JP2012069290A - Secondary battery, vehicle, and device using battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a secondary battery or the like provided with a wound electrode body, which is capable of preventing or suppressing battery reaction variations depending on the position in the wound electrode body due to winding-stop processing.SOLUTION: In the secondary battery, a wound electrode body 120 is composed of: an electrode body part 120f in which a cathode active material layer, an intervening body 141, and an anode active material layer are in close contact with each other in a thickness direction; and body outer winding parts 120g1 and 120g2 other than the electrode body part. The wound electrode body 120 is formed by performing winding-stop processing which fixes, in the body outer winding parts 120g1 and 120g2, a winding-finish end 141di of an intervening body outermost periphery 141d of the intervening body 141 to the body outer winding parts 120g1 and 120g2 themselves.

Description

  The present invention relates to a secondary battery including a wound electrode body in which a positive electrode plate and a negative electrode plate are overlapped with each other with an interposed body and wound around an axis. Moreover, it is related with the vehicle and battery use apparatus which mount this secondary battery.

  Conventionally, a wound type in which a long positive electrode plate and a long negative electrode plate are overlapped with each other via a long inclusion (such as a separator or a solid electrolyte layer) and wound around an axis. A secondary battery such as a lithium ion secondary battery including an electrode body is known. Since the wound electrode body is liable to be loosened, in order to prevent this, a wound adhesive tape member is sometimes attached to the wound electrode body. For example, Patent Document 1 below discloses a secondary battery in which such a wound adhesive tape member is attached to a wound electrode body.

  That is, the flat battery (secondary battery) described in Patent Document 1 is an electrode body wound in a flat shape with a strip-shaped separator (intervening body) interposed between the strip-shaped positive electrode and the strip-shaped negative electrode. (Refer to Claim 1 of Patent Document 1, FIGS. 1 and 6, the description thereof, etc.). Three tapes (winding adhesive tape members) are affixed to the electrode body, and two of these tapes are affixed in the axial direction to the central portion of the electrode body in the axial direction. It has been.

  The central part of the electrode body in the axial direction is the part where the positive electrode, negative electrode, and separator are in close contact with each other and the battery reaction occurs (the part where lithium ions are inserted and removed between the electrodes during charge and discharge). is there. Then, one of the tapes is attached to the central portion of the electrode body in the axial direction between the winding end of the first separator and the positive electrode adjacent to the end of the first separator. is doing. In addition, the other tape is in a form that spans between the winding end of the second separator and the negative electrode adjacent to the end of the second separator at the central portion in the axial direction of the electrode body. is doing.

JP 2009-26655 A

  However, when the tape is applied to the central portion of the electrode body in the axial direction as described above, a difference in battery reaction occurs between the portion where the tape is applied and the portion where the tape is not applied. It has been found that there is a risk of lithium precipitation. In the state accommodated in the battery case, the electrode body has a level difference corresponding to the thickness of the tape, and the electrode body is strongly pressed only in the portion where the tape is present. This is probably because there was a difference in battery reaction between the unexposed parts.

  The present invention has been made in view of the present situation, and in a secondary battery including a wound electrode body, it is possible to prevent the occurrence of uneven battery reaction due to the location in the wound electrode body due to the winding process. Another object is to provide a suppressed secondary battery. Moreover, it aims at providing the vehicle and battery use apparatus which mount this lithium ion secondary battery.

  In one embodiment of the present invention for solving the above-described problem, a positive electrode plate including a positive electrode active material layer and a negative electrode plate including a negative electrode active material layer are overlapped with each other with an inclusion interposed therebetween and wound around an axis. And it is a secondary battery provided with the winding type electrode body by which the outermost periphery of itself is comprised by the outermost periphery part of the said interposition body, Comprising: Of the said winding type electrode body, the said positive electrode active material layer When the intermediate body and the negative electrode active material layer are disposed in close contact with each other in the thickness direction, the electrode main body portion, and a portion other than the electrode main body portion is a main body winding portion, The wound electrode body is subjected to a winding process for fixing the winding end end portion of the interposer outermost peripheral portion of the interposer to the main body outer winding portion itself in the main body outer winding portion. It is a secondary battery.

This secondary battery has a winding process in which the winding end of the outermost periphery of the interposer is fixed to the outer winding part itself in the outer winding part of the wound electrode body. The wound electrode body is wound.
The electrode main body portion, which is a portion where the positive electrode active material layer, the intervening material, and the negative electrode active material layer are disposed in close contact with each other in the thickness direction, is a portion that causes a battery reaction. On the other hand, the main body outer winding part, which is a part other than the electrode main body part, is a part that does not cause a battery reaction or has a smaller degree of battery reaction than the electrode main body part. In addition, the outer winding portion of the main body is a portion including a gap where the positive electrode active material layer, the intermediate body, and the negative electrode active material layer are not in close contact with each other.

  Therefore, even if the winding operation is performed on the outer winding portion of the main body, the outer winding portion of the main body has a portion that is strongly pressed depending on the location due to the presence of an adhesive tape member or an adhesive used for the winding processing. hard. In addition, the outer winding portion of the main body has little or no battery reaction itself. For this reason, the battery reaction unevenness hardly occurs in the main body outer winding portion. Thus, in this secondary battery, it is possible to prevent or suppress the occurrence of uneven cell reaction in the wound electrode body due to the winding process, while preventing the wound electrode body from loosening.

  Examples of the “intervening body” include a separator made of a porous film such as polyethylene (PE) or polypropylene (PP), a completely solid electrolyte body in which a lithium salt or the like is dissolved in a polymer, or an electrolyte solution in a matrix polymer. Examples include a layer made of an inorganic solid electrolyte including a gel-like solid electrolyte, a sulfide-based solid electrolyte, and an oxide-based solid electrolyte. These “intervening bodies” may be in the form of separate members independent of the positive electrode plate or the negative electrode plate, or may be formed and integrated on the positive electrode plate or the negative electrode plate.

As described above, the “main body winding part” is a part other than the electrode main body part, that is, a part where the positive electrode active material layer, the interposition, and the negative electrode active material layer are not arranged in close contact with each other in the thickness direction. It is.
As a specific part of the “main body winding part”, for example, since at least one of the positive electrode active material layer and the negative electrode active material layer is not present in the wound electrode body, the positive electrode active material layer and the intervening part are interposed. Examples thereof include a portion where the body and the negative electrode active material layer are not in close contact with each other in the thickness direction. In addition, since the thickness of at least one of the positive electrode active material layer and the negative electrode active material layer is made thinner than the thickness of the positive electrode active material layer and the negative electrode active material layer constituting the electrode main body, A part where the inclusion and the negative electrode active material layer are not in close contact with each other is also included.
Further, as a form of the wound electrode body having the “main body winding part”, for example, the “electrode body part” is provided in the central portion in the axial direction of the wound electrode body, and both end sides thereof are respectively “main body”. A form called “outer winding part” can be mentioned. In addition to this, there may be mentioned a mode in which the “electrode body” is divided into two in the axial direction of the wound electrode body and the “winding portion outside the body” is also provided between the two. .

In addition, as described above, the “winding process” is performed in the outer periphery of the main body outer peripheral portion of the wound electrode body, in the outer peripheral portion of the wound electrode body. It is a process of fixing to the turn part itself, and refers to a process of preventing unwinding (winding loosening) of the interposition of the wound electrode body, the positive electrode plate and the negative electrode plate.
Specific examples of the “winding process” include, for example, a tape process in which the winding end end portion of the interposed body is fixed to the outer winding part of the main body using an adhesive tape member as described later.
Moreover, the adhesion | attachment process which fixes the winding end end part of an interposed body to a main body outer winding part using an adhesive agent is mentioned. Examples of the adhesion treatment include a process of directly applying an adhesive to the back surface (radially inner side surface) of the winding end end portion of the interposed body and fixing the winding end end portion to the main body outer winding portion. . In addition, when the inclusion is integrated on the positive electrode plate or the negative electrode plate, by applying an adhesive to the back surface (radial inner surface) of the positive electrode plate or the like, the winding end end of the inclusion The process which fixes to a main body outer winding part is mentioned.
Moreover, the metal-metal | metal-treatment which fixes the winding end part of an interposed body to a main body outer winding part using metal fittings, such as a wire and a caulking ring, is also mentioned.

  Further, in the above secondary battery, the wound electrode body is not subjected to the winding process on the electrode body part, and the winding process is performed on the outer wound part of the body. A secondary battery is preferable.

  In this secondary battery, since the winding process is not performed on the electrode body, it is possible to prevent partial battery reaction unevenness due to the winding process in the electrode body. Therefore, in this secondary battery, it is possible to more reliably prevent the battery reaction unevenness from occurring in the wound electrode body due to the winding process, while preventing the wound electrode body from loosening.

  Furthermore, in the above secondary battery, the main body winding portion includes a first main body winding portion adjacent to one end side in the axial direction of the electrode main body portion, and the axis line of the electrode main body portion. A second main body outer winding portion adjacent to the other end side of the direction, and the first main body outer winding portion and the second main body outer winding portion are each subjected to the winding process. A secondary battery is preferable.

  In this secondary battery, the main body outer winding part has the first main body outer winding part and the second main body outer winding part, and each of these is subjected to a winding process. As a result, the wound electrode body is wound around both ends in the axial direction across the electrode main body, so that it is possible to more reliably prevent the wound electrode body from being loosened.

  Further, in the secondary battery according to any one of the above, the winding process is performed by attaching the winding end edge of the winding end to the outermost periphery of the interposition of the interposition. It is good to make it the secondary battery which is a tape process which affixes and affixes a tape member, fixing the said winding end end part.

  In this secondary battery, the winding process is a tape process for fixing the winding end end using an adhesive tape member. Such tape treatment can easily and reliably prevent winding-up of the wound electrode body.

  Another aspect is a vehicle in which the secondary battery described in any of the above is mounted and the electric energy stored in the secondary battery is used as all or part of the driving energy of the driving source.

As described above, the secondary battery can prevent or suppress the occurrence of battery reaction unevenness depending on the location in the wound electrode body with the winding process while preventing the winding electrode body from loosening. The performance and durability of a vehicle equipped with this secondary battery can be increased.
Examples of the “vehicle” include an electric vehicle, a hybrid vehicle, a plug-in hybrid vehicle, a hybrid railway vehicle, a forklift, an electric wheelchair, an electrically assisted bicycle, and an electric scooter.

  Moreover, another aspect is a battery-using device in which the secondary battery according to any one of the above is mounted and the secondary battery is used as at least one energy source.

As described above, the secondary battery can prevent or suppress the occurrence of battery reaction unevenness depending on the location in the wound electrode body with the winding process while preventing the winding electrode body from loosening. The performance, durability, etc. of the battery using equipment equipped with the secondary battery can be increased.
Examples of the “battery-using device” include various home appliances driven by a battery, such as a personal computer, a mobile phone, a battery-powered electric tool, and an uninterruptible power supply, office equipment, and industrial equipment.

1 is a longitudinal sectional view of a lithium ion secondary battery according to Embodiment 1. FIG. FIG. 3 is a perspective view showing a wound electrode body according to the first embodiment. FIG. 3 is a plan view illustrating a positive electrode plate according to the first embodiment. FIG. 3 is a plan view illustrating the negative electrode plate according to the first embodiment. It is a top view which concerns on Embodiment 1 and shows a separator. FIG. 3 is a partial plan view illustrating a state in which the positive electrode plate and the negative electrode plate are overlapped with each other via a separator according to the first embodiment. FIG. 3 is an exploded perspective view illustrating a case lid member, a positive electrode terminal member, a negative electrode terminal member, and the like according to the first embodiment. FIG. 10 is a perspective view showing a wound electrode body according to the second embodiment. It is explanatory drawing which shows the vehicle which concerns on Embodiment 3. FIG. It is explanatory drawing which shows the hammer drill which concerns on Embodiment 4. FIG.

(Embodiment 1)
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a lithium ion secondary battery (secondary battery) 100 according to the first embodiment. FIG. 2 shows a wound electrode body 120 constituting the lithium ion secondary battery 100. Further, the positive electrode plate 121 constituting the wound electrode body 120 is shown in FIG. 3, the negative electrode plate 131 is shown in FIG. 4, and the separator (intervening body) 141 is shown in FIG. FIG. 6 shows a state in which the positive electrode plate 121 and the negative electrode plate 131 are overlapped with each other via the separator 141. FIG. 7 shows details of the case lid member 113, the positive electrode terminal member 150, the negative electrode terminal member 160, and the like.

  The lithium ion secondary battery 100 is a prismatic battery mounted on a vehicle such as a hybrid vehicle or an electric vehicle, or a battery-operated device such as a hammer drill, and has a battery capacity of 5 Ah. The lithium ion secondary battery 100 includes a rectangular battery case 110, a wound electrode body 120 accommodated in the battery case 110, a positive electrode terminal member 150 and a negative electrode terminal member 160 supported by the battery case 110. Etc. (see FIG. 1). In addition, an electrolyte solution (not shown) is injected into the battery case 110.

  Among these, the battery case 110 is composed of a box-shaped case main body member 111 opened only on the upper side, and a rectangular plate-shaped case cover member 113 welded in a form to close the opening 111 h of the case main body member 111. ing. The case lid member 113 is provided with a safety valve portion 113j that is broken when the internal pressure of the battery case 110 reaches a predetermined pressure (see FIGS. 1 and 7). In addition, the case lid member 113 is provided with an electrolyte solution inlet 113 d for injecting the electrolyte solution into the battery case 110.

  Further, a positive electrode terminal member 150 and a negative electrode terminal member 160 are fixed to the case lid member 113 via three insulating members 155, 156, and 157, respectively (see FIG. 7). The positive electrode terminal member 150 and the negative electrode terminal member 160 are constituted by three terminal fittings 151, 152, and 153, respectively. In the battery case 110, the positive electrode terminal member 150 is connected to a positive electrode current collector 121 m (described in detail below) of the positive electrode plate 121 of the wound electrode body 120 (specifically, the external positive electrode current collector 121 m 2). The electrode terminal member 160 is connected to a later-described negative electrode current collector 131m (specifically, an external negative electrode current collector 131m2) of the negative electrode plate 131 in the wound electrode body 120 (see FIG. 1).

  Next, the wound electrode body 120 will be described. The wound electrode body 120 is housed in an insulating film enclosure 115 formed in a bag shape with only the upper opening of the insulating film, and is housed in the battery case 110 in a laid state (FIG. 1). reference). The wound electrode body 120 includes a long positive electrode plate 121 (see FIG. 3) and a long negative electrode plate 131 (see FIG. 4), and a long separator 141 having air permeability (see FIG. 5). 2), wound around the axis AX (clockwise as viewed from above in FIG. 2), and compressed into a flat shape (see FIGS. 2 and 6).

Among these, the positive electrode plate 121 has the positive electrode current collection foil 122 which consists of elongate aluminum foil as a core material, as shown in FIG.3 and FIG.6. On both main surfaces of the positive electrode current collector foil 122, positive electrode active material layers 123 and 123 are respectively formed in the longitudinal direction (in FIG. 3 and FIG. It is provided in a strip shape in the left-right direction. The positive electrode active material layer 123 includes a positive electrode active material, a conductive agent, and a binder.
In the positive electrode plate 121, a belt-like portion where the positive electrode current collector foil 122 and the positive electrode active material layers 123 and 123 exist in the thickness direction of the positive electrode plate 121 is the positive electrode portion 121 w. In the state where the wound electrode body 120 is configured, the entire positive electrode portion 121w is located in an electrode main body portion 120f described later, and the negative electrode plate is interposed via the separator 141 (specifically, the separator central portion 141a). It faces a negative electrode portion 131w (in detail, a negative electrode central portion 131wa) of 131 (see FIG. 6).
In addition, with the formation of the positive electrode portion 121w on the positive electrode plate 121, one end portion in the width direction (upward in FIGS. 3 and 6) of the positive electrode current collector foil 122 extends in a band shape in the longitudinal direction, It is a positive electrode current collector 121m in which the positive electrode active material layer 123 does not exist in its own thickness direction.

  Furthermore, the positive electrode current collector 121m can be distinguished into an internal positive electrode current collector 121m1 and an external positive electrode current collector 121m2 in the width direction. The internal positive electrode current collector 121m1 is adjacent to the one axial side SA (upward in FIGS. 2 and 6) of the positive electrode part 121w in the state in which the wound electrode body 120 is configured. It is a strip-shaped part located in the 1-1 main body outer winding part 120g11 of the winding part 120g1. On the other hand, the external positive electrode current collector 121m2 is a strip-shaped part that is further adjacent to the one side SA in the axial direction of the internal positive electrode current collector 121m1 and protrudes from the separator 141 to the one side SA in the axial direction. It is a site | part which comprises the 1-2nd main body outer winding part 120g12 of the main body outer winding part 120g1.

  Next, the negative electrode plate 131 will be described. As shown in FIGS. 4 and 6, the negative electrode plate 131 has a negative electrode current collector foil 132 made of a long copper foil. On both main surfaces of the negative electrode current collector foil 132, on the regions extending in the longitudinal direction and part of the width direction, the negative electrode active material layers 133 and 133 are respectively disposed in the longitudinal direction (in FIGS. 4 and 6, It is provided in a strip shape in the left-right direction). The negative electrode active material layer 133 includes a negative electrode active material, a binder, and a thickener. In the negative electrode plate 131, a strip-shaped portion where the negative electrode current collector foil 132 and the negative electrode active material layers 133 and 133 are present in the thickness direction of the negative electrode plate 131 is the negative electrode portion 131w.

The negative electrode portion 131w can be distinguished in the width direction into a negative electrode central portion 131wa, a negative electrode one end side portion 131wb, and a negative electrode other end side portion 131wc. The negative electrode central portion 131wa is a strip-shaped portion located in an electrode main body portion 120f described later in the state where the wound electrode body 120 is configured, and as described above, via the separator 141 (separator central portion 141a). It faces the positive electrode part 121w of the positive electrode plate 121.
In addition, the negative electrode one end portion 131wb is adjacent to the one axial side SA (upward in FIGS. 2 and 6) of the negative electrode central portion 131wa in the state where the wound electrode body 120 is configured. It is a strip-shaped part located in the 1-1 main body outer winding part 120g11 of the main body outer winding part 120g1.
In addition, the negative electrode other end portion 131wc is adjacent to the other end side SB in the axial direction of the negative electrode central portion 131wa (downward in FIGS. 2 and 6) in the state where the wound electrode body 120 is configured, and will be described later. It is a strip-shaped part located in the 2-1 main body outer winding part 120g21 of the second main body outer winding part 120g2.

Further, along with the formation of the negative electrode portion 131w on the negative electrode plate 131, one end in the width direction of the negative electrode current collector foil 132 (downward in FIGS. 4 and 6) extends in a band shape in the longitudinal direction, The negative electrode current collector 131m has no negative electrode active material layer 133 in its own thickness direction.
Furthermore, the negative electrode current collector 131m can be divided into an internal negative electrode current collector 131m1 and an external negative electrode current collector 131m2 in the width direction. The internal negative electrode current collector 131m1 is adjacent to the other axial side SB (downward in FIGS. 2 and 6) of the negative electrode portion 131w in the state in which the wound electrode body 120 is configured. This is a belt-like portion located in the 2-1 main body outer winding portion 120g21 of the winding portion 120g2. On the other hand, the external negative electrode current collector 131m2 is a belt-like portion that is further adjacent to the other axial side SB of the internal negative electrode current collector 131m1 and protrudes from the separator 141 to the other axial side SB. The 2-2 main body outer winding part 120g22 of the main body outer winding part 120g2 is configured.

  Next, the separator 141 will be described. The separator 141 is made of a resin such as PP or PE, is porous, and has a long shape as shown in FIGS. The separator 141 is divided in the width direction into a separator central portion (intervening body central portion) 141a, a separator one end side portion (interposing body one end side portion) 141b, and a separator other end side portion (interposing body other end side portion) 141c. it can. Among these, the separator center part 141a is a belt-like part located in the electrode main body part 120f described later in a state where the wound electrode body 120 is configured.

In addition, the separator one end portion 141b is adjacent to the one axial side SA (upward in FIGS. 2 and 6) of the separator central portion 141a in the state where the wound electrode body 120 is configured. It is a strip-shaped part located in the 1-1 main body outer winding part 120g11 of the main body outer winding part 120g1.
In addition, the separator other end portion 141c is adjacent to the other end side SB in the axial direction of the separator central portion 141a (downward in FIGS. 2 and 6) in the state where the wound electrode body 120 is configured, and will be described later. It is a strip-shaped part located in the 2-1 main body outer winding part 120g21 of the second main body outer winding part 120g2.

The wound electrode body 120 formed by the positive electrode plate 121, the negative electrode plate 131, and the separator 141 has an electrode main body 120f at the center in the axis AX direction. The electrode main body portion 120f is formed by three members of the positive electrode active material layer 123 of the positive electrode plate 121, the separator 141, and the negative electrode active material layer 133 of the negative electrode plate 131 in the thickness direction (a direction orthogonal to the paper surface in FIG. 6). It is the site | part arrange | positioned mutually closely.
In addition, the wound electrode body 120 is a portion outside the main body outer casing which is a portion other than the electrode main body portion 120f described above, that is, a portion where the positive electrode active material layer 123, the separator 141, and the negative electrode active material layer 133 are not in close contact with each other. It has a turning part 120g1, 120g2. These main body outer winding parts 120g1 and 120g2 are adjacent to each other in the axis AX direction of the electrode main body part 120f. Among these, one main body outer winding part 120g1 is the first main body outer winding part 120g1 adjacent to one axial end side SA (upward in FIGS. 2 and 6) of the electrode main body part 120f, and the other The main body outer winding part 120g2 is a second main body outer winding part 120g2 that is adjacent to the other end SB in the axial direction of the electrode main body part 120f (downward in FIGS. 2 and 6).

  Further, the first main body outer winding part 120g1 is divided into a 1-1 main body outer winding part 120g11 and a first-2 main body outer winding part 120g12 in the axis AX direction. Among these, the 1-1 main body outer winding part 120g11 is adjacent to the axial direction one end side SA of the electrode main body part 120f, and among the positive electrode current collector part 121 of the positive electrode plate 121, the internal positive electrode current collector part 121m1 and the separator 141 is composed of a separator one end side portion 141b and a negative electrode one end side portion 131wb of the negative electrode portion 131w of the negative electrode plate 131. On the other hand, the 1-2 main body outer winding part 120g12 is adjacent to the axial end one side SA of the 1-1 main body outer winding part 120g11, and the external positive electrode current collector 121m of the positive electrode plate 121 is included in the external positive electrode current collector 121m. Only the electric part 121m2 is a wound part.

  As described above, the first main body outer winding portion 120g1 does not cause the battery reaction because the negative electrode portion 131w (negative electrode one end portion 131wb) is present but the positive electrode portion 121w (positive electrode active material layer 123) is not present. It has become a part. Further, in the first main body outer winding portion 120g1, the positive electrode active material layer 123 or the positive electrode active material layer 123 and the negative electrode plate 131 do not exist, and a gap is generated accordingly. For this reason, even if the 1st winding adhesive tape member 171 mentioned later is affixed on this 1st main body outer winding part 120g1, a big pressure is applied to the 1st main body outer winding part 120g1 in the state of the lithium ion secondary battery 100. Does not hang (does not press hard).

  The second main body outer winding part 120g2 is divided into an 2-1 main body outer winding part 120g21 and a 2-2 main body outer winding part 120g22 in the axis AX direction. Among these, the 2-1 main body outer winding part 120g21 is adjacent to the axial other end side SB of the electrode main body part 120f, and the negative electrode other end side part 131wc of the negative electrode plate 131 and the inner negative electrode current collector part 131m1, This is a portion where the separator other end portion 141c of the separator 141 overlaps with each other. The 2-2 main body outer winding portion 120g22 is adjacent to the other axial end SB of the 2-1 main body outer winding portion 120g21, and the negative electrode current collector 131m of the negative electrode plate 131 has an external negative electrode. Only the current collector 131m2 is wound.

  As described above, the second main body outer winding portion 120g2 can cause a battery reaction because the negative electrode portion 131w (negative electrode other end portion 131wc) is present but the positive electrode portion 121w (positive electrode active material layer 123) is not present. There is no part. Further, in the second main body outer winding portion 120g2, the positive electrode plate 121 or the positive electrode plate 121 and the negative electrode active material layer 133 do not exist, and a gap is generated accordingly. For this reason, even if the 2nd winding adhesive tape member 173 mentioned later is stuck on this 2nd main body outer winding part 120g2, a big pressure is applied to the 2nd main body outer winding part 120g2 in the state of lithium ion secondary battery 100. Does not hang (does not press hard).

  Next, the separator outermost peripheral part (interposer outermost peripheral part) 141d of the separator 141 that constitutes the outermost peripheral part of the wound electrode body 120 will be described (see FIGS. 2 and 6). When the separator outermost peripheral portion 141d is viewed in the axis AX direction, the separator outermost peripheral portion 141d is separated from the separator outermost peripheral main body portion (interposer outermost peripheral main body portion) 141da located within the electrode main body portion 120f, and the main body outer winding portion. It is divided into separator outermost peripheral main body exterior (interposer outermost peripheral main body exterior) 141db and 141dc located in 120g1 and 120g2. Further, the separator outermost periphery main body exterior 141db and 141dc are a first separator outermost periphery main body exterior (outside of the first intermediate body outermost periphery main body) 141db located in the first main body outer winding part 120g1, and a second main body outer winding. It is divided into the second separator outermost peripheral main body outside (the second interposer outermost peripheral main body outer) located in the portion 120g2.

  On the other hand, when the separator outermost peripheral portion 141d is viewed in the circumferential direction, the separator outermost peripheral portion 141d includes a winding start portion 141dj located at the start of winding of the separator outermost peripheral portion 141d and a winding end end of the separator outermost peripheral portion 141d. And a winding end portion 141di along the edge 141dt. The winding start portion 141dj is adjacent to the winding end portion 141di with the winding end edge 141dt as a boundary.

  In the wound electrode body 120 according to the first embodiment, the winding process is performed in the outer winding parts 120g1 and 120g2 without the winding process in the electrode body 120f. Specifically, the wound electrode body 120 is affixed to the separator outermost peripheral part 140d, and a plurality of (two in the first embodiment) wound adhesive tape members that wind the wound electrode body 120 171 and 173 (see FIGS. 2 and 6). The winding adhesive tape members 171 and 173 are not attached to the separator outermost peripheral body part 141da of the separator outermost peripheral part 141d, but are attached to the separator outermost peripheral body exteriors 141db and 141dc to form wound electrodes. The body 120 is fastened.

  One first winding adhesive tape member 171 is attached to the outermost outer peripheral main body 141 db of the first separator to wind the wound electrode body 120. Specifically, the first winding adhesive tape member 171 is arranged such that its longitudinal direction is along the circumferential direction of the wound electrode body 120. And the first winding adhesive tape member 171 spans between the winding end edge 141di and the winding start part 141dj across the winding end edge 141dt in the first separator outermost peripheral main body exterior 141db, Affixed to these, the winding end portion 141di is fixed to the winding start portion 141dj.

  The other second winding adhesive tape member 173 is attached to the outermost outer periphery main body 141 dc of the second separator to wind the wound electrode body 120. Specifically, the second wound adhesive tape member 173 is disposed such that its longitudinal direction is along the circumferential direction of the wound electrode body 120. And, in the second separator outermost peripheral main body outer 141dc, the second winding fastening adhesive tape member 173 spans between the winding end edge 141di and the winding start portion 141dj across the winding end edge 141dt, Affixed to these, the winding end portion 141di is fixed to the winding start portion 141dj.

As described above, the lithium ion secondary battery 100 according to the first embodiment includes the winding end end portion of the separator outermost peripheral portion 141d in the main body outer wound portions 120g1 and 120g2 of the wound electrode body 120. The wound electrode body 120 is wound by a winding process of fixing 141di to the main body outer wound portions 120g1 and 120g2 itself.
The electrode main body portion 120f, which is a portion where the positive electrode active material layer 123, the separator 141, and the negative electrode active material layer 133 are disposed in close contact with each other in the thickness direction, is a portion that generates a battery reaction. On the other hand, the main body outer winding parts 120g1 and 120g2, which are parts other than the electrode main body part 120f, are parts that cannot cause a battery reaction as described above, and are parts that include a gap.

  Therefore, even if these body outer winding portions 120g1 and 120g2 are wound, the main body outer winding portions 120g1 and 120g2 have the winding adhesive tape members 171 and 173 used for the winding processing. It is difficult to produce a portion that is strongly pressed depending on the location. Moreover, these main body outer winding parts 120g1 and 120g2 do not have battery reaction itself. For this reason, battery reaction nonuniformity does not occur in these main body outer winding parts 120g1 and 120g2. Thus, in the lithium ion secondary battery 100, it is possible to prevent the battery reaction unevenness from occurring in the wound electrode body 120 due to the winding process while preventing the winding electrode body 120 from loosening. .

  Moreover, in this lithium ion secondary battery 100, since the winding process is not performed to the electrode main-body part 120f, it is prevented that the partial battery reaction nonuniformity accompanying the winding process generate | occur | produces in the electrode main-body part 120f. it can. Therefore, in the lithium ion secondary battery 100, it is possible to more reliably prevent unevenness of the battery reaction depending on the location in the wound electrode body 120 with the winding process while preventing the wound electrode body 120 from being loosened. Can be prevented.

Furthermore, in the first embodiment, the first main body outer winding portion 120g1 and the second main body outer winding portion 120g2 positioned at both ends of the electrode main body portion 120f in the axis AX direction are each subjected to the winding process. As a result, the wound electrode body 120 is wound around both ends in the axis AX direction with the electrode body portion 120f interposed therebetween, so that the wound electrode body 120 can be more reliably prevented from loosening.
Further, the winding process according to the first embodiment is performed by pasting the winding adhesive tape members 171 and 173 over the separator outermost peripheral part 141d with the winding end edge 141dt of the winding end edge 141di in between. Thus, the tape processing is to fix the winding end portion 141di. By such tape processing, loose winding of the wound electrode body 120 can be easily and reliably prevented.

Next, a method for manufacturing the lithium ion secondary battery 100 will be described.
First, the positive electrode plate 121 is manufactured. That is, a positive electrode current collector foil 122 made of a long aluminum foil is prepared. Then, a positive electrode active material paste containing a positive electrode active material, a conductive material and a binder is applied to one main surface of the positive electrode current collector foil 122 while forming a strip-like positive electrode current collector portion 121m extending in the longitudinal direction. Then, it is dried with hot air to form a strip-like positive electrode portion 121w. Similarly, the above-described positive electrode active material paste is applied to the main surface on the opposite side of the positive electrode current collector foil 122 while the strip-shaped positive electrode current collector portion 121m is formed, and dried with hot air, thereby forming the strip-shaped positive electrode portion 121w. Form. Then, in order to improve an electrode density, the positive electrode active material layer 123 is compressed with a pressure roll. Thus, the positive electrode plate 121 is formed (see FIG. 3).

  Separately, the negative electrode plate 131 is manufactured. That is, a negative electrode current collector foil 132 made of a long copper foil is prepared. Then, a negative electrode active material paste containing a negative electrode active material, a binder and a thickener is applied to one main surface of the negative electrode current collector foil 132 while forming a strip-shaped negative electrode current collector portion 131m extending in the longitudinal direction. And it is made to dry with hot air, and the strip | belt-shaped negative electrode part 131w is formed. Similarly, the negative electrode current collector foil 131 is applied to the main surface on the opposite side of the negative electrode current collector foil 132 while the negative electrode active material paste is applied and dried with hot air to form the belt-shaped negative electrode portion 131w. Form. Then, in order to improve an electrode density, the negative electrode active material layer 133 is compressed with a pressure roll. Thus, the negative electrode plate 131 is formed (see FIG. 4).

  Next, a long separator 141 is prepared, the positive electrode plate 121 and the negative electrode plate 131 are overlapped with each other via the separator 141 (see FIG. 6), and wound around the axis AX using a winding core. Thereafter, in the compression step, this is compressed into a flat shape (see FIG. 2). Further, after that, the wound electrode body 120 is fastened by sticking the wound adhesive tape members 171 and 173 to the wound electrode body 120.

  Next, a case lid member 113, three types of insulating members 155, 156, and 157 and three types of terminal fittings 151, 152, and 153 are prepared (see FIG. 7). 150 and the negative electrode terminal member 160 are fixed, the positive electrode terminal member 150 is connected to the positive electrode current collector 121m (external positive electrode current collector 121m2) of the wound electrode body 120, and the negative electrode terminal member 160 is The negative electrode current collector 131m (external negative electrode current collector 131m2) of the rotary electrode body 120 is connected.

  Next, the case main body member 111 is prepared, and the wound electrode body 120 is inserted into the case main body member 111. Thereafter, the battery case 110 is formed by welding the case lid member 113 and the case main body member 111 by laser welding. Next, an electrolytic solution is injected into the battery case 110 from the electrolytic solution inlet 113d, and the electrolytic solution inlet 113d is sealed. After that, high temperature aging and various inspections are performed. Thus, the lithium ion secondary battery 100 is completed.

(Example)
Subsequently, the result of the test conducted in order to verify the effect of this invention is demonstrated.
As an example of the present invention, the lithium ion secondary battery 100 of Embodiment 1 was prepared. Further, as a comparative example, the winding adhesive tape member is attached to the separator outermost peripheral body part 141da located in the electrode main body part 120f in the separator outermost peripheral part 141d (as described in the related art, the wound type) A lithium secondary battery was prepared in the same manner as in Embodiment 1 except that the electrode body 120 was affixed to the central portion of the electrode body 120 in the axis AX direction in a form along the axis AX direction.

  About each lithium ion secondary battery 100 grade | etc., Of these Examples and comparative examples, the charge / discharge cycle test was done and the change of battery capacity was investigated. That is, in a 0 ° C. environment, a charge / discharge cycle in which discharge for 10 seconds and charge for 10 seconds was performed at a constant current of 100 A was performed 1000 times, and the battery capacity before and after the test was examined. As a result, the capacity reduction rate of the lithium ion secondary battery of the comparative example was 10%, whereas the capacity reduction rate of the lithium ion secondary battery 100 of the example was greatly improved to 3%. For this reason, the adhesive tape member for winding is not attached to the outermost body part of the separator in the outermost part of the separator, but is attached and wound outside the outermost body of the separator, thereby suppressing a decrease in battery capacity. I understand that I can do it.

(Embodiment 2)
Next, a second embodiment will be described. In the lithium ion secondary battery (secondary battery) 200 according to the second embodiment, the wound electrode body 220 has a wound electrode body 220 (see FIG. 8) that is the wound type of the lithium ion secondary battery 100 according to the first embodiment. It is different from the form of the electrode body 120 (see FIG. 2). Other than that, the second embodiment is the same as the first embodiment, and the description of the same parts as the first embodiment is omitted or simplified.

  In the wound electrode body 220 of the second embodiment, as in the first embodiment, a long positive electrode plate 121 and a long negative electrode plate 131 are overlapped with each other via a long separator 141. It is wound around the axis AX and compressed into a flat shape (see FIG. 8). Therefore, similarly to the first embodiment, the wound electrode body 220 includes a first main body portion 220f, a first main body outer winding portion 220g11, and a first main body outer winding portion 220g12. It has a main body outer winding part 220g1, and a second main body outer winding part 220g2 including a 2-1 main body outer winding part 220g21 and a 2-2 main body outer winding part 220g22.

  However, in the second embodiment, the winding adhesive tape members 271 and 273 for winding the wound electrode body 220 are different from the winding adhesive tape members 171 and 173 of the first embodiment. That is, the winding adhesive tape members 171 and 173 of the first embodiment are attached only to a part of the wound electrode body 120 in the circumferential direction, whereas the winding adhesive tape members of the second embodiment. 271 and 273 are attached over the entire circumference of the wound electrode body 220.

Specifically, one first winding adhesive tape member 271 is stuck over the entire circumference of the first separator outermost peripheral main body 141db while being spanned between the winding end portion 141di and the winding start portion 141dj. ing. Thus, the winding end portion 141di is fixed to the winding start portion 141dj.
In addition, the other second winding fastening adhesive tape member 273 is stuck over the entire circumference of the second separator outermost periphery main body 141dc while being spanned between the winding end portion 141di and the winding start portion 141dj. Thus, the winding end portion 141di is fixed to the winding start portion 141dj.

Even in such a wound electrode body 220, the winding end portion 141 di of the separator outermost peripheral portion 141 d is connected to the outer winding portion of the main body in the outer winding portions 220 g 1 and 220 g 2 of the wound electrode body 220. The wound electrode body 220 is wound by a winding process of fixing to 220g1 and 220g2 itself. Therefore, even in the lithium ion secondary battery 200, battery reaction unevenness occurs depending on the location in the wound electrode body 220 with the winding process (tape process) while preventing the wound electrode body 220 from loosening. Can be prevented.
In particular, in the second embodiment, since the winding adhesive tape members 271 and 273 are pasted over the entire circumference of the wound electrode body 220, loose winding of the wound electrode body 220 can be more reliably prevented. In addition, the same parts as those of the first embodiment have the same effects as those of the first embodiment.

(Embodiment 3)
Next, a third embodiment will be described. A vehicle 700 according to the third embodiment includes a plurality of lithium ion secondary batteries 100 according to the first embodiment, and is driven by using an engine 740, a front motor 720, and a rear motor 730 in combination as shown in FIG. It is a hybrid car. Specifically, the vehicle 700 includes a vehicle body 790, an engine 740, a front motor 720, a rear motor 730, a cable 750, and an inverter 760 attached thereto. Further, the vehicle 700 includes an assembled battery 710 having a plurality of lithium ion secondary batteries 100, 100,... Inside thereof, and the electric energy stored in the assembled battery 710 is transmitted to the front motor 720 and the rear motor 730. It is used for driving.

  As described above, in the lithium ion secondary battery 100, the winding electrode body 120 is prevented from being loosened, and the battery reaction unevenness occurs depending on the location in the wound electrode body 120 due to the winding process. Since it can prevent, the performance, durability, etc. of the vehicle 700 carrying this can be made high. In place of the lithium ion secondary battery 100 of the first embodiment, the lithium ion secondary battery 200 of the second embodiment may be mounted.

(Embodiment 4)
Next, a fourth embodiment will be described. As shown in FIG. 10, the hammer drill 800 according to the fifth embodiment is a battery using device on which a battery pack 810 including the lithium ion secondary battery 100 according to the first embodiment is mounted. Specifically, in this hammer drill 800, a battery pack 810 is accommodated in a bottom portion 821 of a main body 820, and this battery pack 810 is used as an energy source for driving the drill.

  As described above, in the lithium ion secondary battery 100, the winding electrode body 120 is prevented from being loosened, and the battery reaction unevenness occurs depending on the location in the wound electrode body 120 due to the winding process. Since this can be prevented, the performance and durability of the hammer drill 800 equipped with this can be increased. In place of the lithium ion secondary battery 100 of the first embodiment, the lithium ion secondary battery 200 of the second embodiment may be mounted.

In the above, the present invention has been described with reference to the embodiments. However, the present invention is not limited to the above-described first to fourth embodiments, and it is needless to say that the present invention can be appropriately modified and applied without departing from the gist thereof. Yes.
For example, in Embodiments 1 to 4 described above, a so-called prismatic battery in which the wound electrode bodies 120 and 220 are compressed into a flat shape is illustrated, but a so-called columnar type (cylindrical) in which the wound electrode body is a columnar shape. The present invention can also be applied to a battery.

  In the first to fourth embodiments, the case where the intervening body between the positive electrode plate 121 and the negative electrode plate 131 is the separator 141 is exemplified. However, the interposing body may be a solid electrolyte layer made of a solid electrolyte body. it can. In this case, the solid electrolyte layer is formed on one main surface of the positive electrode plate 121 (on the positive electrode active material layer 123) and also on one main surface of the negative electrode plate 131 (on the negative electrode active material layer 133). Form. Then, the positive electrode plate and the negative electrode plate with the solid electrolyte layer may be wound on top of each other to form a wound electrode body.

  In Embodiments 1 to 4, the winding-type electrode bodies 120 and 220 are wound using the winding adhesive tape members 171, 173, 271, 273, and the winding end portion 141di of the separator outermost peripheral portion 141d. Although the tape process which fixes to the main body outer winding part 120g1 and 120g2 was illustrated, it is not restricted to this. The winding process may be an adhesive process for fixing the winding end part 141di of the separator outermost peripheral part 141d to the main body outer wound part 120g1, 120g2, for example, using an adhesive. In this case, an adhesive is applied to the back surface (radially inner side surface) of the winding end end portion 141di of the separator outermost peripheral portion 141d in the main body outer winding portion 120g1 and 120g2, and the winding end end portion 141di is attached to the outer winding end portion 141di. The parts 120g1 and 120g2 themselves may be bonded and fixed.

  Further, in the first to fourth embodiments, as the wound electrode bodies 120 and 220, the electrode main body portions 120f and 220f are provided in the central portion in the axis AX direction, and both end sides thereof are respectively disposed on the first main body outer wound portions 120g1 and 120g1, respectively. Although what was set as 120g2 and the 2nd main body outer winding part 220g1,220g2 was illustrated, it is not restricted to this. For example, the electrode main body portions 120f and 220f can be divided into two electrode main body portions at the center in the axis AX direction, and a third main body outer winding portion can be provided between these electrode main body portions. In this case, the winding process can also be performed on the third main body outer winding part in the center or only on the third main body outer winding part.

100,200 Lithium ion secondary battery (secondary battery)
120, 220 Winding-type electrode bodies 120f, 220f Electrode body portions 120g1, 220g1 First body outer winding portion 120g2, 220g2 Second body outer winding portion 121 Positive electrode plate 121w Positive electrode portion 121m Positive electrode current collector 123 Positive electrode active material layer 131 Negative electrode plate 131w Negative electrode part 131m Negative electrode current collector part 133 Negative electrode active material layer 141 Separator (inclusion body)
141d Separator outermost part (interposer outermost part)
141da Separator outermost body part (interposer outermost body part)
141db 1st separator outermost peripheral main body outside (1st inclusion outermost peripheral main body outside)
141 dc Second separator outermost peripheral main body outside (second inclusion outermost peripheral main body outer)
141dt Winding end edge 141di Winding end portion 141dj Winding start portion 171, 271 First winding adhesive tape member 173, 273 Second winding adhesive tape member 700 Vehicle 800 Hammer drill AX Axis SA One axial direction SB Axis other ~ side

Claims (6)

A positive electrode plate including a positive electrode active material layer and a negative electrode plate including a negative electrode active material layer are overlapped with each other via an inclusion and wound around an axis, and the outermost circumference of the inclusion is an inclusion of the inclusion It is a secondary battery comprising a wound electrode body composed of the outermost peripheral part,
Of the wound electrode body,
A portion where the positive electrode active material layer, the inclusions, and the negative electrode active material layer are disposed in close contact with each other in the thickness direction is an electrode main body portion,
When a portion other than the electrode main body portion is a main body outer winding portion,
The wound electrode body is:
A secondary battery obtained by applying a winding process for fixing the winding end portion of the outermost periphery of the interposition body to the main body outer winding portion itself in the main body outer winding portion. The secondary battery according to claim 1,
The wound electrode body is:
A secondary battery in which the winding process is performed on the outer winding part of the main body without performing the winding process on the electrode body part. The secondary battery according to claim 1 or 2, wherein
The outer winding part of the main body is
A first body outer winding part adjacent to one end side in the axial direction of the electrode body part;
A second main body winding portion adjacent to the other end side of the electrode body in the axial direction,
The first main body outer winding part and the second main body outer winding part are:
Rechargeable batteries that are each subjected to the winding process. The secondary battery according to any one of claims 1 to 3,
The winding process is
It is a tape process in which the winding end edge is fixed to the intermediate body outermost peripheral portion of the intermediate body, with the winding end edge of the winding end in between, with an adhesive tape member being stretched over. Secondary battery. A vehicle equipped with the secondary battery according to any one of claims 1 to 4 and using the electric energy stored in the secondary battery as all or part of the driving energy of the driving source. The battery use apparatus which mounts the secondary battery as described in any one of Claims 1-4, and uses this secondary battery as at least 1 of an energy source.

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