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`
`[19] National Intellectual Property Administration of the People’s
`Republic of China
`
`[51] Int. CL
`HO1M10/38 (2006.01)
`HO1M10/40 (2006.01)
`[12] Invention Patent Application Publication
`
`
`
`
`
`[21] Application No. 200810092164.6
`
`[43] Disclosure Date October 15, 2008
`[22] Application Date 2008.4.10
`[21] Application Date 200810092164.6
`
`[30] Priority to
`[32] 2007.4.12 [33] JP [31] 2007-105148
`Hitachi Maxell Ltd.
`[71] Applicant
`Address Osaka, Japan
`Hayato Higuchi, Kazuyuki Nakasou,
`[72] Inventor
`Kenichi Sano
`
`
`
`
`
`[11] Disclosure Number CN101286572A
`Dragon Intellectual Property Law
`(74) Patent Agency
`Firm, Beijing
`Agent Ge, Songsheng
`
`
`
`
`
`Claims: 1 page Specifications: 13 pages Drawings: 6 pages
`
`[54] Invention Name
`Coin type non-aqueous electrolyte secondary battery
`[57] Abstract
`Provided is a coin type non-aqueous electrolyte
`secondary battery
`that has a high-rate discharge
`characteristic and no deformation while charging and
`discharging. The present invention relates to a coin type
`non-aqueous electrolyte secondary battery that has a
`strip-shaped positive electrode (1) and a strip-shaped
`negative electrode (2) wound with a strip-shaped separator
`(3) that acts as an intermediate, forming a cylindrical
`wound body (10). The winding axis direction of the wound
`body (10) is the same as the height direction of the battery
`can (13), and the specific value of the ratio of the outer
`diameter D (mm) of the wound body (10) to the height of
`the wound body (10) in the winding direction H (mm) D/H
`is 1–25. The specific value of the ratio of the area A (mm2)
`of the upper part of the wound body (10) to the effective
`area of reaction R (mm2) between the positive electrode (1)
`and the negative electrode (2) R/A is 9–25.
`
`
`
`
`
`
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`200810092164.6
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`
`Claims
`
`Page 1 of 1
`
`1. A coin type non-aqueous electrolyte secondary battery, comprising a strip-shaped positive
`
`electrode, a strip-shaped negative electrode, a strip-shaped separator (separator), and a coin shaped
`
`battery can, characterized in that:
`
`Said positive electrode and said negative electrode are wound with said separator interposed
`
`between them to form a cylindrical wound body;
`
`The direction of the winding axis of said wound body is the same as the height direction of said
`
`battery can;
`
`The specific value of the ratio of the outer diameter D (mm) of said wound body to the height of
`
`said wound body in the winding direction H (mm) D/H is 1–25.
`
`The specific value of the ratio of the area A (mm2) of the upper part of said wound body to the
`
`effective area of reaction R (mm2) between said positive electrode and said negative electrode R/A is
`
`9–25.
`
`2. The coin type non-aqueous electrolyte secondary battery according to claim 1, wherein the
`
`specific value of the ratio of said D/H is 1.5–23.
`
`3. The coin type non-aqueous electrolyte secondary battery according to claim 1, wherein the
`
`volume of said coin type non-aqueous electrolyte secondary battery is between 1 cm3 and 7 cm3.
`
`4. The coin type non-aqueous electrolyte secondary battery according to claim 1, wherein the
`
`outer diameter of said battery can is between 20 mm and 50 mm.
`
`5. The coin type non-aqueous electrolyte secondary battery according to claim 1, wherein said
`
`positive electrode and said negative electrode are capable of adsorbing and desorbing lithium ions.
`
`
`
`
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`Field of the Invention
`
`Description
`
`
`Page 1 of 13
`
`Coin type non-aqueous electrolyte secondary battery
`
`The present invention relates to a coin type non-aqueous electrolyte secondary battery having a
`
`high-rate discharge characteristic.
`
`Prior Art
`
`Coin type non-aqueous electrolyte secondary batteries represented by coin type lithium-ion
`
`secondary batteries, also known as button-type or flat-type non-aqueous electrolyte secondary
`
`batteries, are attracting attention. They are small batteries used for heavy load applications such as
`
`communication devices, like headphone sets and watches, and in what are referred to as wearables,
`
`medical devices attached to the body.
`
`Prior coin type lithium-ion secondary batteries, for example, have been batteries using an
`
`electrode body in which a positive electrode and a negative electrode punched into a circular shape
`
`are laminated with a separator between them. However, since the electrode is thick in this type of
`
`battery, the diffusion resistance of lithium ions in the thickness direction of the electrode increases
`
`and the discharge load characteristic decreases, limiting these batteries to low-output applications.
`
`In order to solve the aforementioned problems, there has been proposed a method of thinning the
`
`electrode by using an electrode body in which a strip-shaped positive electrode and a strip-shaped
`
`negative electrode are wound with a strip-shaped separator interposed between them (for example,
`
`see Patent document 1, Patent document 2, Patent document 3, and Patent document 4).
`
`Patent document 1: KR200377543Y1
`
`Patent document 2: JP2005310578A
`
`Patent document 3: JPH11345626A
`
`Patent document 4: JPH11354150A
`
`Summary of the Invention
`
`In the batteries proposed in Patent document 1 and Patent document 2, an electrode body is
`
`formed by winding a strip-shaped positive electrode and a strip-shaped negative electrode with a
`
`strip-shaped separator interposed between them, and this electrode body is formed into a flat shape to
`
`form an electrode body. The electrode body was inserted into a battery can in a state where the
`
`winding axis direction of the electrode body was perpendicular to the height direction (thickness
`
`direction) of the battery can. At this time, since the electrode body in the battery can has a
`
`quadrangular shape when viewed from the height direction of the battery, a gap is formed between the
`
`electrode body and the battery can, resulting in lost volume. Additionally, with this electrode
`
`structure, the direction of expansion and contraction of the electrode when charging and discharging
`
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`the battery corresponds to the height direction of the battery can. Therefore, if the battery is
`
`repeatedly charged and discharged, the battery may deform in the height direction.
`
`
`
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`Description Page 2 of 13
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`On the other hand, in the batteries proposed in Patent document 3 and Patent document 4, since
`
`the direction of the winding axis of the electrode body is the same as the height direction of the battery
`
`can, there is no gap between the electrode body and the battery can. The direction of expansion and
`
`contraction of the electrodes involved in charging and discharging of the battery is the same as the
`
`radial direction of the battery can. Therefore, even if the battery is repeatedly charged and discharged,
`
`it will not deform.
`
`However, Patent document 3 and Patent document 4 only disclose the basic electrode structure
`
`and do not disclose any specific configuration for improving the heavy-load characteristic. Of course,
`
`Patent document 1 and Patent document 2 also do not disclose any specific configuration for
`
`improving the heavy-load characteristics.
`
`The present invention solves the aforementioned problems and provides a coin type
`
`non-aqueous electrolyte secondary battery with a high-rate discharge load characteristic.
`
`The coin type non-aqueous electrolyte secondary battery of the present invention includes a
`
`strip-shaped positive electrode, a strip-shaped negative electrode, a strip-shaped separator, and a
`
`coin-shaped battery can, wherein said separator is interposed between said positive electrode and said
`
`negative electrode wound together to form a cylindrical wound body. The winding axis direction of
`
`said wound body is the same as the height direction of said battery can. The specific value of the ratio
`
`of the outer diameter D of said wound body to the height H of said wound body D/H is 1–25. The
`
`specific value of the ratio of the area of the upper part of said wound body A to the effective area of
`
`reaction R between said positive electrode and said negative electrode R/A is 9–25.
`
`According to the present invention, it is possible to provide a coin type non-aqueous electrolyte
`
`secondary battery that has a high-rate discharge load characteristic and no deformation when
`
`charging and discharging.
`
`Brief Description of the Drawings
`
`Fig. 1 is a perspective view of the wound body used in the present invention.
`
`Fig. 2 is a perspective view showing the step of inserting the wound body into the cylindrical
`
`battery can.
`
`Fig. 3 is a perspective view showing the step of arranging an upper insulating plate on the upper
`
`surface of the wound body after inserting the wound body into the battery can.
`
`Fig. 4 is a perspective view of the state in which the upper insulating plate is placed on the
`
`wound body, and the negative lead and the inside of the negative terminal at the center of the cap are
`
`welded together.
`
`Fig. 5A is a perspective view of the state in which the battery can and the cap are joined by laser
`
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`welding or the like. Fig. 5B is a cross-sectional view taken along the B-B line in Fig. 5A.
`
`Fig. 6 is a schematic view of the wound body.
`
`Fig. 7 is a schematic diagram of the positive electrode and is used to explain the parameters of
`
`the present invention.
`
`
`
`
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`Description Page 3 of 13
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`Fig. 8 is a cross-sectional view along the I-I line in Fig. 7.
`
`Fig. 9 is a cross-sectional view along the II-II line in Fig. 7.
`
`Fig. 10 is a perspective view showing another form of the positive electrode lead of Fig. 7.
`
`Symbol Descriptions
`
`1 Positive electrode
`
`2 Negative electrode
`
`3 Separator
`
`10 Wound body
`
`11 Positive electrode lead
`
`12 Negative electrode lead
`
`13 Battery can
`
`14 Upper insulating plate
`
`15 Cap
`
`16 Negative terminal
`
`17 Insulating packing
`
`18 Injection port
`
`19 Lower insulating plate
`
`20 Positive electrode
`
`21 Positive current collector
`
`22 First layer of positive electrode active material
`
`23 Second layer of positive electrode active material
`
`24 Positive electrode lead
`
`25 Positive electrode lead
`
`Detailed Description of Embodiments
`
`Hereinafter, embodiments of the coin type non-aqueous electrolyte secondary battery of the
`
`present invention will be described.
`
`The coin type non-aqueous electrolyte secondary battery of the present invention comprises a
`
`battery can and a strip-shaped positive electrode and a strip-shaped negative electrode wound with a
`
`strip-shaped separator that acts as an intermediate, forming a cylindrical wound body. By adopting
`
`this structure, the electrode can be made thinner, and the discharge load characteristic can be
`
`improved to a certain extent.
`
`
`
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`Description Page 4 of 13
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`In addition, the winding axis direction of the said wound body corresponds to the height
`
`direction of the battery can. By adopting this structure, the direction of expansion and contraction of
`
`the electrodes are consistent with the radial direction of the battery can, which has the greatest
`
`strength, so deformation of the battery can be prevented even if the battery is repeatedly charged and
`
`discharged.
`
`In addition, the specific value of the ratio of the outer diameter D of said wound body to the
`
`height of said wound body in the winding direction H D/H is 1–25. If D/H is less than 1, it cannot be
`
`called a coin-shaped battery, nor is it suitable for use as a coin type non-aqueous electrolyte
`
`secondary battery for wearable devices that are thin, small, and require high capacity.
`
`Moreover, a design where D/H exceeds 25 exceeds the allowable range of normal battery design.
`
`Specifically, the minimum width for the wound electrodes that can withstand the manufacturing
`
`process is about 2 mm, making the minimum value of the height H in the winding axis direction of the
`
`wound body 2 mm. In addition, the maximum value of the outer diameter D of the wound body is
`
`considered to be 50 mm according to the size of devices into which the battery is installed. Therefore,
`
`the maximum specific value of D/H is 25. Additionally, in consideration of the battery capacity
`
`required by the device into which the battery is installed, the ideal value of D/H is 1.5–23.
`
`In addition, in the coin type non-aqueous electrolyte secondary battery of the present invention,
`
`the specific value of the ratio R/A of the area A of the upper part of the wound body to the effective
`
`area of reaction R between the positive electrode and the negative electrode is set to 9–25, and ideally
`
`15–20. In this way, the discharge load characteristic can be further improved, and the battery is more
`
`suitable for various devices requiring a heavy load characteristic. Here, the effective area of reaction
`
`R refers to the area between the wound active material layers of the positive electrode and the
`
`negative electrode. In a normal secondary lithium-ion battery, in order not to generate lithium
`
`dendrites during charging, the area of the negative electrode active material layer is larger than that of
`
`the positive electrode active material layer, and the entire surface of the positive electrode active
`
`material layer faces the negative electrode active material layer. Therefore, the effective area of
`
`reaction is actually the portion of the area that has the positive electrode active material layer.
`
`In addition, the volume of the coin type non-aqueous electrolyte secondary battery of the present
`
`invention is preferably between 1 cm3 and 7 cm3. A coin type non-aqueous electrolyte secondary
`
`battery within this range is more suitable for use in a wearable device that requires a small, thin and
`
`high-capacity battery.
`
`Furthermore, the outer diameter of the battery can of the coin type non-aqueous electrolyte
`
`secondary battery of the present invention is preferably between 20 mm and 50 mm. A coin type
`
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`non-aqueous electrolyte secondary battery within this range is likewise more suitable for use in
`
`wearable equipment that requires a small, thin and high-capacity battery.
`
`Following are reference drawings of the coin type non-aqueous electrolyte secondary battery of
`
`the present invention provided as examples. Figs. 1–10 use the same symbol for the same component,
`
`and repeated descriptions may be omitted.
`
`Fig. 1 is a perspective view of the wound body used in the present invention. In Fig. 1, the
`
`wound body 10 is formed by winding a strip-shaped separator between a strip-shaped positive
`
`electrode and a strip-shaped negative electrode.
`
`The aforementioned positive electrode can be formed by the following method: adding a solvent
`
`to a mixture containing said positive electrode active material, a conductive auxiliary agent for said
`
`positive electrode, and a binder for said positive electrode, and then thoroughly mix. Apply the
`
`resulting positive electrode paste to both sides of the positive electrode current collector. After drying,
`
`the positive electrode mixture layer is controlled to the specified thickness and electrode density.
`
`
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`Description Page 5 of 13
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`Examples of material that can be used for the aforementioned positive electrode active material
`
`are lithium cobalt oxides such as LiCoCO2, lithium manganese oxides such as LiMn2O4, and lithium
`
`nickel oxides such as LiNiO2. However, as long as the material can adsorb and desorb lithium ions, it
`
`is not limited to these oxides.
`
`The aforementioned positive electrode current collector is not particularly limited as long as it is
`
`an electron conductor that is substantially chemically stable in the constituted battery. An example of
`
`a possible positive electrode current collector is aluminum foil.
`
`The positive electrode lead 11 is formed by folding an end of the current collector that has not
`
`had the positive electrode paste applied. In addition, exposed portions of the current collector may be
`
`provided at both ends of the current collector, and the positive electrode lead may be provided at both
`
`ends of the current collector. Furthermore, instead of forming the positive electrode lead by folding
`
`the exposed portion of the current collector as described above, a tab used for another component can
`
`be welded onto one or both ends of the positive electrode current collector as the positive electrode
`
`lead.
`
`The aforementioned negative electrode can be formed by the following method: adding a
`
`solvent to a mixture containing said negative electrode active material, a conductive auxiliary agent
`
`for said negative electrode, and a binder for said negative electrode, and then thoroughly mix. Apply
`
`the resulting negative electrode paste to both sides of the negative electrode current collector. After
`
`drying, the negative electrode mixture layer is controlled to the specified thickness and electrode
`
`density.
`
`Examples of material that can be used for the aforementioned negative electrode active material
`
`are carbon materials such as natural graphite, whether lump graphite, flake graphite, or amorphous
`
`graphite, and synthetic graphite. However, as long as the material can adsorb and desorb lithium ions,
`
`it is not limited to these oxides.
`
`The aforementioned negative electrode current collector is not particularly limited as long as it is
`
`an electron conductor that is substantially chemically stable in the constituted battery. An example of
`
`a possible negative electrode current collector is copper foil.
`
`The negative electrode lead 12 is formed by folding an end of the current collector that has not
`
`had the negative electrode paste applied. In addition, exposed portions of the current collector may be
`
`provided at both ends of the current collector, and the negative electrode lead may be provided at both
`
`ends of the current collector. Furthermore, instead of forming the negative electrode lead by folding
`
`the exposed portion of the current collector as described above, a sheet used for another component
`
`can be welded onto one or both ends of the negative electrode current collector as the negative
`
`10
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`electrode lead.
`
`In Fig. 1 the positive electrode lead 11 is provided on the outer peripheral side of the wound
`
`body 10, and the negative electrode lead 12 is provided on the inner peripheral side of the wound
`
`body 10. However, the positive electrode lead 11 may be provided on the inner peripheral side of the
`
`wound body 10, and the negative electrode lead 12 may be provided on the outer peripheral side of
`
`the wound body 10. Moreover, both the positive electrode lead 11 and the negative electrode lead 12
`
`may be provided on the outer peripheral side of the wound body 10.
`
`
`
`
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`11
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`Description Page 6 of 13
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`An insulating microporous thin film that has high ion transmittance and a predetermined
`
`mechanical strength can be used as the aforementioned separator. In addition, from the viewpoint of
`
`improving the safety of the battery, it is preferable to use a film that increases resistance by blocking
`
`micropores above a certain temperature (100 to 140℃). Specifically, the aforementioned separator
`
`may be composed of an olefin-based polymer that is resistant to organic solvents and hydrophobic,
`
`such as polypropylene (PP) or polyethylene (PE), or a glass fiber sheet, non-woven fabric, woven
`
`fabric, or a porous body layer in which olefin-based particles are fixed with an adhesive.
`
`Fig. 2 is a perspective view showing the step of inserting the wound body 10 into the cylindrical
`
`battery can 13. The wound body 10 is inserted into the battery can 13 so that the winding axis
`
`direction N matches the height direction M of the battery can 13. Aluminum or something similar
`
`may be used for as the material for the battery can 13. In addition, a lower insulating plate (not shown
`
`in the figure) is arranged on the bottom of the battery can 13. The material used for the lower
`
`insulating plate is not particularly limited; a polymer such as polyphenylene sulfide (PPS) can be
`
`used.
`
`Fig. 3 is a perspective view showing the step of arranging an upper insulating plate 14 on the
`
`upper surface of the wound body 10 after inserting the wound body 10 into the battery can 13. The
`
`material used for the upper insulating plate 14 can be the same as that of the aforementioned lower
`
`insulating plate.
`
`Fig. 4 is a perspective view of the state in which the upper insulating plate 14 is placed on the
`
`wound body 10, and the negative lead 12 and the inside of the negative terminal 16 at the center of the
`
`cap 15 are welded together. The cap 15 and the negative terminal 16 are insulated using insulating
`
`packing 17. The same material (aluminum or similar) used for the battery can 13 can be used for the
`
`cap 15. Nickle or something similar may be used for the negative electrode terminal 16. The material
`
`of the insulating packing 17 can be a polymer material such as polypropylene (PP).
`
`Fig. 5A is a perspective view of a state in which the battery can 13 and the cap 15 are laser
`
`welded. Fig. 5B is a cross-sectional view taken along the B-B line in Fig. 5A. In Fig. 5B, the wound
`
`body 10 is placed in the airtight container formed by the cap 15 and the battery can 13, and the lower
`
`insulating plate 19 is arranged on the bottom of the battery can 13. However, in Fig. 5B, the inner
`
`peripheral side of the wound body 10 is not shown on the cross section. As described above, the
`
`wound body 10 has a structure in which the strip-shaped separator 3 is interposed between the
`
`strip-shaped positive electrode 1 and the strip-shaped negative electrode 2 and wound into a spiral. In
`
`addition, the positive electrode lead 11 is joined by being inserted between the battery can 13 and the
`
`cap 15. In this way, the battery can 13 and the cap 15 act as the positive electrode terminal. However,
`
`12
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`depending on the material of the battery can 13, the battery can 13 and the cap 15 may become the
`
`negative electrode. Finally, the electrolyte is injected using the injection port 18. A coin type
`
`non-aqueous electrolyte secondary battery is produced when the injection port 18 is sealed with a
`
`sealing body (not shown).
`
`
`
`
`
`13
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`Description Page 7 of 13
`
`The aforementioned electrolyte can be obtained by dissolving at least one lithium salt, for
`
`example LiClO4, LiPF6, LiBF4, LiAsF6, LiSbF6, and LiCF3SO3, in an organic solvent or a mixture of
`
`two or more organic solvents, including the following: vinylene carbonate (VC), propylene carbonate
`
`(PC), ethylene carbonate (EC), butylene carbonate (BC), dimethyl carbonate (DMC), diethyl
`
`carbonate (DEC), methyl ethyl carbonate (MEC), and γ-butyrolactone. The Li ion concentration in
`
`the electrolyte may be 0.5–1.5 mol/L.
`
`Fig. 6 is a schematic view of the wound body 10. Illustrations of the positive electrode lead and
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`the negative electrode lead are omitted in Fig. 6. The specific value of the ratio D/H of the outer
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`diameter D (mm) of the wound body 10 to the height H (mm) in the winding axis direction of the
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`wound body 10 is set to 1–25. In addition, the specific value of the ratio of the area A (mm2) of the
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`upper part of the wound body 10 to the effective area of reaction R (mm2) between said positive
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`electrode and said negative electrode R/A is 9–25.
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`Fig. 7 is a schematic diagram of the positive electrode and is used to explain the parameters of
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`the present invention. In Fig. 7, on both sides of the positive electrode current collector 21 of the
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`strip-shaped positive electrode 20, a first layer of positive electrode active material 22 and a second
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`layer of positive electrode active material 23 are formed. This second layer of positive electrode
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`active material 23 is formed in such a way that it is shorter than the first layer of positive electrode
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`active material 22. The end portion of the positive electrode current collector 21 that has not been
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`formed into the positive electrode active material layer is bent to form the positive electrode lead 24.
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`Where the length of the first layer of positive electrode active material 22 is L (mm), the length of the
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`second layer of positive electrode active material layer 23 is J (mm), and the width of the positive
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`electrode current collector 21 is W (mm), the effective area of reaction R (mm2) is R=(L+J)×W.
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`In addition, where the cross-sectional area of the positive electrode 20 is B (mm2), including the
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`positive electrode current collector 21, the first layer of positive electrode active material 22, and the
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`second layer of positive electrode active material 23, and the number of positive electrode leads is n,
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`the ratio L/(B×n) is preferably 2,000–8,000.
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`Fig. 8 is a cross-sectional view taken along the I-I line in Fig. 7. Additionally, Fig. 9 is a
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`cross-sectional view taken along the II-II line in Fig. 7. Here, where the cross-sectional area of the
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`positive electrode lead 24 is C (mm2), the number of positive electrode leads is n, and the
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`cross-sectional area of the positive electrode current collector 21 is S (mm2), the specific value of the
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`ratio (C×n)/S is preferably 1 or more.
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`14
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`Eve Energy Co., Ltd v. Varta Microbattery Gmbh
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`Eve Ex. 1007, p. 36
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`200810092164.6
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`Description Page 8 of 13
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`Fig. 10 is a perspective view showing another form of the positive electrode lead of Fig. 7. In Fig.
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`10, the positive electrode lead 25 is formed by welding a sheet to the end of the positive electrode
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`current collector 21. Even when using the method in Fig. 10, the suitable ranges of the
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`aforementioned L/(B×n) and (C×n)/S are the same.
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`Examples
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`The present invention will be illustrated by the following examples, which do not limit the scope
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`of the present invention.
`
`Example 1
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`[Production of Positive Electrode]
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`N-methyl-2-pyrrolidone (NMP) was added as a solvent to 80 parts by weight of LiCoO2 as the
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`positive electrode active material, 10 parts by weight of acetylene black as the conductive auxiliary
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`agent, and 5 parts by weight of polyvinylidene fluoride (PVDF) as a binder. These were mixed
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`uniformly to prepare the positive electrode paste. The positive electrode paste was coated on both
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`sides of the positive electrode current collector, which was made of aluminum foil with a thickness of
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`20 μm, so that the active material coating length on the front side was 1,221 mm, and the active
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`material coating length on the back side was 1,155 mm. This was then dried and calendered. The
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`thickness of the electrode was adjusted so that the total thickness was 134 μm. It was cut to a width of
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`3.0 mm to obtain a strip-shaped positive electrode. On both ends of the produced strip-shaped
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`positive electrode were formed portions that were uncoated by the active material.
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`The front side of the positive electrode current collector mentioned above refers to the outer
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`peripheral side when the wound body is formed, and the back side refers to the inner peripheral side
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`when the wound body is formed. The same applies to the negative electrode current collector that is
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`described later.
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`[Production of Negative Electrode]
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`NMP was added as a solvent to 90 parts by weight of graphite as the negative electrode active
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`material and 5 parts by weight of PVDF as a binder. These were mixed uniformly to prepare the
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`negative electrode paste. The negative electrode paste was coated on both sides of the negative
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`electrode current collector, which was made of copper foil with a thickness of 12 μm, so that the
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`active material coating length on the front side was 1,207 mm, and the active material coating length
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`on the back side was 1,207 mm. This was then dried and calendered. The thickness of the electrode
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`was adjusted so that the total thickness was 142 μm. It was cut to a width of 3.5 mm to obtain a
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`strip-shaped negative electrode. On both ends of the produced strip-shaped negative electrode were
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`formed portions that were uncoated by the active material.
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`15
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`Eve Energy Co., Ltd v. Varta Microbattery Gmbh
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`Eve Ex. 1007, p. 37
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`[Production of Wound Body]
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`
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`16
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`Eve Energy Co., Ltd v. Varta Microbattery Gmbh
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`Eve Ex. 1007, p. 38
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`200810092164.6
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`Description Page 9 of 13
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`A separator made of polyethylene microporous film having a thickness of 20 μm and a width of
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`4.3 mm was placed between the strip-shaped positive and negative electrodes obtained as described
`
`above, and then wound to obtain the wound body. In the wound body thus formed, the portions of the
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`positive electrode coated with the active material on both sides of the positive electrode were all
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`facing portions of the negative electrode coated with the active material. Next, the aluminum foil of
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`the portion of the positive electrode not coated with the active material was folded and taken out from
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`the end portion on the outer peripheral portion side of the wound body to form one positive electrode
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`lead. Also, the copper foil of the portion of the negative electrode not coated with the active material
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`was folded and taken out from the end portion on the inner peripheral portion side (center side) of the
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`wound body to form one negative electrode lead.
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`The outer diameter D of the produced wound body was 23.5 mm, the height H of the wound
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`body was 3.7 mm, and the specific value of the ratio D/H was 6.4. In addition, the area of the upper
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`surface of the wound body A was 398 mm2, the effective area of reaction R was 7,128 mm2, and the
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`specific value of the ratio R/A was 17.9.
`
`[Production of Electrolyte]
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`LiPF6 was dissolved at a concentration of 1.2 mol/L into a mixture of the solvents ethylene
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`carbonate (EC) and diethyl carbonate (DEC) (EC:DEC was 1:2) to prepare the electrolyte.
`
`[Production of Battery]
`
`An aluminum battery can having an outer diameter of 24 mm, a height of 5.0 mm, a side
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`thickness of 0.25 mm, and a bottom thickness of 0.3 mm and an aluminum cap of 24 mm in diameter
`
`an