WO2018180167A1 - Procédé de production de batterie secondaire - Google Patents

Procédé de production de batterie secondaire Download PDF

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Publication number
WO2018180167A1
WO2018180167A1 PCT/JP2018/007751 JP2018007751W WO2018180167A1 WO 2018180167 A1 WO2018180167 A1 WO 2018180167A1 JP 2018007751 W JP2018007751 W JP 2018007751W WO 2018180167 A1 WO2018180167 A1 WO 2018180167A1
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WIPO (PCT)
Prior art keywords
secondary battery
negative electrode
manufacturing
battery according
positive electrode
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PCT/JP2018/007751
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English (en)
Japanese (ja)
Inventor
佳介 島田
徹 川合
昌史 樋口
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株式会社村田製作所
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Publication of WO2018180167A1 publication Critical patent/WO2018180167A1/fr

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/04—Construction or manufacture in general
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/058—Construction or manufacture
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/058—Construction or manufacture
    • H01M10/0585—Construction or manufacture of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/058—Construction or manufacture
    • H01M10/0587—Construction or manufacture of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators
    • 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
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/102—Primary casings; Jackets or wrappings characterised by their shape or physical structure
    • H01M50/103—Primary casings; Jackets or wrappings characterised by their shape or physical structure prismatic or rectangular
    • 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
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/102—Primary casings; Jackets or wrappings characterised by their shape or physical structure
    • H01M50/105—Pouches or flexible bags
    • 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

Definitions

  • the present invention relates to a method for manufacturing a secondary battery.
  • the secondary battery has a structure in which an electrode assembly including a positive electrode, a negative electrode, and a separator disposed between the positive electrode and the negative electrode, and an electrolyte are enclosed in an exterior body.
  • an electrode assembly including a positive electrode, a negative electrode, and a separator disposed between the positive electrode and the negative electrode, and an electrolyte are enclosed in an exterior body.
  • lithium ions move between the positive electrode and the negative electrode through the electrolyte, and the battery is charged and discharged.
  • the electrode assembly is accommodated in the exterior body, the electrolyte is injected into the exterior body, the inside of the exterior body is sealed, and the secondary battery precursor is obtained, and then the initial charge is performed. It is common.
  • a solid-electrolyte interface coating (hereinafter referred to as “SEI coating”) is formed on the negative electrode surface to suppress decomposition of electrolyte components on the negative electrode surface when used as a secondary battery, It is known to extend the life of batteries.
  • a secondary battery is provided by applying a restraining force in the thickness direction z of the electrode in the secondary battery precursor 300 by a restraining jig 200.
  • a method of performing initial charging while restraining the precursor 300 is known. According to such a method, bubbles are prevented from adhering to the electrode surface of the secondary battery precursor 300, and formation of an SEI film having a uniform thickness is promoted.
  • the restraining jig 200 applies a restraining force in the z direction to the one or more secondary battery precursors 300 via the restraining plate 205 between the movable plate 202 and the fixed plate 203 by the rotation of the bolt 201. It is supposed to be.
  • the binding force is applied relatively uniformly over the entire surface of the upper surface 310 and the lower surface of the secondary battery precursor 300 (the surface facing the upper surface 310 in the secondary battery precursor) (not shown). For this reason, the SEI film can be formed with a relatively uniform thickness over the entire surface of the negative electrode during initial charging.
  • Patent Documents 1 and 2 A secondary battery provided with a stepped portion has been reported as a secondary battery that meets such requirements.
  • the inventors of the present invention constrain the secondary battery precursor 350 having a step portion (for example, a step portion 351 constituted by two upper surfaces having different heights as shown in FIG. 6) by the above-described method.
  • a step portion for example, a step portion 351 constituted by two upper surfaces having different heights as shown in FIG. 6
  • problems relating to safety and battery capacity due to unevenness in the thickness of the SEI film occur again.
  • FIG. 6 when a restraining force is applied to the secondary battery precursor 350 having the step portion 351 using the restraining jig 200 as described above, the lower stage of the secondary battery precursor 350 is reduced.
  • the present invention can perform initial charging while imparting a binding force to the entire surface of the secondary battery precursor more uniformly. It aims at providing the manufacturing method of a battery.
  • the present invention performs the initial charging while more uniformly applying the binding force to the entire surface of the secondary battery precursor, thereby providing the SEI coating.
  • An object of the present invention is to provide a method for manufacturing a secondary battery in which is formed with a more uniform thickness over the entire surface of the negative electrode surface.
  • the present invention An electrode assembly including a positive electrode, a negative electrode, and a separator disposed between the positive electrode and the negative electrode, and an electrolyte are sealed in an exterior body, and a secondary battery precursor having a stepped portion is restrained by a fluid,
  • the present invention relates to a method for manufacturing a secondary battery including a step of performing initial charging.
  • a restraining force of an appropriate size is more uniformly applied to the entire surface of the secondary battery precursor.
  • the initial charging can be performed while applying to the above. For this reason, in the initial charging step, charging unevenness due to bubbles is more sufficiently suppressed over the entire surface of the negative electrode surface, so that the SEI film is formed with a more uniform thickness.
  • precipitation of lithium is more sufficiently suppressed, so that safety is improved and a decrease in battery capacity is suppressed.
  • the typical perspective view of an example of the secondary battery precursor which has a level difference part is shown.
  • the typical perspective view of another example of the secondary battery precursor which has a level difference part is shown.
  • the typical perspective view which shows one embodiment of the process of performing initial charge, restraining the secondary battery precursor of FIG. 1 with a fluid in this invention is shown.
  • the typical perspective view which shows one embodiment of the process of performing initial charge, restraining a secondary battery precursor with a restraint jig in a prior art is shown.
  • the schematic perspective view of an example of the secondary battery precursor used in the schematic perspective view of FIG. 4 is shown.
  • FIG. 4 is a schematic perspective view of the secondary battery precursor for explaining a binding force applied to the secondary battery precursor when a secondary battery precursor having a stepped portion is used.
  • the present invention provides a method for manufacturing a secondary battery.
  • the term “secondary battery” refers to a battery that can be repeatedly charged and discharged. Therefore, the “secondary battery” is not excessively bound by the name, and may include, for example, “electric storage device”.
  • initial charging is performed while the secondary battery precursor is restrained by a fluid.
  • the secondary battery precursor is an intermediate body or an intermediate structure of a secondary battery obtained by enclosing the electrode assembly and the electrolyte in an exterior body before the initial charging step.
  • the overall shape of the secondary battery precursor used in the method of the present invention is not particularly limited.
  • the shape may not have a portion (for example, a rectangular parallelepiped shape and a plate shape)
  • a shape having a step portion is preferable from the viewpoint of practical utility in the field of secondary batteries.
  • the step portion is a discontinuous portion of the upper surface that is configured by two upper surfaces having different heights in a side view, and the height of the steps locally changes between the two upper surfaces.
  • the side view is a state when an object (for example, a secondary battery precursor) is placed and viewed from the side in the thickness (height) direction, and is in agreement with the side view.
  • the placement is placement with the surface (plane) having the maximum area constituting the appearance of the object (for example, the secondary battery precursor) as the bottom surface.
  • Side view includes side view by fluoroscopy. That is, the stepped portion is not only a stepped portion that can clearly distinguish the height difference when viewed from the side as shown in FIG. 1, but also the height difference when viewed from the side as shown in FIG. Actually includes a step portion that cannot be discriminated but can be discriminated by fluoroscopy.
  • the stepped portion is generally composed of two upper surfaces 11a and 12a having different heights and a side surface 10a connecting the two upper surfaces therebetween.
  • the upper surface is an upper surface when an object (for example, a secondary battery precursor) is placed.
  • the planar shape of the secondary battery precursor is not particularly limited, and may be a rectangular shape or an irregular shape in the planar view.
  • the plan view is a state when an object (for example, a secondary battery precursor) is placed and viewed from directly above the thickness (height) direction, and is in agreement with the plan view.
  • the rectangular shape may be a rectangular shape or a square shape.
  • the irregular shape in the plan view shape of the secondary battery precursor is a shape having a notch in the plan view.
  • the notch is a part where a part of the cutout is intentionally lost from the initial shape.
  • the initial shape before the formation of the notch is usually rectangular.
  • the planar view shape of the notch is not particularly limited, and examples thereof include a rectangular shape, a triangular shape, a fan shape, a semicircular shape, and a circular shape.
  • the shape of the secondary battery precursor is not particularly limited, and the secondary battery precursor may have any shape. It is clear that the effects of the present invention can be obtained.
  • various elements in the drawings are merely schematically and exemplarily shown for understanding of the present invention, and the appearance and size ratio may be different from the actual ones.
  • the “vertical direction”, “left / right direction”, and “front / back direction” used directly or indirectly in this specification correspond to directions corresponding to the vertical direction, left / right direction, and front / back direction in the drawing, respectively.
  • the same reference numerals or symbols indicate the same members or the same meaning contents except that the shapes are different.
  • the initial charging step is an initial charging step of the secondary battery precursor performed for the purpose of forming an SEI film on the negative electrode surface, and is also referred to as an initial charging step, a conditioning step, or a formation step.
  • the SEI coating is formed by reducing and decomposing the additive contained in the electrolyte in the present step on the negative electrode surface, and suppresses further decomposition of the additive on the negative electrode surface during use as a secondary battery.
  • the SEI coating typically includes one or more materials selected from the group consisting of LiF, Li 2 CO 3 , LiOH, and LiOCOOR (R represents a monovalent organic group such as an alkyl group).
  • the initial charging is performed while restraining the secondary battery precursor with a fluid.
  • the restraint by the fluid is tightening from the outside by the fluid for the secondary battery precursor, in other words, pressurization to the surface of the secondary battery precursor through the fluid. Or “fluid pressurization”.
  • fluid uniform clamping or “fluid uniform pressurization” is used. I can also say.
  • the secondary battery precursor is restrained (pressurized) using a fluid
  • the fluid is subjected to a pressure (restraint force or pressure) applied to a part thereof based on Pascal's principle. Transmits to all other parts of the fluid as it is in a sealed container.
  • a pressure straint force or pressure
  • the binding force on the entire surface including the upper surface, the lower surface and the side surface (particularly the side surface of the stepped portion) of the secondary battery precursor ( Pressure) can be applied more uniformly.
  • the binding force (pressure) can be more uniformly applied to the entire surface of the secondary battery precursor.
  • the adhesion of bubbles during initial charging is more sufficiently suppressed over the entire surface of the negative electrode, and charging unevenness due to bubbles is also sufficiently suppressed over the entire surface of the negative electrode, so that the SEI coating is more uniform over the entire surface of the negative electrode surface. It is formed with an appropriate thickness.
  • the initial charging is performed while restraining (pressurizing) the secondary battery precursor using an instrument such as the restraining jig described above without using a fluid, for example, in the low stage portion 11 in FIG.
  • the SEI film cannot be formed with a uniform thickness over the entire surface.
  • the method of restraining with the fluid is not particularly limited as long as the surface of the secondary battery precursor is pressurized with the fluid.
  • the secondary battery is contained in the fluid 2 previously contained in the pressurized chamber 20.
  • a method of placing the precursor 1 and pressurizing the inside of the pressurizing chamber 20 can be employed. Specifically, a pressurizing pump (not shown) is connected to the pressurizing chamber 20, and the fluid 2 is supplied to the inside of the pressurizing chamber 20 by the pressurizing pump, so Pressurization is achieved, and pressurization of the secondary battery precursor surface by the fluid is achieved.
  • the fluid restraining method is to increase the size of the pressurizing chamber, so that even if two or more secondary battery precursors 1 are used as shown in FIG.
  • the binding force can be applied more uniformly, it is advantageous for mass production of secondary batteries. Since the fluid 2 transmits a restraining force (pressure) inside the pressurizing chamber 20, the restraining force does not change depending on the position where the secondary battery precursor 1 is disposed, and is constant.
  • the secondary battery precursor 1 may be placed on a flat shelf or the like inside the pressurized chamber 20, or a cloth-like, mesh-like or net-like shape having both ends suspended like a hammock. It may be placed on a cloth or the like.
  • the direction in which the secondary battery precursor 1 is arranged may be horizontal (flat) or vertical.
  • the fluid is not particularly limited as long as it can transmit pressure, and may be a gas, a liquid, or a composite thereof (both gas and liquid).
  • the gas include air, water vapor, inert gas, or a mixed gas thereof.
  • the inert gas include helium, neon, argon, and nitrogen.
  • Specific examples of the liquid include water and oil. It is preferable to use a gas (particularly air) alone as the fluid from the viewpoint of restraint work ease.
  • water and / or water vapor is used as the fluid, the secondary battery precursor is accommodated in a water-resistant bag to avoid direct contact between the secondary battery precursor and the fluid. It is preferable to carry out.
  • the fluid stored in advance in the pressurization chamber and the fluid supplied to the pressurization chamber by the pressurization pump are independently from the above-described fluids. May be selected.
  • the fluid supplied by the pressurized pump into the pressurized chamber may be either or both of a gas and a liquid.
  • a gas (especially air) is preliminarily contained in the interior of the pressurized chamber, the gas (especially air) is independently added to the inside of the pressurized chamber from the viewpoint of further improving the workability of restraint. Supply by a pressure pump is preferred.
  • the secondary battery precursor is placed in the gas inside the pressurizing chamber, and the gas inside the pressurizing chamber is supplied by the pressurizing pump alone, thereby increasing the pressure inside the pressurizing chamber. As a result, pressurization of the secondary battery precursor surface with gas is achieved.
  • the fluid supplied by the pressurized pump into the pressurized chamber is either one or both of gas and liquid.
  • the secondary battery precursor is disposed in the liquid inside the pressurized chamber, and one or both of gas and liquid are supplied to the inside of the pressurized chamber by a pressure pump. Pressurization of the secondary battery precursor surface by the fluid is achieved as a result.
  • a liquid or a composite of liquid and gas is previously stored in the pressurized chamber, the secondary battery precursor is disposed in the liquid in the pressurized chamber, and the gas is singly contained in the pressurized chamber.
  • the pressurizing pump When supplied by the pressurizing pump, the liquid level inside the pressurizing chamber is pressed by the supplied gas. Thereby, the liquid transmits the pressing force, and as a result, pressurization of the secondary battery precursor surface is achieved.
  • the binding force by the fluid (that is, the pressure on the surface of the secondary battery precursor) is not particularly limited as long as adhesion of the gas generated in this step to the negative electrode surface is suppressed, and is usually a pressure higher than atmospheric pressure. .
  • the binding force by the fluid is usually in the range of 0.1 MPa to 1.0 MPa, particularly 0.1 MPa to less than 1.0 MPa, and preferably 0 from the viewpoint of further suppressing the adhesion of gas to the negative electrode surface. Within the range of 1 MPa to 0.5 MPa. In this way, the restraining force when using a fluid is considerably smaller than the restraining force when using an instrument such as the restraining jig described above.
  • a restraining force of, for example, 1.0 MPa or more and 3.0 MPa or less is required to sufficiently suppress the adhesion of gas to the negative electrode surface. Met. For this reason, the electrode, separator, etc. which are accommodated in the exterior body may be damaged by the binding force.
  • the restraint force since the restraint force is applied by the fluid, the restraint force within the above-described range is sufficient to sufficiently suppress the adhesion of gas to the negative electrode surface. For this reason, in this invention, the damage by restraint force, such as an electrode and a separator accommodated in the inside of an exterior body, can be suppressed.
  • the secondary battery precursor is preferably maintained at a temperature in the range of 25 ° C. or higher and 100 ° C. or lower, more preferably 35 ° C. or higher and 90 ° C., from the viewpoint of further suppressing the adhesion of gas to the negative electrode surface. It is maintained at a temperature within the following range, more preferably 40 ° C. or more and 85 ° C. or less. Specifically, the temperature of the surrounding fluid (atmosphere) where the secondary battery precursor is disposed in this step may be maintained within the above range.
  • initial charging is performed while restraining the secondary battery precursor with the fluid as described above.
  • charging may be performed at least once.
  • charge and discharge is performed at least once.
  • One charge / discharge includes one charge and one subsequent discharge. If charging / discharging is performed twice or more, the charging-discharging is repeated the corresponding number of times.
  • the secondary battery precursor may be restrained by the fluid during at least the first charge, and preferably during all charging and discharging.
  • the charging method may be a constant current charging method or a constant voltage charging method, or a combination thereof. For example, constant voltage charging and constant voltage charging may be repeated during one charge.
  • the charging conditions are not particularly limited as long as the SEI film is formed. From the viewpoint of further improving the uniformity of the thickness of the SEI film, it is preferable to perform constant voltage charging after performing constant current charging. When performing constant voltage charging after performing constant current charging, it is preferable to employ the following charging conditions from the viewpoint of further improving the uniformity of the SEI film thickness.
  • the temperature at the time of charge should just be in the range similar to the temperature of the above-mentioned secondary battery precursor.
  • Constant current charging method Constant current charging is performed until a voltage value of 1 V or more and 6 V or less, particularly 3 V or more and 5 V or less at a constant current value of 0.01 CA or more and 3 CA or less, particularly 0.05 CA or more and 2 CA or less.
  • 1CA is a current value when the rated capacity of the secondary battery is discharged in 1 hour.
  • Constant voltage charging method The constant voltage charging is performed until the voltage value achieved by the constant current charging reaches a predetermined value smaller than the constant current value at the time of constant current charging or until a predetermined time elapses.
  • the discharge method may be a constant current discharge method, a constant voltage discharge method, or a combination thereof.
  • the discharge conditions are not particularly limited as long as the SEI film is formed. From the viewpoint of further improving the uniformity of the thickness of the SEI film, it is preferable to perform constant current discharge. When performing constant current discharge, it is preferable to employ the following discharge conditions from the viewpoint of further improving the uniformity of the SEI film thickness.
  • the temperature at the time of discharge may be in the same range as the temperature of the secondary battery precursor described above, or may be a temperature lower than that at the time of charging.
  • Constant current discharge method Constant current discharge is performed at a constant current value of 0.1 CA or more and 3 CA or less, particularly 0.2 CA or more and 2 CA or less until a voltage value of 1 V or more and 4 V or less, particularly 2 V or more and 3.5 V or less.
  • a wet adhesion process may be performed immediately before the initial charging process. From the viewpoint of further improving the uniformity of the SEI coating thickness, it is preferable to perform the initial charging step described above after the wet bonding step.
  • the wet adhesion process is a process of pressurizing the secondary battery precursor in the thickness direction.
  • the wet adhesion process promotes adhesion between the electrodes (positive electrode and negative electrode) and the separator, and as a result, uniform battery characteristics are achieved.
  • the thickness and shape of the secondary battery can be controlled. Wet means that the electrode is wetted by the electrolyte inside the secondary battery precursor.
  • the pressurizing method is not particularly limited as long as the pressure can be applied to the precursor from the outside of the secondary battery precursor, and for example, a press plate pressurizing method can be mentioned.
  • the press plate type pressurizing method is a method of applying pressure to the precursor from the outside of the secondary battery precursor by a press plate, and may apply pressure between a pair of press plates, or one A pressure may be applied between the press plate and one fixed plate.
  • you may perform restraint (or pressurization) by the fluid in an above-mentioned initial charge process as pressurization in a wet adhesion process.
  • the pressure on the surface of the secondary battery precursor is not particularly limited as long as adhesion between the electrodes (positive electrode and negative electrode) and the separator is promoted, and is usually a pressure higher than atmospheric pressure.
  • the pressure is usually in the range of 0.1 MPa to 5.0 MPa, and preferably in the range of 0.8 MPa to 2.5 MPa from the viewpoint of further promoting the adhesion.
  • the temperature of the secondary battery precursor is not particularly limited, and may be maintained within a range of 25 ° C. or more and 110 ° C. or less, for example.
  • the secondary battery precursor is preferably maintained at a temperature in the range of 50 ° C. to 100 ° C., more preferably 70 ° C., from the viewpoint of further promoting adhesion between the electrode (positive electrode and negative electrode) and the separator.
  • the temperature is maintained within a range of 95 ° C. or lower, more preferably 75 ° C. or higher and 90 ° C. or lower.
  • the temperature of the secondary battery precursor can be maintained within the above range by heating the press plate to the above temperature.
  • the pressurization time in the wet adhesion step is not particularly limited as long as adhesion between the electrode (positive electrode and negative electrode) and the separator is promoted, and is usually 1 second or more and 10 minutes or less, and is a viewpoint of further promotion of the adhesion. To preferably within a range of 5 seconds to 9 minutes, and more preferably within a range of 10 seconds to 8 minutes.
  • An aging process may be performed after the initial charging process.
  • the aging process is a process of stabilizing the SEI film by leaving the secondary battery after the initial charging process in an open circuit state. It is also called an aging process.
  • the temperature of the secondary battery is not particularly limited, and may be maintained within a range of 15 ° C. or more and 80 ° C. or less, for example.
  • the secondary battery is preferably maintained at a temperature in the range of 20 ° C. or more and 70 ° C. or less, more preferably 25 ° C. or more and 60 ° C. or less, from the viewpoint of further stabilization of the SEI coating.
  • the temperature can be maintained within the above range by leaving the secondary battery in a space set at a constant temperature.
  • the standing time in the aging step is not particularly limited as long as the stabilization of the SEI film is promoted, and is usually 1 hour or more and 30 days or less, and preferably 5 hours or more and 14 days or less from the viewpoint of further stabilization of the SEI film. More preferably, it is in the range of 10 hours or more and 7 days or less.
  • the secondary battery precursor used in the present invention includes an electrode assembly and an electrolyte, which will be described later, enclosed in an exterior body, and has one or more step portions.
  • the secondary battery precursor 1 has only one step portion 10, a low step portion 11 having a relatively low top surface height, and a high step portion 12 having a relatively high top surface height.
  • the low step portion 11 is disposed at the end of the secondary battery precursor in a plan view.
  • the secondary battery precursor 1 of FIG. 11 may be arrange
  • the step size (level difference) of each step portion (that is, the height difference between the two upper surfaces constituting each step portion) h is independently
  • the maximum thickness t of the battery precursor is usually 0.01 ⁇ t or more and 0.9 ⁇ t or less, and preferably 0.1 ⁇ t or more and 0 from the viewpoint of further improving the uniformity of the thickness of the SEI coating. ⁇ 8 ⁇ t.
  • the step size h of the step portion in the secondary battery precursor is maintained even after the subsequent steps (for example, the initial charge / discharge and aging step), that is, the step size h of the secondary battery is maintained.
  • the step size h of each step portion is the number of electrodes constituting the electrode assembly when the electrode assembly has a planar laminated structure or a winding structure, which will be described later, and the winding when the electrode assembly has a winding structure. Can be controlled by adjusting the number of times.
  • the step portion is useful for the arrangement of the substrate described later. That is, by arranging the substrate on the upper surface of the lower step portion in the step portion, it is possible to secure a space for arranging the substrate.
  • all the upper surfaces of the secondary battery precursor 1 are substantially parallel to the horizontal plane and have a planar shape.
  • the secondary battery precursor 1 is inclined with respect to the horizontal plane. It may have an upper surface and / or an upper surface having a curved shape.
  • the fluid that restrains (pressurizes) the secondary battery precursor in the initial charging step transmits the pressure (restraint force or pressure) based on Pascal's principle as described above. Even if the body has such an upper surface, the binding force can be more uniformly applied to the entire surface of the secondary battery precursor.
  • the secondary battery precursor is accommodated in the outer package of the electrode assembly and the electrolyte is injected into the outer package, the inside (opening) of the outer package is sealed, so that the electrode assembly and the electrolyte are sealed. It is manufactured by a method including a step of enclosing in an exterior body.
  • the inside of the exterior body is usually sealed under reduced pressure. That is, the opening of the exterior body is sealed while the electrode assembly is accommodated and the inside of the exterior body into which the electrolyte is injected is maintained in a reduced pressure state.
  • the sealing method is not particularly limited as long as the sealing of the opening of the exterior body is achieved.
  • the sealing may be achieved by a heat seal method.
  • sealing may be achieved by a laser welding method.
  • the pressure inside the outer package during sealing is usually in the range of 1 kPa to 20 kPa, and preferably in the range of 5 kPa to 12 kPa.
  • the electrode assembly includes a positive electrode, a negative electrode, and a separator, and the positive electrode and the negative electrode are alternately arranged via the separator.
  • the two external terminals 5 are usually connected to electrodes (positive electrode or negative electrode) via current collecting leads, and as a result, are led out from the exterior body.
  • the electrode assembly may have a planar laminated structure in which a plurality of electrode units (electrode constituent layers) including a positive electrode, a negative electrode, and a separator disposed between the positive electrode and the negative electrode are laminated in a planar shape.
  • the structure of the electrode assembly is not limited to a planar laminated structure.
  • a winding structure in which an electrode unit (electrode constituent layer) including a positive electrode, a negative electrode, and a separator disposed between the positive electrode and the negative electrode is wound in a roll shape. (Jelly roll type) may be included.
  • the electrode assembly may have a so-called stack and folding structure in which a positive electrode, a separator, and a negative electrode are stacked on a long film and then folded.
  • the positive electrode is composed of at least a positive electrode material layer and a positive electrode current collector (foil), and it is sufficient that the positive electrode material layer is provided on at least one side of the positive electrode current collector.
  • a positive electrode material layer may be provided on both surfaces of the positive electrode current collector, or a positive electrode material layer may be provided on one surface of the positive electrode current collector.
  • a positive electrode preferable from the viewpoint of further increasing the capacity of the secondary battery is provided with a positive electrode material layer on both surfaces of the positive electrode current collector.
  • the positive electrode material layer contains a positive electrode active material.
  • the negative electrode is composed of at least a negative electrode material layer and a negative electrode current collector (foil), and it is sufficient that the negative electrode material layer is provided on at least one surface of the negative electrode current collector.
  • a negative electrode material layer may be provided on both surfaces of the negative electrode current collector, or a negative electrode material layer may be provided on one surface of the negative electrode current collector.
  • a negative electrode preferable from the viewpoint of further increasing the capacity of the secondary battery is provided with a negative electrode material layer on both surfaces of the negative electrode current collector.
  • the negative electrode material layer contains a negative electrode active material.
  • the positive electrode active material included in the positive electrode material layer and the negative electrode active material included in the negative electrode material layer are materials directly involved in the transfer of electrons in the secondary battery, and are the main materials of the positive and negative electrodes that are responsible for charge / discharge, that is, the battery reaction. is there. More specifically, ions are brought into the electrolyte due to the “positive electrode active material included in the positive electrode material layer” and the “negative electrode active material included in the negative electrode material layer”, and the ions are interposed between the positive electrode and the negative electrode. Then, the electrons are transferred and the electrons are delivered and charged and discharged. As will be described later, the positive electrode material layer and the negative electrode material layer are particularly preferably layers capable of occluding and releasing lithium ions.
  • the secondary battery according to the present invention corresponds to a so-called “lithium ion battery”.
  • the positive electrode active material of the positive electrode material layer is made of, for example, a granular material, and it is preferable that a binder is included in the positive electrode material layer for sufficient contact between the particles and shape retention. Furthermore, it is also preferable that a conductive additive is included in the positive electrode material layer in order to facilitate the transmission of electrons that promote the battery reaction.
  • the negative electrode active material of the negative electrode material layer is made of, for example, a granular material, and it is preferable that a binder is included for sufficient contact and shape retention between the particles, and smooth transmission of electrons that promote the battery reaction. In order to do so, a conductive aid may be included in the negative electrode material layer.
  • the positive electrode material layer and the negative electrode material layer can also be referred to as “positive electrode composite material layer” and “negative electrode composite material layer”, respectively.
  • the positive electrode active material is preferably a material that contributes to occlusion and release of lithium ions.
  • the positive electrode active material is preferably, for example, a lithium-containing composite oxide.
  • the positive electrode active material is preferably a lithium transition metal composite oxide containing lithium and at least one transition metal selected from the group consisting of cobalt, nickel, manganese, and iron. That is, in the positive electrode material layer of the secondary battery according to the present invention, such a lithium transition metal composite oxide is preferably included as a positive electrode active material.
  • the positive electrode active material may be lithium cobaltate, lithium nickelate, lithium manganate, lithium iron phosphate, or a part of those transition metals replaced with another metal. Although such a positive electrode active material may be included as a single species, two or more types may be included in combination.
  • the positive electrode active material contained in the positive electrode material layer is lithium cobalt oxide.
  • the binder that can be included in the positive electrode material layer is not particularly limited, but includes polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-tetrafluoroethylene copolymer, and Mention may be made of at least one selected from the group consisting of polytetrafluoroethylene and the like.
  • the conductive auxiliary agent that can be included in the positive electrode material layer is not particularly limited, but carbon black such as thermal black, furnace black, channel black, ketjen black, and acetylene black, graphite, carbon nanotube, and vapor phase growth.
  • the binder of the positive electrode material layer is polyvinylidene fluoride
  • the conductive additive of the positive electrode material layer is carbon black.
  • the binder and conductive additive of the positive electrode material layer are a combination of polyvinylidene fluoride and carbon black.
  • the negative electrode active material is preferably a material that contributes to occlusion and release of lithium ions. From this point of view, the negative electrode active material is preferably, for example, various carbon materials, oxides, or lithium alloys.
  • Examples of various carbon materials of the negative electrode active material include graphite (natural graphite, artificial graphite), hard carbon, soft carbon, diamond-like carbon, and the like.
  • graphite is preferable in that it has high electron conductivity and excellent adhesion to the negative electrode current collector.
  • Examples of the oxide of the negative electrode active material include at least one selected from the group consisting of silicon oxide, tin oxide, indium oxide, zinc oxide, lithium oxide, and the like.
  • the lithium alloy of the negative electrode active material may be any metal that can be alloyed with lithium.
  • Al, Si, Pb, Sn, In, Bi, Ag, Ba, Ca, Hg, Pd, Pt, Te, Zn It may be a binary, ternary or higher alloy of a metal such as La and lithium.
  • a binary, ternary or higher alloy of a metal such as La and lithium.
  • Such an oxide is preferably amorphous in its structural form. This is because deterioration due to non-uniformity such as crystal grain boundaries or defects is less likely to be caused.
  • the negative electrode active material of the negative electrode material layer is artificial graphite.
  • the binder that can be included in the negative electrode material layer is not particularly limited, but is at least one selected from the group consisting of styrene butadiene rubber, polyacrylic acid, polyvinylidene fluoride, polyimide resin, and polyamideimide resin. Can be mentioned.
  • the binder contained in the negative electrode material layer is styrene butadiene rubber.
  • the conductive aid that can be included in the negative electrode material layer is not particularly limited, but carbon black such as thermal black, furnace black, channel black, ketjen black, and acetylene black, graphite, carbon nanotube, and vapor phase growth.
  • Examples thereof include at least one selected from carbon fibers such as carbon fibers, metal powders such as copper, nickel, aluminum and silver, and polyphenylene derivatives.
  • the component resulting from the thickener component for example, carboxymethylcellulose used at the time of battery manufacture may be contained in the negative electrode material layer.
  • the negative electrode active material and the binder in the negative electrode material layer are a combination of artificial graphite and styrene butadiene rubber.
  • the positive electrode current collector and the negative electrode current collector used for the positive electrode and the negative electrode are members that contribute to collecting and supplying electrons generated in the active material due to the battery reaction.
  • a current collector may be a sheet-like metal member and may have a porous or perforated form.
  • the current collector may be a metal foil, a punching metal, a net or an expanded metal.
  • the positive electrode current collector used for the positive electrode is preferably made of a metal foil containing at least one selected from the group consisting of aluminum, stainless steel, nickel and the like, and may be, for example, an aluminum foil.
  • the negative electrode current collector used for the negative electrode is preferably made of a metal foil containing at least one selected from the group consisting of copper, stainless steel, nickel and the like, and may be, for example, a copper foil.
  • the separator is a member provided from the viewpoint of preventing short circuit due to contact between the positive and negative electrodes and holding the electrolyte.
  • the separator can be said to be a member that allows ions to pass while preventing electronic contact between the positive electrode and the negative electrode.
  • the separator is a porous or microporous insulating member and has a film form due to its small thickness.
  • a polyolefin microporous film may be used as the separator.
  • the microporous membrane used as the separator may include, for example, only polyethylene (PE) or only polypropylene (PP) as the polyolefin.
  • the separator may be a laminate composed of “a microporous membrane made of PE” and “a microporous membrane made of PP”.
  • the surface of the separator may be covered with inorganic particles and / or an adhesive layer.
  • the surface of the separator may have adhesiveness.
  • Electrolyte helps the movement of metal ions released from the electrodes (positive and negative electrodes).
  • the electrolyte may be a “non-aqueous” electrolyte, such as an organic electrolyte and an organic solvent, or may be a “aqueous” electrolyte containing water.
  • the secondary battery of the present invention is preferably a non-aqueous electrolyte secondary battery in which an electrolyte containing a “non-aqueous” solvent and a solute is used as an electrolyte.
  • the electrolyte may have a form such as liquid or gel (in the present specification, “liquid” non-aqueous electrolyte is also referred to as “non-aqueous electrolyte solution”).
  • a solvent containing at least carbonate is preferable.
  • Such carbonates may be cyclic carbonates and / or chain carbonates.
  • examples of the cyclic carbonates include at least one selected from the group consisting of propylene carbonate (PC), ethylene carbonate (EC), butylene carbonate (BC), and vinylene carbonate (VC). be able to.
  • examples of the chain carbonates include at least one selected from the group consisting of dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), and dipropyl carbonate (DPC).
  • DMC dimethyl carbonate
  • DEC diethyl carbonate
  • EMC ethyl methyl carbonate
  • DPC dipropyl carbonate
  • a combination of cyclic carbonates and chain carbonates is used as the non-aqueous electrolyte, for example, a mixture of ethylene carbonate and diethyl carbonate.
  • Li salts such as LiPF 6 and LiBF 4 are preferably used.
  • Electrolytes particularly non-aqueous electrolytes contain additives such as vinylene carbonate, 1,3-propane sultone, and fluorinated ethylene carbonate.
  • additives such as vinylene carbonate, 1,3-propane sultone, and fluorinated ethylene carbonate.
  • any current collecting lead used in the field of secondary batteries can be used.
  • a current collecting lead may be made of a material capable of achieving electron movement, and is usually made of a conductive material such as aluminum, nickel, iron, copper, and stainless steel.
  • the form of the current collecting lead is not particularly limited, and may be, for example, a linear shape or a plate shape.
  • any external terminal used in the field of secondary batteries can be used.
  • Such an external terminal may be made of a material capable of achieving electron movement, and is usually made of a conductive material such as aluminum, nickel, iron, copper, and stainless steel.
  • the form of the external terminal 5 is not particularly limited, and is usually plate-shaped.
  • the external terminal 5 may be electrically and directly connected to the substrate, or may be electrically and indirectly connected to the substrate via another device.
  • the current collecting lead can also be used as an external terminal.
  • the exterior body is preferably a flexible pouch (soft bag), but may be a hard case (hard housing).
  • the flexible pouch is usually formed from a laminate film, and sealing is achieved by heat-sealing the peripheral edge.
  • the laminate film a film obtained by laminating a metal foil and a polymer film is generally used.
  • a film having a three-layer structure including an outer layer polymer film / metal foil / inner layer polymer film is exemplified.
  • the outer layer polymer film is for preventing damage to the metal foil due to permeation and contact of moisture and the like, and polymers such as polyamide and polyester can be suitably used.
  • the metal foil is for preventing the permeation of moisture and gas, and a foil of copper, aluminum, stainless steel or the like can be suitably used.
  • the inner layer polymer film is for protecting the metal foil from the electrolyte accommodated therein, and for melting and sealing at the time of heat sealing, and polyolefin or acid-modified polyolefin can be suitably used.
  • the thickness of the laminate film is not particularly limited, and is preferably 1 ⁇ m or more and 1 mm or less, for example.
  • the hard case is usually formed from a metal plate, and sealing is achieved by irradiating the peripheral edge with a laser.
  • a metal plate a metal material made of aluminum, nickel, iron, copper, stainless steel or the like is common.
  • the thickness of a metal plate is not specifically limited, For example, 1 micrometer or more and 1 mm or less are preferable.
  • a substrate in the secondary battery manufactured by the method of the present invention, a substrate may be disposed using the step portion.
  • the substrate may be disposed on the upper surface of the low step portion constituting the step portion of the secondary battery.
  • the substrate may be a so-called rigid substrate or a flexible substrate.
  • a rigid substrate is preferred. When a rigid substrate is used, the formation of a dead space and the damage of the secondary battery due to the substrate are likely to be a problem. Even when a rigid substrate is used in the present invention, such a problem can be sufficiently avoided.
  • the rigid substrate any rigid substrate used in the field of substrates used with secondary batteries can be used, and examples thereof include a glass / epoxy resin substrate.
  • the substrate examples include an electronic circuit substrate such as a printed circuit board, a semiconductor substrate such as a silicon wafer, and a glass substrate such as a display panel.
  • an electronic circuit substrate such as a printed circuit board
  • a semiconductor substrate such as a silicon wafer
  • a glass substrate such as a display panel.
  • a secondary battery pack is constituted by the protection circuit board and the secondary battery.
  • the secondary battery manufactured by the method of the present invention can be used in various fields where power storage is assumed. Although only illustrative, secondary batteries manufactured by the method of the present invention, particularly non-aqueous electrolyte secondary batteries, are used in the electrical / information / communication field (for example, mobile phones, smartphones, smart phones) where mobile devices are used.
  • Mobile devices such as watches, notebook computers, digital cameras, activity meters, arm computers and electronic paper), home and small industrial applications (eg, power tools, golf carts, home, nursing and industrial robots) , Large industrial applications (eg, forklifts, elevators, bay harbor cranes), transportation systems (eg, hybrid vehicles, electric cars, buses, trains, electric assist bicycles, electric motorcycles), power system applications (eg, , Various power generation, road conditioners, smart grids, general home storage Field), IoT areas such as the stem, as well as, it is possible to utilize space and deep sea applications (for example, spacecraft, areas such as submersible research vessel) and the like.
  • space and deep sea applications for example, spacecraft, areas such as submersible research vessel

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  • Manufacturing & Machinery (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Secondary Cells (AREA)

Abstract

La présente invention concerne un procédé de production d'une batterie secondaire permettant d'effectuer une charge initiale tout en appliquant uniformément une force de retenue sur l'ensemble de la surface d'un précurseur de batterie secondaire même lorsque ce dernier présente des sections étagées. Le procédé de production d'une batterie secondaire selon l'invention comprend l'étape consistant à réaliser la charge initiale tout en retenant, au moyen d'un fluide (2), le précurseur (1) de la batterie secondaire comportant, scellés dans un corps extérieur, un électrolyte et un ensemble électrode comprenant une électrode positive, une électrode négative et un séparateur disposé entre les électrodes positive et négative.
PCT/JP2018/007751 2017-03-31 2018-03-01 Procédé de production de batterie secondaire WO2018180167A1 (fr)

Applications Claiming Priority (2)

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JP2017072428 2017-03-31
JP2017-072428 2017-03-31

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003059538A (ja) * 2001-08-20 2003-02-28 Sony Corp 電池の製造方法
JP2009295289A (ja) * 2008-06-02 2009-12-17 Panasonic Corp リチウムイオン二次電池およびその製造方法
JP5779828B2 (ja) * 2012-05-25 2015-09-16 エルジー・ケム・リミテッド 段差を有する電極組立体、それを含む電池セル、電池パック及びデバイス

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003059538A (ja) * 2001-08-20 2003-02-28 Sony Corp 電池の製造方法
JP2009295289A (ja) * 2008-06-02 2009-12-17 Panasonic Corp リチウムイオン二次電池およびその製造方法
JP5779828B2 (ja) * 2012-05-25 2015-09-16 エルジー・ケム・リミテッド 段差を有する電極組立体、それを含む電池セル、電池パック及びデバイス

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