CN108134066B - Lithium ion battery positive electrode slurry and preparation method thereof, lithium ion battery and preparation method thereof - Google Patents
Lithium ion battery positive electrode slurry and preparation method thereof, lithium ion battery and preparation method thereof Download PDFInfo
- Publication number
- CN108134066B CN108134066B CN201711402851.9A CN201711402851A CN108134066B CN 108134066 B CN108134066 B CN 108134066B CN 201711402851 A CN201711402851 A CN 201711402851A CN 108134066 B CN108134066 B CN 108134066B
- Authority
- CN
- China
- Prior art keywords
- mixture
- lithium ion
- ion battery
- lithium
- percent
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- 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
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/362—Composites
-
- 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
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/058—Construction or manufacture
-
- 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
- H01M4/04—Processes of manufacture in general
-
- 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
- H01M4/139—Processes of manufacture
- H01M4/1391—Processes of manufacture of 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
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/362—Composites
- H01M4/364—Composites as mixtures
-
- 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
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
- 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
-
- 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
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
- H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
- 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
-
- 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
- H01M4/621—Binders
- H01M4/622—Binders being polymers
- H01M4/623—Binders being polymers fluorinated polymers
-
- 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
- H01M4/624—Electric conductive fillers
- H01M4/625—Carbon or graphite
-
- 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
-
- 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
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Composite Materials (AREA)
- Materials Engineering (AREA)
- Inorganic Chemistry (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
The invention discloses a lithium ion battery anode slurry, and relates to the technical field of batteries. The positive electrode slurry comprises the following components in percentage by weight: 90-95% of active substance, 1-4% of binder, 1-9% of conductive agent and 30-50% of solvent, wherein the active substance is a mixture of lithium cobaltate and lithium manganate and/or nickel cobalt lithium manganate, and the mixture contains 10-90% of lithium cobaltate and the balance of lithium manganate and/or nickel cobalt lithium manganate in percentage by weight; the binder is polyvinylidene fluoride, the conductive agent comprises one or more of carbon black, carbon nanotubes, graphene and Super P Li, and the solvent is N-methylpyrrolidone. According to the invention, the mixture of lithium cobaltate and/or nickel cobalt lithium manganate is used as an active substance for preparing the lithium ion battery anode slurry, and the prepared lithium ion battery has excellent high-rate discharge performance, better heavy-current ignition performance, long cycle life, good storage performance and low manufacturing cost.
Description
Technical Field
The invention relates to the technical field of batteries, in particular to a lithium ion battery anode slurry and a preparation method thereof, and a lithium ion battery comprising the lithium ion battery anode slurry and a preparation method of the lithium ion battery.
Background
With the development of new energy industry, lithium ion batteries are increasingly appearing in people's lives as green and environment-friendly new energy batteries in the field of power batteries. At present, lithium ion batteries of lithium cobaltate systems are commonly used in emergency starting power supplies in the market, and have the advantages of excellent high-rate discharge performance, high energy density and the like. However, the market selling price of the battery is low all the time, the material price is high all the time, and the selling pressure of the battery product is large, so that the product is difficult to sell. Therefore, it is desirable to provide a lithium ion battery cathode slurry with excellent high-rate discharge performance and low manufacturing cost and a preparation method thereof, and also to provide a lithium ion battery with the lithium ion battery cathode slurry and a preparation method of the lithium ion battery.
Disclosure of Invention
Technical problem to be solved
In order to solve the above problems in the prior art, the invention provides a lithium ion battery anode slurry with excellent high-rate discharge performance and low manufacturing cost and a preparation method thereof, and also provides a lithium ion battery with the lithium ion battery anode slurry and a preparation method of the lithium ion battery.
(II) technical scheme
In order to achieve the purpose, the invention adopts the main technical scheme that:
the invention provides a lithium ion battery anode slurry which comprises the following components in percentage by weight: 90-95% of active substance, 1-4% of binder, 1-9% of conductive agent and 30-50% of solvent, wherein the active substance is a mixture of lithium cobaltate and lithium manganate and/or nickel cobalt lithium manganate, and the mixture contains 10-90% of lithium cobaltate and the balance of lithium manganate and/or nickel cobalt lithium manganate in percentage by weight; the binder is polyvinylidene fluoride, the conductive agent comprises one or more of carbon black, carbon nanotubes, graphene and Super P Li, and the solvent is N-methylpyrrolidone.
According to the invention, when the active material is a mixture of lithium cobaltate and lithium manganate, the weight ratio of lithium cobaltate to lithium manganate is 3: 7.
According to the invention, when the active material is a mixture of lithium cobaltate and lithium nickel cobalt manganese oxide, the weight ratio of lithium cobaltate to lithium nickel cobalt manganese oxide is 1: 1.
According to the invention, when the active material comprises lithium nickel cobalt manganese oxide, the molar ratio of nickel, cobalt and manganese in the lithium nickel cobalt manganese oxide is 1:1:1 or 5:2:3 or 5:3: 2.
According to the invention, the particle size of D50 of lithium manganate is 8-15 μm, and the particle size of D50 of nickel cobalt lithium manganate is 3-9 μm.
Meanwhile, the invention provides a preparation method of the lithium ion battery anode slurry, which comprises the following steps:
and 4, adding the remaining N-methyl pyrrolidone accounting for 30 percent of the total weight of the solvent, adjusting the viscosity of the slurry to be 6000 +/-2000 mpa.S, and adjusting the solid content to be 62% +/-5%, thereby obtaining the anode slurry.
According to the invention, in the step 1, the rotation is 45Hz, the revolution is 40Hz, the vacuum degree is less than or equal to-0.08 MPa, and the stirring time is 2-2.5 h; in the step 2, the rotation is 45Hz, the revolution is 40Hz, the vacuum degree is less than or equal to minus 0.08MPa, and the stirring time is 2h to 3 h; in the step 3, after the first feeding, the materials are automatically rotated for 45Hz, revolved for 40Hz, the vacuum degree is less than or equal to minus 0.08MPa, and the stirring time is 0.5h to 1 h; after the second feeding, the mixture is autorotated for 45Hz and revolved for 40Hz, the vacuum degree is less than or equal to minus 0.08MPa, and the stirring time is 3 to 4 hours.
The invention also provides a lithium ion battery, which comprises the lithium ion battery anode slurry.
Further, the invention provides a preparation method of a lithium ion battery, which comprises the following steps of:
coating the battery slurry and compacting a pole piece; die cutting pole pieces, laminating or winding the pole pieces to form a battery cell, and completing top side sealing and vacuum baking after spot welding of a tab of the battery cell; and injecting electrolyte into the baked and cooled battery core, standing the injected electrolyte, and then performing formation, air exhaust, sealing and capacity grading to obtain a finished product battery core.
According to the invention, the surface density of the pole piece is 100-200g/cm2The compacted density of the pole piece is 3.0-3.5g/cm3(ii) a When the electrolyte is injected, 4.0-7.0g of electrolyte is injected according to the volume per ampere hour.
(III) advantageous effects
The invention has the beneficial effects that:
compared with the prior art that pure lithium cobaltate is used as an active substance for preparing the lithium ion battery anode slurry, the invention adopts the mixture of the lithium cobaltate and/or the nickel cobalt lithium manganate as the active substance for preparing the lithium ion battery anode slurry, the prepared lithium ion battery has excellent high-rate discharge performance, the high-current ignition performance of an igniter (in the field of emergency starting power sources) is better, the cycle life and the storage performance are good, meanwhile, the cost of the anode material of the invention is reduced to about 40 percent of that of the pure lithium cobaltate, and the manufacturing cost is low.
Drawings
FIG. 1 is a comparative graph of the discharge curve at 40C of a lithium ion battery provided in example 1 of the present invention;
fig. 2 is a discharge curve diagram of a simulated automobile ignition in which a lithium ion battery provided in embodiment 1 of the present invention is discharged for 2S at 150C, left for 30S, and continuously discharged for 3 times, wherein a light color curve is a current time curve, and a dark color curve is a voltage time curve;
FIG. 3 is a graph of cycle life test results of a lithium ion battery provided in example 1 of the present invention discharging to 3.0V at 4.2V for 2C charging, 0.05C for charge cutoff/30 min/6C for rest;
fig. 4 is a graph comparing the discharge curves at 35C of the lithium ion battery and the pure LCO system battery provided in example 2 of the present invention;
FIG. 5 is a discharge curve graph of simulated automobile ignition of the lithium ion battery provided in example 2, which was discharged at 120C for 2S, left alone for 30S, and continuously discharged for 3 times;
fig. 6 is a graph comparing the discharge curves at 35C of the lithium ion battery provided in example 3 of the present invention and a pure LCO system battery;
fig. 7 is a discharge curve diagram of a simulated automobile ignition of a lithium ion battery provided in embodiment 3 of the present invention, which is discharged for 2S at 120C, left for 30S, and continuously discharged for 3 times, wherein the light color curve is a current time curve, and the dark color curve is a voltage time curve.
Detailed Description
For the purpose of better explaining the present invention and to facilitate understanding, the present invention will be described in detail by way of specific embodiments with reference to the accompanying drawings.
The positive electrode slurry of the lithium ion battery comprises the following components in percentage by weight: 90-95% of active substance, 1-4% of binder, 1-9% of conductive agent and 30-50% of solvent, wherein the active substance is a mixture of Lithium Cobaltate (LCO) and Lithium Manganate (LMO) and/or lithium Nickel Cobalt Manganese (NCM), and the mixture contains 10-90% of LCO and the balance of LMO and/or NCM by weight percentage. The binder is polyvinylidene fluoride (PVDF), and the conductive agent comprises one or more of carbon black, carbon nanotubes, graphene and conductive graphite. CNT can be selected from CNT, which is a carbon nanotube conductive agent, mainly plays a role in electric conduction and has better electric conduction performance than that of a common carbon black conductive agent. The conductive carbon black can be selected from Super P Li. The solvent is N-methylpyrrolidone (NMP).
The active substance may be a mixture of LCO and LMO, preferably in a 3:7 weight ratio. The active substance may be a mixture of LCO and NCM, preferably, the weight ratio of LCO to NCM is 1: 1. The active substance may also be a mixture of LCO with LMO and NCM, wherein, when the active substance is a mixture of LCO and LMO, the weight ratio of LCO to LMO is 3: 7. When the active substance is a mixture of LCO and NCM, the weight ratio of LCO to NCM is 1: 1. When the active material comprises an NCM, the molar ratio of nickel, cobalt and manganese in the NCM is 1:1:1 or 5:2:3 or 5:3: 2.
In the invention, the active material with high specific surface area and small particles needs to be selected to ensure the high-rate discharge performance of the battery. Specifically, the D50 particle size of LMO or NCM is small, the D50 particle size is less than 15 μm, the D50 particle size of LMO is 8-15 μm, and the specific surface area is 0.3-1.0 m2(g) NCM has a D50 particle diameter of 3-9 μm and a specific surface area of 0.4-3.0 m2The lithium ion battery has the advantages that excellent high-rate discharge performance of the lithium ion battery can be realized, high-current ignition performance of an igniter (in the field of emergency starting power supplies) is better, the cycle life is prolonged, the storage performance is good, and the manufacturing cost can be greatly reduced.
Meanwhile, the invention provides a preparation method of the lithium ion battery anode slurry, which comprises the following steps:
and 4, adding the remaining NMP accounting for 30 percent of the total weight of the solvent, adjusting the viscosity of the slurry to be 6000 +/-2000 mpa.S, and adjusting the solid content to be 62% +/-5%, thereby obtaining the anode slurry.
According to the invention, in the step 1, the rotation is 45Hz, the revolution is 40Hz, the vacuum degree is less than or equal to-0.08 MPa, and the stirring time is 2-2.5 h; in the step 2, the rotation is 45Hz, the revolution is 40Hz, the vacuum degree is less than or equal to minus 0.08MPa, and the stirring time is 2h to 3 h; in the step 3, after the first feeding, the materials are automatically rotated for 45Hz, revolved for 40Hz, the vacuum degree is less than or equal to minus 0.08MPa, and the stirring time is 0.5h to 1 h; after the second feeding, the mixture is autorotated for 45Hz and revolved for 40Hz, the vacuum degree is less than or equal to minus 0.08MPa, and the stirring time is 3 to 4 hours. The stirring speed and the stirring time in the steps are not limited, and the uniform mixing or the uniform dispersion can be realized.
The invention also provides a lithium ion battery, which comprises the lithium ion battery anode slurry.
Further, the invention provides a preparation method of a lithium ion battery, which comprises the following steps of:
coating the battery slurry by adopting a coating machine and compacting the pole piece, wherein the surface density of the pole piece is 200g/cm in 100-2The compacted density of the pole piece is 3.0-3.5g/cm3(ii) a Die cutting is carried out by a die cutting machine according to the size of the process, the die-cut pole pieces are laminated or wound on a laminating machine or a winding machine to form a battery cell, the battery cell is welded with a tab, then the battery cell is placed into a rubber shell to complete top side sealing, and then the battery cell is placed into a vacuum oven to be vacuum-baked for 24-48h at the temperature of 80-120 ℃; and injecting electrolyte into the baked and cooled battery cell, injecting 4.0-7.0g of electrolyte according to the volume per ampere hour, standing the electrolyte, and then performing formation, air extraction, sealing and capacity grading to obtain a finished product battery cell.
Compared with a pure lithium cobaltate system battery, the lithium ion battery prepared by the invention has excellent high-rate discharge performance, has better high-current discharge performance in an igniter (in the field of emergency starting power supplies), has small difference in cycle life and storage performance, and greatly reduces the manufacturing cost.
The present invention will be specifically described below with reference to preferred examples.
Example 1
In the first step, NMP accounting for 70% of the total weight of a solvent and all PVDF as a binder are weighed and respectively added into a stirring cylinder, the mixture is rotated at 45Hz, revolved at 40Hz and the vacuum degree is less than or equal to-0.08 MPa, and the mixture is stirred for 2 hours until the mixture is uniformly mixed to obtain a mixed solution; secondly, weighing conductive agent Super P Li and CNT carbon nanotube dry powder (PVP containing 0.8% of carbon nanotube powder weight), adding into the stirring cylinder, rotating for 45Hz, revolving for 40Hz, and stirring for 3h until the conductive agent particles are not more than-0.08 MPaUniformly dispersing in a solvent; thirdly, respectively weighing LCO and D50 with the particle size of 10 μm and the specific surface area of 0.62m, wherein the LCO and the D50 account for 50 percent of the formula by mass percent2The LMO is weighed, namely a mixture of LCO and LMO accounting for 50 percent of the total weight of the active substance mixture is weighed, wherein the molar ratio of the LCO to the LMO in the mixture is 3:7, the active substance mixture is added into the mixed liquid obtained in the second step, the LCO and the LMO rotate 45Hz, revolve 40Hz, the vacuum degree is less than or equal to-0.08 MPa, the mixture is stirred for 0.5 hour and mixed evenly, then the rest LCO and the LMO accounting for 50 percent of the mass of the formula are added, and then the mixture rotates 45Hz, revolves 40Hz, the vacuum degree is less than or equal to-0.08 MPa, and is stirred for 3.5 hours until the slurry is evenly dispersed; fourthly, adding the remaining NMP accounting for 30 percent of the total weight of the solvent to adjust the viscosity of the slurry, so that the viscosity and the solid content meet the requirements (the viscosity is 6750mpa.S, and the solid content is 65 percent), obtaining the anode slurry, and taking the anode slurry out of the cylinder for coating; fifthly, coating the positive pole slurry by a coating machine, wherein the coating requirement is that the surface density of the pole piece is 150g/cm2The compacted density of the pole piece is 3.2g/cm3(ii) a Sixthly, die cutting is carried out by a die cutting machine according to the size of the process, the die-cut pole pieces are laminated or wound on a laminating machine or a winding machine to form a battery cell, a tab is welded on the battery cell, then the battery cell is placed into a rubber shell to complete top side sealing, and then the battery cell is placed into a vacuum oven to be vacuum-baked for 36 hours at the temperature of 100 ℃; and seventhly, injecting electrolyte into the baked and cooled battery cell, injecting 6.1g of electrolyte according to the volume per ampere hour, standing the electrolyte, and then performing formation, air extraction, sealing and volume division to obtain a finished product battery cell.
The battery core adopting the process has excellent performance and the manufacturing cost is very low. The discharge performance of the manufactured battery at 40 ℃ and the discharge performance of the battery which is discharged for 3 times at 150 ℃ for 2S and 30S after standing are respectively shown in the figure 1 and the figure 2.
As can be seen from fig. 1, the lithium ion battery manufactured in this example has a superior high rate discharge performance compared to the pure lithium cobaltate system battery, and the discharge voltage plateau of the battery of this example is about 3570mV when discharged at 40C, whereas the discharge voltage plateau of the pure lithium cobaltate system battery is about 3500 mV. This may be determined by the following factors: in the first aspect, the electrochemical reaction is carried out under the condition of high-rate dischargeDiffusion control is required, and diffusion of lithium ions in the active material is a reaction control step, and since the LMO added in this example has a smaller D50 particle size and a more stable structure, the lithium ions have a short diffusion path and a small polarization. In the second aspect, because the LMO has a three-dimensional tunnel structure, the insertion and the desorption of lithium ions are facilitated, and the diffusion efficiency of the lithium ions is high; the lithium cobaltate of the pure lithium cobaltate system battery has a two-dimensional layered structure, lithium ions can only be intercalated and deintercalated between layers, and the diffusion efficiency of the lithium ions is low. In a third aspect, the compaction density of the active substance is optimally designed in the electrode design, and the compaction density (3.0 g/m) is properly reduced according to the characteristic of the particle size difference of the LMO and LCO materials3) Therefore, the compaction of the LMO is met, the compaction of the LCO is guaranteed, the porosity of active substances on the pole piece is guaranteed to be higher, the pole piece can absorb electrolyte better, the diffusion path of lithium ions in positive active substances is effectively shortened, the diffusion rate of the lithium ions is guaranteed, the discharge of large current of the electrode is facilitated, and meanwhile, the cycle life of the battery is guaranteed.
The automobile emergency starting power supply is mainly a product for emergency ignition when a storage battery configured for an automobile cannot ignite, and the ignition time of the automobile is generally 0.2-0.5S, the ignition current of different automobiles is generally 120-400A, and most of the ignition current is generally about 200A, so that the high-current discharge 2S of the emergency starting battery is set, and the ignition requirement of the automobile can be well met.
As can be seen from fig. 2, the lithium ion battery manufactured in this example has excellent large current ignition performance. When discharging at 150C, the battery-simulated automobile of this example had a discharge voltage of 7.79V for the 1 st ignition, 8.71V for the 2 nd ignition, and 8.98V for the 3 rd ignition. The 1 st heavy current discharge is also determined by the three factors, the 2 nd and 3 rd heavy current discharge voltages can rise, the temperature inside the battery rises to 35-45 ℃ when the battery is subjected to the influence of the temperature rise for the first discharge, the temperature rise is more favorable for the promotion of the reaction rate and the diffusion rate inside the battery, and the heavy current discharge is more favorable, so the discharge voltage rise of the battery is obvious.
FIG. 3 is a graph showing the cycle life test results of the battery manufactured in this example after charging at 2C, 4.2V, 0.05C, charge cut-off/resting for 30min/6C, and discharging to 3.0V. As can be seen from fig. 3, the capacity retention rate of the battery manufactured in this embodiment is 80% after 1000 cycles, which is much greater than that of the battery with 500 cycles in the current market, and the battery has excellent cycle life. The method is mainly characterized in that the active material of the battery is selected to have high specific surface area, and the density of the pole piece surface is designed in place, so that the liquid absorption and retention performance of the battery cell are ensured, and the battery has good cycle life.
Example 2
In the first step, NMP accounting for 70% of the total weight of a solvent and all PVDF as a binder are weighed and respectively added into a stirring cylinder, the mixture is rotated at 45Hz, revolved at 40Hz and the vacuum degree is less than or equal to-0.08 MPa, and the mixture is stirred for 2.5 hours until the mixture is uniformly mixed to obtain a mixed solution; secondly, weighing conductive agent Super P Li and CNT carbon nanotube dry powder (PVP containing 0.8 percent of the weight of the carbon nanotube powder) and adding the conductive agent Super P Li and the CNT carbon nanotube dry powder into the stirring cylinder, rotating for 45Hz, revolving for 40Hz, and stirring for 2 hours until conductive agent particles are uniformly dispersed in a solvent, wherein the vacuum degree is less than or equal to-0.08 MPa; thirdly, respectively weighing LCO and D50 with the particle size of 6 mu m and the specific surface area of 0.83m, wherein the LCO and the D50 account for 50 percent of the mass percentage of the formula2The NCM is a mixture of LMO and NCM which accounts for 50 percent of the total weight of the active substance mixture, wherein the molar ratio of LCO and NCM (the NCM is 1:1:1 type, the molar ratio of nickel, cobalt and manganese is 1:1:1) in the mixture is 1:1, the active substance mixture is added into the mixed solution obtained in the second step, the mixture rotates 45Hz, revolves 40Hz, the vacuum degree is less than or equal to-0.08 MPa, after the mixture is stirred for 1 hour and uniformly mixed, the rest LCO and NCM which account for 50 percent of the formula mass are added, then the mixture rotates 45Hz, revolves 40Hz, the vacuum degree is less than or equal to-0.08 MPa, and the mixture is stirred for 4 hours until the slurry is uniformly dispersed; and fourthly, adjusting the viscosity of the slurry by using the residual NMP accounting for 30 percent of the total weight of the solvent to ensure that the viscosity and the solid content meet the requirements (the viscosity is 5800mpa.S, and the solid content is 62 percent), obtaining the anode slurry, and taking the anode slurry out of the cylinder for coating. Fifthly, coating the anode slurry by adopting a coating machine,the coating requirement is that the surface density of the pole piece is 160g/cm2The compacted density of the pole piece is 3.35g/cm3(ii) a Sixthly, die cutting is carried out by a die cutting machine according to the size of the process, the die-cut pole piece is laminated or wound on a laminating machine or a winding machine to form a battery cell, a tab is welded on the battery cell, then the battery cell is placed into a rubber shell to complete top side sealing, and then the battery cell is placed into a vacuum oven to be vacuum-baked for 48 hours at the temperature of 80 ℃; and seventhly, injecting electrolyte into the baked and cooled battery cell, injecting 4.5g of electrolyte according to the volume per ampere hour, standing the electrolyte, and then performing formation, air extraction, sealing and volume division to obtain a finished product battery cell.
The battery core adopting the process has excellent performance and the manufacturing cost is very low. The discharge performance of the battery manufactured by the method at 35C and the discharge performance of the battery manufactured by the method at 120C for discharging 2S, standing for 30S and continuously discharging 3 times for simulating the large-current ignition of the automobile are respectively shown in the graph of fig. 4 and the graph of fig. 5.
As can be seen from fig. 4, the lithium ion battery manufactured in this example has a superior high rate discharge performance compared to the pure lithium cobaltate system battery, and the discharge voltage plateau of the battery of this example is about 3570mV when discharged at 35C, whereas the discharge voltage plateau of the pure lithium cobaltate system battery is about 3500 mV. This may be determined by two factors: on the other hand, since the electrochemical reaction is diffusion-controlled under the high-rate discharge condition and the diffusion of lithium ions in the active material is a reaction control step, the particle size of D50 of NCM added in this example is small and the structure is more stable, and the diffusion path of lithium ions is short and the polarization is small. On the other hand, the NCM has a three-dimensional tunnel structure, so that the insertion and the desorption of lithium ions are facilitated, and the diffusion efficiency of the lithium ions is high; the lithium cobaltate of the pure lithium cobaltate system battery has a two-dimensional layered structure, lithium ions can only be intercalated and deintercalated between layers, and the diffusion efficiency of the lithium ions is low.
As can be seen from fig. 5, the lithium ion battery manufactured in this example also has excellent large current ignition performance. When discharging at 120C, the battery-simulated automobile of this example had a discharge voltage of 7.47V for the 1 st ignition, 8.37V for the 2 nd ignition, and 8.69V for the 3 rd ignition. The 1 st heavy current discharge is determined by the two factors, the 2 nd and 3 rd heavy current discharge voltages can rise, the temperature rise of the battery is mainly influenced, and when the temperature is higher, the reaction rate and the diffusion rate of the battery can be promoted, so that the heavy current discharge is facilitated.
Example 3
In the first step, NMP accounting for 70% of the total weight of a solvent and all binders PVDF are weighed and respectively added into a stirring cylinder, and then the mixture is rotated by 45Hz, revolved by 40Hz and the vacuum degree is less than or equal to-0.08 MPa, and stirred for 2 hours until the mixture is uniformly mixed to obtain a mixed solution; secondly, weighing the conductive agent Super P Li and the CNT carbon nano-tube dry method (0.8 percent PVP) and adding the conductive agent Super P Li and the CNT carbon nano-tube dry method into the stirring cylinder, rotating for 45Hz, revolving for 40Hz, and stirring for 2.5 hours until the conductive agent particles are uniformly dispersed in the solvent, wherein the vacuum degree is less than or equal to-0.08 MPa; thirdly, respectively weighing LCO accounting for 50 percent of the formula by mass, wherein the grain diameter of D50 is 3.5 mu m, and the specific surface area is 1.2m2NCM per g, and D50 particle size 8 μm and specific surface area 0.56m2The LMO is weighed and accounts for 50 percent of the total weight of the active substance mixture, namely the mixture of LCO, NCM and LMO is weighed, wherein the molar ratio of LCO and NCM (the NCM is 1:1:1 type, the molar ratio of nickel, cobalt and manganese is 1:1:1) and LMO is 3:3:4, the active substance mixture is added into the mixed solution obtained in the second step, the mixture is rotated for 45Hz and revolved for 40Hz, the vacuum degree is less than or equal to-0.08 MPa, the mixture is stirred for 1 hour and evenly mixed, the rest LCO, NCM and LMO accounting for 50 percent of the formula mass are added, then the mixture is rotated for 45Hz and revolved for 40Hz, the vacuum degree is less than or equal to-0.08 MPa, and the mixture is stirred for 3 hours until the slurry is evenly dispersed; and fourthly, adjusting the viscosity of the slurry by using the residual NMP accounting for 30 percent of the total weight of the solvent to ensure that the viscosity and the solid content meet the requirements (the viscosity is 5800mpa.S, and the solid content is 62 percent), obtaining the anode slurry, and taking the anode slurry out of the cylinder for coating. Fifthly, coating the positive pole slurry by a coating machine, wherein the coating requirement is that the surface density of the pole piece is 150g/cm2The compacted density of the pole piece is 3.1g/cm3(ii) a Sixthly, die cutting is carried out by adopting a die cutting machine according to the size of the process, then the die-cut pole pieces are laminated or wound on a laminating machine or a winding machine to form a battery cell, and glue is added after the electrode lugs are spot-welded on the battery cellShell, finishing top side sealing, then putting into a vacuum oven, and vacuum baking for 48h at 80 ℃; and seventhly, injecting electrolyte into the baked and cooled battery cell, injecting 5.6g of electrolyte according to the volume per ampere hour, standing the electrolyte, and then performing formation, air extraction, sealing and volume division to obtain a finished product battery cell.
The battery core adopting the process has excellent performance and the manufacturing cost is very low. The discharge performance of the battery manufactured by the method at 35C and the discharge performance of the battery manufactured by the method at 120C for discharging 2S, standing for 30S and continuously discharging 3 times are respectively shown in the figures 6 and 7.
As can be seen from fig. 6, the lithium ion battery manufactured in this example has a superior high rate discharge performance compared to the pure lithium cobaltate battery, and when discharged at 35C, the discharge voltage plateau of the battery of this example is about 3517mV, whereas the discharge voltage plateau of the pure lithium cobaltate battery is about 3505mV, and the two curves substantially coincide. This may be determined by two factors: on one hand, under the condition of high-rate discharge, electrochemical reaction is controlled by diffusion, and the diffusion of lithium ions in active substances is a reaction control step, so that the added NCM and LMO have small D50 particle size, stable crystal grain structure and large specific surface area, can be uniformly dispersed and attached with conductive agent particles, and the tubular conductive channel can better build a diffusion path of the lithium ions and has small polarization due to the addition of the carbon nanotube conductive agent. On the other hand, although the NCM material has poor relative rate performance, the NCM material more suitable for high-rate discharge, such as 1:1:1 type NCM or 5:2:3 type single crystal structure NCM, is selected to ensure that the NCM material can better perform rate discharge. In addition, the compaction density of the active substance is also optimally designed in the aspect of electrode design, and the compaction density (3.0 g/m) is properly reduced according to the characteristic of the particle size difference of the LMO and LCO materials3) Therefore, the compaction of LMO is met, the compaction of LCO is guaranteed, the porosity of active substances on the pole piece can be guaranteed to be higher, the pole piece can absorb electrolyte better, the diffusion path of lithium ions in positive active substances is effectively shortened, the diffusion rate of the lithium ions is guaranteed, the discharge of large current of the electrode is facilitated, and meanwhile, the cycle life of the battery is guaranteed.
As can be seen from fig. 7, the lithium ion battery manufactured in this example has more excellent large current ignition performance than the pure lithium cobalt oxide system battery. When discharging at 120C, the battery-simulated automobile of this example has a discharge voltage of 7.95V for the 1 st ignition, 8.50V for the 2 nd ignition, and 8.84V for the 3 rd ignition.
It should be understood that the above description of specific embodiments of the present invention is only for the purpose of illustrating the technical lines and features of the present invention, and is intended to enable those skilled in the art to understand the contents of the present invention and to implement the present invention, but the present invention is not limited to the above specific embodiments. It is intended that all such changes and modifications as fall within the scope of the appended claims be embraced therein.
Claims (2)
1. A method of making a lithium ion battery, comprising:
weighing the raw materials according to the formula proportion, wherein the mass ratio of LCO to LMO to PVDF to CNT to SuperPLi to NMP is 28.5:66.5:2:1:2: 55;
step one, weighing NMP accounting for 70 percent of the total weight of the solvent and all PVDF as a binder, respectively adding the NMP and the PVDF as the binder into a stirring cylinder, rotating the cylinder for 45Hz and revolving the cylinder for 40Hz, wherein the vacuum degree is less than or equal to-0.08 MPa, and stirring the mixture for 2 hours until the mixture is uniformly mixed to obtain a mixed solution;
secondly, weighing the conductive agent SuperPLi, CNT carbon nano-tube dry powder and the CNT carbon nano-tube dry powder, wherein the content of PVP in the CNT carbon nano-tube dry powder is 0.8 percent of the weight of carbon nano-tube powder, adding the weighed materials into the stirring cylinder, rotating for 45Hz, revolving for 40Hz, and stirring for 3 hours until the conductive agent particles are uniformly dispersed in the solvent;
thirdly, respectively weighing LCO and D50 with the particle size of 10 μm and the specific surface area of 0.62m, wherein the LCO and the D50 account for 50 percent of the formula by mass percent2The LMO is weighed, namely a mixture of LCO and LMO accounting for 50 percent of the total weight of the active substance mixture is weighed; wherein, the molar ratio of LCO to LMO in the mixture is 3:7, the active substance mixture is added into the mixed solution obtained in the second step, the mixture is rotated for 45Hz and revolved for 40Hz, the vacuum degree is less than or equal to minus 0.08MPa, after being stirred for 0.5h and uniformly mixed, the rest LCO and LMO accounting for 50 percent of the mass percentage of the formula are added completely, and thenThen autorotation is carried out for 45Hz, revolution is carried out for 40Hz, the vacuum degree is less than or equal to minus 0.08MPa, and stirring is carried out for 3.5 hours until the slurry is uniformly dispersed;
fourthly, adding the remaining NMP accounting for 30 percent of the total weight of the solvent to adjust the viscosity of the slurry, so that the viscosity and the solid content meet the requirements, the viscosity is 6750mpa.S, the solid content is 65 percent, obtaining anode slurry, and taking the anode slurry out of a cylinder for coating;
fifthly, coating the positive pole slurry by a coating machine, wherein the coating requirement is that the surface density of the pole piece is 150g/cm2The compacted density of the pole piece is 3.2g/cm3；
Sixthly, die cutting is carried out by a die cutting machine according to the size of the process, the die-cut pole pieces are laminated or wound on a laminating machine or a winding machine to form a battery cell, a tab is welded on the battery cell, then the battery cell is placed into a rubber shell to complete top side sealing, and then the battery cell is placed into a vacuum oven to be vacuum-baked for 36 hours at the temperature of 100 ℃;
and seventhly, injecting electrolyte into the baked and cooled battery cell, injecting 6.1g of electrolyte according to the volume per ampere hour, standing the electrolyte, and then performing formation, air extraction, sealing and volume division to obtain a finished product battery cell.
2. A lithium ion battery, characterized by: prepared by the preparation method of claim 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711402851.9A CN108134066B (en) | 2017-12-22 | 2017-12-22 | Lithium ion battery positive electrode slurry and preparation method thereof, lithium ion battery and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711402851.9A CN108134066B (en) | 2017-12-22 | 2017-12-22 | Lithium ion battery positive electrode slurry and preparation method thereof, lithium ion battery and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108134066A CN108134066A (en) | 2018-06-08 |
| CN108134066B true CN108134066B (en) | 2021-02-02 |
Family
ID=62391481
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201711402851.9A Active CN108134066B (en) | 2017-12-22 | 2017-12-22 | Lithium ion battery positive electrode slurry and preparation method thereof, lithium ion battery and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108134066B (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP7220851B2 (en) * | 2017-10-31 | 2023-02-13 | 住友金属鉱山株式会社 | Positive electrode active material for non-aqueous electrolyte secondary battery, manufacturing method thereof, and non-aqueous electrolyte secondary battery using positive electrode active material |
| CN109088033B (en) * | 2018-08-07 | 2022-08-30 | 江西省汇亿新能源有限公司 | High-safety high-energy long-cycle lithium iron phosphate 18650 lithium battery and preparation method thereof |
| CN109192941A (en) * | 2018-08-10 | 2019-01-11 | 欣旺达电子股份有限公司 | Lithium ion battery, positive plate, lithium ion battery anode glue size and preparation method thereof |
| CN109192986A (en) * | 2018-08-21 | 2019-01-11 | 凤凰新能源(惠州)有限公司 | A kind of lithium ion battery cell material and preparation method thereof |
| CN112467129A (en) * | 2020-11-02 | 2021-03-09 | 东莞市煜信恩能源科技有限公司 | Preparation method of conductive agent material capable of improving comprehensive performance of battery |
| CN112786864A (en) * | 2021-01-27 | 2021-05-11 | 深圳好电科技有限公司 | Lithium ion battery anode slurry and preparation method thereof |
| CN113921891A (en) * | 2021-09-07 | 2022-01-11 | 山东派智新能源科技有限公司 | Low-temperature large-magnification cylindrical lithium ion battery and manufacturing method thereof |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8906549B1 (en) * | 2010-09-24 | 2014-12-09 | Greatbatch Ltd. | Development of mixed binder system for primary cell cathodes |
| CN104218233A (en) * | 2014-09-11 | 2014-12-17 | 海宁美达瑞新材料科技有限公司 | Composite lithium ion battery positive electrode material with high rate performance and preparation method of material |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100492721C (en) * | 2006-03-15 | 2009-05-27 | 浙江南都电源动力股份有限公司 | Lithium ion battery pole piece with high multiplying power and production thereof |
| CN101685878B (en) * | 2008-09-27 | 2013-09-18 | 深圳市比克电池有限公司 | Preparation method of polymer lithium ion battery |
| CN101388449B (en) * | 2008-10-31 | 2011-06-08 | 浙江南都电源动力股份有限公司 | Positive plate of high power lithium ionic cell and lithium ionic cell containing the same |
| CN101752550B (en) * | 2008-12-10 | 2014-01-08 | 深圳市比克电池有限公司 | Method for confecting lithium ion battery anode sizing agent |
| CN103456941B (en) * | 2013-08-20 | 2015-07-22 | 中信大锰矿业有限责任公司大新锰矿分公司 | Power type lithium manganate and preparation method thereof |
| CN104377348A (en) * | 2014-11-14 | 2015-02-25 | 刘广源 | High safety anti-overcharging lithium ion battery positive electrode paste formula and production method of positive plate |
-
2017
- 2017-12-22 CN CN201711402851.9A patent/CN108134066B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8906549B1 (en) * | 2010-09-24 | 2014-12-09 | Greatbatch Ltd. | Development of mixed binder system for primary cell cathodes |
| CN104218233A (en) * | 2014-09-11 | 2014-12-17 | 海宁美达瑞新材料科技有限公司 | Composite lithium ion battery positive electrode material with high rate performance and preparation method of material |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108134066A (en) | 2018-06-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108134066B (en) | Lithium ion battery positive electrode slurry and preparation method thereof, lithium ion battery and preparation method thereof | |
| CN105932229B (en) | A kind of preparation method of high capacity lithium ion cells cathode piece | |
| KR102239750B1 (en) | Microcapsule type silicon-carbon composite negative electrode material, and manufacturing method and use thereof | |
| US20210351395A1 (en) | Cathode additive and preparation method therefor, cathode electrode and preparation method therefor, and lithium ion battery | |
| CN103794781A (en) | Lithium battery as well as preparation method thereof | |
| CN103682307B (en) | Nickel ion doped/lithium titanate battery and preparation method thereof | |
| CN101901932A (en) | Quick-chargeable, high-security and high-multiplying-power battery and production method thereof | |
| CN103985841A (en) | Negative electrode of lithium ion battery and preparation method thereof | |
| CN107895776A (en) | A kind of preparation method of efficiently pulp of lithium ion battery | |
| CN1960040A (en) | High-powered lithium ferric phosphate dynamic battery, and preparation technique | |
| CN106356502A (en) | High-rate-performance lithium iron phosphate battery positive electrode plate and preparation method thereof | |
| CN113066962B (en) | Silicon-containing negative plate and high-energy-density battery | |
| CN115566170B (en) | Preparation method of high-energy-density quick-charging lithium ion battery anode material | |
| CN103762335A (en) | Lithium titanate electrode plate and lithium ion battery | |
| CN101640263A (en) | Lithium ion battery composite cathode material and preparation method thereof | |
| CN115472898A (en) | Secondary battery and electric equipment | |
| CN113991089B (en) | Sodium ion battery and preparation method thereof | |
| KR20190136382A (en) | Lithium secondary battery | |
| CN105720267A (en) | Preparation method of lithium ion phosphate power battery cathode plate | |
| CN113270579A (en) | Lithium ion battery negative plate, battery and preparation method thereof | |
| CN108183231A (en) | Lithium ion battery with high charging upper limit voltage and preparation method thereof | |
| CN104979525B (en) | A kind of positive plate, electrochemical energy storing device containing the positive plate and preparation method thereof | |
| CN117117337A (en) | High-energy-density quick-charging lithium iron phosphate battery and preparation method thereof | |
| CN115172644B (en) | 14500 steel shell cylindrical sodium ion battery positive plate and preparation method thereof | |
| CN104993097B (en) | A kind of negative plate, the electrochemical energy storing device containing the negative plate and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |