CN114497448A - Pole piece, battery and electronic equipment - Google Patents
Pole piece, battery and electronic equipment Download PDFInfo
- Publication number
- CN114497448A CN114497448A CN202210124041.6A CN202210124041A CN114497448A CN 114497448 A CN114497448 A CN 114497448A CN 202210124041 A CN202210124041 A CN 202210124041A CN 114497448 A CN114497448 A CN 114497448A
- Authority
- CN
- China
- Prior art keywords
- lithium cobaltate
- battery
- particles
- pole piece
- cobaltate particles
- 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.)
- Pending
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
- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
- H01M4/131—Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/362—Composites
- H01M4/366—Composites as layered products
-
- 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
- H01M4/624—Electric conductive fillers
- H01M4/625—Carbon or graphite
-
- 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
- H01M2004/021—Physical characteristics, e.g. porosity, surface area
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Composite Materials (AREA)
- Manufacturing & Machinery (AREA)
- Inorganic Chemistry (AREA)
- Battery Electrode And Active Subsutance (AREA)
- Secondary Cells (AREA)
Abstract
The invention provides a pole piece, a battery and electronic equipment, relates to the technical field of batteries, and aims to solve the technical problem of poor power discharge cycle performance of the battery in the prior art, wherein the pole piece at least comprises: a substrate layer and two functional layers; the substrate layer is positioned between the two functional layers; the functional layer includes: a plurality of lithium cobaltate particles and a plurality of conductive particles dispersed around the lithium cobaltate particles; wherein the aluminum content in the lithium cobaltate particles is more than or equal to 4500 PPM. The battery provided by the embodiment of the invention can effectively improve the power discharge cycle performance of the battery under high voltage.
Description
Technical Field
The invention relates to the technical field of batteries, in particular to a pole piece, a battery and electronic equipment.
Background
With the continuous development of scientific technology, in order to improve the standby time of electronic equipment (such as computers or mobile phones), higher and higher requirements are put on the energy density of lithium ion batteries. For example, in order to increase the energy density of the lithium ion battery, the upper charging limit voltage of the lithium ion battery has been gradually expanded from the past 4.35V and 4.4V to 4.45V, 4.48V, 4.5V, and even higher.
Under the high-voltage use condition of 4.45V and above, some relatively more limited test results of the lithium battery show deviation. For example, in the lithium ion battery of the currently more commonly used high-voltage 4.45V charging voltage system, at an ambient temperature of 45 ℃ and under a constant power of 1.5CP, the continuous discharge of the common lithium ion battery can only meet the cycle life of about 400 times, and there is a large gap from the 500-800 times of requirements of the user. Therefore, how to effectively improve the power discharge cycle performance of the lithium ion battery becomes a difficult problem to be solved urgently.
Disclosure of Invention
In view of the above problems, embodiments of the present invention provide a pole piece, a battery and an electronic device, which can effectively improve the power discharge cycle performance of the battery under high voltage.
In order to achieve the above object, the embodiments of the present invention provide the following technical solutions:
a first aspect of an embodiment of the present invention provides a pole piece, where the pole piece at least includes: a substrate layer and two functional layers; the substrate layer is positioned between the two functional layers; the functional layer includes: a plurality of lithium cobaltate particles and a plurality of conductive particles dispersed around the lithium cobaltate particles; wherein the aluminum content in the lithium cobaltate particles is more than or equal to 4500 PPM.
In an alternative embodiment, the amount of aluminum in the lithium cobaltate particles is 4800PPM or more.
In an alternative embodiment, the mass ratio of the lithium cobaltate particles in the functional layer is 94% to 98.2%.
In an alternative embodiment, the mass ratio of the lithium cobaltate particles in the functional layer is 97.6% to 98.2%.
In an alternative embodiment, the mass ratio of the conductive particles in the functional layer is 0.9% to 4%.
In an alternative embodiment, the mass ratio of the conductive particles in the functional layer is 0.9% to 1.3%.
In an alternative embodiment, the conductive particles are any one or more of conductive carbon black, carbon nanotubes, and graphene.
In an alternative embodiment, the functional layer further comprises: an adhesive; the adhesive is dispersedly disposed between the plurality of lithium cobaltate particles and the plurality of conductive particles; the adhesive is used for bonding the lithium cobaltate particles and the conductive particles; the mass percentage of the adhesive in the functional layer is 0.9% -2%.
The second aspect of the embodiments of the present invention also provides a battery, which at least includes: the pole piece provided by the first aspect.
The third aspect of the embodiments of the present invention further provides an electronic device, including an electronic device body and the battery provided in the second aspect, where the battery provides electric energy for the electronic device body.
The pole piece, the battery and the electronic equipment provided by the embodiment of the invention have the following advantages:
in the battery provided by the embodiment of the invention, the pole pieces of the battery at least comprise the following stacked pole pieces: a substrate layer and two functional layers; the substrate layer is positioned between the two functional layers; the functional layer includes: a plurality of lithium cobaltate particles and a plurality of conductive particles dispersed around the lithium cobaltate particles; wherein the aluminum content in the lithium cobaltate particles is more than or equal to 4500 PPM. Compared with the prior art, the pole piece provided by the embodiment of the invention has the advantages that the aluminum content in the lithium cobaltate particles is higher, so that the structural stability of the lithium cobaltate particles is better, the impedance increase rate of the battery in power discharge cycle under high voltage can be reduced, and the power discharge cycle performance of the battery under high voltage can be effectively improved.
In addition to the technical problems solved by the embodiments of the present invention, the technical features constituting the technical solutions, and the advantages brought by the technical features of the technical solutions, other technical problems that can be solved by the pole piece, the battery, and the electronic device provided by the embodiments of the present invention, other technical features included in the technical solutions, and advantages brought by the technical features will be further described in detail in the detailed description.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and those skilled in the art can also obtain other drawings according to the drawings without creative efforts.
Fig. 1 is a schematic structural diagram of a pole piece in a battery provided in an embodiment of the present invention.
Description of reference numerals:
100-pole piece;
110-a substrate layer;
120-a functional layer;
121-lithium cobaltate particles;
122-conductive particles;
123-adhesive.
Detailed Description
With the continuous development of scientific technology, in order to improve the standby time of electronic equipment (such as computers or mobile phones), higher and higher requirements are put on the energy density of lithium ion batteries. For example, in order to increase the energy density of the lithium ion battery, the upper charging limit voltage of the lithium ion battery has been gradually expanded from the past 4.35V and 4.4V to 4.45V, 4.48V, 4.5V, and even higher. Meanwhile, the user puts forward higher demands on the fluency of the electronic equipment, especially on the condition that the electronic equipment does not have an external power supply, namely the lithium ion battery is expected to have the function which is equal to that when the external power supply is available, and the high-power continuous power supply of the lithium ion battery is supported so as to meet the fluency demand of the electronic equipment.
In order to meet the above requirements for electronic devices, based on the difference between lithium ion batteries (mainstream design 45Wh electric quantity/energy battery, supporting 45W power supply) and chargers supporting power (mainstream design supports 65W power supply), it is required to develop a lithium ion battery that can meet cycle life (capacity retention rate standard is greater than or equal to 80%) of 700 times or more under continuous discharge conditions of 1.5CP constant power at ambient temperature of 45 degrees celsius and under high voltage of 4.45V or more.
At present, for a lithium ion battery of a commonly used high-voltage 4.45V charging voltage system, the continuous discharge of a common lithium ion battery can only meet the cycle life of about 400 times (the capacity retention rate standard is more than or equal to 80%) at the ambient temperature of 45 ℃ and under the constant power of 1.5 CP. Therefore, how to effectively improve the power discharge cycle performance of the lithium ion battery becomes a difficult problem to be solved urgently.
In order to solve the above problem, in a battery (for example, a lithium ion battery) provided in an embodiment of the present invention, a pole piece of the battery at least includes: substrate layer and two functional layers, the substrate layer is located between two functional layers, and specifically, the functional layer includes: the lithium battery comprises a plurality of lithium cobaltate particles and a plurality of conductive particles dispersed around the lithium cobaltate particles, wherein the content of aluminum in the lithium cobaltate particles is larger than or equal to 4500 PPM. Compared with the prior art, the pole piece provided by the embodiment of the invention has the advantages that the aluminum content in the lithium cobaltate particles is higher, so that the structural stability of the lithium cobaltate particles is better, the impedance increase rate of the battery in power discharge cycle under high voltage can be reduced, and the power discharge cycle performance of the battery under high voltage can be effectively improved.
In order to make the aforementioned objects, features and advantages of the embodiments of the present invention more comprehensible, embodiments of the present invention are described in detail below with reference to the accompanying drawings. It is to be understood that the described embodiments are merely a few embodiments of the invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Fig. 1 is a schematic structural diagram of a pole piece in a battery provided in an embodiment of the present invention.
As shown in fig. 1, an embodiment of the present invention provides a pole piece 100, where the pole piece 100 can be applied to a battery (e.g., a lithium ion battery). The pole piece 100 may include at least: a substrate layer 110 and two functional layers 120, wherein the substrate layer 110 is located between the two functional layers 120.
Of course, based on the structural design requirement of the battery, the pole piece 100 may also have only one functional layer 120, that is, only one side of the substrate layer 110 has the functional layer 120, which is not limited in this embodiment of the present invention.
As shown with continued reference to fig. 1, the functional layer 120 may be an active material layer, and in particular, the functional layer 120 may include: a plurality of lithium cobaltate particles 121 and a plurality of conductive particles 122 dispersed around the lithium cobaltate particles 121, wherein, in order to ensure that the lithium cobaltate particles 121 have a sufficient high temperature resistant structure and reduce the impedance growth rate during cycling, the content of the metal element doped coating in the lithium cobaltate particles 121 may be 4500PPM (parts per million concentration) or more, that is, the content of aluminum in the lithium cobaltate particles 121 may be 4500PPM or more, and the content of the coated aluminum is to improve the structural stability of the lithium cobaltate particles 121.
Thus, compared with the prior art, in the electrode plate 100 provided by the embodiment of the invention, the content of aluminum in the lithium cobaltate particles 121 is higher, so that the structural stability of the lithium cobaltate particles 121 is better, the impedance increase rate of the battery in power discharge cycle under high voltage can be reduced, and the power discharge cycle performance of the battery under high voltage can be effectively improved.
For example, the content of aluminum in the lithium cobaltate particles 121 may be 4500PPM, 4800PPM, 5000PPM, 5500PPM, 6000PPM, 6500PPM, or the like, which is not limited by the embodiments of the present invention.
It is understood that in embodiments of the present invention, the pole piece 100 may be a positive pole piece. Of course, in some other embodiments, the pole piece 100 may also serve as a negative pole piece. The active material in the negative electrode sheet may be any one or more of graphite, a silicon-oxygen negative electrode, or lithium titanate.
It should be noted that, in the embodiment of the present invention, in order to improve the high power discharge cycle capability of the battery at a high voltage, it is essentially required to reduce the impedance increase rate of the battery. Considering that the proportion of the impedance of the positive plate to the overall impedance of the battery is 60% or more, the embodiment of the invention is mainly optimized from the design of the positive plate, so that the impedance increase rate of the battery is expected to be reduced by optimizing the positive plate, the 1.5CP constant power discharge cycle capacity of the battery at the ambient temperature of 45 ℃ is further improved, and the current supported 400 cycles is further improved to 700 cycles (the capacity retention rate standard is more than or equal to 80%).
Based on the above description, in the design of the electrode sheet 100, the embodiment of the present invention introduces a lithium cobaltate material (i.e., lithium cobaltate particles 121) with a more stable structure, so as to reduce the impedance change rate of the battery under the condition of high-power discharge cycle.
In addition, the battery is taken as a lithium ion battery as an example, and a test method for evaluating the high-power discharge cycle capability of the lithium ion battery is described.
Under the constant temperature environment of 45 ℃, under the constant current and the constant voltage of 1.5 ℃, the lithium ion battery is fully charged to 100% SOC (state of charge), the charge cut-off voltage is 4.45V, the cut-off current is 0.05C, the lithium ion battery is static for 10min, 0.5CP (conventional discharge cycle power) is set, or the 1.5CP constant power is discharged to 3.0V, the lithium ion battery is cycled for 700 times according to the method, if the capacity retention rate is more than 80% after the cycle, the lithium ion battery is judged to be qualified, otherwise, the lithium ion battery is judged to be unqualified.
It should be noted that the charge cut-off voltage mentioned above is not limited to 4.45V, and may be 4.48V, 4.5V or higher, and the like, and the embodiment of the present invention is not limited thereto. Under different charge cut-off voltages, the scheme provided by the embodiment of the invention has the advantage that the cycle performance of the lithium ion battery is improved.
Next, a calculation method for evaluating the impedance of the lithium ion battery will be described.
And (3) after the lithium ion battery discharges for 20min under a certain power, calculating the voltage drop change delta U of the lithium ion battery. The larger Δ represents the larger impedance value of the lithium ion battery. The Δ U was calculated by recording the voltage U1 after leaving to stand for 10min after full charge, and recording the voltage U2 after 20min from the start of discharge, Δ U being U1-U2.
The rate of change of voltage drop is then calculated. For example, if Δ U of cycle 1 is recorded as Δ U1, and Δ U of cycle 700 is recorded as Δ U2, the rate of change is (Δ U2- Δ U1)/Δ U1 × 100%, and the larger the rate of change of voltage drop, the larger the rate of change of impedance of the lithium ion battery is (since the current is dynamically changed in consideration of constant temperature power discharge, the impedance change is measured by the voltage drop and the rate of change of voltage drop).
Of course, in the embodiment of the present invention, in order to further improve the structural stability of the lithium cobaltate particles 121, the content of aluminum in the lithium cobaltate particles 121 may be 4800PPM or more.
In the embodiment of the present invention, the mass ratio of the lithium cobaltate particles 121 in the functional layer 120 may be 94% to 98.2%. Specifically, in some embodiments, the mass ratio of the lithium cobaltate particles 121 in the functional layer 120 may be 97.6% to 98.2%.
Illustratively, in the embodiment of the present invention, the mass ratio of the lithium cobaltate particles 121 in the functional layer 120 may be 97.6%, 97.7%, 97.8%, 97.9%, 98.0%, 98.1%, 98.2%, or the like, which is not limited by the embodiment of the present invention, and is not limited to the above example.
In addition, in the embodiment of the present invention, the mass ratio of the conductive particles 122 in the functional layer 120 may be 0.9% to 4%. Specifically, in some embodiments, the mass fraction of the conductive particles 122 in the functional layer 120 may be 0.9% to 1.3%.
Illustratively, in the embodiment of the present invention, the mass ratio of the conductive particles 122 in the functional layer 120 may be 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, or the like, which is not limited by the embodiment of the present invention.
It is easy to understand that after the lithium cobaltate particles 121 with a more stable structure are introduced into the electrode sheet 100, on the premise of meeting the power discharge requirement, the required content of the conductive agent (i.e., the conductive particles 122) in the electrode sheet 100 can be reduced, so that the mass ratio of the lithium cobaltate particles 121 can be properly increased, and the energy density of the battery can be improved accordingly.
Taking the design of the positive plate of the 4.45V system as an example, after the addition amount of the conductive particles 122 in the positive plate is reduced, the content of the lithium cobaltate particles 121 can be increased by 0.7-3.1%, and the energy density of the battery can be improved by 1-4%.
Based on the design, the battery assembled by the prepared positive plate has 1.5CP constant power continuous discharge circulation at the ambient temperature of 45 ℃, and the capacity retention rate of the battery can reach more than 80% after 700 cycles. The battery made of the pole piece in the prior art can only support 400 cycles (the capacity retention rate standard is more than 80%) under the condition that other designs are the same and the same cycle condition is maintained. Therefore, by combining the above results, the embodiment of the invention has a significant effect of improving the high-power discharge cycle performance under high voltage.
It should be particularly noted that the electrode sheet 100 (e.g., positive electrode sheet) provided in the embodiment of the present invention can be applied not only to a voltage system of 4.45V or less, but also to any voltage system between 3.0V and 4.45V, for example, the charge cut-off voltage can be 4.4V, 4.35V, 4.3V, 4.2V, or 4.0V, and the above power discharge cycle performance can also be simultaneously achieved.
The above-mentioned charge cut-off voltage may be 4.45V or more, for example, the charge cut-off voltage may be 4.48V, 4.5V or higher, and the embodiment of the present invention is not limited thereto. The scheme provided by the embodiment of the invention has the advantage that the cycling performance of the battery is improved under different charge cut-off voltages.
It is understood that the higher the voltage system applied to the electrode sheet 100 (e.g., positive electrode sheet), the higher the lower limit range of the aluminum content in the lithium cobaltate particles 121 is required to be.
In the embodiment of the present invention, the conductive particles 122 may be any one or more of conductive carbon black, carbon nanotubes, and graphene.
For example, the conductive particles 122 may be conductive carbon black, carbon nanotubes, or graphene, the conductive particles 122 may also be a composite material composed of conductive carbon black and carbon nanotubes, a composite material composed of carbon nanotubes and graphite, or a composite material composed of conductive carbon black and graphene, and the conductive particles 122 may also be a composite material composed of conductive carbon black, carbon nanotubes, and graphene.
In addition, in the embodiment of the present invention, the functional layer 120 may further include: and an adhesive 123, the adhesive 123 being disposed between the plurality of lithium cobaltate particles 121 and the plurality of conductive particles 122 in a dispersed manner, the adhesive 123 being used to bond the lithium cobaltate particles 121 and the conductive particles 122.
In one possible implementation manner, the mass ratio of the adhesive 123 in the functional layer 120 may be 0.9% to 2%. For example, in the embodiment of the present invention, the mass ratio of the adhesive 123 in the functional layer 120 may be 0.9%, 1.2%, 1.5%, 1.8%, 2%, or the like, and the embodiment of the present invention does not limit this, and is not limited to the above example.
In the embodiment of the present invention, the substrate layer 110 may be an aluminum foil or an aluminum-plated film. That is, in the electrode sheet 100 provided in the embodiment of the present invention, the functional layer 120 may be disposed on the upper surface and the lower surface of the aluminum foil or the aluminum-plated film.
In the embodiment of the present invention, the thickness of the substrate layer 110 may be 5 to 18 um. Illustratively, the thickness of the substrate layer 110 may be 5um, 7um, 9um, 11um, 13um, 15um, 17um, 18um, etc., which is not limited by the embodiments of the present invention.
In an embodiment of the present invention, the thickness of the functional layer 120 may be 30-100 um. Wherein, as a possible implementation manner, the thickness of the functional layer 120 may be 73-86 um. Illustratively, the thickness of the functional layer 120 may be 73um, 75um, 78um, 80um, 82um, 85um, or 86um, etc., which is not limited by the embodiments of the present invention.
In addition, in the embodiment of the present invention, the area density of the lithium cobaltate particles 121 may be 18mg/cm2 or less. Illustratively, the area density of the lithium cobaltate particles 121 may be 18um, 17um, 16um, 15um, 14um, 13um, 12um, 11um, or 10um, etc., which is not limited by the embodiment of the present invention.
In the embodiment of the present invention, the adhesive 123 may be any one or more of polyvinylidene fluoride and modified polyvinylidene fluoride. For example, the adhesive 123 may be polyvinylidene fluoride or modified polyvinylidene fluoride, and the conductive particles 122 may be a composite material composed of both polyvinylidene fluoride and modified polyvinylidene fluoride.
In the embodiment of the present invention, among the plurality of lithium cobaltate particles 121, the particle size distribution of the lithium cobaltate particles 121 may satisfy D10 < 6.5 μm, D50 < 16 μm, and D90 < 30 μm. That is, of the plurality of lithium cobaltate particles 121, 10% of the lithium cobaltate particles 121 have a particle size of less than 6.5 μm, 50% of the lithium cobaltate particles 121 have a particle size of less than 16 μm, and 90% of the lithium cobaltate particles 121 have a particle size of less than 30 μm.
It should be noted that the numerical values and numerical ranges related to the embodiments of the present invention are approximate values, and there may be a certain range of errors depending on the manufacturing process, and the error may be considered as negligible by those skilled in the art.
In the battery provided in the embodiment of the present invention, the pole piece 100 of the battery may at least include: substrate layer 110 and two functional layers 120, substrate layer 110 is located between two functional layers 120, and functional layer 120 may include: a plurality of lithium cobaltate particles 121 and a plurality of conductive particles 122 dispersed around the lithium cobaltate particles 121, wherein the aluminum content in the lithium cobaltate particles 121 is equal to or greater than 4500 PPM. Thus, compared with the prior art, in the electrode plate 100 provided by the embodiment of the invention, the content of aluminum in the lithium cobaltate particles 121 is higher, so that the structural stability of the lithium cobaltate particles 121 is better, the impedance increase rate of the battery in power discharge cycle under high voltage can be reduced, and the power discharge cycle performance of the battery under high voltage can be effectively improved.
In addition, the embodiment of the invention also introduces a manufacturing method of the pole piece 100. Specifically, taking a battery as a lithium ion battery and taking a pole piece 100 in the lithium ion battery as a positive pole piece as an example, the manufacturing method of the positive pole piece is as follows:
firstly, mixing lithium cobaltate particles 121 with a more stable structure (namely, lithium cobaltate particles 121 with the aluminum content of 4500PPM or more), conductive particles 122 and an adhesive 123 in a solvent according to a certain proportion to form slurry, uniformly coating the slurry on a substrate layer 110, and drying to form the positive plate of the lithium ion battery. And then, rolling, slitting and flaking the prepared positive plate, winding the positive plate, the negative plate and the diaphragm together to form a roll core, and packaging, injecting liquid, aging, forming, secondary sealing and sorting to form the lithium ion battery.
It is understood that the above procedures are all conventional operations in the art, and are not described in detail herein.
In the embodiment of the present invention, the active material in the negative electrode sheet used in the lithium ion battery may be any one or more of graphite, a silicon-oxygen negative electrode, lithium titanate, and the like, and the embodiment of the present invention is not limited to this and is not limited to the above examples.
In addition, the other materials related to the solvent, the membrane and the like are also common materials in the field, and are not described in detail herein.
Next, in the embodiment of the present invention, four different application scenarios of the pole piece 100 (taking a positive pole piece as an example) and the manufacturing method of the lithium ion battery are given, and are compared with two application scenarios in the prior art.
Scene one
Firstly, adding 98 wt% of lithium cobaltate A (lithium cobaltate particles with a more stable structure and a metal element doping coating amount meeting the Al content of 6000 PPM), 1 wt% of polyvinylidene fluoride (PVDF), 0.5 wt% of carbon nanotubes and 0.5 wt% of conductive carbon black into N-Methylpyrrolidone (NMP) to be uniformly mixed to prepare slurry, coating the slurry on an aluminum foil with the thickness of 9 mu m, and drying to form a positive plate.
Then, the positive electrode sheet obtained as described above was rolled, and the thickness of the functional layer 120 was 80 μm. And then, winding the obtained positive plate, a diaphragm and a negative plate to obtain a winding core, packaging, injecting, aging, forming, secondary sealing and sorting to obtain the lithium ion battery with the battery capacity of 4000mAh, and performing 0.5CP and 1.5CP power discharge cycle tests respectively at the environmental temperature of 45 ℃ for reporting and checking.
Scene two
Firstly, 96.5 wt% of lithium cobaltate A (lithium cobaltate particles with a more stable structure and a metal element doping coating amount meeting Al content of 6000 PPM), 1.5 wt% of PVDF, 1 wt% of carbon nanotubes and 1 wt% of conductive carbon black are added into NMP and uniformly mixed to prepare slurry, the slurry is coated on an aluminum foil with the thickness of 9 mu m, and the slurry is dried to form a positive plate.
Then, the positive electrode sheet obtained as described above was rolled, and the thickness of the functional layer 120 was 82 μm. And then, winding the obtained positive plate, a diaphragm and a negative plate to obtain a winding core, packaging, injecting, aging, forming, secondary sealing and sorting to obtain the lithium ion battery with the battery capacity of 4000mAh, and performing 0.5CP and 1.5CP power discharge cycle tests respectively at the environmental temperature of 45 ℃ for reporting and checking.
Scene three
Firstly, adding 98 wt% of lithium cobaltate B (lithium cobaltate particles with a more stable structure and a metal element doping coating amount meeting the Al content of 4800 PPM), 1 wt% of PVDF, 0.5 wt% of carbon nanotubes and 0.5 wt% of conductive carbon black into NMP, uniformly mixing to prepare slurry, coating on an aluminum foil with the thickness of 9 mu m, and drying to form the positive plate.
Then, the positive electrode sheet obtained as described above was rolled, and the thickness of the functional layer 120 was 80 μm. And then, winding the obtained positive plate, a diaphragm and a negative plate to obtain a winding core, packaging, injecting, aging, forming, secondary sealing and sorting to obtain the lithium ion battery with the battery capacity of 4000mAh, and performing 0.5CP and 1.5CP power discharge cycle tests respectively at the environmental temperature of 45 ℃ for reporting and checking.
Scene four
Firstly, 96.5 wt% of lithium cobaltate A (lithium cobaltate particles with a more stable structure and a metal element doping coating amount meeting the Al content of 4800 PPM), 1.5 wt% of PVDF, 1 wt% of carbon nanotubes and 1 wt% of conductive carbon black are added into NMP to be uniformly mixed to prepare slurry, the slurry is coated on an aluminum foil with the thickness of 9 mu m, and the aluminum foil is dried to form a positive plate.
Then, the positive electrode sheet obtained as described above was rolled, and the thickness of the functional layer 120 was 82 μm. And then, winding the obtained positive plate, a diaphragm and a negative plate to obtain a winding core, packaging, injecting, aging, forming, secondary sealing and sorting to obtain the lithium ion battery with the battery capacity of 4000mAh, and performing 0.5CP and 1.5CP power discharge cycle tests respectively at the environmental temperature of 45 ℃ for reporting and checking.
COMPARATIVE EXAMPLE I (PRIOR ART)
Firstly, adding 98 wt% of lithium cobaltate C (lithium cobaltate particles with metal element doping coating amount meeting the Al content of 4000 PPM), 1 wt% of PVDF, 0.5 wt% of carbon nanotubes and 0.5 wt% of conductive carbon black into NMP, uniformly mixing to prepare slurry, coating on an aluminum foil with the thickness of 9 mu m, and drying to form the positive plate.
Then, the positive electrode sheet obtained as described above was rolled, and the thickness of the functional layer 120 was 80 μm. And then, winding the obtained positive plate, a diaphragm and a negative plate to obtain a winding core, packaging, injecting, aging, forming, secondary sealing and sorting to obtain the lithium ion battery with the battery capacity of 4000mAh, and performing 0.5CP and 1.5CP power discharge cycle tests respectively at the environmental temperature of 45 ℃ for reporting and checking.
COMPARATIVE EXAMPLE II (PRIOR ART)
Firstly, 96.5 wt% of lithium cobaltate C (lithium cobaltate particles with the metal element doping coating amount meeting the Al content of 4000 PPM), 1.5 wt% of PVDF, 1 wt% of carbon nanotubes and 1 wt% of conductive carbon black are added into NMP and uniformly mixed to prepare slurry, the slurry is coated on an aluminum foil with the thickness of 9 mu m, and the aluminum foil is dried to form the positive plate.
Then, the positive electrode sheet obtained as described above was rolled, and the thickness of the functional layer 120 was 82 μm. And then, winding the obtained positive plate, a diaphragm and a negative plate to obtain a winding core, packaging, injecting, aging, forming, secondary sealing and sorting to obtain the lithium ion battery with the battery capacity of 4000mAh, and performing 0.5CP and 1.5CP power discharge cycle tests respectively at the environmental temperature of 45 ℃ for reporting and checking.
For the different scenarios described above, the results of the 0.5CP discharge cycle test are compared as follows:
from the above table, it can be seen that, the retention rate and the voltage drop change rate of 0.5CP cycle of lithium cobaltate with different Al contents and the positive electrode sheets with different conductive agent contents have no significant difference.
1.5CP discharge cycle test results are as follows:
as can be seen from the above table, when the Al content is 4000PPM and the addition amount of the conductive agent is 1%, the 1.5CP discharge can support 400 cycles (the capacity retention rate standard is more than 80%). When the content of the conductive agent is increased to 2%, 500 cycles can be supported.
When the Al content is 4800PPM or 6000PPM, 700 cycles can be supported by 1.5CP discharge (the standard of the capacity retention rate is more than 80%). When the content of the conductive agent is increased to 2%, the capacity retention rate can be improved by 1% -2%, but the capacity retention rate is not obviously improved.
Therefore, on the premise of ensuring the requirement of improving the cycle number, the lithium cobaltates A and B with more stable structures are used, the designed content of the conductive agent is maintained to be 1%, and the energy density of the corresponding lithium ion battery can be effectively improved by about 1.2%.
The embodiment of the present invention further provides a battery, which at least includes the pole piece 100 provided in the first embodiment.
Other technical features are the same as those of the first embodiment and can achieve the same technical effects, and are not described herein.
In the battery provided in the embodiment of the present invention, the pole piece 100 of the battery at least includes: substrate layer 110 and two functional layers 120, substrate layer 110 is located between two functional layers 120, and functional layer 120 may include: a plurality of lithium cobaltate particles 121 and a plurality of conductive particles 122 dispersed around the lithium cobaltate particles 121, wherein the aluminum content in the lithium cobaltate particles 121 is equal to or greater than 4500 PPM. Thus, compared with the prior art, in the electrode plate 100 provided by the embodiment of the invention, the content of aluminum in the lithium cobaltate particles 121 is higher, so that the structural stability of the lithium cobaltate particles 121 is better, the impedance increase rate of the battery in power discharge cycle under high voltage can be reduced, and the power discharge cycle performance of the battery under high voltage can be effectively improved.
The embodiment of the invention also provides electronic equipment, which can comprise an electronic equipment body and the battery provided in the second embodiment, wherein the battery is used for providing electric energy for the electronic equipment body.
The electronic device body may be a wearable electronic device or other electronic products, or may also be a medical electronic device used in medical treatment, and the like, which is not limited in the embodiments of the present invention.
Other technical features are the same as those of the first embodiment and the second embodiment, and the same technical effects can be achieved, and are not described in detail herein.
The electronic device provided by the embodiment of the present invention may include an electronic device body and a battery for providing electric energy to the electronic device body, wherein the pole piece 100 of the battery at least includes: substrate layer 110 and two functional layers 120, substrate layer 110 is located between two functional layers 120, and functional layer 120 may include: a plurality of lithium cobaltate particles 121 and a plurality of conductive particles 122 dispersed around the lithium cobaltate particles 121, wherein the aluminum content in the lithium cobaltate particles 121 is equal to or greater than 4500 PPM. Thus, compared with the prior art, in the electrode plate 100 provided by the embodiment of the invention, the content of aluminum in the lithium cobaltate particles 121 is higher, so that the structural stability of the lithium cobaltate particles 121 is better, the impedance increase rate of the battery in power discharge cycle under high voltage can be reduced, and the power discharge cycle performance of the battery under high voltage can be effectively improved.
The embodiments or implementation modes in the present specification are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments may be referred to each other.
In the description of the present specification, references to "one embodiment", "some embodiments", "an illustrative embodiment", "an example", "a specific example", or "some examples", etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
Finally, it should be noted that: the above embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same, although the present invention is described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it is to be understood that modifications may be made to the technical solutions described in the foregoing embodiments, or some or all of the technical features may be equivalently replaced, and the modifications or the replacements may not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.
Claims (10)
1. A pole piece comprising at least in stacked arrangement:
a substrate layer and two functional layers;
the substrate layer is positioned between the two functional layers;
the functional layer includes: a plurality of lithium cobaltate particles and a plurality of conductive particles dispersed around the lithium cobaltate particles; wherein the aluminum content in the lithium cobaltate particles is more than or equal to 4500 PPM.
2. The electrode sheet of claim 1, wherein the lithium cobaltate particles comprise aluminum in an amount of 4800PPM or greater.
3. The pole piece of claim 1, wherein the mass ratio of the lithium cobaltate particles in the functional layer is 94-98.2%.
4. The pole piece of claim 3, wherein the mass ratio of the lithium cobaltate particles in the functional layer is 97.6-98.2%.
5. The pole piece of claim 1, wherein the mass percentage of the conductive particles in the functional layer is 0.9-4%.
6. The pole piece of claim 5, wherein the mass ratio of the conductive particles in the functional layer is 0.9-1.3%.
7. The pole piece of any one of claims 1 to 6, wherein the conductive particles are any one or more of conductive carbon black, carbon nanotubes and graphene.
8. The pole piece of any one of claims 1 to 6, wherein the functional layer further comprises: an adhesive;
the adhesive is dispersedly disposed between the plurality of lithium cobaltate particles and the plurality of conductive particles; the adhesive is used for bonding the lithium cobaltate particles and the conductive particles;
the mass percentage of the adhesive in the functional layer is 0.9% -2%.
9. A battery, characterized by comprising at least: the pole piece of any one of claims 1 to 8.
10. An electronic device, comprising: an electronic device body and the battery according to claim 9;
wherein the battery provides electric energy for the electronic equipment body.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210124041.6A CN114497448A (en) | 2022-02-10 | 2022-02-10 | Pole piece, battery and electronic equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210124041.6A CN114497448A (en) | 2022-02-10 | 2022-02-10 | Pole piece, battery and electronic equipment |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114497448A true CN114497448A (en) | 2022-05-13 |
Family
ID=81478553
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210124041.6A Pending CN114497448A (en) | 2022-02-10 | 2022-02-10 | Pole piece, battery and electronic equipment |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114497448A (en) |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109950482A (en) * | 2019-02-22 | 2019-06-28 | 南通金通储能动力新材料有限公司 | A kind of preparation method of aluminium doping lithium cobaltate cathode material |
| US20190221845A1 (en) * | 2016-12-21 | 2019-07-18 | Lg Chem, Ltd. | Metal-Doped Positive Electrode Active Material For High Voltage |
| CN110797530A (en) * | 2019-09-26 | 2020-02-14 | 惠州锂威新能源科技有限公司 | High-voltage lithium cobalt oxide graphite battery and preparation method thereof |
| US20200067091A1 (en) * | 2018-08-24 | 2020-02-27 | LG Chem, Ltd., Seoul, KOREA, REPUBLIC OF | Positive Electrode Active Material for Lithium Rechargeable Battery, Method of Producing the Same, and Lithium Rechargeable Battery Including the Same |
| US20200259172A1 (en) * | 2017-11-13 | 2020-08-13 | Lg Chem, Ltd. | Lithium Cobalt-Based Positive Electrode Active Material, Preparation Method Thereof, Positive Electrode and Secondary Battery Including the Same |
| CN112531151A (en) * | 2020-10-28 | 2021-03-19 | 珠海冠宇电池股份有限公司 | Positive plate and application thereof |
| CN113193169A (en) * | 2021-04-30 | 2021-07-30 | 珠海冠宇电池股份有限公司 | Positive plate and battery |
| CN113285059A (en) * | 2021-06-11 | 2021-08-20 | 珠海冠宇电池股份有限公司 | Positive plate and battery |
| CN113285058A (en) * | 2021-06-11 | 2021-08-20 | 珠海冠宇电池股份有限公司 | Positive plate and battery |
-
2022
- 2022-02-10 CN CN202210124041.6A patent/CN114497448A/en active Pending
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20190221845A1 (en) * | 2016-12-21 | 2019-07-18 | Lg Chem, Ltd. | Metal-Doped Positive Electrode Active Material For High Voltage |
| US20200259172A1 (en) * | 2017-11-13 | 2020-08-13 | Lg Chem, Ltd. | Lithium Cobalt-Based Positive Electrode Active Material, Preparation Method Thereof, Positive Electrode and Secondary Battery Including the Same |
| US20200067091A1 (en) * | 2018-08-24 | 2020-02-27 | LG Chem, Ltd., Seoul, KOREA, REPUBLIC OF | Positive Electrode Active Material for Lithium Rechargeable Battery, Method of Producing the Same, and Lithium Rechargeable Battery Including the Same |
| CN109950482A (en) * | 2019-02-22 | 2019-06-28 | 南通金通储能动力新材料有限公司 | A kind of preparation method of aluminium doping lithium cobaltate cathode material |
| CN110797530A (en) * | 2019-09-26 | 2020-02-14 | 惠州锂威新能源科技有限公司 | High-voltage lithium cobalt oxide graphite battery and preparation method thereof |
| CN112531151A (en) * | 2020-10-28 | 2021-03-19 | 珠海冠宇电池股份有限公司 | Positive plate and application thereof |
| CN113193169A (en) * | 2021-04-30 | 2021-07-30 | 珠海冠宇电池股份有限公司 | Positive plate and battery |
| CN113285059A (en) * | 2021-06-11 | 2021-08-20 | 珠海冠宇电池股份有限公司 | Positive plate and battery |
| CN113285058A (en) * | 2021-06-11 | 2021-08-20 | 珠海冠宇电池股份有限公司 | Positive plate and battery |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US11522168B2 (en) | Negative electrode sheet, preparation method thereof and lithium ion battery containing the same | |
| CN105742613A (en) | Negative pole piece and lithium-ion battery | |
| JP2015513190A (en) | Electrode assembly, battery cell and device including the same | |
| US10388957B2 (en) | Lithium ion battery electrode | |
| CN113555522B (en) | Pole piece and battery | |
| CN108604667B (en) | Electrode for secondary battery including electrode protection layer | |
| KR20150135434A (en) | Collector, electrode structure, nonaqueous electrolyte battery, and electricity storage component | |
| CN113594408A (en) | Negative plate and battery | |
| US20240128601A1 (en) | Electrode piece, rolled core and battery | |
| CN112349953A (en) | Lithium ion battery | |
| CN114204038B (en) | Current collector and application thereof | |
| CN115275109A (en) | Long-cycle lithium iron phosphate thick electrode, preparation method thereof and lithium ion battery | |
| WO2022156459A1 (en) | Negative electrode sheet of lithium ion battery, lithium ion battery and electronic device | |
| CN112002935A (en) | Lithium ion battery and manufacturing method thereof | |
| CN114678491B (en) | Negative electrode plate, preparation method thereof and electrochemical device | |
| CN114497448A (en) | Pole piece, battery and electronic equipment | |
| CN113707843B (en) | Cell and electrochemical device | |
| WO2022143262A1 (en) | Energy storage device | |
| CN212161973U (en) | Electrode sheet and secondary battery | |
| CN114512670A (en) | Negative plate and battery comprising same | |
| CN110611119B (en) | Composite solid electrolyte and preparation method and application thereof | |
| CN104916834A (en) | Manufacturing method for high-voltage lithium ion anode material | |
| CN111554899A (en) | Mixing method of electrode slurry | |
| CN220553478U (en) | Quick-charging lithium ion battery | |
| CN116705987B (en) | Negative plate, electrochemical device and preparation method of electrochemical device |
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 |