CN113078374A - Symmetric battery and test method - Google Patents
Symmetric battery and test method Download PDFInfo
- Publication number
- CN113078374A CN113078374A CN202110319228.7A CN202110319228A CN113078374A CN 113078374 A CN113078374 A CN 113078374A CN 202110319228 A CN202110319228 A CN 202110319228A CN 113078374 A CN113078374 A CN 113078374A
- Authority
- CN
- China
- Prior art keywords
- electrode
- symmetrical
- battery
- core
- counter electrode
- 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
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/36—Accumulators not provided for in groups H01M10/05-H01M10/34
- H01M10/38—Construction or manufacture
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
- G01R31/389—Measuring internal impedance, internal conductance or related variables
-
- 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
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Secondary Cells (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
The invention discloses a symmetrical battery, which comprises a first winding core, an isolation film and a second winding core, wherein the first winding core, the isolation film and the second winding core are packaged together by an aluminum plastic film, the first winding core consists of a first symmetrical electrode, a first diaphragm and an upper counter electrode, and the second winding core consists of a second symmetrical electrode, a second diaphragm and a lower counter electrode. The manufacturing process of the symmetrical battery is simple and easy to implement, the battery core does not need to be additionally disassembled and reassembled, and the influence of external interference on the test result is greatly reduced; the charge state control method of the symmetrical battery is very convenient, and only the first winding core and the second winding core are required to be respectively subjected to charge and discharge control according to the set charge states; after selecting a proper active material, the symmetrical battery system can be used as a three-electrode system for performance evaluation, and more test results with reference functions can be obtained.
Description
Technical Field
The invention relates to the field of lithium ion batteries, in particular to a symmetrical battery and a test method.
Background
Lithium ion batteries have been widely used in the digital field since now due to their high energy density, high power density and long cycle life characteristics, and have gradually replaced nickel-cadmium batteries and nickel-hydrogen batteries to become the mainstream of digital batteries. With the introduction of various novel high-performance materials, the application field of the lithium ion battery is expanded to the fields of power, energy storage and the like, the market share of the lithium ion battery exceeds that of a lead-acid storage battery, and a very large growth space exists in the future.
The performance of the lithium ion battery can be improved without introducing high-performance key materials. For this reason, accurate assessment of material properties is critical to material development. Currently, button cell and full cell methods are generally adopted for material performance evaluation. The button cell itself adopts lithium metal as a negative electrode, and is an important method for evaluating gram capacity and first efficiency of positive and negative electrode materials. The full battery is a common technical means in battery cell development, and can be used for evaluating basic electrical properties of the battery cell, such as capacity, multiplying power, high and low temperature, circulation, safety and other properties. In order to better monitor the performance change conditions of various materials under the conditions of no charge, charged state, different charge states and multiple charge and discharge, different technical means need to be developed for evaluation. Based on the purposes, researchers develop a symmetrical battery technology to better understand the change rule of the electrode material performance and develop a key material and a battery system with better performance.
At present, the common symmetrical battery technology usually adopts a mode of disassembling different single batteries with set charge states, and then taking out the target pole piece with the same polarity and the diaphragm to assemble the battery core. The method has strict requirements on environment, and needs to carry out the assembly operation of the battery cell in a closed environment with controlled moisture and oxygen content.
Disclosure of Invention
Aiming at the problems, the invention aims to provide a symmetrical battery with low manufacturing cost and good stability and a testing method. The prepared symmetrical battery can conveniently control the charge state of the target pole piece, and is convenient for evaluating the relevant electrical properties of the positive and negative pole materials.
In order to realize the technical purpose, the scheme of the invention is as follows: the utility model provides a symmetrical battery, includes and rolls up core, barrier film and second by the first book of plastic-aluminum membrane encapsulation together, first book core comprises first symmetrical electrode, first diaphragm and last counter electrode, and the second rolls up core comprises second symmetrical electrode, second diaphragm and lower counter electrode.
Preferably, the first symmetrical electrode, the upper counter electrode, the second symmetrical electrode and the lower counter electrode are all in a single-layer structure,
the first symmetrical electrode and the second symmetrical electrode are arranged in a face-to-face alignment mode, and the isolating film is located between the first symmetrical electrode and the second symmetrical electrode;
the isolating membrane is of a porous material structure, the thickness of the isolating membrane is 20-30 mu m, and the porosity of the isolating membrane is 35-55%.
Preferably, the current collectors of the first symmetric electrode and the second symmetric electrode are made of porous conductive materials, the current collectors of the first symmetric electrode and the second symmetric electrode are made of one of foamed metal, open-cell metal foil and porous carbon materials, and active materials used on the first symmetric electrode and the second symmetric electrode can be filled into gaps of the current collectors;
the thickness of the first symmetrical electrode and the thickness of the second symmetrical electrode are not more than 100 mu m.
Preferably, the current collectors of the upper counter electrode and the lower counter electrode are in a metal foil or porous conductive material structure, and the current collectors of the upper counter electrode and the lower counter electrode are one of a copper foil, an aluminum foil, a stainless steel foil, a foam metal, an open-cell metal foil, and a porous carbon material.
Preferably, when the current collector of the upper counter electrode or the lower counter electrode is one of a copper foil, an aluminum foil, and a stainless steel foil, the current collector has a single-sided coating structure, and the active material is located on one side of the current collector.
Preferably, the first coil core is correspondingly welded with a first positive tab and a first negative tab, the second coil core is correspondingly welded with a second positive tab and a second negative tab, the second positive tab and the second negative tab are led out from the top end of the aluminum plastic film of the first positive tab and the first negative tab, the second positive tab and the second negative tab can be led out from the side end, the top end and the bottom end of the aluminum plastic film, and the first positive tab, the first negative tab, the second positive tab and the second negative tab are all not overlapped.
A manufacturing method of a symmetrical battery is used for manufacturing the symmetrical battery and comprises the following specific steps:
s1, preparing a roll core: respectively manufacturing a first winding core and a second winding core according to the basic steps of slurry combination, coating, rolling, slitting, tab arrangement and lamination;
s2, assembling: sequentially placing a first roll core, an isolation film and a second roll core into a punched aluminum-plastic film according to a set sequence, aligning a first symmetrical electrode and a second symmetrical electrode face to face, not overlapping a lug of the first roll core and a lug of the second roll core, packaging the aluminum-plastic film, leaving an opening on one side, and placing the aluminum-plastic film into a vacuum oven for dewatering to obtain a dry battery core;
and S3, testing the moisture of the dry electric core in the vacuum oven to be qualified, and injecting liquid and sealing to obtain the symmetrical battery for evaluating the performances of the positive and negative electrode materials.
A test method of a symmetrical battery adopts the symmetrical battery, and comprises the following specific test steps:
the electrochemical properties of an active material of a symmetrical battery under an uncharged condition are evaluated: connecting the first symmetrical electrode and the second symmetrical electrode to carry out alternating current impedance test;
evaluating the electrochemical properties of the active material at different states of charge when the first symmetrical electrode and the second symmetrical electrode have the same state of charge: firstly, charging and discharging are respectively carried out on a first winding core and a second winding core at a current below 0.50C, then the first winding core and the second winding core are adjusted to corresponding charge states according to the set charge states, and a first symmetrical electrode and a second symmetrical electrode are connected for carrying out alternating current impedance test;
when the first symmetrical electrode and the second symmetrical electrode have different charge states, the electrochemical properties of the active material under different charge states are evaluated under the condition of no electricity by the first symmetrical electrode or the second symmetrical electrode: and respectively charging and discharging the first winding core and the second winding core with a current below 0.50C according to the set state of charge, adjusting the state of charge of the second winding core to be in place according to the set state of charge, and connecting the first symmetrical electrode and the second symmetrical electrode for cycle test.
Preferably, the test is carried out by taking a four-electrode symmetrical battery as a three-electrode battery core:
wherein the active material corresponding to the upper counter electrode or the lower counter electrode is one of graphite, lithium titanate and lithium iron phosphate, and one of the upper counter electrode and the lower counter electrode is selected as a reference electrode in a three-electrode system;
before testing, the first roll core or the second roll core containing the reference electrode is subjected to charging and discharging operations for 1-5 times at a current of 0.33C, so that the surface state of the reference electrode tends to be stable, and after a specified charge state is reached, the selected reference electrode, the first symmetric electrode and the second symmetric electrode are tested according to a wiring mode of three-electrode testing.
Preferably, when the active material coated on the reference electrode is graphite, the charge state adjustment range is 70-90%;
when the active material coated on the reference electrode is lithium titanate, the charge state adjustment range is 25% -75%;
when the active material coated on the reference electrode is lithium iron phosphate, the adjustment range of the charge state is 20-80%.
The manufacturing method has the beneficial effects that the manufacturing process of the symmetrical battery is simple and easy to implement, the battery core does not need to be additionally disassembled and reassembled, and the influence of external interference on the test result is greatly reduced; the charge state control method of the symmetrical battery is very convenient, and only the first winding core and the second winding core need to be subjected to charge and discharge control according to the set charge state; after selecting a proper active material, the symmetrical battery system can be used as a three-electrode system for performance evaluation, and more test results with reference functions can be obtained.
Drawings
FIG. 1 is a schematic view of a layered structure of the present invention;
FIG. 2 is a first reference drawing of the present invention;
FIG. 3 is a second embodiment of the present invention;
FIG. 4 is a reference diagram III of the present invention.
Detailed Description
The invention is described in further detail below with reference to the figures and specific embodiments.
As shown in fig. 1 to 4, the embodiment of the present invention is a symmetrical battery, which includes a first winding core 1, a separation film 3, and a second winding core 2 packaged together by an aluminum plastic film, where the first winding core 1 is composed of a first symmetrical electrode 103, a first diaphragm 102, and an upper counter electrode 101, and the second winding core 2 is composed of a second symmetrical electrode 201, a second diaphragm 202, and a lower counter electrode 203 (in the case of a symmetrical battery test, the first symmetrical electrode 103, the separation film 3, and the second symmetrical electrode 201 constitute a symmetrical cell).
The first symmetrical electrode 103, the upper counter electrode 101, the second symmetrical electrode 201 and the lower counter electrode 203 are all of a single-layer structure, and the first winding core 1 and the second winding core 2 can be fixed by adhesive paper respectively, so that subsequent assembly operation is facilitated.
The coating areas of the first symmetrical electrode 103 and the second symmetrical electrode 201 are aligned face to face (if two winding cores adopt a multilayer structure, the effect cannot be achieved), and the separation film 3 is positioned between the first symmetrical electrode 103 and the second symmetrical electrode 201; the isolating membrane 3 is a porous material structure, the thickness is 20-30 mu m, and the porosity is 35-55%.
The first symmetrical electrode 103 and the second symmetrical electrode 201 have the same active material, electrode formula and area density, compacting and coating size, for example, the same positive electrode material lithium cobaltate (the same material refers to the material with the same specification from the same manufacturer, and if the material is changed to be produced, the material is regarded as different material) can be used for the upper counter electrode and the lower counter electrode, and the same negative electrode material graphite can also be used. The upper counter electrode and the lower counter electrode may be made of the same material or different materials. For example, the upper counter electrode and the lower counter electrode may be made of the same graphite material, or made of different types of graphite materials manufactured by the same manufacturer, or made of graphite materials manufactured by different manufacturers.
The current collectors of the first symmetric electrode 103 and the second symmetric electrode 201 are made of porous conductive materials, the current collectors of the first symmetric electrode 103 and the second symmetric electrode 201 are made of one of foamed metal, open-cell metal foil and porous carbon materials, and slurry (containing corresponding active materials) used on the first symmetric electrode and the second symmetric electrode can be filled into gaps of the current collectors; the thickness of the first symmetrical electrode 103 and the second symmetrical electrode 201 is not more than 100 μm. The current collectors of the upper counter electrode 101 and the lower counter electrode 203 are of metal foils or porous conductive material structures, and the current collectors of the upper counter electrode 101 and the lower counter electrode 203 are one of copper foils, aluminum foils, stainless steel foils, foamed metals, open-cell metal foils and porous carbon materials.
When the current collectors of the upper counter electrode 101 and the lower counter electrode 203 correspond to one of a copper foil, an aluminum foil, and a stainless steel foil, the upper counter electrode 101 and the lower counter electrode 203 are coated on one side, and the slurry (containing the corresponding active material) is located on one side of the current collectors.
When copper foil (or one of aluminum foil and stainless steel foil) is selected as the current collectors of the first symmetrical electrode 103 and the second symmetrical electrode 201, in order to adjust the state of charge, the two surfaces with active materials of the first symmetrical electrode 103 and the upper counter electrode 101 of the first winding core 1 are aligned face to face, and the optical foil surface of the first symmetrical electrode 103 is in contact with the separator 3. In this case, if the symmetric cell formed by the first symmetric electrode 103, the separator 3, and the second symmetric electrode 201 is opposite to the foil, it is difficult to realize the test function of the symmetric battery. Based on this, the current collectors of the first symmetrical electrode 103 and the second symmetrical electrode 201 must be selected from porous conductive materials.
And the foil with the porous conductive material structure is used as a current collector, and the active material can penetrate through the two surfaces of the current collectors of the first symmetrical electrode 103 and the second symmetrical electrode 201, so that the charge states of the first winding core 1 and the second winding core 2 can be conveniently controlled, and the face-to-face alignment of the active materials of the first symmetrical electrode 103 and the second symmetrical electrode 201 is realized. The first symmetrical electrode 103 and the second symmetrical electrode 201 control the thickness of the pole pieces, mainly to better control the influence of the diffusion process on the charge uniformity of the first symmetrical electrode 103 and the second symmetrical electrode 201, and on the other hand, to facilitate the charging and discharging operations of the first winding core 1 and the second winding core 2 under a relatively large multiplying power.
In the aspect of selecting materials of the first symmetric electrode 103 and the second symmetric electrode 201, when the first symmetric electrode and the second symmetric electrode correspond to positive electrode materials, one of materials such as lithium cobaltate, lithium manganate, lithium nickel cobalt manganate ternary materials, lithium nickel cobalt aluminate, lithium iron phosphate, lithium iron manganese phosphate and the like can be selected.
The upper counter electrode 101 and the lower counter electrode 203 may be selected from graphite (natural graphite, artificial graphite, mesocarbon microbeads, composite graphite), soft carbon, hard carbon, lithium titanate, silicon-containing materials, and the like. The upper counter electrode and the lower counter electrode can select the same negative electrode material according to different test settings, and can also select different negative electrode materials. For example: selecting artificial graphite of the same type from the same manufacturer for an upper counter electrode and a lower counter electrode; selecting different types of artificial graphite of the same manufacturer for the upper counter electrode and the lower counter electrode; selecting artificial graphite and natural graphite from the same manufacturer as the upper counter electrode and the lower counter electrode; selecting graphite and lithium titanate materials of the same manufacturer as the upper counter electrode and the lower counter electrode; selecting graphite materials of different manufacturers for the upper counter electrode and the lower counter electrode; sixthly, selecting graphite of a manufacturer A as the upper counter electrode and selecting lithium titanate of a manufacturer B as the lower counter electrode.
When the first symmetric electrode 103 and the second symmetric electrode 201 correspond to negative electrode materials, for example, one of graphite (natural graphite, artificial graphite, mesocarbon microbeads, composite graphite), soft carbon, hard carbon, lithium titanate, silicon-containing materials, and the like, the upper counter electrode and the lower counter electrode may be made of the same positive electrode material, or different positive electrode materials, similar to the above section.
Still correspond the welding on the first core winding 1 and have first anodal ear 104 and first negative pole ear 105, still correspond the welding on the second core winding 2 and have second anodal ear 204 and second negative pole ear 205, draw forth by first anodal ear 104 and 4 tops of first negative pole ear 105 plastic-aluminum membrane, second anodal ear 204 and second negative pole ear 205 can be drawn forth by 4 sides of plastic-aluminum membrane, top, bottom, all do not overlap between first anodal ear 104, first negative pole ear 405, the anodal ear 204 of second and the second negative pole ear 405.
A manufacturing method of a symmetrical battery is used for manufacturing the symmetrical battery and comprises the following specific steps:
s1, preparing a roll core: respectively manufacturing a first winding core and a second winding core according to the basic steps of slurry combination, coating, rolling, slitting, tab arrangement and lamination;
s2, assembling: sequentially placing a first roll core, an isolation film and a second roll core into a punched aluminum-plastic film according to a set sequence, aligning a first symmetrical electrode and a second symmetrical electrode face to face, not overlapping a lug of the first roll core and a lug of the second roll core, packaging the aluminum-plastic film, leaving an opening on one side, and placing the aluminum-plastic film into a vacuum oven for dewatering to obtain a dry battery core;
and S3, testing the moisture of the dry electric core in the vacuum oven to be qualified, and injecting liquid and sealing to obtain the symmetrical battery for evaluating the performances of the positive and negative electrode materials.
A test method of a symmetrical battery adopts the symmetrical battery, and comprises the following specific test steps:
the electrochemical properties of an active material of a symmetrical battery under an uncharged condition are evaluated: connecting the first symmetrical electrode and the second symmetrical electrode to carry out alternating current impedance test;
evaluating the electrochemical properties of the active material at different states of charge when the first symmetrical electrode and the second symmetrical electrode have the same state of charge: firstly, charging and discharging are respectively carried out on a first winding core and a second winding core at a current below 0.50C, then the first winding core and the second winding core are adjusted to corresponding charge states according to the set charge states, and a first symmetrical electrode and a second symmetrical electrode are connected for carrying out alternating current impedance test;
when the first symmetrical electrode and the second symmetrical electrode have different charge states, the electrochemical characteristics of the active material under different charge states are evaluated by the condition that the first symmetrical electrode and the second symmetrical electrode are not charged: and respectively charging and discharging the first winding core and the second winding core with a current below 0.50C according to the set state of charge, then adjusting the second winding core to a corresponding voltage according to the set state of charge, and connecting the first symmetrical electrode and the second symmetrical electrode for cycle test.
The four symmetrical batteries are used as three-electrode battery cores for testing:
wherein the active material corresponding to the upper counter electrode or the lower counter electrode is one of graphite, lithium titanate and lithium iron phosphate, and one of the upper counter electrode and the lower counter electrode is selected as a reference electrode in a three-electrode system;
before testing, the first roll core or the second roll core containing the reference electrode is subjected to charging and discharging operations for 1-5 times at a current of 0.33C, so that the surface state of the reference electrode tends to be stable, and after a specified charge state is reached, the reference electrode, the first symmetric electrode and the second symmetric electrode are selected to be tested according to a wiring mode of a three-electrode test.
When the active material coated on the reference electrode is graphite, the charge state adjustment range is 70% -90%;
when the active material coated on the reference electrode is lithium titanate, the charge state adjustment range is 25% -75%;
when the active material coated on the reference electrode is lithium iron phosphate, the adjustment range of the charge state is 20-80%.
Example 1
The active materials corresponding to the first symmetrical electrode and the second symmetrical electrode are the same negative electrode graphite, the upper counter electrode corresponds to a lithium cobaltate material, and the lower counter electrode corresponds to a lithium iron phosphate material.
Preparation of first and second symmetric electrodes: first, slurry preparation is performed. The negative electrode formula is graphite: conductive agent (carbon black): thickener (sodium carboxymethylcellulose): the binder (styrene-butadiene rubber) was 95:1:1.5:1.5, and slurry preparation was performed using an aqueous system. And (3) preparing the negative electrode slurry by adopting a double-planet stirrer according to a negative electrode formula under the condition of controlling the temperature and the vacuum degree, discharging when the performance of the slurry meets the requirements of viscosity and fineness, uniformly coating the slurry on porous foamy copper, drying to obtain a non-rolled pole piece, rolling the thickness of the pole piece to 80 mu m, punching the pole piece, and arranging pole lugs to obtain a first symmetric electrode and a second symmetric electrode for later use.
Preparing an upper counter electrode: the corresponding formula of the upper counter electrode is lithium cobaltate: conductive agent (carbon black): the binder (polyvinylidene fluoride) was 97:1.5:1.5, and slurry preparation was performed using an oily system. According to the formula, a double-planet stirrer is adopted to manufacture the slurry under the condition of controlling the temperature and the vacuum degree, the slurry is discharged when the performance of the slurry meets the requirements of viscosity and fineness, the slurry is uniformly coated on one surface of an aluminum foil (with the thickness of 12-18 mu m), dried and rolled to obtain a pole piece, and the upper counter electrode is obtained by punching and arranging a pole lug.
Preparation of the lower counter electrode: the corresponding formula of the lower counter electrode is lithium iron phosphate: conductive agent (carbon black): the binder (polyvinylidene fluoride) was 95:2.5:2.5, and slurry preparation was performed using an oily system. According to the formula, a double-planet stirrer is adopted to manufacture slurry under the condition of controlling the temperature and the vacuum degree, the slurry is discharged when the performance of the slurry meets the requirements of viscosity and fineness, the slurry is uniformly coated on one surface of an aluminum foil (with the thickness of 12-18 mu m), dried and rolled to obtain a pole piece, and the lower counter electrode is obtained by punching and arranging a pole lug.
Manufacturing a first roll core: the first symmetric electrode, the first separator and the upper counter electrode (the coating surface of the upper counter electrode is opposite to the coating surface of the first symmetric electrode) are aligned and stacked in sequence, and the stacked first roll core is fixed by adhesive paper.
And (3) manufacturing a second roll core: and aligning the second symmetrical electrode, the second diaphragm and the upper counter electrode (the coating surface of the upper counter electrode is opposite to the coating surface of the second symmetrical electrode), stacking the two in sequence, and fixing the stacked first winding core by using adhesive paper.
Manufacturing a symmetrical battery: aligning and stacking a first roll core (a first symmetrical electrode is over against a diaphragm membrane), an isolation film and a second roll core (a second symmetrical electrode is over against the diaphragm membrane) according to the designed mode that the first roll core and the second roll core are used for outputting lugs, fixing the first roll core and the second roll core by using adhesive paper, putting the first roll core and the second roll core into an aluminum-plastic film which is used for punching a shell in advance for packaging, leaving an opening at one side, and putting the first roll core and the second roll core into a vacuum oven for dewatering. And after the moisture test is qualified, injecting liquid and sealing to obtain the symmetrical battery.
And (3) testing: 1) and (6) testing alternating current impedance. And connecting the first symmetrical electrode and the second symmetrical electrode according to the alternating current impedance test requirement, and carrying out the alternating current impedance test according to the potential amplitude of 5mV and the frequency range of 100kHz-0.1 mHz.
2) And (3) state of charge control: and respectively carrying out activation treatment (0.3C charging and discharging) on the first battery cell and the second battery cell, then fully filling the first battery cell and the second battery cell with 0.3C, and controlling the state of charge according to a discharging mode.
3) And (3) cycle testing: the activated first core and the activated second core can be respectively subjected to cycle test, and only one of the first core and the second core can be subjected to cycle test.
4) Other tests: other combination tests may be performed as desired.
The manufacturing process of the symmetrical battery is simple and easy to implement, the battery core does not need to be additionally disassembled and reassembled, and the influence of external interference on the test result is greatly reduced; the charge state control method of the symmetrical battery is very convenient, and only the first winding core and the second winding core need to be subjected to charge and discharge control according to the set charge state; after selecting a proper active material, the symmetrical battery system can be used as a three-electrode system for performance evaluation, and more test results with reference functions can be obtained.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and any minor modifications, equivalent replacements and improvements made to the above embodiment according to the technical spirit of the present invention should be included in the protection scope of the technical solution of the present invention.
Claims (10)
1. A symmetrical battery, characterized by: the device comprises a first roll core, an isolation film and a second roll core which are packaged together by an aluminum plastic film, wherein the first roll core consists of a first symmetric electrode, a first diaphragm and an upper counter electrode, and the second roll core consists of a second symmetric electrode, a second diaphragm and a lower counter electrode.
2. The symmetric battery of claim 1, wherein: the first symmetrical electrode, the upper counter electrode, the second symmetrical electrode and the lower counter electrode are all in a single-layer structure,
the first symmetrical electrode and the second symmetrical electrode are arranged in a face-to-face alignment mode, and the isolating film is located between the first symmetrical electrode and the second symmetrical electrode;
the isolating membrane is of a porous material structure, the thickness of the isolating membrane is 20-30 mu m, and the porosity of the isolating membrane is 35-55%.
3. The symmetric battery of claim 1, wherein: the current collectors of the first symmetrical electrode and the second symmetrical electrode adopt a porous conductive material structure, the current collectors of the first symmetrical electrode and the second symmetrical electrode are one of foam metal, open-cell metal foil and porous carbon material, and active materials used on the first symmetrical electrode and the second symmetrical electrode can be filled into gaps of the current collectors;
the thickness of the first symmetrical electrode and the thickness of the second symmetrical electrode are not more than 100 mu m.
4. The symmetric battery of claim 3, wherein: the current collectors of the upper counter electrode and the lower counter electrode are of metal foils or porous conducting material structures, and the current collectors of the upper counter electrode and the lower counter electrode are one of copper foils, aluminum foils, stainless steel foils, foamed metals, open-cell metal foils and porous carbon materials.
5. The symmetric battery of claim 1, wherein: when the current collector of the upper counter electrode or the lower counter electrode is one of copper foil, aluminum foil and stainless steel foil, the current collector is of a single-side coating structure, and the active material is positioned on one side of the current collector.
6. The symmetric battery of claim 1, wherein: the first coil core is provided with a first positive tab and a first negative tab in a corresponding welding mode, the second coil core is provided with a second positive tab and a second negative tab in a corresponding welding mode, the second positive tab and the second negative tab are led out from the top end of the aluminum plastic film of the first positive tab and the first negative tab, the second positive tab and the second negative tab can be led out from the side end, the top end and the bottom end of the aluminum plastic film, and the first positive tab, the first negative tab, the second positive tab and the second negative tab are all not overlapped.
7. A method for manufacturing a symmetrical battery is characterized in that: the method is used for preparing the symmetrical battery of any one of claims 1 to 6, and comprises the following specific preparation steps:
s1, preparing a roll core: respectively manufacturing a first winding core and a second winding core according to the basic steps of slurry combination, coating, rolling, slitting, tab arrangement and lamination;
s2, assembling: sequentially placing a first roll core, an isolation film and a second roll core into a punched aluminum-plastic film according to a set sequence, aligning a first symmetrical electrode and a second symmetrical electrode face to face, not overlapping a lug of the first roll core and a lug of the second roll core, packaging the aluminum-plastic film, leaving an opening on one side, and placing the aluminum-plastic film into a vacuum oven for dewatering to obtain a dry battery core;
and S3, testing the moisture of the dry electric core in the vacuum oven to be qualified, and injecting liquid and sealing to obtain the symmetrical battery for evaluating the performances of the positive and negative electrode materials.
8. A test method of a symmetrical battery is characterized in that: the symmetrical battery of any of claims 1-6 is used, and the specific test steps are as follows:
the electrochemical properties of an active material of a symmetrical battery under an uncharged condition are evaluated: connecting the first symmetrical electrode and the second symmetrical electrode to carry out alternating current impedance test;
evaluating the electrochemical properties of the active material at different states of charge when the first symmetrical electrode and the second symmetrical electrode have the same state of charge: firstly, charging and discharging are respectively carried out on a first winding core and a second winding core at a current below 0.50C, then the first winding core and the second winding core are adjusted to corresponding charge states according to the set charge states, and a first symmetrical electrode and a second symmetrical electrode are connected for carrying out alternating current impedance test;
when the first symmetrical electrode and the second symmetrical electrode have different charge states, the electrochemical properties of the active material under different charge states are evaluated under the condition of no electricity by the first symmetrical electrode or the second symmetrical electrode: and respectively charging and discharging the first winding core and the second winding core with a current below 0.50C according to the set state of charge, adjusting the state of charge of the second winding core to be in place according to the set state of charge, and connecting the first symmetrical electrode and the second symmetrical electrode for cycle test.
9. The method of testing a symmetric battery according to claim 8, wherein: the four symmetrical batteries are used as three-electrode battery cores for testing:
wherein the active material corresponding to the upper counter electrode or the lower counter electrode is one of graphite, lithium titanate and lithium iron phosphate, and one of the upper counter electrode and the lower counter electrode is selected as a reference electrode in a three-electrode system;
before testing, the first roll core or the second roll core containing the reference electrode is subjected to charging and discharging operations for 1-5 times at a current of 0.33C, so that the surface state of the reference electrode tends to be stable, and after a specified charge state is reached, the selected reference electrode, the first symmetric electrode and the second symmetric electrode are tested according to a wiring mode of three-electrode testing.
10. The method of testing a symmetrical battery according to claim 9, wherein: when the active material coated on the reference electrode is graphite, the charge state adjustment range is 70% -90%;
when the active material coated on the reference electrode is lithium titanate, the charge state adjustment range is 25% -75%;
when the active material coated on the reference electrode is lithium iron phosphate, the adjustment range of the charge state is 20-80%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110319228.7A CN113078374A (en) | 2021-03-25 | 2021-03-25 | Symmetric battery and test method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110319228.7A CN113078374A (en) | 2021-03-25 | 2021-03-25 | Symmetric battery and test method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113078374A true CN113078374A (en) | 2021-07-06 |
Family
ID=76610361
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110319228.7A Pending CN113078374A (en) | 2021-03-25 | 2021-03-25 | Symmetric battery and test method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113078374A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114824663A (en) * | 2022-07-01 | 2022-07-29 | 河南锂动电源有限公司 | Preparation method of symmetrical battery and symmetrical battery |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20090104510A1 (en) * | 2007-09-14 | 2009-04-23 | A123 Systems, Inc. | Lithium rechargeable cell with reference electrode for state of health monitoring |
| US20110250478A1 (en) * | 2010-04-08 | 2011-10-13 | Gm Global Technology Operations, Inc. | Lithium-ion cell with an array of reference electrodes |
| CN104241586A (en) * | 2014-08-25 | 2014-12-24 | 深圳市雄韬电源科技股份有限公司 | Lithium battery with reference electrode |
| CN109585932A (en) * | 2018-12-20 | 2019-04-05 | 惠州亿纬锂能股份有限公司 | A kind of production method and Symmetrical cells of Symmetrical cells |
| CN111009679A (en) * | 2019-12-25 | 2020-04-14 | 天津荣盛盟固利新能源科技有限公司 | Three-electrode battery cell, three-electrode soft package battery and preparation method thereof |
| CN111009688A (en) * | 2019-11-12 | 2020-04-14 | 浙江锋锂新能源科技有限公司 | Novel adjustable SOC symmetrical battery and preparation method thereof |
| CN210897343U (en) * | 2019-12-26 | 2020-06-30 | 陕西煤业化工技术研究院有限责任公司 | Symmetrical battery |
-
2021
- 2021-03-25 CN CN202110319228.7A patent/CN113078374A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20090104510A1 (en) * | 2007-09-14 | 2009-04-23 | A123 Systems, Inc. | Lithium rechargeable cell with reference electrode for state of health monitoring |
| US20110250478A1 (en) * | 2010-04-08 | 2011-10-13 | Gm Global Technology Operations, Inc. | Lithium-ion cell with an array of reference electrodes |
| CN104241586A (en) * | 2014-08-25 | 2014-12-24 | 深圳市雄韬电源科技股份有限公司 | Lithium battery with reference electrode |
| CN109585932A (en) * | 2018-12-20 | 2019-04-05 | 惠州亿纬锂能股份有限公司 | A kind of production method and Symmetrical cells of Symmetrical cells |
| CN111009688A (en) * | 2019-11-12 | 2020-04-14 | 浙江锋锂新能源科技有限公司 | Novel adjustable SOC symmetrical battery and preparation method thereof |
| CN111009679A (en) * | 2019-12-25 | 2020-04-14 | 天津荣盛盟固利新能源科技有限公司 | Three-electrode battery cell, three-electrode soft package battery and preparation method thereof |
| CN210897343U (en) * | 2019-12-26 | 2020-06-30 | 陕西煤业化工技术研究院有限责任公司 | Symmetrical battery |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114824663A (en) * | 2022-07-01 | 2022-07-29 | 河南锂动电源有限公司 | Preparation method of symmetrical battery and symmetrical battery |
| CN114824663B (en) * | 2022-07-01 | 2022-09-02 | 河南锂动电源有限公司 | Preparation method of symmetrical battery and symmetrical battery |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101867060B (en) | Lithium-ion energy storage battery | |
| CN201682023U (en) | Lithium ion battery | |
| CN109817473B (en) | Lithium pre-embedding method of lithium ion electrochemical energy storage device | |
| US20050153173A1 (en) | Energy device | |
| CN101438448A (en) | Lithium ion accumulator | |
| CN105958124B (en) | A kind of lithium ion battery and preparation method thereof | |
| CN101577324A (en) | Mixed type anode sizing agent of LiFePO4 battery and LiFePO4 battery using the anode sizing agent | |
| CN111244381A (en) | Full-tab button battery and manufacturing method thereof | |
| CN113823849A (en) | Lithium ion battery and lithium supplement positive plate thereof | |
| CN201311953Y (en) | Lithium ion battery | |
| CN101847748A (en) | Lithium-ion power battery | |
| WO2023124570A1 (en) | Pole piece, roll core, and battery | |
| CN111403739A (en) | Nickel-cobalt-manganese acid lithium battery cell positive electrode active material, aluminum shell battery cell and manufacturing method thereof | |
| WO2024149399A1 (en) | Lithium supplementing structure for battery, battery, and electrical apparatus | |
| CN114497464A (en) | Lithium ion battery positive electrode pulse pre-lithiation method and lithium ion battery | |
| CN102122725B (en) | Lithium-iron disulfide battery | |
| CN102013512A (en) | Power storage device with high potential and making method | |
| CN110600285B (en) | Lithium separation-free pre-lithium intercalation method for cathode of lithium ion electrochemical energy storage device | |
| CN113078374A (en) | Symmetric battery and test method | |
| CN113823851A (en) | Lithium ion battery and lithium-supplementing negative plate thereof | |
| CN107785537A (en) | A kind of method of modifying of new type lithium ion battery anode pole piece, its purposes and pole piece | |
| CN217822407U (en) | Lithium ion capacitor | |
| CN112713301B (en) | Energy storage device | |
| JP2011165930A (en) | Power storage device, and method of manufacturing shared negative electrode of the same | |
| CN201374362Y (en) | Square lithium ion battery and pole core used for same |
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 | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20210706 |