JP2019067653A - Nonaqueous electrolyte secondary battery - Google Patents

Abstract

To provide a nonaqueous electrolyte secondary battery of such a configuration that a stop tape is placed at the flat part of a wound electrode body, and Li precipitation can be restrained appropriately.SOLUTION: A nonaqueous electrolyte secondary battery includes a wound electrode body, a nonaqueous electrolyte, a battery case, and an insulator film. The end part of the wound electrode body in the winding direction is fixed by sticking a tape to the end part and one flat surface. The insulator film is provided with a recess at a part adjacent to the tape and facing the tape. Average thickness (a) of the insulator film at a part facing one flat surface to which the tape was stuck, excepting the recess, is larger than the average thickness (b) of the insulator film at a part facing the other flat surface to which the tape is not stuck.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a non-aqueous electrolyte secondary battery. Specifically, the present invention relates to a non-aqueous electrolyte secondary battery including a wound electrode body, a non-aqueous electrolyte, and an insulating film.

  Lithium ion secondary batteries and other non-aqueous electrolyte secondary batteries are becoming increasingly important as power sources for vehicle mounting or as power sources for personal computers, portable terminals and the like. In particular, a lithium ion secondary battery which is light in weight and capable of obtaining a high energy density is preferably used as a high output power supply for vehicle mounting. In this type of battery, there is known a battery structure including a wound electrode body in which a sheet-like positive electrode and a sheet-like negative electrode are laminated together with a separator and wound, and a non-aqueous electrolytic solution. In addition, a metal case is used as the battery case from the viewpoint of high physical strength. In this case, in order to insulate the battery case from the electrode body, typically, the electrode body is made of an insulating film. Coating is done. For example, Patent Documents 1, 2 and 3 describe that, in a battery provided with an electrode body and a battery case, an insulating film is disposed between a wound electrode body and the battery case.

JP, 2015-153454, A JP, 2014-235930, A JP, 2015-11895, A

  By the way, in the wound electrode body, the end portion in the winding direction of the electrode body may be fixed to the outer surface of the electrode body by a winding tape in order to hold the wound state. With regard to the position of the end portion in the wound electrode body, for example, in Patent Document 1, the winding end of the positive electrode and the winding end of the negative electrode are disposed in the lower bent portion (lower R portion) or flat portion of the wound electrode body. A wound electrode assembly is disclosed. However, when the winding tape is disposed at the lower R portion of the wound electrode body, the metal element in the positive electrode active material is easily eluted locally at such a portion, which is not preferable. On the other hand, when the winding stop tape is disposed on the flat portion of the wound electrode body, the surface pressure of the tape attachment portion locally increases, the distance between the positive and negative electrodes is reduced, and the current is concentrated. It may be easy to precipitate. In particular, when a battery assembly is constructed using a plurality of batteries in which the winding tape is disposed on the flat portion of the wound electrode assembly in this manner, a restraint pressure is applied to the battery from the outside. The contact pressure tends to rise more.

  Therefore, in the present invention, the winding stop tape is disposed on the flat portion of the wound electrode body (that is, the end of the wound electrode body in the winding direction is disposed on the flat portion of the wound electrode body) It is an object of the present invention to provide a non-aqueous electrolyte secondary battery in which the deposition pressure can be appropriately suppressed by preventing a local increase in the surface pressure of the tape application portion.

The non-aqueous electrolyte secondary battery provided by the present invention comprises a flat wound electrode body, a non-aqueous electrolyte solution, a battery case containing the wound electrode body and the non-aqueous electrolyte solution, and the battery. An insulating film is disposed between the inner wall of the case and the wound electrode body to electrically insulate the battery case and the wound electrode body. The wound electrode body is formed by stacking a long positive electrode and a long negative electrode via a long separator, and winding the long electrode in the longitudinal direction of the long positive and negative electrodes. Further, the wound electrode body has a flat portion in a cross section orthogonal to the winding axis.
And the said flat part has two opposing flat surfaces which comprise the surface of the said winding electrode body. The end of the wound electrode body in the winding direction is fixed by sticking a tape to the end and the one flat surface. The said insulating film is provided with the recessed part in the part which adjoins and opposes the said tape. The average thickness a of the insulating film in a portion opposite to the flat surface to which the tape is attached and excluding the recess is the other flat surface to which the tape is not attached. It is larger than the average thickness b of the said insulating film of the opposing part.

  According to this configuration, since the thickness of the insulating film in the portion opposite to the flat surface on one side to which the tape is attached and excluding the concave portion is sufficiently large, the insulating film has sufficient insulation for practical use. It becomes possible to provide the recessed part corresponding to the thickness of a winding stop tape, maintaining. As a result, at least a part (preferably all) of the winding tape is properly enclosed in the recess, and the occurrence of irregularities on the outer surface of the insulating film covering the wound electrode body is suppressed, and the wound electrode body is flattened. The surface pressure applied to the part is made more uniform. Therefore, according to the non-aqueous electrolyte secondary battery provided with the wound electrode body and the insulating film, even when the assembled battery is constructed by combining a plurality of the secondary batteries, the restraint can be applied to the battery from the outside Pressure can be prevented from being applied locally in the vicinity of the sticking portion of the winding tape, and thus Li deposition due to the local surface pressure increase can be prevented in advance.

It is a perspective view which shows typically the external shape of the non-aqueous electrolyte secondary battery which concerns on one Embodiment of this invention. It is a disassembled perspective view which shows typically the structure of the non-aqueous-electrolyte secondary battery which concerns on one Embodiment. It is a longitudinal cross-sectional view which shows typically the cross-section which follows the III-III line in FIG. It is a schematic diagram which shows the structure of the winding electrode body which concerns on one Embodiment. It is a longitudinal cross-sectional view which shows typically the longitudinal cross-section structure in alignment with the VV line | wire in FIG.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. The matters other than the matters specifically mentioned in the present specification and necessary for the implementation of the present invention can be understood as the design matters of those skilled in the art based on the prior art in the relevant field. The present invention can be implemented based on the contents disclosed in the present specification and common technical knowledge in the field. Moreover, in the following drawings, the same code | symbol may be attached | subjected to the member and site | part which show the same effect | action, and the overlapping description may be abbreviate | omitted or simplified. The dimensional relationships (length, width, thickness, etc.) in the drawings do not necessarily reflect the actual dimensional relationships.

  In the present specification, the term "secondary battery" refers to a storage device in general that can be repeatedly charged and discharged, and is a term including so-called storage batteries such as lithium ion secondary batteries and storage elements such as electric double layer capacitors. In addition, “non-aqueous electrolyte secondary battery” refers to a battery provided with a non-aqueous electrolyte (typically, an electrolyte containing a support salt (support electrolyte) in a non-aqueous solvent). The term "lithium ion secondary battery" refers to a secondary battery that uses lithium ions as charge carriers and that is charged and discharged by the movement of lithium ions between the positive and negative electrodes. In addition, the electrode active material refers to a material capable of reversibly inserting and extracting a chemical species (lithium ion in a lithium ion secondary battery) serving as a charge carrier. Hereinafter, the structure of the battery of the present invention will be described in detail by taking a prismatic lithium ion secondary battery as an example, but the present invention is not intended to be limited to those described in the embodiments.

  FIG. 1 is a perspective view schematically showing an outline of a lithium ion secondary battery according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view schematically showing a configuration of a lithium ion secondary battery according to an embodiment. FIG. FIG. 3 is a longitudinal sectional view schematically showing a sectional structure taken along the line III-III in FIG. The lithium ion secondary battery 100 disclosed herein is, roughly speaking, a flat battery case (i.e., a flat-shaped wound electrode body 80, an insulating film 10, and a non-aqueous electrolyte (not shown)). It is accommodated in the exterior container) 30, and is comprised.

  The battery case 30 according to the present embodiment seals a box-shaped rectangular case main body 32 having an opening at one end (corresponding to the upper end in a normal use state of the battery) and the opening of the case main 32 And a rectangular cover 34. The insulating film 10 and the wound electrode body 80 can be accommodated in the battery case from the opening. The case body 32 includes a pair of wide surfaces 37 facing the flat surface (flat portion) of the wound electrode body 80 housed in the case, a pair of narrow surfaces 38 adjacent to the wide surface 37, and a bottom surface 39. It consists of The material of the battery case 30 is preferably a metal material having high strength, light weight and good thermal conductivity, and examples of such metal materials include aluminum, stainless steel, nickel plated steel and the like.

  When the internal pressure of the positive electrode terminal 42 and the negative electrode terminal 44 for external connection on the lid 34 and the battery case 30 rises above a predetermined level (for example, about a set valve opening pressure of about 0.3 MPa to 1.0 MPa) A thin-walled safety valve 36 set to open and an inlet (not shown) for injecting the non-aqueous electrolyte are provided. Further, although not shown, a current interrupt device (CID) operated by an increase in internal pressure of the battery case 30 may be provided in the battery case 30. The dimensions of the battery case 30 are not particularly limited as long as members accommodated in the battery case, such as the wound electrode body 80, the insulating film 10, and the non-aqueous electrolyte can be accommodated. A battery case 30 (battery case main body 32) that can accommodate the wound electrode body 80, the insulating film 10, and the like and has a small dead space is preferable.

  FIG. 4 is a schematic view showing the configuration of a wound electrode body 80 according to an embodiment. FIG. 5 is a longitudinal sectional view schematically showing a longitudinal sectional structure taken along the line V-V in FIG. The wound electrode body 80 includes a long sheet-like positive electrode (positive electrode sheet) 50, a long sheet-like negative electrode (negative electrode sheet) 60, and two separators (separator sheets) interposed between the positive and negative electrode sheets. And 70) are wound and formed in a state of being stacked in the longitudinal direction.

  The positive electrode sheet 50 is configured by forming a positive electrode active material layer 54 along the longitudinal direction on one side or both sides (here, both sides) of a long (strip-like) positive electrode collector 52. A portion where the positive electrode current collector 52 is exposed without forming the positive electrode active material layer 54 in a strip shape along the edge portion on one edge in the width direction of the positive electrode current collector 52 (that is, the positive electrode active material layer is not A forming portion 53) is provided. The negative electrode sheet 60 is configured by forming a negative electrode active material layer 64 along the longitudinal direction on one side or both sides (here, both sides) of a long (strip-like) negative electrode current collector 62. A portion where the negative electrode current collector 62 is exposed without forming the negative electrode active material layer 64 in a strip shape along the edge on one edge in the width direction of the negative electrode current collector 62 (that is, the negative electrode active material layer is not A forming portion 63) is provided.

  As shown in FIG. 4, when laminating, the positive electrode sheet 50 is a part of the positive electrode active material layer non-forming portion 53 of the positive electrode sheet 50 at one end (left side in the figure) of the wound electrode body 80. The negative electrode sheet 60 is overlapped with each other in the width direction so that a part of the negative electrode active material layer non-formed portion 63 of the negative electrode sheet 60 protrudes at the other end (right side in the figure) so that There is. As a result, while the positive electrode sheet 50, the negative electrode sheet 60, and the separator sheet 70 are stacked and wound in the center of the wound electrode body 80, a wound portion of the wound electrode body 80 is formed. The positive electrode active material layer non-forming portion 53 and the negative electrode active material layer non-forming portion 63 are formed at both ends of the axis WL. As shown in FIG. 3, the positive electrode current collector plate 42a and the negative electrode current collector plate 44a are respectively joined to the positive electrode active material layer non-forming portion 53 and the negative electrode active layer non-forming portion 63 by ultrasonic welding, resistance welding or the like. ing. The positive electrode current collector plate 42 a and the negative electrode current collector plate 44 a are electrically connected to the positive electrode terminal 42 and the negative electrode terminal 44, respectively.

  As shown in FIG. 4, the flat-shaped wound electrode body 80 has two R portions (80R1 and 80R2) which are both end portions in the longitudinal direction and the electrode body surface is a curved surface in a cross section orthogonal to the winding axis WL. And a flat portion 80F which is a central portion in the longitudinal direction of the cross section and is sandwiched between two R portions (80R1 and 80R2). The wound electrode body 80 has a longitudinal direction in the vertical direction of the battery case in a cross section orthogonal to the wound axis WL (in a posture in which the wound axis WL of the wound electrode body 80 falls sideways, that is, winding) The opening of the battery case body 32 is formed in the normal direction of the winding axis WL of the winding electrode body 80), and one R portion 80R1 of the two R portions (80R1 and 82R2) is a battery case The battery case 30 (that is, the battery case main body 32) is housed so as to face the bottom surface 39 of the battery 30.

The flat portion 80F of the wound electrode body 80 has, as shown in FIG. 5, two opposing flat surfaces 82a and 82b that constitute the surface of the wound electrode body 80. The end portion 88 in the winding direction of the wound electrode body 80 disclosed herein (typically, as shown in FIG. 4, the winding direction of the separator sheet 70 constituting the outer surface of the wound electrode body 80 End portion 88 is disposed on the flat surface 82a of the flat portion 80F. The lithium ion secondary battery 100 including the wound electrode body 80 in which the end portion 88 is disposed in the flat portion 80F is, for example, a lithium ion secondary battery having a configuration in which the end portion 88 is disposed in R portions 80R1 and 80R2. In comparison, it is preferable because the internal micro short circuit in the R portions 80R1 and 80R2 does not easily occur. The end portion 88 is fixed on the flat surface 82a of the flat portion 80F with a winding stop tape 86 so that the wound electrode body 80 is not unwound.
In addition, although not particularly limited, in the state (posture) in which wound electrode body 80 is wound in the direction from the bottom face 39 side of battery case 30 toward lid 34 and arranged on flat surface 82 a It is preferable to be accommodated in the case 30. By arranging in such a state (posture), the wound electrode body 80 can be accommodated in the battery case main body 32 more smoothly regardless of the presence of the end portion 88 and the winding stop tape 86.

  The material of the winding stop tape 86 is not particularly limited, but a winding stop tape 86 excellent in insulation, adhesiveness, chemical resistance and the like may be preferably employed. The shape and size of the winding stop tape 86 are not particularly limited as long as the effects of the present invention can be exhibited. From the viewpoint of equalizing the surface pressure applied to the flat portion 80F of the wound electrode body 80, a thin flat winding stop tape 86 is preferable. For example, the thickness of the winding stop tape 86 may be 10 μm to 150 μm (typically 25 μm to 75 μm).

  The insulating film 10 is disposed between the inner wall of the battery case 30 and the wound electrode assembly 80 so as to separate the battery case 30 (battery case main body 32) and the electrode assembly 80, as shown in FIG. . The insulating film 10 prevents the contact between the wound electrode body 80, which is a power generation element, and the battery case 30 (battery case main body 32), and the insulation between the wound electrode body 80 and the battery case 30 can be secured.

  The shape of the insulating film 10 is not particularly limited as long as it can insulate the electrode body 20 and the battery case 30 (battery case main body 32). As shown in FIGS. 2 and 3, the insulating film 90 according to the present embodiment is formed in a bottomed bag shape having an open upper end corresponding to the shape of the wound electrode body 80, and the opening The wound electrode assembly 80 can be housed therein through the interposition.

  Insulating film 10 is, for example, for taking out a notch or terminal for positioning in part thereof as long as insulation between wound electrode body 80 and battery case 30 (battery case body 32) is secured. The terminal extraction hole etc. of this may be provided. Further, the insulating film 10 may have a single-layer structure or a laminated structure of two or more layers as long as the effects of the present invention can be exhibited.

  The configuration of the insulating film 10 according to an embodiment disclosed herein will be further described with reference to FIG. Insulating film 10 is, broadly speaking, one flat surface of wound electrode body 80 and flat surface 82 a of one to which winding tape 86 is attached (ie, the end 88 is disposed). A flat surface 82b of the opposite first wide portion 12 and the other wide surface of the wound electrode body 80 which is not attached with the winding stop tape 86 (that is, the end where the end portion 88 is not disposed) And a bottom portion 16 which is a portion existing between the pair of wide portions 12 and 14 and which is opposed to the bottom portion of the wound electrode body 80.

  In the insulating film 10 disclosed herein, a recess 18 is formed on the inner wall of the insulating film 10 at the portion facing the winding stop tape 86 in the first wide portion 12 and the recess 18 is relatively thinner than the periphery It is formed. According to this configuration, at least a part of the winding stop tape 86 is properly included in the recess 18 of the insulating film 10 for the wound electrode body 80 in which the thickness tends to increase locally at the sticking portion of the winding stop tape 86. As a result, generation of local unevenness on the outer surface of the aspect in which the insulating film 10 covers the wound electrode body 80 can be suppressed. The wound electrode body 80 coated with the insulating film 10 tends to make the surface pressure applied to the flat portion 80F uniform. According to the lithium ion secondary battery 100 including the wound electrode body 80 and the insulating film 10, local Li deposition in the vicinity of the sticking portion of the winding stop tape 86 can be prevented in advance.

  The recess 18 is preferably formed in a shape corresponding to the shape of the winding stop tape 86. For example, the recess 18 may be formed in a rectangular shape corresponding to the shape of the flat wound tape 86. In a preferred embodiment, as shown in FIG. 5, the recess 18 has an inclined portion 20 formed at its edge so that the thickness of the insulating film 10 gradually changes. When the insulating film 10 of this aspect is used, higher uniformity of the surface pressure at the flat portion 80F of the wound electrode body 80 can be realized.

  As shown in FIG. 5, in a preferred embodiment, the average thickness of the portion of the first wide portion 12 of the insulating film 10 excluding the recess 18 is a, and the average thickness of the second wide portion 14 of the insulating film 10 is b When it does, average thickness a is larger than average thickness b. According to the insulating film 10 having such a configuration, it is easy to provide the recess 18 in which the winding stop tape 86 can be properly contained while maintaining sufficient insulation by the insulating film 10. The average thicknesses a and b of the insulating film 10 are not particularly limited as long as the effects of the present invention can be exhibited. For example, the average thickness a of the insulating film 10 can be 75 μm or more and 200 μm or less (typically, 125 μm or more and 175 μm or less). The average thickness b of the insulating film 10 can be 10 μm or more and 75 μm or less (typically, 25 μm or more and less than 75 μm). Moreover, although it does not specifically limit, the difference (ab) of average thickness a and b can be 10 micrometers or more and 150 micrometers or less. If the above (a-b) is more than 150 μm, the mechanical strength of the insulating film 10 tends to decrease. When the above (ab) is smaller than 10 μm, the Li precipitation suppressing effect is hardly exhibited.

  When the average thickness of the recesses 18 of the insulating film 10 is c, the average thickness c is not particularly limited. In a preferred embodiment, the average thickness c of the recess 18 is greater than the thickness of the winding tape 86. According to this aspect, equalization of the surface pressure in the flat portion 80F of the wound electrode body 80 and insulation by the insulating film 10 are easily achieved at the same time.

  After covering the wound electrode body 80 with the insulating film 10, the wound electrode body 80 and the insulating film 10 are inserted by inserting the wound electrode body 80 together with the insulating film 10 into the battery case 30 (battery case body 32). It can be accommodated in the battery case 30. Alternatively, the insulating film 10 is stretched over the opening of the battery case 30 (battery case body 32), and the stretched insulating film 10 is pressed by the wound electrode body 80 while the insulating film 10 and the wound electrode body are 80 may be accommodated in the battery case 30 (battery case main body 32).

  As a material of the insulating film 10, it is preferable to use a material excellent in insulation and chemical resistance. Typically, a flexible material that can be curved along the shape of wound electrode body 80 is preferred. Specifically, it includes at least one polymeric material selected from the group consisting of polypropylene, thermoplastic polyester, polyvinyl alcohol, polyethylene, polyamide, polyethylene terephthalate, polyvinyl chloride, polycarbonate and ethylene vinyl acetate copolymer, etc. Resin materials can be used. In a preferred embodiment, the insulating film 10 comprises polypropylene (PP).

  Next, each member constituting the wound electrode body 80 according to the present embodiment will be briefly described, but the present invention is not limited by the structure or composition of each member constituting the wound electrode body 80. The same electrode as the wound electrode assembly 80 of the conventional lithium ion secondary battery 100 can be used.

The positive electrode 50 which concerns on this embodiment is not specifically limited, What can be used for a conventionally well-known lithium ion battery can be used conveniently. For example, as the positive electrode current collector 52 constituting the positive electrode 50, an aluminum foil or the like can be mentioned. As a positive electrode active material, for example, lithium composite metal oxides such as layered structure and spinel structure (for example, LiNi _1/3 Co _1/3 Mn _1/3 O ₂ , LiNiO ₂ , LiCoO ₂ , LiFeO ₂ , LiMn ₂ O ₄ , LiNi _0.5 Mn _1.5 O ₄ , LiFePO ₄ etc.). The positive electrode active material layer 54 can contain components other than the active material, such as a conductive material, a binder, and the like. As the conductive material, carbon black such as acetylene black (AB) and other carbon materials such as graphite (graphite and the like) can be suitably used. As a binder, PVDF or the like can be used.
Such a positive electrode 50 is, for example, a paste-like (slurry-like) composition by dispersing a positive electrode active material having a suitable particle size, a conductive material and a binder in a suitable solvent (for example, N-methyl-2-pyrrolidone). And then apply an appropriate amount of the composition to the surface of the positive electrode current collector 52, followed by drying to remove the solvent. Further, the properties of the positive electrode active material layer 54 can be adjusted by applying an appropriate pressing process as necessary.

The negative electrode 60 which concerns on this embodiment is not specifically limited, What can be used for a conventionally well-known lithium ion battery can be used conveniently. For example, as the negative electrode current collector 62 constituting the negative electrode 60, copper foil and the like can be mentioned. As a negative electrode active material, carbon materials, such as graphite, hard carbon, soft carbon, can be used, for example. The negative electrode active material layer 64 may contain components other than the active material, such as a binder and a thickener. A styrene butadiene rubber (SBR) etc. can be used as a binder. As a thickener, for example, carboxymethylcellulose (CMC) and the like can be used.
Such a negative electrode 60 can be formed, for example, in the same manner as in the case of the positive electrode 50 described above. That is, a negative electrode active material having a suitable particle size and a binder are dispersed in a suitable solvent (for example, ion exchanged water) to prepare a paste-like (slurry-like) composition, and then an appropriate amount of the composition is After applying to the surface of the negative electrode current collector 62, it can be formed by removing the solvent by drying. In addition, the properties of the negative electrode active material layer 64 can be adjusted by performing an appropriate pressing process as necessary.

  The separator 70 according to the present embodiment is not particularly limited, and any conventional lithium ion may be used as long as it electrically isolates (insulates) the positive electrode 50 and the negative electrode 60 and has the function of holding the non-aqueous electrolyte and the shutdown function. It may be similar to that provided in the secondary battery. Preferred examples include porous sheets (films) made of resins such as polyethylene (PE), polypropylene (PP), polyester, cellulose, and polyamide. The porous sheet may have a single layer structure, or may have a two or more layer laminated structure (for example, a three-layer structure in which a PP layer is laminated on both sides of a PE layer).

In addition, as the non-aqueous electrolyte according to the present embodiment, for example, one in which at least a supporting salt is contained in an organic solvent (non-aqueous solvent) can be preferably used. The non-aqueous electrolytic solution is liquid at normal temperature (e.g., 25 [deg.] C.), and in a preferred embodiment is always liquid under the use environment of the battery (e.g., -30 [deg.] C. to 60 [deg.] C.). The organic solvent is not particularly limited, and various organic solvents known to be usable in the electrolyte of a general lithium ion secondary battery can be used alone or in combination. For example, carbonates, ethers, esters, nitriles, sulfones, lactones and the like can be mentioned. Preferred examples include ethylene carbonate (EC), propylene carbonate (PC), diethyl carbonate (DEC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC) and the like.
The supporting salt is not particularly limited as long as it contains a charge carrier (typically, lithium ion), and one or two or more similar ones to those used in general lithium ion secondary batteries may be used. it can. For example, lithium salts such as LiPF ₆ , LiBF ₄ , LiClO ₄ , LiAsF ₆ , Li (CF ₃ SO ₂ ) ₂ N, LiCF ₃ SO _{3 and the} like can be mentioned. LiPF ₆ may be mentioned as particularly preferred support salt. Moreover, it is preferable to prepare a non-aqueous electrolyte so that the density | concentration of the said supporting salt may become in the range of 0.7 mol / L-1.3 mol / L.

  The battery disclosed herein can be one in which a local increase in surface pressure of the electrode body is suppressed. Therefore, the battery disclosed herein can be preferably applied to a battery assembly in which a plurality of batteries are electrically connected and further subjected to restraint pressure. In addition, according to the battery disclosed herein, a highly reliable battery (for example, a lithium ion secondary battery) can be provided. Therefore, the battery disclosed herein can be suitably used, for example, as a driving power source mounted on a vehicle such as a car. In particular, it is suitable as a drive power source for plug-in hybrid vehicles (PHVs), hybrid vehicles (HVs), electric vehicles (EVs) and the like. Further, according to the present invention, there is provided a vehicle provided with the battery (for example, lithium ion secondary battery) disclosed herein, preferably as a power source.

  Although the specific examples of the present invention have been described above in detail, these are merely examples and do not limit the scope of the claims. The art set forth in the claims includes various variations and modifications of the specific examples illustrated above.

DESCRIPTION OF SYMBOLS 10 insulation film 12 1st wide part 14 2nd wide part 16 bottom part 18 recessed part 30 battery case 32 case main body 34 lid 36 safety valve 37 wide surface 38 wide width surface 39 bottom surface 42 positive electrode terminal 42a positive electrode current collection plate 44 negative electrode Terminal 44a Negative electrode current collector plate 50 Positive electrode 52 Positive electrode current collector 53 Positive electrode active material layer non-forming portion 54 Positive electrode active material layer 60 Negative electrode current collector 63 Negative electrode active material layer non-forming portion 64 Negative electrode active material layer 70 Separator 80 Rotating electrode body 80R1, 80R2 R part 80F Flat part 82a Flat surface 82b Flat surface 86 Winding tape 88 Termination part 100 Non-aqueous electrolyte secondary battery (lithium ion secondary battery)

Claims (1)

Flat wound electrode body,
Non-aqueous electrolyte,
A battery case in which the wound electrode body and the non-aqueous electrolyte are contained;
An insulating film disposed between the inner wall of the battery case and the wound electrode body to electrically insulate the battery case from the wound electrode body;
A non-aqueous electrolyte secondary battery comprising
The wound electrode body is formed by stacking a long positive electrode and a long negative electrode via a long separator and winding the long positive electrode and the negative electrode in the longitudinal direction.
The wound electrode body has a flat portion in a cross section orthogonal to the winding axis,
The flat portion has two opposing flat surfaces that constitute the surface of the wound electrode body,
The end of the wound electrode body in the winding direction is fixed by sticking a tape to the end and the one flat surface,
The insulating film is provided with a recess at a portion adjacent to and facing the tape,
The average thickness a of the insulating film in a portion opposite to the flat surface to which the tape is attached and excluding the recess is opposite to the other flat surface to which the tape is not attached. Greater than the average thickness b of the part of the insulating film,
A non-aqueous electrolyte secondary battery characterized in that.

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