CN112086621B - Negative plate and laminated lithium ion battery comprising same - Google Patents

Negative plate and laminated lithium ion battery comprising same Download PDF

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Publication number
CN112086621B
CN112086621B CN202011053193.9A CN202011053193A CN112086621B CN 112086621 B CN112086621 B CN 112086621B CN 202011053193 A CN202011053193 A CN 202011053193A CN 112086621 B CN112086621 B CN 112086621B
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edge
negative electrode
active material
material layer
area
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CN112086621A (en
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石越
彭冲
李俊义
徐延铭
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Zhuhai Cosmx Battery Co Ltd
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Zhuhai Cosmx Battery 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
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/133—Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • 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
    • H01M10/0585—Construction or manufacture of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators
    • 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
    • H01M4/1393—Processes of manufacture of electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • 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
    • H01M2004/027—Negative electrodes
    • 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

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  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Battery Electrode And Active Subsutance (AREA)
  • Secondary Cells (AREA)

Abstract

The invention provides a negative plate and a laminated lithium ion battery comprising the same. The negative plate adopts a double-layer coating technology, active substances and surface density of the negative plate are specially designed according to the potential and polarization distribution of the negative plate, and the double-layer coating technology is utilized to control the edge position of the negative plate to adopt double-layer coating; on one hand, the accumulation mode of the negative active material particles can be changed through double-layer coating, the edge polarization is reduced, reaction sites are increased, the internal resistance is reduced, and the lithium precipitation can not occur at the edge; on the other hand, compared with single-layer coating, double-layer coating can ensure that the charging speed can be supported at the same surface density, and therefore, the energy density is not lost.

Description

Negative plate and laminated lithium ion battery comprising same
Technical Field
The invention belongs to the technical field of lithium ion batteries, and particularly relates to a negative plate and a laminated lithium ion battery comprising the same.
Background
With the development of electronic products, people no longer pursue high energy density for lithium ion batteries singly, and the charging speed also becomes one of the criteria of the important evaluation of consumers. However, the current lithium ion battery is not well compatible with the high energy density and the fast charging.
Disclosure of Invention
The invention provides a negative plate and a laminated lithium ion battery comprising the same.
The negative pole piece adopts a double-layer coating technology, different active material layers and surface densities of different areas of the negative pole piece are specially designed according to the potential and polarization distribution of the negative pole piece, the double-layer coating technology is utilized, the edge position of the pole piece of the negative pole piece is controlled to adopt double-layer coating, the edge area of the double-layer coating enables a lithium precipitation window of the edge area to be remarkably widened on the premise that the energy density of a battery is not changed, and the overall quick charge level of a battery core is remarkably improved. The laminated lithium ion battery containing the negative plate greatly meets the requirement of quick charge, can reduce the waste of energy density, and realizes the consideration of quick charge and high energy density.
The purpose of the invention is realized by the following technical scheme:
a negative plate comprises a negative current collector, wherein a central area, a first edge, a second edge, a third edge and a fourth edge are arranged on a first surface of the negative current collector; the first edge, the second edge, the third edge and the fourth edge are arranged around the central area, and the first edge and the third edge are oppositely arranged; the second edge and the fourth edge are oppositely arranged;
wherein a first coated area is provided within the central region, the second edge, and the fourth edge, and a second coated area is provided within the first edge and the third edge; alternatively, the first and second electrodes may be,
a first coating area is arranged in the central area, the first edge and the third edge, and a second coating area is arranged in the second edge and the fourth edge; alternatively, the first and second electrodes may be,
a first coating area is arranged in the central area, and second coating areas are arranged in the first edge, the second edge, the third edge and the fourth edge;
the first coating area is provided with a first negative electrode active material layer which is coated on a first surface of the negative electrode current collector;
the second coating area is provided with a first negative electrode active material layer and a second negative electrode active material layer, the first negative electrode active material layer is coated on the first surface of the negative electrode current collector, and the second negative electrode active material layer is coated on the surface of the first negative electrode active material layer; the first anode active material layer includes a first anode active material, and the second anode active material layer includes a second anode active material;
a median particle diameter D of the first negative electrode active material50Larger than the median particle diameter D of the second negative electrode active material50。
According to the present invention, the negative electrode current collector has an extension portion extending beyond an edge in a width direction or a length direction of the negative electrode current collector, and the extension portion forms a negative electrode tab.
The extension part can be bent to form a negative pole lug and can also be directly formed into the negative pole lug.
According to the present invention, the number of the negative electrode tabs is not particularly defined, and may be, for example, 1 or more, such as 1, 2, 3, 4 or 5.
According to the present invention, the first anode active material layer is integrally coated in the first coating region.
According to the invention, the same arrangement mode as the first surface is adopted on the second surface of the negative current collector opposite to the first surface, and exemplarily, a central area, a first edge, a second edge, a third edge and a fourth edge are further arranged on the second surface of the negative current collector opposite to the first surface; the first edge, the second edge, the third edge and the fourth edge are arranged around the central area, and the first edge and the third edge are oppositely arranged; the second edge and the fourth edge are oppositely disposed.
According to the present invention, the first edge on the first surface of the negative current collector and the first edge on the second surface of the negative current collector are symmetrically disposed with the negative current collector as a symmetry axis; the second edge on the first surface of the negative current collector and the second edge on the second surface of the negative current collector are symmetrically arranged by taking the negative current collector as a symmetry axis; the third edge on the first surface of the negative current collector and the third edge on the second surface of the negative current collector are symmetrically arranged by taking the negative current collector as a symmetry axis; the fourth edge on the first surface of the negative current collector and the fourth edge on the second surface of the negative current collector are symmetrically arranged by taking the negative current collector as a symmetry axis; the central area on the first surface of the negative current collector and the central area on the second surface of the negative current collector are symmetrically arranged with the negative current collector as an axis of symmetry.
According to the present invention, the shape of the central region, the first edge, the second edge, the third edge and the fourth edge is not particularly defined, and may be a rectangular structure or a curved structure.
According to the present invention, first coating regions are provided in the central region, the second edge, and the fourth edge, and the first coating regions integrally coat a first anode active material layer; providing a second coated region within the first edge and the third edge; the negative current collector is provided with an extension part which extends to the outside of the edge along the width direction or the length direction of the negative current collector, and the extension part forms a negative electrode tab. As shown in particular in figure 1.
According to the present invention, first coating regions are provided in the central region, the first edge, and the third edge, and the first coating regions integrally coat a first anode active material layer; a second coating area is arranged in the second edge and the fourth edge; the negative current collector is provided with an extension part which extends to the outside of the edge along the width direction or the length direction of the negative current collector, and the extension part forms a negative electrode tab. As shown in particular in figure 3.
According to the invention, a first coating area is arranged in the central area, and second coating areas are arranged in the first edge, the second edge, the third edge and the fourth edge, the negative current collector is provided with an extension part which extends to the outside of the edges along the width direction or the length direction of the negative current collector, and the extension part forms a negative pole tab. As shown in particular in fig. 4 and 5.
According to the invention, the widths of the first, second, third and fourth edges are the same or different, preferably the same; the widths of the first edge, the second edge, the third edge and the fourth edge refer to the length of the shorter side in the corresponding edge region.
According to the invention, when a first coating zone is provided within the central zone, the second edge and the fourth edge, a second coating zone is provided within the first edge and the third edge; the sum of the areas of the first edge and the third edge accounts for 1/10-1/2 of the area of the negative electrode current collector, wherein the area of the negative electrode current collector is the sum of the areas of the central area, the first edge, the second edge, the third edge and the fourth edge.
According to the invention, when a first coating zone is provided within the central zone, the first edge and the third edge, and a second coating zone is provided within the second edge and the fourth edge; and the sum of the areas of the second edge and the fourth edge accounts for 1/10-1/2 of the area of the negative electrode current collector, wherein the area of the negative electrode current collector is the sum of the areas of the central area, the first edge, the second edge, the third edge and the fourth edge.
According to the invention, when a first coating area is arranged in the central area and second coating areas are arranged in the first edge, the second edge, the third edge and the fourth edge; the sum of the areas of the first edge, the second edge, the third edge and the fourth edge accounts for 1/10-1/2 of the area of the negative current collector, wherein the area of the negative current collector is the sum of the areas of the central area, the first edge, the second edge, the third edge and the fourth edge.
According to the invention, the area of the second coating region accounts for 1/10-1/2 of the sum of the areas of the first coating region and the second coating region.
According to the present invention, the thickness ratio of the first negative electrode active material layer to the second negative electrode active material layer in the second coating region is 3:7 to 7: 3.
According to the present invention, the sum of the thicknesses of the first anode active material layer and the second anode active material layer in the second coating region is equal to the thickness of the first anode active material layer in the first coating region.
According to the present invention, the lithium conductive kinetic performance of the second anode active material layer is superior to that of the first anode active material layer.
According to the invention, the lithium-conducting kinetic performance refers to the insertion and extraction speed of lithium ions, and the higher the insertion and extraction speed is, the better the kinetic performance is. The lithium ion intercalation and deintercalation capability is mainly represented by: (1) the supportable charging current of the active substance is larger, and the kinetic performance is better; (2) the amount of lithium ions received per unit time, i.e., the rate of receiving lithium ions, is higher, and the kinetic properties are better.
Illustratively, the rate of insertion and extraction of lithium ions of the first anode active material layer is smaller than the rate of extraction of lithium ions of the second anode active material layer.
Illustratively, the supportable charging current of the first anode active material layer is smaller than the supportable charging current of the second anode active material layer.
Illustratively, the rate of accepting lithium ions by the first anode active material layer is smaller than the rate of accepting lithium ions by the second anode active material layer.
According to the present invention, the particle size distribution of the first anode active material forming the first anode active material layer is: 5 μm<D10<8μm，10μm<D50<20μm，20μm<D90<30 mu m; the particle size distribution of the second anode active material forming the second anode active material layer is: 5 μm<D10<8μm，6μm<D50<16μm，19μm<D90<30μm。
In the present invention, the median particle diameter D of the first negative electrode active material forming the first negative electrode active material layer50Larger than the median particle diameter D of the second anode active material forming the second anode active material layer50So selected that the second anode active material layer can ensure excellent kinetic propertiesIn the kinetic performance of the first negative electrode active material layer, the kinetic performance is better because the shorter the diffusion path of lithium ions in the negative electrode active material layer is.
According to the present invention, the first anode active material layer includes a first anode active material, a first conductive agent, and a first binder, and the second anode active material layer includes a second anode active material, a second conductive agent, and a second binder.
The first negative electrode active material and the second negative electrode active material are the same or different, the first conductive agent and the second conductive agent are the same or different, and the first binder and the second binder are the same or different.
According to the invention, the first negative electrode active material layer comprises the following components in percentage by mass: 70-99 wt% of a first negative electrode active material, 0.5-15 wt% of a first conductive agent, and 0.5-15 wt% of a first binder.
Preferably, the first negative electrode active material layer comprises the following components in percentage by mass: 80-98 wt% of a first negative electrode active material, 1-10 wt% of a first conductive agent, and 1-10 wt% of a first binder.
According to the invention, the second anode active material layer comprises the following components in percentage by mass: 70-99 wt% of a second negative electrode active material, 0.5-15 wt% of a second conductive agent, and 0.5-15 wt% of a second binder.
Preferably, the second anode active material layer comprises the following components in percentage by mass: 80-98 wt% of a second negative electrode active material, 1-10 wt% of a second conductive agent, and 1-10 wt% of a second binder.
According to the present invention, the content of the first conductive agent forming the first anode active material layer is smaller than the content of the second conductive agent forming the second anode active material layer. The better the lithium conductivity of lithium ions in the negative electrode active material layer, the better the kinetics, and therefore this choice ensures that the kinetics of the second negative electrode active material layer is better than the kinetics of the first negative electrode active material layer.
According to the invention, the first conductive agent and the second conductive agent are the same or different and are independently selected from at least one of conductive carbon black, acetylene black, ketjen black, conductive graphite, conductive carbon fiber, carbon nano tube, metal powder and carbon fiber.
According to the invention, the first binder and the second binder are the same or different and are independently selected from one or more of polyvinylidene fluoride (PVDF), polymethyl methacrylate (PMMA), Polyacrylonitrile (PAN) and polyethylene oxide (PEO), and can also be at least one of Styrene Butadiene Rubber (SBR) materials or polyacrylate materials.
According to the invention, the first negative electrode active material and the second negative electrode active material are the same or different and are independently selected from at least one of artificial graphite, natural graphite, mesocarbon microbeads and lithium titanate.
According to the invention, the negative plate is used for a lithium ion battery, and is particularly suitable for a laminated lithium ion battery.
The invention also provides a lithium ion battery which comprises the negative plate.
According to the invention, the lithium ion battery is a laminated lithium ion battery.
According to the invention, the lithium ion battery further comprises a positive plate, a separation film and electrolyte.
The invention has the beneficial effects that:
the invention provides a negative plate and a laminated lithium ion battery comprising the same. The negative plate adopts a double-layer coating technology, active substances and surface density of the negative plate are specially designed according to the potential and polarization distribution of the negative plate, and the double-layer coating technology is utilized to control the edge position of the negative plate to adopt double-layer coating; on one hand, the accumulation mode of the negative active material particles can be changed through double-layer coating, the edge polarization is reduced, reaction sites are increased, the internal resistance is reduced, and the lithium precipitation can not occur at the edge; on the other hand, compared with single-layer coating, double-layer coating can ensure that the supportable charging speed is higher under the same areal density, so that the energy density is not lost; on the other hand, the edge area of the double-layer coating enables the lithium separating window at the edge to be remarkably widened on the premise that the energy density of the battery is not changed, the overall quick charging level of the battery core is remarkably improved, namely the double-layer coating can cover the quick charging requirement while realizing high surface density, the laminated lithium ion battery containing the negative plate greatly meets the quick charging requirement and can reduce the waste of the energy density, the quick charging and the high energy density are realized, and the quick charging performance is prevented from being obtained by reducing the surface density (volume energy density).
Drawings
FIG. 1: the structure schematic diagram of the negative plate in the preferred embodiment of the invention;
FIG. 2: the cross section of the negative plate in the z-axis direction in FIG. 1;
FIG. 3: the structure schematic diagram of the negative plate according to another preferred embodiment of the invention;
FIG. 4: the structure schematic diagram of the negative plate in the further preferable scheme of the invention;
FIG. 5: the structure schematic diagram of the negative plate according to still another preferred embodiment of the invention;
FIG. 6: the negative electrode sheet is shown in a cross-sectional view in the z-axis direction in fig. 5.
Detailed Description
The present invention will be described in further detail with reference to specific examples. It is to be understood that the following examples are only illustrative and explanatory of the present invention and should not be construed as limiting the scope of the present invention. All the technologies realized based on the above-mentioned contents of the present invention are covered in the protection scope of the present invention.
The experimental methods used in the following examples are all conventional methods unless otherwise specified; reagents, materials and the like used in the following examples are commercially available unless otherwise specified.
In the description of the present invention, it should be noted that the terms "first", "second", etc. are used for descriptive purposes only and do not indicate or imply relative importance.
The following are providedThe graphite used in the examples was artificial graphite a, D thereof50The value is 15 mu m, and the limit compaction density value can reach 1.8g/cm3The capacity is 360 mAh/g.
The graphite used in the following examples is artificial graphite b, D thereof50The value is 11 μm, and the limit compaction density value can reach 1.75g/cm3The capacity was 355 mAh/g.
Example 1
(1) 0.5 wt% of conductive carbon black, 1.3 wt% of styrene-butadiene rubber and 1.3 wt% of carboxymethyl cellulose are added into 96.9 wt% of graphite a, and then water is used for adjusting to obtain negative electrode slurry A. 0.5 wt% of conductive carbon black, 1.3 wt% of styrene-butadiene rubber and 1.3 wt% of carboxymethyl cellulose are added to 96.9 wt% of graphite B, and then water is used for adjusting to obtain negative electrode slurry B.
As shown in fig. 4, the negative electrode tab includes a negative electrode current collector, and a central region, a first edge, a second edge, a third edge, and a fourth edge are disposed on a first surface of the negative electrode current collector; the first edge, the second edge, the third edge and the fourth edge are arranged around the central area, and the first edge and the third edge are oppositely arranged; the second edge and the fourth edge are oppositely arranged;
wherein a first coated area is arranged in the central area, and a second coated area is arranged in the first edge, the second edge, the third edge and the fourth edge;
coating the anode slurry a on the first coating region by a coating apparatus to form a first anode active material layer; coating negative electrode slurry A and negative electrode slurry B on the second coating region through double-layer coating equipment, forming a first negative electrode active material layer and a second negative electrode active material layer, coating the first negative electrode active material layer on the surface of a negative electrode current collector, coating the second negative electrode active material layer on the surface of the first negative electrode active material layer, drying, rolling, slitting and tabletting to prepare the negative electrode piece.
Wherein the area of the first coated region is 1/3 (as shown in fig. 4, the areas of the first edge, the second edge, the third edge, and the fourth edge are all 1/12) of the sum of the areas of the first coated region and the second coated region.
(2) Mixing a positive electrode active material lithium cobaltate, a conductive agent conductive carbon and a binder PVDF according to the proportion of (97.8 wt%, 1.1 wt% and 1.1 wt%), adding N-methyl pyrrolidone, stirring and dispersing to prepare positive electrode slurry with proper solid content. And coating the positive slurry on a positive current collector, drying, rolling, slitting and tabletting to obtain the positive plate.
(3) And (3) stacking the negative plate prepared in the first step, the positive plate prepared in the second step and a diaphragm together to prepare a winding core, packaging the winding core by using an aluminum plastic film to prepare a battery core, then performing the procedures of liquid injection, aging, formation, secondary packaging and the like, and finally testing the electrochemical performance of the battery.
Example 2
Otherwise as in example 1, the area of only the double coating was different, i.e., the area of the first coated region was 1/2 of the sum of the areas of the first coated region and the second coated region, as shown in fig. 4, where the areas of the first edge, the second edge, the third edge, and the fourth edge were all 1/8.
Example 3
The other was the same as in example 1 except that the compositions of slurry a and slurry B were different.
0.5 wt% of conductive carbon black, 1.3 wt% of styrene-butadiene rubber and 1.3 wt% of carboxymethyl cellulose are added into 96.9 wt% of graphite a, and then water is used for adjustment to prepare negative electrode slurry A. 1.0 wt% of conductive carbon black, 1.3 wt% of styrene-butadiene rubber and 1.3 wt% of carboxymethyl cellulose are added into 96.4 wt% of graphite B, and then water is used for adjustment to prepare negative electrode slurry B.
Example 4
The other is the same as the example 1 except that the coating method is different, as shown in fig. 3, a first coating area is arranged in the central area, the first edge and the third edge, and a second coating area is arranged in the second edge and the fourth edge;
coating the anode slurry a on a first coating region by a coating apparatus, i.e., integrally coating the anode slurry a on the first coating region to form a first anode active material layer; coating negative electrode slurry A and negative electrode slurry B on the second coating region through double-layer coating equipment, forming a first negative electrode active material layer and a second negative electrode active material layer, coating the first negative electrode active material layer on the surface of a negative electrode current collector, coating the second negative electrode active material layer on the surface of the first negative electrode active material layer, drying, rolling, slitting and tabletting to prepare the negative electrode piece.
Wherein the area of the first coated region is 1/3 (as shown in fig. 3, the areas of the first edge, the second edge, the third edge, and the fourth edge are all 1/6) of the sum of the areas of the first coated region and the second coated region.
Example 5
The other is the same as the example 1 except that the coating method is different, as shown in fig. 1, a first coating area is arranged in the central area, the second edge and the fourth edge, and a second coating area is arranged in the first edge and the third edge;
coating the anode slurry a on a first coating region by a coating apparatus, i.e., integrally coating the anode slurry a on the first coating region to form a first anode active material layer; coating negative electrode slurry A and negative electrode slurry B on the second coating region through double-layer coating equipment, forming a first negative electrode active material layer and a second negative electrode active material layer, coating the first negative electrode active material layer on the surface of a negative electrode current collector, coating the second negative electrode active material layer on the surface of the first negative electrode active material layer, drying, rolling, slitting and tabletting to prepare the negative electrode piece.
Wherein the area of the first coated region is 1/3 (as shown in fig. 1, the areas of the first edge, the second edge, the third edge, and the fourth edge are all 1/6) of the sum of the areas of the first coated region and the second coated region.
Comparative example 1
Otherwise, as in example 1, slurry a was coated only in a single layer.
Comparative example 2
Otherwise, as in example 1, slurry B was coated only in a single layer.
The lithium ion battery prepared by the method is subjected to the following performance tests, and the test process is as follows:
(1) normal temperature cycle test at 25 deg.C
Placing the battery in an environment of (25 +/-3) DEG C, standing for 3 hours, charging the battery to 4.45V according to 2C when the battery core body reaches (25 +/-3) DEG C, charging the battery to a cut-off current of 0.05C at a constant voltage of 4.45V, discharging the battery to 3V at a constant voltage of 0.7C, and recording the initial capacity Q0When the cycle reaches the required number, the previous discharge capacity is used as the capacity Q of the battery2The capacity retention (%) was calculated, and the results are reported in table 1. The calculation formula used therein is as follows:
capacity retention (%) ═ Q2/Q0×100％。
(2) High temperature cycle test at 45 deg.C
Placing the battery in an environment of (45 +/-3) DEG C, standing for 3 hours, when the battery core body reaches (45 +/-3) DEG C, charging the battery to 4.45V at a constant current of 2C and a constant voltage of 4.45V until the cut-off current is 0.05C, discharging at 0.7C, and recording the initial capacity Q0And cycling in such a manner that when the cycle reaches the required number of times, the previous discharge capacity is taken as the capacity Q of the battery3The capacity retention (%) was calculated, and the results are reported in table 1. The calculation formula used therein is as follows:
capacity retention (%) ═ Q3/Q0×100％。
Table 1 results of performance test of lithium ion batteries prepared in examples and comparative examples
Figure BDA0002710157050000111
By comparing the embodiment 1 with the comparative example 1, the energy density of the battery cell can be obviously improved but the quick charging performance can be greatly influenced by only coating the coating A;
by comparing the example 1 with the comparative example 2, the quick charging capacity can be improved by only coating the B coating, but the energy density of the cell can be obviously influenced;
in the examples 1, 4 and 5, the conditions of the same double-layer coating area and different coating positions are respectively considered, the overall energy density is similar, the difference of the quick charging capacity is not large, and the quick charging performance of the coating on the side of the tab is comprehensive and better;
in the examples 1 and 2, different double-layer coating areas are inspected, and under the condition of the same coating position, the energy density is relatively small when the coating area is large, and the quick charging performance is improved;
examples 1 and 3 examined two cells in the same coating position and the same area, wherein the upper layer of the conductive agent in example 3 is more, the quick-charging performance is better, and the energy density is relatively low.
The above summary addresses features of several embodiments, which enable one of ordinary skill in the art to more fully understand various aspects of the present application. Those skilled in the art can readily use the present application as a basis for designing or modifying other compositions for carrying out the same purposes and/or achieving the same advantages of the embodiments disclosed herein. Those skilled in the art should also realize that such equivalent embodiments do not depart from the spirit and scope of the present application, and that they may make various changes, substitutions and alterations herein without departing from the spirit and scope of the present application. Although the methods disclosed herein have been described with reference to specific operations being performed in a specific order, it should be understood that these operations may be combined, sub-divided, or reordered to form equivalent methods without departing from the teachings of the present application. Accordingly, unless specifically indicated herein, the order and grouping of the operations is not a limitation of the present application.
The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiment. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. A negative plate comprises a negative current collector, wherein a central area, a first edge, a second edge, a third edge and a fourth edge are arranged on a first surface of the negative current collector; the first edge, the second edge, the third edge and the fourth edge are arranged around the central area, and the first edge and the third edge are oppositely arranged; the second edge and the fourth edge are oppositely arranged;
wherein a first coated area is provided within the central region, the second edge, and the fourth edge, and a second coated area is provided within the first edge and the third edge; alternatively, the first and second electrodes may be,
a first coating area is arranged in the central area, the first edge and the third edge, and a second coating area is arranged in the second edge and the fourth edge; alternatively, the first and second electrodes may be,
a first coating area is arranged in the central area, and second coating areas are arranged in the first edge, the second edge, the third edge and the fourth edge;
the first coating area is provided with a first negative electrode active material layer which is coated on a first surface of the negative electrode current collector;
the second coating area is provided with a first negative electrode active material layer and a second negative electrode active material layer, the first negative electrode active material layer is coated on the first surface of the negative electrode current collector, and the second negative electrode active material layer is coated on the surface of the first negative electrode active material layer; the first anode active material layer includes a first anode active material, and the second anode active material layer includes a second anode active material;
a median particle diameter D of the first negative electrode active material50Larger than the median particle diameter D of the second negative electrode active material50。
2. The negative electrode sheet according to claim 1, wherein the negative electrode current collector has an extension portion extending beyond an edge in a width direction or a length direction of the negative electrode current collector, the extension portion forming a negative electrode tab.
3. The negative electrode sheet according to claim 1 or 2, wherein the first coating region is coated with the first negative electrode active material layer in an integrated manner.
4. The negative electrode sheet of any one of claims 1 to 3, wherein the widths of the first, second, third and fourth edges are the same or different.
5. Negative electrode sheet according to any of claims 1 to 4, wherein when a first coated region is provided within the central region, the second edge and the fourth edge, and a second coated region is provided within the first edge and the third edge; the sum of the areas of the first edge and the third edge accounts for 1/10-1/2 of the area of the negative electrode current collector, wherein the area of the negative electrode current collector is the sum of the areas of the central area, the first edge, the second edge, the third edge and the fourth edge; alternatively, the first and second electrodes may be,
when a first coated area is provided within the central region, the first edge and the third edge, and a second coated area is provided within the second edge and the fourth edge; the sum of the areas of the second edge and the fourth edge accounts for 1/10-1/2 of the area of the negative electrode current collector, wherein the area of the negative electrode current collector is the sum of the areas of the central area, the first edge, the second edge, the third edge and the fourth edge; alternatively, the first and second electrodes may be,
when a first coating area is arranged in the central area, and a second coating area is arranged in the first edge, the second edge, the third edge and the fourth edge; the sum of the areas of the first edge, the second edge, the third edge and the fourth edge accounts for 1/10-1/2 of the area of the negative current collector, wherein the area of the negative current collector is the sum of the areas of the central area, the first edge, the second edge, the third edge and the fourth edge.
6. The negative electrode sheet according to any one of claims 1 to 5, wherein the particle size distribution of the first negative electrode active material forming the first negative electrode active material layer is: 5 μm<D10<8μm，10μm<D50<20μm，20μm<D90<30 mu m; the particle size distribution of the second anode active material forming the second anode active material layer is: 5 μm<D10<8μm，6μm<D50<16μm，19μm<D90<30μm。
7. The negative electrode sheet according to any one of claims 1 to 6, wherein a thickness ratio of the first negative electrode active material layer and the second negative electrode active material layer in the first coating region is 3:7 to 7: 3.
8. The negative electrode sheet according to any one of claims 1 to 7, wherein the sum of the thicknesses of the first negative electrode active material layer and the second negative electrode active material layer in the second coating region is equal to the thickness of the first negative electrode active material layer in the first coating region.
9. The negative electrode sheet according to any one of claims 1 to 8, wherein a content of the first conductive agent forming the first negative electrode active material layer is smaller than a content of the second conductive agent forming the second negative electrode active material layer.
10. A lithium ion battery comprising the negative electrode sheet of any one of claims 1 to 9.
CN202011053193.9A 2020-09-29 2020-09-29 Negative plate and laminated lithium ion battery comprising same Active CN112086621B (en)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
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CN114142038B (en) * 2021-11-29 2023-11-24 珠海冠宇电池股份有限公司 Negative plate and lithium battery
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Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003100350A (en) * 2001-09-20 2003-04-04 Sony Corp Cell and its making method
JP2007172879A (en) * 2005-12-19 2007-07-05 Gs Yuasa Corporation:Kk Battery and its manufacturing method
CN101546844A (en) * 2008-03-26 2009-09-30 Tdk株式会社 Electrochemical device
JP2010262773A (en) * 2009-04-30 2010-11-18 Nissan Motor Co Ltd Manufacturing method of bipolar electrode, bipolar electrode, manufacturing method of bipolar secondary battery, bipolar secondary battery, battery pack, and vehicle
CN101981747A (en) * 2008-04-17 2011-02-23 株式会社Lg化学 Battery having enhanced electrical insulation capability
CN102842735A (en) * 2011-06-24 2012-12-26 夏普株式会社 Nonaqueous secondary battery and production method thereof
JP2013149403A (en) * 2012-01-18 2013-08-01 Hitachi Ltd Lithium ion secondary battery negative electrode, lithium ion secondary battery electrode using the same, and manufacturing method thereof
CN103548196A (en) * 2011-05-27 2014-01-29 丰田自动车株式会社 Bipolar all-solid-state battery
CN106058122A (en) * 2015-04-14 2016-10-26 丰田自动车株式会社 Separator for non-aqueous electrolyte secondary battery and manufacturing method thereof
CN107180995A (en) * 2016-03-11 2017-09-19 日立金属株式会社 Bipolar cascade type all solid lithium secondary battery and its manufacture method

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003100350A (en) * 2001-09-20 2003-04-04 Sony Corp Cell and its making method
JP2007172879A (en) * 2005-12-19 2007-07-05 Gs Yuasa Corporation:Kk Battery and its manufacturing method
CN101546844A (en) * 2008-03-26 2009-09-30 Tdk株式会社 Electrochemical device
CN101981747A (en) * 2008-04-17 2011-02-23 株式会社Lg化学 Battery having enhanced electrical insulation capability
JP2010262773A (en) * 2009-04-30 2010-11-18 Nissan Motor Co Ltd Manufacturing method of bipolar electrode, bipolar electrode, manufacturing method of bipolar secondary battery, bipolar secondary battery, battery pack, and vehicle
CN103548196A (en) * 2011-05-27 2014-01-29 丰田自动车株式会社 Bipolar all-solid-state battery
CN102842735A (en) * 2011-06-24 2012-12-26 夏普株式会社 Nonaqueous secondary battery and production method thereof
JP2013149403A (en) * 2012-01-18 2013-08-01 Hitachi Ltd Lithium ion secondary battery negative electrode, lithium ion secondary battery electrode using the same, and manufacturing method thereof
CN106058122A (en) * 2015-04-14 2016-10-26 丰田自动车株式会社 Separator for non-aqueous electrolyte secondary battery and manufacturing method thereof
CN107180995A (en) * 2016-03-11 2017-09-19 日立金属株式会社 Bipolar cascade type all solid lithium secondary battery and its manufacture method

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