CN105355837B - Electrochemical cell and method of making same - Google Patents
Electrochemical cell and method of making same Download PDFInfo
- Publication number
- CN105355837B CN105355837B CN201510676980.1A CN201510676980A CN105355837B CN 105355837 B CN105355837 B CN 105355837B CN 201510676980 A CN201510676980 A CN 201510676980A CN 105355837 B CN105355837 B CN 105355837B
- Authority
- CN
- China
- Prior art keywords
- positive
- equal
- negative
- plate
- region
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
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
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/04—Processes of manufacture in general
- H01M4/0402—Methods of deposition of the material
- H01M4/0404—Methods of deposition of the material by coating on electrode collectors
-
- 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
- H01M4/06—Electrodes for primary cells
-
- 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
- H01M4/06—Electrodes for primary cells
- H01M4/08—Processes of manufacture
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/50—Current conducting connections for cells or batteries
- H01M50/531—Electrode connections inside a battery casing
-
- 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
-
- 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
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
The invention belongs to the field of electrochemical cells, and particularly relates to an electrochemical cell which comprises the following components: the positive plate comprises a positive current collector and a positive coating layer, the capacity of the positive coating layer per unit area is Cc mAh, the negative plate comprises a negative current collector and a negative coating layer, and the capacity of the negative coating layer per unit area is CamAh; a region with Cc being more than or equal to Ca exists in the region of the positive plate corresponding to the negative plate; the minimum width of the region where Cc is larger than or equal to Ca is L, and L is larger than or equal to 0.5 mm; and the positive plate coating in the area of Cc which is more than or equal to Ca is subjected to inactivation treatment of positive active substances, and the capacity exertion rate of the positive active substances is less than or equal to 95%. The capacity exertion of the positive active material is limited or completely inhibited through inactivation treatment, so that the region of Cc which is more than or equal to Ca is ensured during coating, the capacity exertion still meets the condition that Cc is less than or equal to Ca when a finished product battery core is manufactured, and the influence of negative electrode lithium precipitation on the battery performance is avoided.
Description
Technical Field
The invention belongs to the field of electrochemical cells, and particularly relates to an electrochemical cell and a preparation method thereof.
Background
After the 21 st century, various electronic device products such as mobile phones, notebooks, wearable devices and the like are in endless, and the lives of the users are greatly enriched; meanwhile, electric vehicles and various energy storage power stations can sprout, develop and grow rapidly like spring bamboo shoots in the rainy season. The above high-tech products have one common feature: high performance batteries are required to serve as energy storage components.
The existing batteries mainly comprise a primary battery and a secondary battery; the so-called primary battery, which is a battery that cannot be repeatedly charged, mainly includes a carbon zinc battery, an alkaline battery, a paste zinc-manganese battery, a cardboard zinc-manganese battery, an alkaline zinc-manganese battery, a button cell (a button zinc-silver battery, a button lithium-manganese battery, a button zinc-manganese battery), a zinc-air battery, a primary lithium-manganese battery, and the like, and a mercury battery; the secondary battery, i.e., a rechargeable battery, mainly includes a secondary alkaline zinc-manganese battery, a nickel-cadmium rechargeable battery, a nickel-hydrogen rechargeable battery, a lithium rechargeable battery, a lead-acid battery, and a solar battery. Lead-acid batteries can be divided into: open type lead-acid storage battery and totally-enclosed lead-acid storage battery. From the perspective of external packaging, the conventional batteries are mainly classified into flexible-packaged batteries and hard-shell-packaged batteries, and the flexible-packaged battery packaging film has small thickness and large plasticity, so that the battery is widely applied to various high-grade primary batteries and secondary batteries.
However, with the continuous upgrade of various electric devices, the battery has more requirements on the performance of the battery, such as higher energy density, faster charge and discharge speed, longer cycle life, better safety performance and the like; the energy density is directly related to the user experience effect of the product, and the safety performance of the battery cell is closely related to the safe use of the electric product and the life property and life safety of the user, so the energy density and the safety performance are concerned by battery manufacturers and users. How to improve the energy density of the battery and improve the safety performance of the battery becomes a key research direction of researchers in the field of batteries. In order to improve the energy density of the battery, the utility model patent with patent application number 201420283159.4 invented an effective pole piece cleaning device: the laser system at least comprises a beam shaping mechanism for homogenizing the energy of the laser beam emitted by the laser emitting head, and the laser emitting head is electrically connected with the beam shaping mechanism. Compared with the prior art, the utility model has the advantages that the energy of the laser beam can be homogenized by arranging the beam shaping mechanism, and the foil in the pole piece can not be damaged, so that the welding quality of the pole ear is improved; and the residual of the coating can not be caused, so that the cleaning quality is improved, and the high energy and the low energy in the light beam can be effectively utilized, so that the maximum utilization of the laser energy is realized, and the utilization rate of the energy, the cleaning efficiency and the cleaning quality are improved. However, in the battery core prepared by the method, because the middle area of the negative pole piece is cleaned, the amount of the positive pole active material in a local area is easily larger than that of the negative pole active material, and after charging and discharging or long-time circulation, the lithium precipitation condition in the local area occurs, so that the safety performance of the battery is reduced.
In view of the above, there is a need for a new battery which can improve the energy density of the battery and has high safety performance.
Disclosure of Invention
The invention aims to: in view of the deficiencies of the prior art, an electrochemical cell is provided: the positive plate comprises a positive current collector and a positive coating layer, the capacity of the positive coating layer per unit area is Cc mAh, the negative plate comprises a negative current collector and a negative coating layer, and the capacity of the negative coating layer per unit area is Ca mAh; a region of Cc which is more than or equal to Ca exists in the region of the positive plate corresponding to the negative plate; the minimum width of the region where Cc is larger than or equal to Ca is L, and L is larger than or equal to 0.5mm; and the positive plate coating in the area of Cc which is more than or equal to Ca is subjected to inactivation treatment of positive active substances, and the capacity exertion rate of the positive active substances is less than or equal to 95%. The capacity exertion of the positive active material is limited or completely inhibited through inactivation treatment, so that the region of Cc which is more than or equal to Ca is ensured during coating, the capacity exertion still meets the condition that Cc is less than or equal to Ca when a finished product battery core is manufactured, and the influence of negative electrode lithium precipitation on the battery performance is avoided.
In order to achieve the purpose, the invention adopts the following technical scheme:
an electrochemical cell comprises a positive plate, a negative plate, an isolating membrane, an outer package and electrolyte, wherein the positive plate comprises a positive current collector and a positive coating layer, the capacity of the positive coating layer per unit area is Cc mAh, the negative plate comprises a negative current collector and a negative coating layer, and the capacity of the negative coating layer per unit area is Ca mAh; a region of Cc which is more than or equal to Ca exists in the region of the positive plate corresponding to the negative plate; the minimum width of the area of Cc which is more than or equal to Ca is L which is more than or equal to 0.5mm; when L is small, even if Cc ≧ Ca region is present, cc < Ca is usually present outside this region, and the excess capacity of the positive electrode can be diffused, and the excess positive electrode capacity is taken up by the peripheral negative electrode, and no lithium deposition occurs. And the positive plate coating in the area of Cc which is more than or equal to Ca is subjected to inactivation treatment of positive active substances, and the capacity exertion rate of the positive active substances is less than or equal to 95%. In this case, the positive electrode active material capacity exertion rate can be adjusted according to the negative electrode actual capacity value Ca so that the positive electrode active material capacity exertion rate Cc 'matches the negative electrode capacity Ca (namely Cc' < Ca), and finally, the lithium deposition of the battery is prevented in the use process.
In an improvement of the electrochemical cell of the present invention, the deactivation treatment includes a physical deactivation treatment or/and a chemical deactivation treatment, and after the deactivation treatment, the capacity utilization rate of the positive electrode active material of the positive electrode coating layer in the region where Cc is equal to or greater than Ca is 90% or less.
As an improvement of the electrochemical cell of the present invention, the physical inactivation treatment comprises the electrode electron channel blocking inactivation treatment or the electrode ion channel blocking inactivation treatment; the chemical inactivation treatment is to inactivate the active substance per se.
As an improvement of the electrochemical cell, the electrode electron channel blocking inactivation treatment comprises ultrasonic oscillation treatment, such as at least one of vibration loosening of active material particles to enable the active material particles to lose connection with each other, oxidation treatment of a conductive agent to enable the conductive agent particles to lose conductivity, and heat treatment of the conductive agent; the electrode ion channel blocking inactivation treatment is to fill an electrode hole structure with a non-ionic conduction substance, such as various liquid glues, and the electrode hole is filled and then cured, so that the electrode hole is blocked, and the electrode loses activity; the concrete glue comprises instant glue (one kind of common 502 alpha-ethyl cyanoacrylate strong instant adhesive), epoxy resin bonding glue, anaerobic glue, UV glue (ultraviolet light curing glue), hot melt glue, pressure-sensitive glue, latex glue and the like; the inactivation treatment of the active substance comprises at least one of oxidation inactivation treatment of the active substance, reduction inactivation treatment of the active substance and heat treatment inactivation treatment of the active substance.
As an improvement of the electrochemical cell, L is more than or equal to 1mm; because the ion diffusion supplementary effect is worse when L is more than or equal to 1mm, the cathode coating in the area with Cc < Ca around cannot share the redundant capacity of the anode coating, and if the invention is not adopted, the possibility of lithium precipitation is very high in the charging or circulating process.
The invention also comprises a preparation method of the electrochemical cell, which mainly comprises the following steps:
step 1, preparing an electrode slice: preparing a positive plate and a negative plate corresponding to the positive plate, wherein the capacity of a positive coating layer of the positive plate in unit area is Cc mAh, and the capacity of a negative coating layer of the negative plate in unit area is Ca mAh; and a region with Cc more than or equal to Ca exists in the region of the positive plate corresponding to the negative plate for standby;
step 2, assembling the battery cell: assembling the positive plate, the negative plate and the isolating film to obtain a naked battery cell, and performing inactivation treatment on the positive plate in the area where the Cc of the naked battery cell is larger than or equal to Ca; then, putting the naked electric core into a shell/bag, packaging, injecting liquid and standing;
step 3, preparing a finished product battery core: and (3) forming and shaping the battery cell prepared in the step (2) to obtain a finished product battery cell, wherein in the forming or/and shaping process, the battery cell is placed in an environment at the temperature of not higher than 120 ℃. In this case, if the inactivating substance is high-temperature melt infiltration, the higher temperature will facilitate the melting and infiltration of the adhesive layer into the pores of the positive electrode coating, thereby inactivating the positive electrode coating.
As an improvement of the preparation method of the electrochemical cell, the method for obtaining the region of Cc which is larger than or equal to Ca comprises at least one of controlling the coating weight to enable the region of Cc which is larger than or equal to Ca to appear in the electrode plate, cleaning partial negative electrode on the membrane of Cc which is smaller than or equal to Ca to enable Cc which is larger than or equal to Ca to be larger than or equal to Ca, and completely cleaning the negative electrode coating on the membrane of Cc which is smaller than or equal to Ca to enable Ca = 0.
As an improvement of the method of making an electrochemical cell of the present invention, the cleaning method comprises at least one of solvent cleaning, laser cleaning, and removing a partial coating after pre-structuring the current collector prior to coating; and after the negative coating is completely cleaned on the membrane with Cc less than or equal to Ca so that Ca =0, welding a tab on the current collector.
As an improvement of the method for manufacturing an electrochemical cell of the present invention, the deactivation treatment in step 2 includes a physical deactivation treatment and/or a chemical deactivation treatment, and after the deactivation treatment, the positive electrode active material capacity utilization rate of the positive electrode coating layer in the region where Cc is equal to or greater than Ca is 95% or less.
The invention also comprises another electrochemical cell which comprises a positive plate, a negative plate, an isolating membrane, an outer package and electrolyte, wherein the positive plate comprises a positive current collector and a positive coating layer, the capacity of the positive coating layer per unit area is Cc mAh, the negative plate comprises a negative current collector and a negative coating layer, and the capacity of the negative coating layer per unit area is CamAh; a region of Cc which is more than or equal to Ca exists in the region of the positive plate corresponding to the negative plate; the minimum width of the region where Cc is larger than or equal to Ca is L, and L is larger than or equal to 0.5mm; the Cc is larger than or equal to the Ca area, the isolating film between the anode and the cathode is subjected to inactivation treatment, and the isolating film becomes an ion-barrier and electron-barrier isolating film after the inactivation treatment; the specific process of the deactivation treatment of the separation film comprises a heating treatment or/and a pressurizing treatment so that the separation film is closed.
Compared with the prior art, the invention has the advantages that:
firstly, the electrode ion channel is subjected to blocking inactivation treatment, namely the glue solution is used for filling the positive electrode holes, and then the glue solution is initiated to be cured, so that the complete filling of the electrode holes is realized, the positive electrode plate in the corresponding area can be simply and completely inactivated, the condition that Cc is larger than or equal to Ca is conveniently and effectively solved, and the mass production is facilitated.
Next, the capacity exertion of the positive electrode coating active material can be effectively reduced by the deactivation of the electron channel, and the condition of Cc' < Ca is realized.
Finally, the condition that Cc is larger than or equal to Ca is generated, and the practical reasons include that tab welding is carried out by cleaning a small area in the middle area of the electrode, so that the thickness of the tab is covered in the thickness of the electrode coating, the purpose that the thickness of the tab does not account for the thickness of the battery is realized, and the purpose of improving the energy density of the battery is finally achieved; in practice, as the cathode tab is welded after the middle area of the cathode sheet is cleaned, the condition that the Cc corresponding to the tab is more than or equal to Ca occurs, lithium precipitation easily occurs, and the performance of the battery is affected; the invention inactivates the anode coating of the corresponding anode region to Cc' < Ca, thereby completely eliminating the side effects.
Detailed Description
The present invention and its advantageous effects will be described in detail below with reference to specific embodiments, but the embodiments of the present invention are not limited thereto.
In the comparative example 1, the following examples were conducted,
preparing a positive plate: selecting an aluminum foil with the thickness of 12 microns as a current collector, coating positive electrode slurry on the surface of the aluminum foil, and performing cold pressing to obtain a positive electrode membrane with the single-side coating thickness of 75 microns; then welding an aluminum lug with the width of 1cm and the thickness of 60 mu m on the empty foil area at the head of the membrane to obtain a positive plate for later use;
preparing a negative plate: selecting a copper foil with the thickness of 8 mu m as a current collector, coating negative electrode slurry on the surface of the current collector, and coating a negative electrode sheet with the thickness of 70 mu m on one side after cold pressing; then welding nickel electrode lugs with the width of 1cm and the thickness of 60 mu m on the empty foil area at the head of the diaphragm to obtain a negative plate for later use;
preparing a naked battery cell: selecting an isolating film with the thickness of 12 mu m, and winding the isolating film with the positive plate and the negative plate together to obtain a bare cell with a tab led out from the middle area of a cell electrode for standby, wherein in the bare cell, the thickness of the tab is lower than the thickness of a cleaned coating layer, so that the tab area of the cell is not the thickest area of the cell, the thickness of the tab does not influence the overall thickness of the battery, and the battery with higher energy density is obtained;
preparing a finished battery: and (3) placing the bare cell in an aluminum-plastic film for top-side sealing, then drying, injecting liquid, after the electrolyte is fully soaked, carrying out clamp formation at 75 ℃ and 0.6MPa, and then shaping, degassing and sealing to obtain a finished product cell.
In the comparative example 2, the following examples were conducted,
preparing a positive plate: selecting an aluminum foil with the thickness of 12 microns as a current collector, coating positive electrode slurry on the surface of the aluminum foil, and performing cold pressing to obtain a positive electrode membrane with the single-side coating thickness of 75 microns; then cleaning a double-sided blank area with the length of 4cm and the width of 1.5cm in the middle area of the membrane by using laser, and then welding an aluminum tab with the width of 1cm and the thickness of 60 mu m to obtain a positive plate for later use;
preparing a negative plate: selecting a copper foil with the thickness of 8 mu m as a current collector body, coating negative electrode slurry on the surface of the current collector body, and coating a negative electrode sheet with the thickness of 70 mu m on one side after cold pressing; then, cleaning a double-sided blank area (staggered with the position of the positive electrode lug) with the length of 4cm and the width of 1.5cm in the middle area of the membrane by using laser, and then welding a nickel electrode lug with the width of 1cm and the thickness of 60 mu m to obtain a negative electrode plate for later use;
preparing a naked battery cell: selecting an isolating film with the thickness of 12 mu m, and winding the isolating film with the positive plate and the negative plate together to obtain a bare cell with a tab led out from the middle area of a cell electrode for standby, wherein in the bare cell, the thickness of the tab is lower than the thickness of a cleaned coating layer, so that the tab area of the cell is not the thickest area of the cell, the thickness of the tab does not influence the overall thickness of the battery, and the battery with higher energy density is obtained;
preparing a finished battery: and (3) placing the bare cell in an aluminum-plastic film for top-side sealing, then drying, injecting liquid, after the electrolyte is fully soaked, carrying out clamp formation at 75 ℃ and 0.6MPa, and then shaping, degassing and sealing to obtain a finished product cell.
Example 1, unlike comparative example 2, this example includes the following steps:
preparing a naked battery cell: selecting an isolating film with the thickness of 12 mu m, winding the isolating film together with the positive plate and the negative plate, and simultaneously pasting an adhesive tape with the length of 4.5cm and the width of 2cm at the positive plate corresponding to the negative plate cleaning area, so that the negative cleaning area is positioned in the central area of the adhesive tape, thereby obtaining a naked battery cell with a tab led out from the middle area of the battery cell electrode for standby application, and in the naked battery cell, the tab thickness is lower than the thickness of the cleaned coating, therefore, the tab area of the battery cell is not the thickest area of the battery cell, and the tab thickness does not influence the overall thickness of the battery, thereby obtaining the battery with higher energy density;
the rest is the same as comparative example 2, and is not described herein.
Embodiment 2, unlike embodiment 1, this embodiment includes the following steps:
preparing a naked battery cell: selecting an isolating film with the thickness of 12 mu m, winding the isolating film together with the positive plate and the negative plate, and simultaneously pasting an adhesive tape with the length of 5cm and the width of 3cm at the positive plate corresponding to the negative plate cleaning area, so that the negative cleaning area is positioned in the central area of the adhesive tape, thereby obtaining a bare cell with a tab led out from the middle area of the cell electrode for standby application, and in the bare cell, the thickness of the tab is lower than the thickness of the cleaned coating, therefore, the tab area of the cell is not the thickest area of the cell, and the thickness of the tab does not influence the overall thickness of the battery, thereby obtaining the battery with higher energy density;
the rest is the same as embodiment 1, and the description is omitted.
Embodiment 3, unlike embodiment 1, this embodiment includes the following steps:
preparing a naked battery cell: selecting an isolating film with the thickness of 12 mu m, winding the isolating film together with the positive plate and the negative plate, and simultaneously pasting an adhesive tape with the length of 5.5cm and the width of 4cm at the positive plate corresponding to the negative plate cleaning area, so that the negative cleaning area is positioned in the central area of the adhesive tape, thereby obtaining a naked battery cell with a tab led out from the middle area of the battery cell electrode for standby application, and in the naked battery cell, the tab thickness is lower than the thickness of the cleaned coating, therefore, the tab area of the battery cell is not the thickest area of the battery cell, and the tab thickness does not influence the overall thickness of the battery, thereby obtaining the battery with higher energy density;
the rest is the same as the embodiment 1, and the description is omitted.
Embodiment 4, unlike embodiment 1, this embodiment includes the following steps:
preparing a naked battery cell: selecting an isolating membrane with the thickness of 12 mu m, winding the isolating membrane together with the positive plate and the negative plate, and simultaneously pasting a sticky tape with the length of 6cm and the width of 5cm at the positive plate corresponding to the negative plate cleaning area, so that the negative cleaning area is positioned in the central area of the sticky tape, thereby obtaining a bare cell with a tab led out from the middle area of the cell electrode for standby application, and in the bare cell, the thickness of the tab is lower than the thickness of the cleaned coating, therefore, the tab area of the cell is not the thickest area of the cell, and the thickness of the tab does not influence the whole thickness of the battery, thereby obtaining the battery with higher energy density;
the rest is the same as the embodiment 1, and the description is omitted.
Example 5, unlike example 1, this example includes the following steps:
preparing a naked battery cell: selecting an isolating film with the thickness of 12 mu m, winding the isolating film together with the positive plate and the negative plate, and simultaneously pasting an adhesive tape with the length of 6.5cm and the width of 6cm at the positive plate corresponding to the negative plate cleaning area, so that the negative cleaning area is positioned in the central area of the adhesive tape, thereby obtaining a naked battery cell with a tab led out from the middle area of the battery cell electrode for standby application, and in the naked battery cell, the tab thickness is lower than the thickness of the cleaned coating, therefore, the tab area of the battery cell is not the thickest area of the battery cell, and the tab thickness does not influence the overall thickness of the battery, thereby obtaining the battery with higher energy density;
the rest is the same as the embodiment 1, and the description is omitted.
Embodiment 6, unlike embodiment 1, this embodiment includes the following steps:
preparing a positive plate: selecting an aluminum foil with the thickness of 12 mu m as a current collector, coating the positive electrode slurry on the surface of the current collector, and performing cold pressing to obtain a positive electrode membrane with the single-side coating thickness of 75 mu m; then cleaning a double-sided blank area with the length of 4cm and the width of 0.5cm in the middle area of the membrane by using laser, and then welding an aluminum tab with the width of 0.4cm and the thickness of 60 mu m to obtain a positive plate for later use;
preparing a negative plate: selecting a copper foil with the thickness of 8 mu m as a current collector, coating negative electrode slurry on the surface of the current collector, and coating a negative electrode sheet with the thickness of 70 mu m on one side after cold pressing; then, cleaning a double-sided blank area (staggered with the position of the positive electrode lug) with the length of 4cm and the width of 0.5cm in the middle area of the membrane by using laser, and welding a nickel electrode lug with the width of 0.4cm and the thickness of 60 mu m to obtain a negative electrode plate for later use;
preparing a naked battery cell: selecting an isolating film with the thickness of 12 mu m, winding the isolating film together with the positive plate and the negative plate, and simultaneously pasting an adhesive tape with the length of 4.5cm and the width of 1cm at the positive plate corresponding to the negative plate cleaning area, so that the negative cleaning area is positioned in the central area of the adhesive tape, thereby obtaining a naked battery cell with a tab led out from the middle area of the battery cell electrode for standby application, and in the naked battery cell, the tab thickness is lower than the thickness of the cleaned coating, therefore, the tab area of the battery cell is not the thickest area of the battery cell, and the tab thickness does not influence the overall thickness of the battery, thereby obtaining the battery with higher energy density;
the rest is the same as the embodiment 1, and the description is omitted.
Embodiment 7, different from embodiment 6, this embodiment includes the following steps:
preparing a positive plate: selecting an aluminum foil with the thickness of 12 microns as a current collector, coating positive electrode slurry on the surface of the aluminum foil, and performing cold pressing to obtain a positive electrode membrane with the single-side coating thickness of 75 microns; then cleaning a double-sided blank area with the length of 4cm and the width of 1cm in the middle area of the membrane by using laser, and then welding an aluminum tab with the width of 0.8cm and the thickness of 60 mu m to obtain a positive plate for later use;
preparing a negative plate: selecting a copper foil with the thickness of 8 mu m as a current collector, coating negative electrode slurry on the surface of the current collector, and coating a negative electrode sheet with the thickness of 70 mu m on one side after cold pressing; then, cleaning a double-sided blank area (staggered with the position of the positive electrode lug) with the length of 4cm and the width of 1cm in the middle area of the membrane by using laser, and welding a nickel electrode lug with the width of 0.8cm and the thickness of 60 mu m to obtain a negative electrode plate for later use;
preparing a naked battery cell: selecting an isolating membrane with the thickness of 12 mu m, winding the isolating membrane together with the positive plate and the negative plate, and simultaneously pasting a tape with the length of 4.5cm and the width of 1.5cm at the positive plate corresponding to the negative plate cleaning area, so that the negative cleaning area is positioned in the central area of the tape, thereby obtaining a naked battery cell with a lug led out from the middle area of a battery cell electrode for standby, and in the naked battery cell, the lug thickness is lower than the thickness of the coating cleaned, therefore, the lug area of the battery cell is not the thickest area of the battery cell, the lug thickness does not influence the whole thickness of the battery, and the battery with higher energy density can be obtained;
the rest is the same as example 6, and the description is omitted.
Embodiment 8, different from embodiment 1, this embodiment includes the following steps:
preparing a naked battery cell: selecting an isolating membrane with the thickness of 12 mu m, winding the isolating membrane, the positive plate and the negative plate together, spraying 502 glue with the length of 4.5cm and the width of 2cm on the positive plate corresponding to the negative plate cleaning area, enabling the negative plate cleaning area to be located in the central area of the adhesive tape, enabling the glue to quickly permeate into an electrode hole after being sprayed on the surface of the electrode, solidifying and completely blocking an ion transmission channel, thereby obtaining a bare cell with a tab led out from the middle area of the cell electrode for standby application, wherein in the bare cell, the tab thickness is lower than the thickness of the cleaned coating, so that the tab area of the cell is not the thickest area of the cell, the tab thickness does not influence the overall thickness of the battery, and the battery with higher energy density is obtained;
the rest is the same as the embodiment 1, and the description is omitted.
Example 9, unlike example 1, this example includes the following steps:
preparing a positive plate: selecting an aluminum foil with the thickness of 12 microns as a current collector, coating positive electrode slurry on the surface of the aluminum foil, and performing cold pressing to obtain a positive electrode membrane with the single-side coating thickness of 75 microns; then cleaning a double-sided blank area with the length of 4cm and the width of 1.5cm in the middle area of the membrane by using a solvent, and then welding an aluminum lug with the width of 1cm and the thickness of 60 mu m to obtain a positive plate for later use;
preparing a negative plate: selecting a copper foil with the thickness of 8 mu m as a current collector, coating negative electrode slurry on the surface of the current collector, and coating a negative electrode sheet with the thickness of 70 mu m on one side after cold pressing; then cleaning a double-sided blank area (staggered with the position of the positive electrode lug) with the length of 4cm and the width of 1.5cm in the middle area of the membrane by using a solvent, and welding a nickel electrode lug with the width of 1cm and the thickness of 60 mu m to obtain a negative electrode plate for later use;
preparing a naked battery cell: selecting an isolating membrane with the thickness of 12 microns, winding the isolating membrane together with the positive plate and the negative plate, and spraying hot melt adhesive (the melting point is 100 ℃) with the length of 4.5cm and the width of 2cm at the position of the positive plate corresponding to the negative plate cleaning area, so that a bare cell with a tab led out from the middle area of the cell electrode is obtained for standby application, and in the bare cell, the thickness of the tab is lower than the thickness of the cleaned coating, so that the tab area of the cell is not the thickest area of the cell, and the thickness of the tab does not influence the overall thickness of the battery, and the battery with higher energy density is obtained;
preparing a finished battery: placing the bare cell in an aluminum-plastic film for top-side sealing, drying, injecting liquid, performing clamp formation at 75 ℃ and 0.6MPa after the electrolyte is fully soaked, then shaping at 120 ℃ and 0.8MPa, melting and penetrating the hot melt adhesive into an electrode hole structure at 120 ℃, solidifying the hot melt adhesive again to block the electrode hole after the temperature of the cell is reduced, completely blocking an ion transmission channel, inactivating an anode active substance, shaping, degassing and sealing to obtain a finished product cell.
The rest is the same as the embodiment 1, and the description is omitted.
Embodiment 10, different from embodiment 1, this embodiment includes the following steps:
preparing a positive plate: selecting an aluminum foil with the thickness of 12 micrometers as a current collector, arranging a layer of foaming adhesive with the length of 4cm and the width of 1.5cm in a surface fixing area (the arrangement position of the foaming adhesive is positioned in the middle area of a finished battery pole piece), then coating positive electrode slurry, and in the drying process, enabling the foaming adhesive to fall off to enable a coating coated on the surface of the foaming adhesive to fall off to obtain a hollow foil area (with the length of 4cm and the width of 1.5 cm), and then carrying out cold pressing to obtain a positive electrode membrane with the single-side coating thickness of 75 micrometers; welding an aluminum lug with the width of 1cm and the thickness of 60 mu m on the empty foil area to obtain a positive plate for later use;
preparing a negative plate: selecting a copper foil with the thickness of 8 mu m as a current collector, arranging a layer of foaming adhesive with the length of 4cm and the width of 1.5cm on a fixed area on the surface of the current collector (the arrangement position of the foaming adhesive is positioned in the middle area of a finished battery pole piece), then coating negative electrode slurry on the surface of the current collector, wherein the foaming adhesive falls off in the drying process, so that a coating coated on the surface of the current collector falls off to obtain a hollow foil area (with the length of 4cm and the width of 1.5 cm), and then cold-pressing and coating a negative electrode piece with the thickness of 70 mu m on one side; then cleaning a double-sided blank area (staggered with the position of the positive electrode lug) with the length of 4cm and the width of 1.5cm in the middle area of the membrane by using a solvent, and welding a nickel electrode lug with the width of 1cm and the thickness of 60 mu m on the blank foil area to obtain a negative electrode plate for later use;
preparing a naked battery cell: selecting an isolating membrane with the thickness of 12 mu m, winding the isolating membrane, the positive plate and the negative plate together, spraying epoxy resin glue with the length of 4.5cm and the width of 2cm on the positive plate corresponding to the negative plate cleaning area, enabling the negative plate cleaning area to be located in the central area of the adhesive tape, and enabling the glue to quickly permeate into an electrode hole after being sprayed on the surface of the electrode, curing and completely blocking an ion transmission channel, so that a bare cell with a tab led out from the middle area of the cell electrode is obtained for standby, and in the bare cell, the thickness of the tab is lower than the thickness of the cleaned coating, so that the tab area of the cell is not the thickest area of the cell, the thickness of the tab does not influence the overall thickness of the battery, and the battery with higher energy density is obtained;
preparing a finished battery: and (3) placing the bare cell in an aluminum-plastic film for top-side sealing, then drying, injecting liquid, after the electrolyte is fully soaked, performing clamp formation at 75 ℃ and 0.6MPa, and then shaping, degassing and sealing to obtain a finished product cell.
The rest is the same as embodiment 1, and the description is omitted.
Example 11, unlike example 1, this example includes the steps of:
preparing a naked battery cell: selecting an isolating membrane with the thickness of 12 mu m, winding the isolating membrane with the positive plate and the negative plate together, and simultaneously carrying out 160 ℃ heat treatment on an isolating membrane region corresponding to a negative plate cleaning region to ensure that the isolating membrane is completely closed and loses ion permeability, wherein the length and the width of the isolating membrane heat treatment region are 4.5cm and 2cm, and the isolating membrane heat treatment region is positioned in the central region of the negative plate cleaning region, so that a naked battery cell with a lug led out from the middle region of a battery cell electrode is obtained for standby application, and in the naked battery cell, the thickness of the lug is lower than the thickness of a cleaned coating layer, so that the lug region of the battery cell is not the thickest region of the battery cell, and the thickness of the lug does not influence the overall thickness of the battery, and the battery with higher energy density is obtained;
the rest is the same as the embodiment 1, and the description is omitted.
The testing process comprises the following steps:
and (3) capacity testing: the capacity test of the battery cells of the examples and the comparative examples is carried out in an environment of 35 ℃ according to the following flow: standing for 3min; charging to 4.2V at constant current of 0.5C and charging to 0.05C at constant voltage; standing for 3min; discharging at constant current of 0.5C to 3.0V to obtain first discharge capacity D0; the capacity test was completed after standing for 3min, and the obtained results are shown in table 1.
And (3) thickness testing: the thickness of the battery (thickness between the front and back of the cell) was measured using a micrometer, and the results are shown in table 1.
Volumetric energy density: and calculating according to the tested battery capacity, voltage, length, width and the like.
Lithium deposition after capacity: after the capacity test is completed, the battery core is disassembled, the lithium precipitation condition of the extreme ear area is observed, and the battery core is respectively marked as four conditions of no lithium precipitation, slight lithium precipitation, medium lithium precipitation and lithium precipitation according to the lithium precipitation amount from small to large.
Lithium profile after 500 weeks cycling: the capacity test of the cells of the examples and comparative examples was carried out in an environment of 35 ℃ according to the following procedure: standing for 3min; charging to 4.2V at constant current of 0.5C and charging to 0.05C at constant voltage; standing for 3min; discharging at constant current of 0.5C to 3.0V to obtain first discharge capacity D0; standing for 3min; and repeating the test for 499 weeks, disassembling the cell, observing the lithium precipitation condition in the extreme ear area, and respectively marking the conditions of no lithium precipitation, slight lithium precipitation, medium lithium precipitation and lithium precipitation according to the lithium precipitation amount from small to large.
As can be seen from table 1, the volume energy density of the battery can be increased, and the lithium deposition of the prepared battery cell is avoided.
From the embodiments 1 to 5, when the adhesive tape sticking mode is adopted, the lithium precipitation of the battery is gradually reduced along with the increase of the width of the adhesive tape until the lithium precipitation is not carried out any more; however, since more positive electrode coating capacity cannot exert capacity, the battery capacity is low, and the corresponding energy density is reduced; therefore, this method is not an optimal solution for lithium deposition and energy density.
From the embodiments 8 to 10, when the glue coating mode is adopted, the glue can also completely block the pore structure of the positive coating, so that the positive coating is completely inactivated, and meanwhile, the glue coating area is small, and the influence on the effective area of the positive coating is small, so that the method not only can solve the problem of lithium precipitation, but also can improve the energy density.
The positive electrode coating deactivation treatment obtained in examples 1 to 11 can effectively increase the energy density of the battery and solve the problem of lithium precipitation, which indicates that the present invention has universality.
TABLE 1 summary of test results of each comparative example and example
Variations and modifications to the above-described embodiments may also occur to those skilled in the art, which fall within the scope of the invention as disclosed and taught herein. Therefore, the present invention is not limited to the above-mentioned embodiments, and any obvious improvement, replacement or modification made by those skilled in the art based on the present invention is within the protection scope of the present invention. Furthermore, although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.
Claims (10)
1. An electrochemical cell comprises a positive plate, a negative plate, an isolating membrane, an outer package and electrolyte, wherein the positive plate comprises a positive current collector and a positive coating layer, the capacity of the positive coating layer per unit area is Cc mAh, the negative plate comprises a negative current collector and a negative coating layer, and the capacity of the negative coating layer per unit area is Ca mAh; the method is characterized in that:
a region with Cc being more than or equal to Ca exists in the region of the positive plate corresponding to the negative plate; the width of the area of Cc which is larger than or equal to Ca is L, and L is larger than or equal to 0.5mm;
and the positive plate coating in the area of Cc which is more than or equal to Ca is subjected to positive active substance inactivation treatment, and the capacity exertion rate of the positive active substance is less than or equal to 95%.
2. An electrochemical cell according to claim 1, wherein the deactivation treatment includes a physical deactivation treatment and/or a chemical deactivation treatment, and after the deactivation treatment, a capacity exertion rate of the positive electrode active material of the positive electrode coating layer in the region where Cc is equal to or greater than Ca is 90% or less.
3. An electrochemical cell according to claim 2, wherein the physical deactivation process is an electrode electron channel blocking deactivation process or an electrode ion channel blocking deactivation process; the chemical inactivation treatment is to inactivate the positive electrode active substance.
4. An electrochemical cell according to claim 3, wherein the electrode electron channel blocking deactivation process comprises at least one of an ultrasonic shaking process, a conductive agent oxidation process, and a conductive agent heat treatment; the electrode ion channel blocking inactivation treatment is to fill a pore structure of the electrode with a non-ionic conduction substance; the inactivation treatment of the positive electrode active substance comprises at least one of oxidation inactivation treatment of the positive electrode active substance, reduction inactivation treatment of the positive electrode active substance and heat treatment inactivation treatment of the positive electrode active substance.
5. An electrochemical cell according to claim 1, wherein L.gtoreq.1 mm.
6. A method of making an electrochemical cell according to claim 1, comprising the steps of:
step 1, preparing an electrode slice: preparing a positive plate and a negative plate corresponding to the positive plate, wherein the capacity of a positive coating layer of the positive plate in unit area is Cc mAh, and the capacity of a negative coating layer of the negative plate in unit area is CamAh; and a region with Cc being more than or equal to Ca exists in the region of the positive plate corresponding to the negative plate;
step 2, assembling the battery cell: assembling the positive plate, the negative plate and the isolating film to obtain a naked battery cell, and performing inactivation treatment on the positive plate in the area where the Cc of the naked battery cell is larger than or equal to Ca; then, putting the naked electric core into a shell/bag, packaging, injecting liquid and standing;
step 3, preparing a finished product battery core: and (3) forming and shaping the battery cell prepared in the step (2) to obtain a finished product battery cell, and placing the battery cell in an environment of not higher than 120 ℃ in the forming or/and shaping process.
7. A method for preparing an electrochemical cell according to claim 6, wherein the method for obtaining the region where Cc is greater than or equal to Ca comprises at least one of controlling the coating weight so that the region where Cc is greater than or equal to Ca appears in the electrode sheet, washing off part of the negative electrode on the membrane where Cc is less than or equal to Ca so that Cc is greater than or equal to Ca, and completely washing off the negative electrode coating on the membrane where Cc is less than or equal to Ca so that Ca = 0.
8. A method of making an electrochemical cell according to claim 7, wherein the cleaning process comprises at least one of solvent cleaning, laser cleaning, and removing a partial coating after pre-structuring the current collector prior to coating; and after the negative coating is completely cleaned on the membrane with Cc less than or equal to Ca so that Ca =0, welding a tab on the current collector.
9. A method for manufacturing an electrochemical cell according to claim 6, wherein the deactivation treatment in step 2 includes a physical deactivation treatment and/or a chemical deactivation treatment, and after the deactivation treatment, a capacity utilization rate of the positive electrode active material in the positive electrode coating layer in the region where Cc is equal to or greater than Ca is 95% or less.
10. An electrochemical cell comprises a positive plate, a negative plate, an isolating membrane, an outer package and electrolyte, wherein the positive plate comprises a positive current collector and a positive coating layer, the capacity of the positive coating layer per unit area is Cc mAh, the negative plate comprises a negative current collector and a negative coating layer, and the capacity of the negative coating layer per unit area is Ca mAh; the method is characterized in that:
a region with Cc being more than or equal to Ca exists in the region of the positive plate corresponding to the negative plate; the width of the region where Cc is larger than or equal to Ca is L, and L is larger than or equal to 0.5mm;
and the isolating membrane which is positioned between the positive plate and the negative plate and corresponds to the area where Cc is more than or equal to Ca is subjected to inactivation treatment, and after the inactivation treatment, the isolating membrane becomes an ion-blocking and electron-blocking isolating membrane.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510676980.1A CN105355837B (en) | 2015-10-16 | 2015-10-16 | Electrochemical cell and method of making same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510676980.1A CN105355837B (en) | 2015-10-16 | 2015-10-16 | Electrochemical cell and method of making same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105355837A CN105355837A (en) | 2016-02-24 |
| CN105355837B true CN105355837B (en) | 2017-11-07 |
Family
ID=55331757
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510676980.1A Active CN105355837B (en) | 2015-10-16 | 2015-10-16 | Electrochemical cell and method of making same |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN105355837B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106025365A (en) * | 2016-07-05 | 2016-10-12 | 深圳市海太阳实业有限公司 | Making method of battery and battery |
| CN109560286A (en) * | 2018-09-28 | 2019-04-02 | 桑顿新能源科技有限公司 | A kind of lithium ion battery improving high temperature short-circuit capability |
| CN111632887B (en) * | 2020-04-23 | 2022-04-15 | 惠州锂威新能源科技有限公司 | Method for cleaning lithium ion battery pole piece |
| WO2023000289A1 (en) * | 2021-07-23 | 2023-01-26 | 宁德时代新能源科技股份有限公司 | Battery assembly and processing method and apparatus, battery cell, battery and electric device |
| CN115863779A (en) * | 2022-12-29 | 2023-03-28 | 蔚来汽车科技(安徽)有限公司 | Method for inactivating positive electrode of lithium ion battery and lithium ion battery |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101017891A (en) * | 2006-03-06 | 2007-08-15 | 松下电器产业株式会社 | Lithium ion secondary battery |
| CN102224621A (en) * | 2008-11-20 | 2011-10-19 | 株式会社Lg化学 | Lithium secondary battery having improved characteristics |
| CN102403554A (en) * | 2011-11-10 | 2012-04-04 | 大连交通大学 | Method for recycling waste lithium iron phosphate ion battery anode material |
| CN105280925A (en) * | 2014-07-16 | 2016-01-27 | 辉能科技股份有限公司 | Negative pole plate |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3392011B2 (en) * | 1997-06-17 | 2003-03-31 | 三井金属鉱業株式会社 | Method for producing positive electrode material for lithium secondary battery and battery using the same |
-
2015
- 2015-10-16 CN CN201510676980.1A patent/CN105355837B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101017891A (en) * | 2006-03-06 | 2007-08-15 | 松下电器产业株式会社 | Lithium ion secondary battery |
| CN102224621A (en) * | 2008-11-20 | 2011-10-19 | 株式会社Lg化学 | Lithium secondary battery having improved characteristics |
| CN102403554A (en) * | 2011-11-10 | 2012-04-04 | 大连交通大学 | Method for recycling waste lithium iron phosphate ion battery anode material |
| CN105280925A (en) * | 2014-07-16 | 2016-01-27 | 辉能科技股份有限公司 | Negative pole plate |
Also Published As
| Publication number | Publication date |
|---|---|
| CN105355837A (en) | 2016-02-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105261727B (en) | Electrochemical cell and preparation method thereof | |
| CN105355837B (en) | Electrochemical cell and method of making same | |
| CN105355921B (en) | Electrochemical cell and preparation method thereof | |
| CN105390627B (en) | Electrochemical cell and preparation method thereof | |
| CN109004234A (en) | A kind of lithium ion secondary battery | |
| CN105261730B (en) | Electrode of electrochemical cell, electrochemical cell using same and preparation method thereof | |
| CN108878775A (en) | It is a kind of to mend lithium composite negative pole pole piece and preparation method thereof safely | |
| CN105355956B (en) | Electrochemical cell and preparation method thereof | |
| CN109004304B (en) | Lithium supplementing method for soft package lithium ion battery and preparation method for lithium ion battery | |
| CN105261781B (en) | Electrochemical cell and preparation method thereof | |
| CN109585932B (en) | Manufacturing method of symmetrical battery and symmetrical battery | |
| CN105470564A (en) | Solid electrolyte membrane, preparation method of solid electrolyte membrane and lithium ion battery | |
| CN104733783B (en) | A kind of preparation method of lithium ion battery | |
| CN105958124B (en) | A kind of lithium ion battery and preparation method thereof | |
| CN110335992A (en) | A kind of electrodes of lithium-ion batteries prelithiation device | |
| CN110556495A (en) | lithium ion battery diaphragm and lithium ion battery containing same | |
| CN206639875U (en) | Soft package battery | |
| CN105368336B (en) | Electrochemical cell and preparation method thereof | |
| CN105390749A (en) | Preparation method of electrochemical cell | |
| CN104882630B (en) | A kind of preparation method of the naked battery core of lithium ion battery and the lithium ion battery containing the naked battery core | |
| CN105355957B (en) | Electrochemical cell and method of making same | |
| CN109037591B (en) | Electrode, all-solid-state battery, preparation method of all-solid-state battery and lithium ion battery | |
| CN107863487B (en) | Lithium-sulfur battery positive electrode and preparation method thereof, lithium-sulfur battery cell and lithium-sulfur battery | |
| CN206059547U (en) | A kind of lithium ion battery structure of quickly-chargeable | |
| CN105355806B (en) | Electrochemical battery packaging material, battery using packaging material and preparation method of battery |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |