WO2012053556A1 - Élément secondaire à électrolyte non aqueux - Google Patents

Élément secondaire à électrolyte non aqueux Download PDF

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Publication number
WO2012053556A1
WO2012053556A1 PCT/JP2011/074062 JP2011074062W WO2012053556A1 WO 2012053556 A1 WO2012053556 A1 WO 2012053556A1 JP 2011074062 W JP2011074062 W JP 2011074062W WO 2012053556 A1 WO2012053556 A1 WO 2012053556A1
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Prior art keywords
positive electrode
negative electrode
exposed portion
tab
core exposed
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PCT/JP2011/074062
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English (en)
Japanese (ja)
Inventor
吉田　聡司
大下　竜司
秀行 猪俣
和幸 川上
濱田　拓哉
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三洋電機株式会社
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Publication of WO2012053556A1 publication Critical patent/WO2012053556A1/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
    • H01M10/0431—Cells with wound or folded electrodes
    • 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
    • H01M50/536—Electrode connections inside a battery casing characterised by the method of fixing the leads to the electrodes, e.g. by welding
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • 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
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/531—Electrode connections inside a battery casing
    • H01M50/534—Electrode connections inside a battery casing characterised by the material of the leads or tabs
    • 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 non-aqueous electrolyte secondary battery, and more specifically, a non-aqueous electrolyte secondary battery in which the generation of a magnetic field due to a current flow during use is small and the influence of noise caused by the magnetic field on a hearing aid or the like is small. It relates to batteries.
  • non-aqueous electrolyte secondary batteries represented by high-capacity lithium ion secondary batteries are widely used.
  • These non-aqueous electrolyte secondary batteries generally include a positive electrode in which a positive electrode mixture containing a positive electrode active material that absorbs and releases lithium ions is applied to both surfaces of a positive electrode core made of an elongated sheet-like aluminum foil, and an elongated sheet.
  • the separator is made of and wound into a cylindrical or elliptical shape with the positive electrode and the negative electrode insulated from each other by the separator to form a wound electrode body.
  • the wound electrode body is further crushed and flattened.
  • a positive electrode tab and a negative electrode tab are connected to predetermined portions of the positive electrode and the negative electrode, respectively, and the outside is covered with an exterior.
  • the positive electrode tab or the negative electrode tab is electrically connected by ultrasonic welding, resistance welding or pressure welding (including pressure bonding) to the exposed portion of the positive electrode core or negative electrode core, respectively. It is connected to the.
  • An example of a configuration for electrically connecting such a conventional positive electrode tab or negative electrode tab to the exposed portion of the positive electrode core or negative electrode core will be described with reference to FIG.
  • FIG. 5 is a plan view showing a configuration of a positive electrode tab or a negative electrode tab disclosed in Patent Document 1 below.
  • An electrode 50 shown in Patent Document 1 below has a structure in which an electrode material layer 52 is formed on a core body 51 and an electrode tab 54 made of a metal lead is resistance-welded to an electrode material layer non-formed portion 53. And the contact resistance between the core 51 and the electrode tab 54 is increased by forming an uneven portion having an average diameter of 0.5 ⁇ m or more and 10.0 ⁇ m or less on the surface of the electrode tab 54. A good welding spot point 55 is formed, and a decrease in welding strength and displacement between the core 51 and the electrode tab 54 can be suppressed. According to the electrode disclosed in Patent Document 1, there is an effect that resistance welding between the core and the electrode tab can be performed more firmly and reliably.
  • the hearing aid has a function of capturing and amplifying external sound with a microphone, and a function of capturing and amplifying magnetic flux generated from the speaker portion of the telephone by an electromagnetic coil with an electromagnetic pickup (also referred to as “telephone pickup”). In particular, it is easily affected by external magnetic field noise.
  • an electromagnetic pickup also referred to as “telephone pickup”. The reason why the hearing aid uses such an electromagnetic pickup is that when the sound output from the speaker of the telephone is picked up and amplified by the microphone of the hearing aid, ambient noise is picked up by the microphone, so that the clarity of the sound is lowered. Because.
  • the magnetic field generated from the mobile phone tends to adversely affect the hearing aid. For this reason, even in a non-aqueous electrolyte secondary battery that is a power source of a mobile phone, it is desired to suppress the generation of a magnetic field due to the current flowing through the non-aqueous electrolyte secondary battery.
  • the magnetic field caused by the current flowing in the active material formation region of the positive electrode plate and the negative electrode plate has the positions of the positive electrode tab or the negative electrode tab both on the winding start side or the winding end side of each electrode plate and overlap each other. Or if it arrange
  • the positions of the positive electrode tab and the negative electrode tab are arranged at positions overlapping each other, it is difficult to electrically insulate and attach each tab, so that it is difficult to adopt immediately.
  • the positive electrode plate has a positive electrode tab attached to the winding end side and the negative electrode plate has a negative electrode tab attached to the winding start side
  • a current whose current value sequentially increases on the right side flows, and on the negative electrode side, a current whose current value decreases sequentially from the left side to the right side.
  • the current flowing in the positive electrode active material forming region of the positive electrode plate is parallel and in the same direction as the current flowing in the negative electrode active material forming region of the negative electrode plate, so that the magnetic field caused by the current flowing through the battery is increased.
  • the current flowing through the positive electrode active material forming region of the positive electrode plate is parallel and opposite to the current flowing through the negative electrode active material forming region of the negative electrode plate, so that the magnetic fields caused by the current flowing through the battery cancel each other.
  • welding of the positive electrode tab or the negative electrode tab is performed at a plurality of spots in a spot manner as is apparent from the description of FIG. It is not performed uniformly throughout. Therefore, in the vicinity of the welding location, the current flowing through the core body portion flows in a complicated direction at each welding location, so that various magnetic fields are generated. In addition, when the end of the active material formation region and the tab welding position are close, the current flow becomes more complicated and becomes a factor that a magnetic field is easily generated. Therefore, there is room for further improvement in the attachment structure of the positive electrode tab or the negative electrode tab in order to suppress the generation of a magnetic field due to the current flowing in the nonaqueous electrolyte secondary battery.
  • the inventors have made various studies to solve the above-mentioned problems, and as a result, the welding positions of the positive electrode tab or the negative electrode tab are both set to the winding start side or the winding end side of the electrode plate, and the positive electrode tab or the negative electrode.
  • the width of each core exposed portion forming the tab and welding the positive electrode tab or the negative electrode tab to the core exposed portion the generation of the magnetic field due to the current flowing in the battery can be extremely reduced.
  • the present inventors have found out what can be done and have completed the present invention.
  • Patent Document 2 in a positive electrode plate or negative electrode plate 60 in which an active material layer 62 is formed on a current collector (core body) 61 of a lithium ion polymer battery.
  • the electrode lead (current collecting tab) 63 is an example in which an active material layer non-formation portion 64 of the core body 61 is cut and bent, and the electrode lead (current collection tab) 63 is formed of the bent portion.
  • Patent Document 3 an electrode body (not shown) in which a positive electrode plate 71 and a negative electrode plate 72 are wound in a state of being insulated from each other via a separator 73 is provided.
  • a positive electrode tab 76 is welded to the positive electrode core exposed portion 75 of the positive electrode plate 71 where the positive electrode active material layer 74 is not formed, and a negative electrode active material layer 77 of the negative electrode plate 73 is formed.
  • An example in which the negative electrode core exposed portion 78 has a negative electrode tab 79 formed by cutting and bending a part of the terminal end of the negative electrode core exposed portion 78 in the width direction of the negative electrode core exposed portion 78 more than 1/2. It is shown.
  • Reference numerals 80a to 80d are insulating tapes.
  • Patent Documents 2 and 3 do not consider anything about the generation of a magnetic field due to the current flowing in the battery, and the positive electrode core exposed portion or the width of the active material layer forming region is the same as the width of the active material layer forming region.
  • a negative electrode core exposed portion is formed, and there is no suggestion about the problem of generation of a magnetic field due to the presence of the positive electrode core exposed portion or the negative electrode core exposed portion having the same width as the active material layer forming region. It has not been.
  • an object of the present invention is to provide a non-aqueous electrolyte secondary battery in which generation of a magnetic field due to a current flow during use is small and the influence of noise due to the magnetic field on a hearing aid or the like is reduced.
  • the nonaqueous electrolyte secondary battery of the present invention includes a positive electrode plate in which a positive electrode mixture layer is applied to both surfaces of a positive electrode core, and a negative electrode active material layer applied to both surfaces of the negative electrode core.
  • a flat wound electrode body wound with a separator sandwiched between each of the negative electrode plates, an exterior body housing the flat wound electrode body, and nonaqueous electrolysis injected into the exterior body A positive electrode core having a width shorter than 1 ⁇ 2 of the width of the positive electrode plate on the winding start side or the winding end side of the positive electrode plate.
  • An exposed portion is formed, and a positive electrode tab is welded or pressed to the exposed portion of the positive electrode core, and the negative electrode plate is disposed on the same side as the exposed portion of the positive electrode core on the same side as the 1 / width of the negative electrode plate.
  • a negative electrode core exposed portion having a width shorter than 2 is formed, and the positive electrode core exposed portion and the negative electrode core exposed portion It faces through the separator, and a negative electrode tab is welded or pressed to the negative electrode core exposed portion, and the positive electrode tab and the negative electrode tab are in a winding axis direction of the wound electrode body. It is derived in the same direction.
  • the welding point or the pressure contact of the positive electrode tab and the negative electrode tab is composed of welding means or pressure welding means such as a known resistance welding apparatus, ultrasonic welding apparatus, laser welding apparatus, etc., and the positive electrode tab or the negative electrode tab is exposed to the positive electrode core. It is not formed uniformly over the entire surface in contact with the portion or the negative electrode core exposed portion, but is formed partially.
  • the nonaqueous electrolyte secondary battery is manufactured such that the area of the negative electrode plate is larger than that of the positive electrode plate in order to suppress generation of lithium dendrite in the negative electrode plate.
  • the current flowing from each active material layer forming region side tends to flow at the shortest distance to the welding point or pressure contact of each electrode tab, but at least the negative electrode plate
  • a component flows from the lower negative electrode active material layer side to the upper side of the battery (the side where the negative electrode tab is formed). This component tends to become prominent when the distance between the end of the negative electrode active material layer forming region and the negative electrode tab is short.
  • the magnetic field formed by the current flowing upward from the lower negative electrode active material layer side on the negative electrode plate side is not canceled by the magnetic field formed by the current flowing through the positive electrode plate. Will be adversely affected.
  • the positive electrode plate has a positive electrode core exposed portion having a width shorter than 1 ⁇ 2 of the width of the positive electrode plate on the winding start side or winding end side of the positive electrode plate.
  • a positive electrode tab is welded or pressed to the exposed portion of the positive electrode core, and the negative electrode plate is on the same side as the exposed portion of the positive electrode core, and is less than half the width of the negative electrode plate.
  • a negative electrode core exposed portion with a short width is formed so as to face the positive electrode core exposed portion via the separator, and a negative electrode tab is welded or pressed to the negative electrode core exposed portion.
  • the tab and the negative electrode tab are led out in the same direction with respect to the winding axis direction of the wound electrode body. Therefore, according to the nonaqueous electrolyte secondary battery of the present invention, the current flowing through the positive electrode tab or the negative electrode tab through the positive electrode core exposed portion or the negative electrode core exposure is concentrated on the upper side of the battery, and the directions are opposite to each other. In addition, since the current flows in parallel, the magnetic fields caused by the currents flowing through the positive electrode plate and the negative electrode plate cancel each other, so that the magnetic field can be reduced.
  • the width of the positive electrode core exposed portion or the width of the negative electrode core exposed portion is 1 ⁇ 2 or more of the width of each electrode plate, the current flowing based on the difference in area between the positive electrode plate and the negative electrode plate Since a difference occurs in the direction, the magnetic fields cannot cancel each other, which is not preferable. Therefore, in the nonaqueous electrolyte secondary battery of the present invention, the width of the positive electrode core exposed portion or the width of the negative electrode core exposed portion provided in the prior art is the same as the width of the positive electrode plate or the negative electrode plate. It is essential not to.
  • the positive electrode tab and the negative electrode tab are wound electrode bodies because an effect is obtained if the current flowing in the positive electrode plate and the current flowing in the negative electrode plate flow in opposite directions. It may be provided on the winding start side or on the winding end side.
  • the core body exposed portion of the electrode having the same polarity as the polarity of the exterior body is used from the viewpoint of preventing a short circuit. It is preferable to arrange
  • the length of the core exposed portion of the electrode disposed on the outermost periphery of the wound electrode body is preferably longer than the length of the core exposed portion of the opposite electrode, and further the portion where the tab is attached. Considering the strength, it is preferably at least 1/2 of the length of the outer circumference of the wound electrode body. However, if the length is too long, the battery capacity may be reduced. The following is preferable.
  • the lengths of the positive electrode core exposed part and the negative electrode core exposed part are the innermost circumference of the wound electrode body. It is preferable that the length is about 1/4 to 1/2 of the length of one circle. If it is too short, the strength of the core exposed portion may be insufficient, and if it is too long, the battery capacity may be reduced.
  • the electrode tab provided in the core body exposed portion of one electrode plate is opposed to one electrode plate having the same polarity.
  • the core exposed portion of either the positive electrode plate or the negative electrode plate is formed in advance so as to be longer than the other core exposed portion, and the winding start timing is set as the positive electrode when the wound electrode body is manufactured. Shift it with the negative electrode, start winding one electrode plate with a long core exposed portion first, wind up the tab welded portion in one core exposed portion, and then start winding the other electrode plate together This can be easily achieved.
  • a transition metal can be substituted with another element, or another element can be added alone or as a compound.
  • the negative electrode active material used for the negative electrode at least one selected from the group consisting of a carbonaceous material, a siliconaceous material and a metal oxide capable of inserting and extracting lithium can be used.
  • a carbonaceous material that has been graphitized is particularly preferable because of its high capacity.
  • Nonaqueous solvents that can be used in the nonaqueous electrolyte of the nonaqueous electrolyte secondary battery of the present invention include cyclic carbonates, chain carbonates, esters, cyclic ethers, chain ethers, nitriles, amides, etc. Is mentioned.
  • the cyclic carbonate include ethylene carbonate, propylene carbonate, butylene carbonate, vinylene carbonate and the like, and those in which some or all of these hydrogen groups are fluorinated can also be used.
  • trifluoropropylene Carbonate and fluoroethylene carbonate can be used.
  • chain carbonate symmetric chain carbonates such as dimethyl carbonate and diethyl carbonate
  • asymmetric chain carbonates such as ethyl methyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, and methyl isopropyl carbonate
  • Those in which part or all of these hydrogens are fluorinated can also be used.
  • the electrolyte constituting the organic electrolyte is lithium perchlorate (LiClO 4 ), lithium hexafluorophosphate (LiPF 6 ), lithium borofluoride (LiBF 4 ), lithium hexafluoroarsenate (LiAsF 6 ), trifluoromethyl.
  • lithium salts such as lithium sulfonate (LiCF 3 SO 3 ) and lithium bistrifluoromethylsulfonylimide [LiN (CF 3 SO 2 ) 2 ].
  • LiPF 6 and LiBF 4 are preferably used, and the amount dissolved in the organic solvent is preferably 0.5 to 2.0 mol / L.
  • the nonaqueous electrolyte can be used not only in a solution state but also in a gelled state.
  • the positive electrode core exposed portion and the negative electrode core exposed portion are formed at the center of the width of the wound electrode body because the magnetic field in the vicinity of the core exposed portion tends to be small.
  • welding between the positive electrode core exposed portion and the positive electrode tab and welding between the negative electrode core exposed portion and the negative electrode tab are performed by resistance welding. Or it is preferable that it was what was performed by the ultrasonic welding method.
  • Laser welding can be used for welding between the positive electrode core exposed portion and the positive electrode tab and between the negative electrode core exposed portion and the negative electrode tab, but resistance welding or ultrasonic welding is also used. Then, the electrical resistance between each core body exposed portion and the electrode tab can be reduced, and the manufacturing cost can be reduced.
  • the pressure contact between the positive electrode core exposed portion and the positive electrode tab and the pressure contact between the negative electrode core exposed portion and the negative electrode tab are obtained by an eyelet pressure bonding method. It is preferable that it was performed by.
  • the eyelet pressure bonding method can be used. Since this method can simply and reliably connect the core and the tab, the manufacturing cost can be reduced.
  • welding or pressure welding between the positive electrode core exposed portion and the positive electrode tab and welding or pressure welding between the negative electrode core exposed portion and the negative electrode tab are: These are preferably performed at a plurality of locations.
  • the outer package is a metal rectangular outer package, and one of the positive electrode tab and the negative electrode tab closes an opening of the metal rectangular outer package. It is preferable that the metal sealing plate is electrically connected directly, and the other is electrically connected to a terminal portion attached to the sealing plate in an insulated state.
  • an exterior body made of an aluminum laminate film can also be used.
  • the exterior body is a metal square exterior body such as aluminum or aluminum alloy, iron whose outer surface is plated with nickel, etc., and one of the positive electrode tab and the negative electrode tab has an opening of the metal square exterior body. If the metal sealing plate that is to be closed is electrically connected directly, and the other is electrically connected to a terminal portion that is attached to the sealing plate in an insulated state, the mechanical strength of the battery is high.
  • the leakage of the non-aqueous electrolyte can be reduced, and the dimensional accuracy is improved.
  • the influence of the magnetic field from the inside of the battery on the outside can be further reduced by selecting the materials for the metal rectangular outer casing and the sealing plate.
  • the tabs on both electrodes do not overlap (do not face each other).
  • the tabs of both poles can be arranged so as not to face each other.
  • FIG. 2A is a development view showing a state in which the positive electrode plate and the negative electrode plate of the embodiment are overlapped
  • FIG. 2B is a front view of the wound electrode body of the embodiment
  • FIG. 3A is a development view in which the positive electrode plate and the negative electrode plate of the comparative example are overlapped
  • FIG. 3B is a front view of the wound electrode body of the comparative example.
  • FIG. 4A is a schematic diagram of the current flow of the positive electrode plate and the negative electrode plate of the example
  • FIG. 4B is a schematic diagram of the current flow of the positive electrode plate and the negative electrode plate of the comparative example.
  • FIG. 6A is an explanatory diagram of a magnetic field generation state when the positive electrode tab and the negative electrode tab are formed at both end sides
  • FIG. 6B is the same end portion side.
  • It is a plane schematic diagram which shows the measurement location of a magnetic field common to an Example and a comparative example.
  • FIG. 1 is a perspective view which shows the connection condition of the flat wound electrode body and sealing plate which are common in an Example and a comparative example.
  • the flat wound electrode body 10 of this non-aqueous electrolyte secondary battery has, for example, a positive electrode plate disposed on the outer peripheral side and a negative electrode plate disposed on the inner peripheral side, and is flattened via separators (both not shown). The end of the winding is insulated by the insulating tape 11.
  • the flat wound electrode body 10 has a positive electrode tab 12 connected to a positive electrode core exposed portion and a negative electrode tab 13 connected to a negative electrode core exposed portion.
  • the flat wound electrode body 10 is provided with insulating spacers 14 and 15 on the upper surface and the lower surface, respectively, and the positive electrode tab 12 is bent through the outer peripheral side of the upper insulating spacer 14 to be the inner surface of the sealing plate 16.
  • the negative electrode tab 13 is resistance-welded to a negative electrode terminal 18 formed on the sealing plate 16 through a slit 17 formed in the upper insulating spacer 14.
  • the flat wound electrode body 10 is not shown in the drawing, it is inserted into a substantially flat conductive box-type battery outer casing whose one end surface in the longitudinal direction is open and whose peripheral surface is closed, The opening is sealed by the sealing plate 16 and sealed by laser welding between the opening edge of the battery outer can and the sealing plate 16, and then a predetermined amount of nonaqueous electrolyte is injected from the electrolyte injection hole 19.
  • the electrolyte solution injection hole 19 is sealed.
  • FIGS. 2 and 3 are development views in which the positive electrode plate and the negative electrode plate of the example are overlapped, and FIG. 2B is a plan view of the wound electrode body 10A of the example.
  • FIG. 3A is a development view in which the positive electrode plate and the negative electrode plate of the comparative example are overlapped, and FIG. 3B is a plan view of the wound electrode body 10B of the comparative example. 2A and 3A, the separator is not shown.
  • the difference in configuration between the positive electrode plate and negative electrode plate of the example and the positive electrode plate and negative electrode plate of the comparative example is the shape of the positive electrode core exposed portion and the negative electrode core exposed portion, and the welding of the positive electrode tab and the negative electrode tab. Since it is in a state, hereinafter, the same reference numerals are given to the common components to be described.
  • Lithium cobaltate as a positive electrode active material, acetylene black as a carbon-based conductive agent, and PVDF (polyvinylidene fluoride) are mixed at a mass ratio of 95: 2.5: 2.5 to obtain NMP (N-methylpyrrolidone).
  • NMP N-methylpyrrolidone
  • a positive electrode mixture slurry was applied to both surfaces of a 13 ⁇ m thick aluminum positive electrode core 21 by a doctor blade method and dried to form positive electrode active material layers 22 on both surfaces of the positive electrode core 21. Then, it compressed using the compression roller and produced the positive electrode plate whose short side length is 43 mm.
  • non-aqueous electrolyte a non-aqueous electrolyte obtained by dissolving LiPF 6 in a mixed solvent having a volume mixing ratio of ethylene carbonate, ethyl methyl carbonate and diethyl carbonate of 40:30:30 so as to have a concentration of 1 mol / L was used. .
  • the positive electrode plate 20 is provided with a positive electrode core exposed portion that does not have the positive electrode active material layer 22 on both surfaces of the positive electrode core 21 at a certain distance from the winding end portion of the positive electrode core 21.
  • the lengths of the positive electrode core exposed part 21a of the example and the positive electrode core exposed part 21b of the comparative example are both 35 mm, and the width of the positive electrode core exposed part 21a of the example is 1 of the width of the positive electrode plate 20.
  • the width of the positive electrode core exposed portion 21b of the comparative example is the same as the width of the positive electrode plate 20, whereas the width is 1/2 mm or less, specifically 5 mm.
  • the negative electrode plate 24 is provided with a negative electrode core exposed portion that does not have the negative electrode active material layer 26 on both surfaces of the negative electrode core 25 by a certain distance from the winding end of the negative electrode core 25.
  • the length of the negative electrode core exposed portion 25a in the example and the length of the negative electrode core exposed portion 25b in the comparative example are both 15 mm, and the width of the negative electrode core exposed portion 25a in the example is 1/2 of the width of the negative electrode plate 24.
  • the thickness is specifically reduced to 6 mm, and the width of the negative electrode core exposed portion 25 b of the comparative example is made the same as the width of the negative electrode plate 24. Therefore, in the wound electrode body 10A of the example, as shown in FIG.
  • the wound portion of the positive electrode core exposed portion 21a is formed only on the uppermost outermost side. Further, as shown in FIG. 3B, the wound electrode body 10B of the comparative example is formed with the wound portion of the positive electrode core exposed portion 21b over the entire width on the outermost peripheral side, and the positive electrode core exposed portion 21b is greatly exposed. To come.
  • the positive electrode core exposed portion 21b and the negative electrode core exposed portion 25b of the comparative example have the same width as the positive electrode plate 20 and the negative electrode plate 24, that is, the positive electrode core 21 and the negative electrode core 25, respectively. Both have the same width over the entire length.
  • the positive electrode tab 12a is made of aluminum metal having a thickness of 0.1 mm, a width of 3 mm, and a length of 50 mm
  • the negative electrode tab 13b is made of nickel metal having a thickness of 0.1 mm, a width of 3 mm, and a length of 50 mm.
  • spot welding is performed by spot welding at 8 locations at intervals of 5 mm at intervals of 4 mm from the top and 3 mm from the bottom. did.
  • the positive electrode tab 12a is made of aluminum metal.
  • the negative electrode tab 13b is made of nickel metal with a thickness of 0.1 mm, a width of 3 mm, and a length of 10 mm. Since the contact length with the negative electrode tab 13a is short, the positive electrode tab 12a thru
  • or the negative electrode tab 13a and the welding point of the positive electrode core body exposed part 21a and the negative electrode core body exposed part 25a may be one each, but the positive electrode core body exposed part 21a and the negative electrode core body Since the exposed portion 25a is weak in mechanical strength, the positive electrode tab 12a or the negative electrode tab 13a is easily rotated when the number of welded portions is one, and the position of the positive electrode tab 12a or the negative electrode tab 13a is likely to change during battery assembly. . Therefore, it is desirable that the number of welding points between the positive electrode tab 12a or the negative electrode tab 13a, the positive electrode core exposed portion 21a, and the negative electrode core exposed portion 25a in the embodiment be two or more.
  • the positive electrode plate 20 and the negative electrode plate 24 produced as described above are wound in a state where the outer peripheral side is the positive electrode plate 20 and insulated from each other with a separator made of a polyethylene microporous film interposed therebetween, The end portion of the winding was fixed with the insulating tape 11 and crushed to produce the flat wound electrode body 10A of the example and the wound electrode body 10B of the comparative example.
  • the positive electrode tabs 12a and 12b and the negative electrode tabs 13a and 13b were protruded from the upper portions of the respective flat wound electrode bodies 10A and 10B.
  • the schematic configurations of the flat wound electrode bodies 10A and 10B are as shown in FIGS. 2B and 3B, respectively.
  • non-aqueous electrolyte secondary battery the flat wound electrode bodies 10A and 10B manufactured in this way are not shown in the figure, but are substantially flat conductive with one end surface in the longitudinal direction opened and the peripheral surface closed. It is inserted into the battery outer can, the opening is sealed with the sealing plate 16, and sealed between the opening edge of the battery outer can and the sealing plate 16 by laser welding.
  • Non-aqueous electrolyte secondary batteries corresponding to Examples and Comparative Examples were manufactured by injecting a fixed amount of non-aqueous electrolyte and sealing the electrolyte injection hole 19.
  • the dimensions of the obtained nonaqueous electrolyte secondary battery are thickness 5.2 mm ⁇ width 34 mm ⁇ height 50 mm, and the design capacity is 1150 mAh.
  • the prepared battery was charged under the same conditions as described above, and one end of each lead wire was connected to the battery surface side of the negative electrode terminal 18 and the sealing plate 16 (positive electrode). In order to eliminate the influence of the magnetic field due to the current flowing in the lead wires, the lead wires were twisted together. Then, the other end of the lead wire was connected to the output terminal of the power supply, and the magnetic field around the battery was measured while applying a discharge load having a pulse waveform of GSM specifications to the battery using the power supply.
  • the pulse waveform shape of the GSM specification is that the frequency is 217 Hz, the current 2A is 0.6 milliseconds, and 0.1 A is 1.4 milliseconds.
  • the side where the area of the battery is the maximum is left in the vertical direction, and the plane is 1 cm above the side of the battery.
  • the magnitude of the magnetic field was obtained at 8 locations shown in FIG. The results are shown in Table 1.
  • FIG. 7 is a plan view schematically showing a state in which the side surface having the largest battery area is left in a vertical direction.
  • the upper side of the flat wound electrode body 10 inside the battery (the sealing plate 16 is shown).
  • the height direction of the battery is defined as the x-axis
  • the width direction is defined as the y-axis
  • the thickness direction is defined as the z-axis (not shown).
  • Table 1 also shows the magnetic field strength (unit: xyz) in the xyz directions with respect to the strength of the magnetic field at 8 locations shown in FIG. 7 (however, located on a plane 1 cm away from the battery surface in the z-axis direction).
  • dB ⁇ A / m the magnetic field strength in the x-axis direction at the position of the circled numeral 2 in FIG.
  • the positive electrode core exposed portion 21a to the negative electrode core exposed portion 25a are not present in the same part as the width of the positive electrode plate 20 to the negative electrode plate 24.
  • the positive electrode active material layer 22 or the negative electrode active material layer 26 is formed to have a constant narrow width immediately from the formation portion. Therefore, in the positive electrode plate 20 and the negative electrode plate 24 of the embodiment, even if the welding points between the positive electrode tab 12a or the negative electrode tab 13a and the positive electrode core exposed portion 21a or the negative electrode core exposed portion 25a are separated from each other.
  • the direction of the current flowing through the positive electrode core exposed portion 21a or the negative electrode core exposed portion 25a is parallel to each other in the opposite direction as shown in FIG. 4A. Since the magnetic fields to be canceled out, the magnitude of the magnetic field leaking to the outside is reduced.
  • the positive electrode core exposed portion 21b to the negative electrode core exposed portion 25b are all equal to the width of the formed portion of the positive electrode plate 20 to the negative electrode plate 24. It has become. Further, in the nonaqueous electrolyte secondary battery, the negative electrode plate 24 has a larger area than the positive electrode plate 20 in order to suppress generation of lithium dendrite on the negative electrode plate.
  • the current flowing from each active material layer forming region side should flow to the welding point of each electrode tab at the shortest distance.
  • a component that flows from the lower negative electrode active material layer 26 to the upper side of the battery (the side where the negative electrode tab 13b is formed) is generated.
  • the magnetic field formed by the current flowing upward from the lower negative electrode active material layer 26 on the negative electrode plate side 24 is not canceled by the magnetic field formed by the current flowing through the positive electrode plate 20, and therefore leaks to the outside.
  • the magnetic field is not sufficiently small, and there is a high possibility that the hearing aid will be adversely affected.
  • the positive electrode core exposed portion 21a and the negative electrode core exposed portion 25a are formed on the upper side of the battery (the protruding side of the positive electrode tab 12a and the negative electrode tab 13a).
  • the present invention can be carried out even if it is not on the upper side of the battery.
  • the magnetic field generated becomes smaller as the positive electrode core exposed portion 21a and the negative electrode core exposed portion 25a are formed closer to the center in the width direction of the wound electrode body. There was a trend. Therefore, it is more preferable to form the positive electrode core exposed portion 21a and the negative electrode core exposed portion 25a at the central portion in the winding axis direction of the wound electrode body.
  • a magnetic field due to the current flowing in the battery is less likely to occur than the non-aqueous electrolyte secondary battery of the comparative example corresponding to the conventional example.
  • An adverse effect on a user such as a hearing aid is suppressed.
  • the nonaqueous electrolyte secondary battery in which the positive electrode core exposed portion and the negative electrode core exposed portion are provided on the winding end side of the wound electrode body and the positive electrode tab and the negative electrode tab are attached is shown. Since the present invention is effective when the current flowing in the positive electrode plate and the current flowing in the negative electrode plate flow in opposite directions, the winding start side and the winding end side of the wound electrode body If either one of the positive electrode tab and the negative electrode tab is provided on both of them, and the positive electrode tab and the negative electrode tab are led out in the same direction with respect to the winding axis direction of the wound electrode body, the positive electrode tab Even if the negative electrode tab is provided on the winding start side or the winding end side of the wound electrode body, the present invention can be implemented.

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Secondary Cells (AREA)
  • Connection Of Batteries Or Terminals (AREA)

Abstract

L'objectif de l'invention est de fournir un élément secondaire à électrolyte non aqueux conçu de telle manière que la génération d'un champ magnétique en raison de la circulation du courant pendant l'utilisation soit réduite, et que l'effet de bruit sur un appareil auditif, etc. à cause du champ magnétique soit réduit. Cet élément secondaire à électrolyte non aqueux comprend : une plaque d'électrode positive (20) comportant une section d'exposition d'âme d'électrode positive (21a), dont la largeur est inférieure à la moitié de la largeur de la plaque d'électrode positive (20), formée sur le côté sur lequel l'enroulement de la plaque d'électrode positive (20) commence ou finit, ainsi qu'une languette d'électrode positive (12a) soudée ou soudée à froid sur la section d'exposition d'âme d'électrode positive (21a); et une plaque d'électrode négative (24) comportant une section d'exposition d'âme d'électrode négative (25a), dont la largeur est inférieure à la moitié de la largeur de la plaque d'électrode négative (24), formée sur le même côté que la section d'exposition d'âme d'électrode positive (21a), ainsi qu'une languette d'électrode négative (13a) soudée ou soudée à froid sur la section d'exposition d'âme d'électrode négative (25a).
PCT/JP2011/074062 2010-10-20 2011-10-19 Élément secondaire à électrolyte non aqueux WO2012053556A1 (fr)

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Cited By (4)

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WO2013127313A1 (fr) * 2012-02-28 2013-09-06 华为终端有限公司 Batterie et terminal
CN113381079A (zh) * 2021-06-08 2021-09-10 歌尔科技有限公司 一种卷绕式电池及tws蓝牙耳机
JPWO2021229847A1 (fr) * 2020-05-14 2021-11-18
CN114284611A (zh) * 2021-12-27 2022-04-05 湖北亿纬动力有限公司 二次电池、电池模组、电池包及二次电池制造方法

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CN115335938A (zh) * 2020-04-20 2022-11-11 路碧康株式会社 蓄电设备
CN112736294A (zh) * 2021-01-13 2021-04-30 广东维都利新能源有限公司 一种无电磁干扰的电芯、软包锂电池及其制作方法
CN113381078A (zh) * 2021-06-08 2021-09-10 歌尔科技有限公司 一种卷绕式电池及tws蓝牙耳机

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JPH09161837A (ja) * 1995-12-06 1997-06-20 Matsushita Electric Ind Co Ltd 円筒型電池
JPH11329411A (ja) * 1998-05-08 1999-11-30 Japan Storage Battery Co Ltd 電 極
JP2002313311A (ja) * 2001-04-11 2002-10-25 Ngk Spark Plug Co Ltd リチウム二次電池
JP2004253381A (ja) * 2003-02-19 2004-09-09 Samsung Sdi Co Ltd ジェリーロール型の電池部と、このワインディング方法及びこれを具備したリチウム二次電池
JP2010033888A (ja) * 2008-07-29 2010-02-12 Sumitomo Electric Ind Ltd 非水電解質電池用リード線および非水電解質電池

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JPH09161837A (ja) * 1995-12-06 1997-06-20 Matsushita Electric Ind Co Ltd 円筒型電池
JPH11329411A (ja) * 1998-05-08 1999-11-30 Japan Storage Battery Co Ltd 電 極
JP2002313311A (ja) * 2001-04-11 2002-10-25 Ngk Spark Plug Co Ltd リチウム二次電池
JP2004253381A (ja) * 2003-02-19 2004-09-09 Samsung Sdi Co Ltd ジェリーロール型の電池部と、このワインディング方法及びこれを具備したリチウム二次電池
JP2010033888A (ja) * 2008-07-29 2010-02-12 Sumitomo Electric Ind Ltd 非水電解質電池用リード線および非水電解質電池

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Publication number Priority date Publication date Assignee Title
WO2013127313A1 (fr) * 2012-02-28 2013-09-06 华为终端有限公司 Batterie et terminal
JPWO2021229847A1 (fr) * 2020-05-14 2021-11-18
WO2021229847A1 (fr) * 2020-05-14 2021-11-18 株式会社村田製作所 Batterie secondaire
CN113381079A (zh) * 2021-06-08 2021-09-10 歌尔科技有限公司 一种卷绕式电池及tws蓝牙耳机
CN114284611A (zh) * 2021-12-27 2022-04-05 湖北亿纬动力有限公司 二次电池、电池模组、电池包及二次电池制造方法

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