2, uniformly coating the slurry prepared in the step 1 on a 10-micron aluminum foil current collector, drying, rolling and performing die cutting to obtain a positive pole piece;
and 3, assembling the positive pole piece prepared in the step 2 with a proper negative pole piece, a diaphragm and electrolyte to form the battery. The negative pole piece is manufactured by uniformly coating negative pole slurry on a 6um copper foil, and is formed by baking, rolling and die cutting. The negative electrode slurry is prepared from artificial graphite, a conductive agent super P, a thickening agent carboxymethylcellulose sodium (CMC) and a binder Styrene Butadiene Rubber (SBR) in a mass ratio of 96.2%:0.8%:1.2%:1.8 percent of the total saponin is obtained by high-speed stirring. The diaphragm is a PP/PE diaphragm, and the electrolyte is lithium salt LiPF 6 Is 1mol/L of organic solvent.
And 4, carrying out a normal-temperature and 45-DEG C high-temperature cycle test on the battery prepared in the step 3, wherein the cycle charge-discharge current is 1C.
Example 6
Step 1, adding LiNi serving as a positive electrode active material 6 Co 1 Mn 3 O 2 The weight ratio of the conductive agent super P, the Carbon Nanotubes (CNTs) and the binder PVDF is 97.5%:0.8%:0.4%:1.3 percent of the slurry is added into NMP solvent together for slurry mixing, and then phosphate silicon-based additives are added into the mixture during high-speed stirring to prepare the anode slurry. Wherein, the amount of the phosphate ester additive is 0.3wt% of the positive active material, and the chemical formula of the phosphate ester silicon-based additive is shown as formula 1, and is as follows:
Figure BDA0003644849540000101
step 2, uniformly coating the slurry prepared in the step 1 on a 10-micron aluminum foil current collector, drying, rolling and performing die cutting to obtain a positive pole piece;
and 3, matching the positive pole piece prepared in the step 2 with a proper negative pole piece, a diaphragm and electrolyte to assemble the battery. The negative pole piece is uniformly coated with 6u of negative pole slurryAnd m, manufacturing on the copper foil, baking, rolling and die cutting. The negative electrode slurry is prepared from artificial graphite, a conductive agent super P, a thickening agent carboxymethylcellulose sodium (CMC) and a binder Styrene Butadiene Rubber (SBR) in a mass ratio of 96.2%:0.8%:1.2%:1.8 percent of the total saponin is obtained by high-speed stirring. The diaphragm is a PP/PE diaphragm, and the electrolyte is lithium salt LiPF 6 Is 1mol/L of organic solvent.
And 4, carrying out a normal-temperature and 45-DEG C high-temperature cycle test on the battery prepared in the step 3, wherein the cycle charge-discharge current is 1C.
Example 7
Step 1, adding LiNi serving as a positive electrode active material 6 Co 1 Mn 3 O 2 The weight ratio of the conductive agent super P, the Carbon Nanotubes (CNTs) and the binder PVDF is 97.5%:0.8%:0.4%:1.3 percent of the slurry is added into NMP solvent together for slurry mixing, and then phosphate silicon-based additives are added into the mixture during high-speed stirring to prepare the anode slurry. Wherein, the amount of the phosphate ester additive is 2.0wt% of the positive active material, and the chemical formula of the phosphate ester silicon-based additive is shown as formula 1, and is as follows:
Figure BDA0003644849540000111
step 2, uniformly coating the slurry prepared in the step 1 on a 10-micron aluminum foil current collector, drying, rolling, and performing die cutting to obtain a positive pole piece;
and 3, matching the positive pole piece prepared in the step 2 with a proper negative pole piece, a diaphragm and electrolyte to assemble the battery. The negative pole piece is manufactured by uniformly coating negative pole slurry on a 6um copper foil, and is formed by baking, rolling and die cutting. The negative electrode slurry is prepared from artificial graphite, a conductive agent super P, a thickening agent carboxymethylcellulose sodium (CMC) and a binder Styrene Butadiene Rubber (SBR) in a mass ratio of 96.2%:0.8%:1.2%:1.8 percent of the total saponin is obtained by high-speed stirring. The diaphragm is a PP/PE diaphragm, and the electrolyte is lithium salt LiPF 6 Is 1mol/L of organic solvent.
And 4, carrying out a normal-temperature and 45-DEG C high-temperature cycle test on the battery prepared in the step 3, wherein the cycle charge-discharge current is 1C.
Comparative example 1
In this comparative example, no additive was added to the positive electrode slurry, and the preparation steps were as follows:
step 1: the positive electrode active material LiNi6Co1Mn3O2, the conductive agent super P, the Carbon Nanotubes (CNTs) and the binder PVDF are mixed according to the weight ratio of 97.5%:0.8%:0.4%:1.3 percent of the positive electrode slurry is added into NMP solvent together for slurry combination.
Step 2: and (3) uniformly coating the slurry prepared in the step (1) on a 10-micron aluminum foil current collector, drying, rolling and performing die cutting to obtain the positive pole piece.
And 3, step 3: and (3) assembling the positive pole piece prepared in the step (2) with a proper negative pole piece, a diaphragm and electrolyte to form the battery. Wherein, the negative pole piece is made on 6um copper foil by the even coating of negative pole thick liquids, through toasting, the roll-in, the cross cutting forms. The negative electrode slurry is prepared from artificial graphite, a conductive agent super P, a thickening agent carboxymethylcellulose sodium (CMC) and a binder Styrene Butadiene Rubber (SBR) in a mass ratio of 96.2%:0.8%:1.2%:1.8 percent of the total saponin is obtained by high-speed stirring. The separator and electrolyte used were identical to those of example 1.
The above examples 1 to 7 and comparative example 1 were subjected to normal temperature and high temperature cycle tests as follows:
and (3) normal-temperature circulation: discharging at 1.0 deg.C under constant current to 3.0V, standing for 10min; and charging the battery to 4.35V at a constant current and a constant voltage of 1.0C for performing 800-circle cycle performance test.
High-temperature circulation: discharging at 1.0 deg.C under constant current to 3.0V, standing for 10min; and charging the battery to 4.35V at a constant current and a constant voltage of 1.0C for performing 800-circle cycle performance test.
The cycle data are shown in table 1, and the capacity retention rate after the cycle = discharge capacity after the cycle/first discharge capacity 100% was calculated according to the following formula.
TABLE 1 Cyclic test data
Numbering Additive structure Additive content Capacity retention rate
Example 1 Formula 1 0.5wt％ 82.0％
Example 2 Formula 1 0.8wt％ 82.5％
Example 3 Formula 1 1.0wt％ 83.7％
Example 4 Formula 2 1.0wt％ 83.5％
Example 5 Formula 3 1.0wt％ 83.6％
Example 6 Formula 1 0.3wt％ 81.5％
Examples7 Formula 1 2.0wt％ 89.2％
Comparative example 1 / Is free of 79.7％
As can be seen from the results in table 1, after the positive electrode slurry provided in examples 1 to 7 of the present invention is used to form a positive electrode, and the positive electrode is assembled into a lithium ion battery, since the silicon phosphate-based additive in the positive electrode can preferentially perform a film forming reaction during the first charge and discharge of the battery, the side reaction between the positive active material and the electrolyte can be prevented, thereby improving the cycle performance of the lithium ion battery.
It is to be understood that the invention is not limited to the examples described above, but that modifications and variations may be effected thereto by those of ordinary skill in the art in light of the foregoing description, and that all such modifications and variations are intended to be within the scope of the invention as defined by the appended claims.

Claims (8)

1. The positive electrode slurry comprises a positive electrode active material, a conductive agent and a binder, and is characterized by further comprising a phosphate silicon-based additive, wherein the chemical structural general formula of the phosphate silicon-based additive is as follows:
Figure FDA0003644849530000011
wherein, R1-R8 are independently selected from one of H, halogen atom, phenyl, carboxyl, C1-C4 alkyl, C1-C4 halogenated alkyl, C1-C4 alkoxy and C1-C4 halogenated alkoxy.
2. The positive electrode slurry according to claim 1, wherein R1 to R5 are each independently selected from H or a halogen atom; R6-R7 are each independently selected from phenyl or carboxyl; r8 is selected from C1-C4 alkyl or C1-C4 haloalkyl.
3. The positive electrode slurry according to claim 1, wherein the phosphate silicon-based additive is one of the following chemical structural formulas:
Figure FDA0003644849530000012
Figure FDA0003644849530000013
4. the positive electrode slurry according to any one of claims 1 to 3, wherein the phosphate silicon-based additive accounts for 0.2 to 2% by weight of the positive electrode active material.
5. The positive electrode slurry according to any one of claims 1 to 3, wherein the conductive agent is one or more selected from the group consisting of conductive carbon black, conductive graphite, carbon nanotubes, carbon fibers and graphene.
6. The positive electrode slurry according to any one of claims 1 to 3, wherein the binder is one or more selected from the group consisting of polyvinylidene fluoride, polytetrafluoroethylene, polyvinyl alcohol, carboxymethyl cellulose and polyolefin.
7. A positive pole piece, which is characterized by comprising a current collector and an active layer arranged on the current collector, wherein the active layer is formed by coating the positive pole slurry of any one of claims 1 to 6 on the surface of the current collector and curing.
8. A lithium ion battery comprising the positive electrode sheet according to claim 7.
CN202210526812.4A 2022-05-16 2022-05-16 Positive electrode slurry, positive electrode plate and lithium ion battery Pending CN115172747A (en)

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CN117059804A (en) * 2023-10-13 2023-11-14 瑞浦兰钧能源股份有限公司 Chemical pre-lithium agent, lithium ion battery and preparation method of lithium ion battery
CN117457910A (en) * 2023-12-22 2024-01-26 天鹏锂能技术(淮安)有限公司 Positive pole piece and sodium ion battery

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117059804A (en) * 2023-10-13 2023-11-14 瑞浦兰钧能源股份有限公司 Chemical pre-lithium agent, lithium ion battery and preparation method of lithium ion battery
CN117059804B (en) * 2023-10-13 2024-03-19 瑞浦兰钧能源股份有限公司 Chemical pre-lithium agent, lithium ion battery and preparation method of lithium ion battery
CN117457910A (en) * 2023-12-22 2024-01-26 天鹏锂能技术(淮安)有限公司 Positive pole piece and sodium ion battery
CN117457910B (en) * 2023-12-22 2024-04-02 天鹏锂能技术(淮安)有限公司 Positive pole piece and sodium ion battery

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