JP4931409B2 - Battery pack - Google Patents

Description

  The present invention relates to a chargeable / dischargeable nonaqueous electrolyte secondary battery mainly used as a power source of a portable electronic device such as a video camera, a mobile computer, a cellular phone, and the like, specifically a lithium ion secondary battery, etc. The present invention relates to a battery pack surrounded by a frame.

  In recent years, as power sources for portable electronic devices such as video cameras, mobile computers, and mobile phones, which are rapidly spreading, chargeable / dischargeable rectangular parallelepiped nonaqueous electrolyte secondary batteries such as lithium ion secondary batteries are mainly used. It has been.

  In a lithium ion secondary battery, a protective circuit board for controlling the battery voltage is provided on one side surface to prevent overcharge and overdischarge, and these are provided in an insulating outer case made of synthetic resin, for example. The battery pack is installed in an electronic device. The protective circuit board and the battery are electrically connected by a connecting lead plate.

Figure 8 is an exploded perspective view showing a conventional battery pack, FIG. 9 is a longitudinal sectional view of the long-side direction of the battery pack of FIG. 8, in the figure, 31 is a battery pack.
The unit cell 32 of the battery pack 31 is a non-aqueous electrolyte secondary battery comprising a power generation element in which a positive electrode and a negative electrode are wound through a separator, specifically a secondary battery such as a lithium ion secondary battery. The power generation element is housed in a case made of aluminum or aluminum alloy. A negative electrode terminal 32a is provided on one end face of the unit cell 32 via an insulating plate, and the entire unit cell 32 other than the portion where the negative electrode terminal 32a is provided is a positive electrode (terminal).

A protection circuit unit 35 is attached to one side surface adjacent to one end surface of the unit cell 32 where the negative electrode terminal 32 a is provided via an insulating plate 33 and a spacer 34. The protection circuit board 35 a of the protection circuit unit 35 includes a protection circuit for preventing overcharge or overdischarge of the unit cell 32. A circuit element (not shown) is mounted on the surface of the protection circuit board 35a facing the unit cell 32. Electric power is taken out to the opposite side, that is, one end side of the outer surface, and charged reversely. Therefore, positive and negative electrode terminals 35b for taking in electric power from the outside are provided by gold plating. A PTC (Positive Temperature Coefficient) element 35c is provided on the other end side. The PTC element 35c is a protective element that cuts off the circuit by becoming high resistance in response to the temperature when the temperature of the unit cell 32 is abnormally increased. Lead plate portions 35d and 35d are provided at both end portions of the protection circuit board 35a so as to extend along both end surfaces of the unit cell 32.
The spacer 34 has a shape that matches the protection circuit board 35a. The insulating plate 33 includes a base portion 33a having a shape coinciding with the spacer 34, and an end surface portion 33b extending along the end surface on the side where the negative electrode terminal 32a is provided, and a double-sided adhesive tape is provided on the back surface.

  The first exterior case 36 made of synthetic resin includes a substrate covering portion 36a that covers the protection circuit substrate 35a, an end surface covering portion 36b that covers the one end surface side, and an other end surface covering portion 36c that covers the other end surface side. A window portion 36d for exposing the electrode terminal 35b of the protection circuit substrate 35a is formed in the substrate covering portion 36a. The one end surface covering portion 36b is provided with a locking concave portion 36e, and the other end surface covering portion 36c is provided with a locking convex portion 36f.

  The second exterior case 37 includes an other side surface covering portion 37 a that covers the other side surface of the unit cell 32, one end surface covering portion 37 b that covers the one end surface side, and another end surface covering portion 37 c that covers the other end surface side. The one end surface covering portion 37b is provided with a locking convex portion 37d, and the other end surface covering portion 37c is provided with a locking concave portion 37e.

Upon assembly of the battery pack 31 along the other side surface and both end faces of the unit cell 32, after sticking a double-sided adhesive tape 38, on one side, sequentially, an insulating plate 33, the spacer 34 and the protective circuit unit 35 heavy sleeping . Further, one side surface is covered with the first outer case 36, the other side surface is covered with the second outer case 37, the locking recess 36e and the locking projection 37d are locked, and the locking projection 36f and the locking recess 37e. The first outer case 36 and the second outer case 37 are integrated. Finally the label 40 affixed and positioning the flat portion of the cell 32, the battery pack 31 is obtained by sticking involving a first external case 36 and the second external case 37.

In Patent Document 1, an outer case is formed into a rectangular frame shape that covers both side surfaces and both end surfaces of a unit cell, and both flat surfaces of the unit cell and upper and lower end surfaces and one side surface of the outer case are covered with an insulating sheet. An invention of a battery pack is disclosed. In this battery pack, the thickness of the battery pack is reduced.
Patent Document 2 discloses an invention of a battery pack in which a label has a notch and includes a base material layer attached to the surface of a unit cell and a surface layer laminated on the surface of the base material layer. . This battery pack is prevented from being broken when a label is attached to the unit cell.
JP 2004-327176 A JP 2005-135770 A

In the above-described conventional battery pack, when the label is attached to the unit cell, a rotational force is applied to the frame-shaped outer case, and the outer case is displaced in the vicinity of the separated portion, or there is a step due to the displacement in the portion. It was easy to occur and this had to be prevented.
In the case of the battery pack of Patent Document 2, since the peripheral edge portion of the outer case protrudes up and down to the flat surface of the unit cell, displacement of the outer case is suppressed, but the outer case protrudes above and below the battery pack. Accordingly, there is a problem that the thickness of the battery pack is increased and the thickness cannot be reduced.

In the case of the battery pack having the configuration of Patent Document 1, when the radius of curvature of the curved portion provided at the peripheral edge of the unit cell is large, a sufficient allowance for the unit cell plane at the peripheral edge of the outer case is provided. However, as shown in Fig. 9, when the radius of curvature is small, the engagement margin of the outer peripheral edge of the outer case to the unit cell plane is small or cannot be removed at all, so use an adhesive or adhesive. As a result, there is a problem that the outer case must be fixed to the unit cell.
At this time, if it is fixed using an adhesive, there is a possibility that problems in appearance may occur due to protrusion of the adhesive and whitening due to an additive (drying agent). In addition, there is a possibility that a gap and a gap are generated between the outer case and the unit cell until the adhesive is cured. Usually, an adhesive is often used to avoid problems caused by this adhesive, but it is difficult to ensure a sufficient adhesion area between the outer case and the unit cell from the structural point of the battery pack. In some cases, the strength could not be sufficiently secured, and the outer case was dragged by the tension applied to the label when the label was wound, resulting in deviation from the proper position.

  The present invention has been made in view of such circumstances, and by locking the exterior frame to the spacer, the exterior frame is not dragged when the label is wound, and the exterior frame is not displaced from an appropriate position. An object is to provide a battery pack.

The battery pack of the first invention, a flat plate shape having two planes and four side surfaces, a unit cell in which the electrode terminals on one side is projected, is arranged on the outside of either side of the unit cell, the external output a protection circuit board having a terminal, and a lead plate connecting the electrode terminal and the protective circuit board, and the electrode terminal of opposite polarity terminal and the is a side surface other than the one side surface of the unit cell, respectively, wherein An exterior frame that covers the four side surfaces of the unit cell, the protection circuit board, and the lead plate, and the exterior frame has at least one divided portion that is formed in a portion different from the portion that covers the protection circuit board. and, in the battery pack that fits the ends of opposing該分cross section, and the segmented portion, between the side surface of the unit cell facing converting said cross section, extends along the side surface, engaging comprising a spacer having a stop portion, to the outer frame, the engagement Wherein the parts are engaged to.

In the present invention, a spacer is arranged on the side surface of the unit cell corresponding to the position where the opposite ends of the exterior frame are fitted to each other, and the latching portion of the spacer is engaged with the exterior frame and then opposed. since fitting the end, even under tension to the label when winding the unit cells and the outer frame in a label not dragged is exterior frame, without the exterior frame is deviated from the proper position, it is possible to assemble the battery pack.

In the battery pack according to a second aspect of the present invention, the locking portion includes a rib that extends in the extending direction of the spacer, and includes a concave groove that fits in the rib in the vicinity of the end portion in the short direction of the exterior frame. It is characterized by that.

  In the present invention, after the ribs of the spacer are fitted in the concave grooves of the exterior frame, the opposing ends of the exterior frame are fitted, so that the exterior frame is securely locked to the locking portion, The deviation is further reliably suppressed.

In the battery pack according to a third aspect of the present invention, the locking portion is formed of a concave groove extending in the extending direction of the spacer, and a rib that fits into the concave groove is provided in the vicinity of the end portion in the short direction of the exterior frame. It is characterized by providing.

  In the present invention, the recesses of the spacer are fitted to the ribs of the exterior frame, and the opposite ends of the exterior frame are fitted, so that the exterior frame is securely locked to the locking portion, The deviation is further reliably suppressed.

The battery pack of the fourth invention is characterized in that the spacer insulates between the lead plate and a side surface of the unit cell on which the spacer is disposed .

  In the present invention, since the spacer also serves as the insulating plate, the number of parts can be reduced, and the battery pack becomes compact.

The battery pack of the fifth invention, prior Symbol spacer is characterized in that are arranged in at least the one side surface of the unit cell.

  The side surface on which the electrode terminals are provided cannot sufficiently secure the adhesive area of the double-sided pressure-sensitive adhesive tape, protrudes outward from the other side surface, and the exterior frame is liable to shift when a label is applied. In the present invention, the side surface on which the electrode terminal is provided locks the outer frame to the spacer to suppress the displacement of the outer frame, and the other side surface is controlled by the adhesive force of the double-sided adhesive tape. The cost of the mold for manufacturing the spacer and the unit price of the spacer itself can be further reduced.

  A battery pack according to a sixth aspect of the invention is characterized in that a longitudinal end portion of a side surface of a unit cell on which the spacer is disposed has a curved surface, and a curvature radius of the curved surface is 1.0 or less.

  In the present invention, even when the radius of curvature of the longitudinal end portion of the side surface of the unit cell is small and the allowance of the longitudinal end portion of the exterior frame to the plane of the unit cell is small or cannot be taken at all, By locking the locking portion to the exterior frame, it is possible to suppress the displacement of the exterior frame without fixing the exterior frame using an adhesive and an adhesive.

The battery pack of the seventh invention, the spacer is characterized by having a substrate contact portion interposed between the side surface and the protective circuit board to dispose the protection circuit board of the unit cell.

In the present invention, it has a substrate contact portion, on which the spacers were opposed to two or more sides of the unit cell, since placing a protection circuit board by contacting a protective circuit board to the substrate contact portion The positioning of the protection circuit board to the unit cell is ensured.

  According to the present invention, since the exterior frame is locked to the spacer, the exterior frame is not dragged even if the label is tensioned when the label is wound, and the battery pack is assembled without the exterior frame being displaced from the proper position. I can do it. And since an exterior frame can be fixed to a unit cell, without an exterior frame projecting in the thickness direction of a unit cell, the thickness of a battery pack can be made thin. Further, since the spacer is housed inside the exterior frame, the outer dimensions of the battery pack do not increase.

Hereinafter, the present invention will be specifically described with reference to the drawings showing embodiments thereof.
Embodiment 1 FIG.
FIG. 1 is a perspective view showing a battery pack 1 according to Embodiment 1 of the present invention, and FIG. 2 is an exploded perspective view of the battery pack 1.
The unit cell 2 of the battery pack 1 includes a non-aqueous electrolyte secondary battery comprising a power generation element in which a positive electrode and a negative electrode are wound through a separator, for example, a secondary battery such as a lithium ion secondary battery. The element is made of aluminum or an aluminum alloy, and is housed in a rectangular parallelepiped case. A negative electrode terminal 2a is provided on one end surface of the unit cell 2 via an insulating plate, and the entire unit cell 2 other than the portion where the negative electrode terminal 2a is provided is a positive electrode (terminal).

  A double-sided adhesive tape 3 is attached in a U-shape to one end surface of the unit cell 2 where the negative electrode terminal 2a is provided, one side surface adjacent thereto and the other end surface facing the one end surface. The double-sided pressure-sensitive adhesive tape 3 is affixed with a spacer 4 whose shape matches that of the double-sided pressure-sensitive adhesive tape 3. The spacer 4 includes end surface contact portions 4a and 4b disposed on both end surface sides, and a substrate contact portion 4c disposed on the side surface side.

  A protective circuit portion 5 is attached to the spacer 4. The protection circuit board 5 a of the protection circuit unit 5 includes a protection circuit for preventing overcharge or overdischarge of the unit cell 2. A circuit element (not shown) is mounted on the surface of the protection circuit board 5a facing the unit cell 2, and power is taken out to the opposite side, that is, one end side of the outer surface, and charged in reverse. Therefore, positive and negative electrode terminals 5b for taking in electric power from the outside are provided by gold plating. A PTC element 5c is provided on the other end side. Lead plate portions 5d and 5e are provided at both end portions of the protection circuit board 5a.

  The first exterior case 6 made of synthetic resin includes a substrate covering portion 6a that covers the protective circuit board 5a, an end surface covering portion 6b that covers approximately half of the one end surface, and an other end surface covering portion 6c that covers approximately half of the other end surface. With. A window portion 6d for exposing the electrode terminal 5b of the protection circuit substrate 5a is formed in the substrate covering portion 6a. The one end face covering portion 6b is provided with a locking concave portion 6e, and the other end face covering portion 6c is provided with a locking convex portion 6f.

  The second exterior case 7 includes an other side surface covering portion 7a covering the other side surface of the unit cell 2, one end surface covering portion 7b covering substantially half of the one end surface, and another end surface covering portion 7c covering substantially half of the other end surface. Is provided. The one end surface covering portion 7b is provided with a locking convex portion 7d, and the other end surface covering portion 7c is provided with a locking concave portion 7e.

FIG. 3 is an enlarged perspective view showing the spacer 4, the first outer case 6, and the second outer case 7.
Ribs 4e and 4f extending in the longitudinal direction are provided at the upper and lower ends of the end surface contact portion 4a of the spacer 4, and similarly, the upper and lower ends of the end surface contact portion 4b are provided in the longitudinal direction. Ribs 4g and 4h are provided. A through hole 4d is provided in the central portion of the end surface abutting portion 4a to allow the negative electrode terminal 2a of the unit cell 2 to pass through. The central portion of the end surface abutting portion 4b is provided in the unit cell 2. A through hole 4i is provided for allowing a lead mounting plate (not shown) to pass therethrough.

The first exterior case 6 is provided with projections 6g and 6i extending in the longitudinal direction of the other end surface covering portion 6c at a position spaced from the upper and lower ends of the other end surface covering portion 6c by a predetermined distance. Groove portions 6h and 6j are formed between the portions 6g and 6i and both ends so that the ribs 4g and 4h can be smoothly fitted without play. The one end surface covering portion 6b is also provided with a protrusion, and a groove is formed between both ends and the protrusion (not shown).
The second exterior case 7 is provided with projections 7f and 7h extending in the longitudinal direction of the one end surface covering portion 7b at a position spaced from the upper and lower ends of the one end surface covering portion 7b by a predetermined distance. Grooves 7g and 7i are formed between the portions 7f and 7h and both ends so that the ribs 4e and 4f can be smoothly fitted without play. Similarly, the projections 7j and 7m are also provided on the other end surface covering portion 7c, and the grooves 7k are fitted so that the ribs 4g and 4h are fitted between the projections 7j and 7m and both ends. , 7n are formed.

When assembling the battery pack 1, a double-sided adhesive tape 3 is applied along the other side surface and both end surfaces of the unit cell 2, and the negative electrode terminal 2a is passed through the through-hole 4d in the double-sided adhesive tape 3. The spacer 4 is stuck. Furthermore, arranged protection circuit 5 to the outside of the spacer 4, spot welding the lead plate portion 5d and 5e to the negative terminal 2a and the lead mounting plate, respectively.

And the board | substrate coating | coated part 6a of the 1st exterior case 6 is distribute | arranged to the outer side of the protection circuit board 5a, the one end surface coating | coated part 6b is attached so that the ribs 4e and 4f of the spacer 4 may fit in the groove part, and the other end surface The covering portion 6c is attached so that the ribs 4g and 4h of the spacer 4 are fitted in the groove portions 6h and 6j.
The other side surface covering portion 7a of the second exterior case 7 is arranged on the other side surface, and the one end surface covering portion 7b is attached so that the ribs 4e and 4f of the spacer 4 are fitted in the groove portions 7g and 7i, and the fitting convex portion 7 d is fitted into the fitting recess 6 e of the first outer case 6. Then, the other end surface covering portion 7c is attached so that the ribs 4g and 4h of the spacer 4 are fitted in the groove portions 7k and 7n, and the fitting concave portion 7e is fitted to the fitting convex portion 6f of the first outer case 6. . Thereby, the 1st exterior case 6 and the 2nd exterior case 7 are integrated, and it becomes frame shape (exterior frame).

Figure 4 shows a state of attaching the second outer casing 7 in the unit cell 2 is a longitudinal sectional view in the longitudinal direction of the cell 2. When the size of the unit cell 2 is approximately 25 mm long × 36 mm wide × 6 mm thick, it is preferable that the rib 4e and the like have both a cross-sectional width dimension and a height dimension of 0.2 mm or more. Is 0.25 mm, and the cross-sectional height dimension is 0.25 mm. The groove portion 7g and the like need only have dimensions that allow the ribs 4e and the like to be smoothly fitted without looseness. For example, the cross-sectional width dimension is 0.3 mm and the cross-sectional height (depth) dimension is 0.3 mm. Is mentioned.
Both end portions in the thickness direction of the side surface on which the spacer 4 of the unit cell 2 is disposed form curved surfaces 2b and 2b, and the curvature radii of the curved surfaces 2b and 2b are 0.75. Thus, even if the radius of curvature is 1.0 or less and the engagement between the both ends of the second exterior case 7 and the flat surface of the unit cell 2 is small or cannot be taken at all, the spacer 4 by engaging the ribs 4e like the groove 7g like of the second exterior case 7, without using an adhesive or a pressure-sensitive adhesive, the second outer casing 7 is fixed to the unit cell 2.

Finally the label 10 affixed and positioning the flat surface portion of the unit cell 2, the battery pack 1 can be obtained by sticking involving a first external case 6 and the second outer casing 7.

In this embodiment, the spacer 4 is arranged on the side surface of the unit cell 2 corresponding to the position where the first outer case 6 and the second outer case 7 are fitted, and the first outer case 6 and the second outer case 7 are arranged. when fitted, the locking the rib 4e like spacer 4 in the groove 7g and the like of the first outer case 6 and the second outer casing 7, the unit cell 2, a first outer case 6 and the second outer casing 7 Even if tension is applied to the label 10 when the label 10 is wound, the first outer case 6 and the second outer case 7 are not dragged, and the first outer case 6 and the second outer case 7 are not displaced from their proper positions. 1 can be assembled.
The spacer 4 also serves as an insulating plate, between the outer shell (positive electrode) of the unit cell 2 and the lead plate portion 5d, between the outer shell of the unit cell 2 and the PTC element 5c, and the outer shell of the unit cell 2 and the protection circuit board 5a. And the vicinity of the periphery of the negative electrode terminal 2a of the unit cell 2 and the like. Thereby, the number of parts can be reduced and the battery pack 1 becomes compact. Further, after the end surface contact portions 4a and 4b are brought into contact with both end surfaces of the unit cell 2 and the substrate contact portion 4c is brought into contact with the side surface of the unit cell 2, the protective circuit board 5a is attached to the substrate contact portion 4c. Since the protection circuit unit 5 is arranged in a contact state, the positioning of the protection circuit unit 5 to the unit cell 2 is ensured.

Embodiment 2. FIG.
FIG. 5 is an exploded perspective view showing the battery pack 11 according to Embodiment 2 of the present invention, and FIG. 6 is an enlarged perspective view showing the spacer 15, the first exterior case 17, and the second exterior case 18.
A negative electrode terminal 12a is provided on one end surface of the unit cell 12 of the battery pack 11 via an insulating plate, and the entire unit cell 12 other than the portion where the negative electrode terminal 12a is provided serves as a positive electrode (terminal). The

  A double-sided pressure-sensitive adhesive tape 13 is affixed to a substantially half of one end surface of the unit cell 12 where the negative electrode terminal 12a is provided, one side surface adjacent thereto and the other end surface facing the one end surface. . Similarly, a double-sided adhesive tape 14 is also affixed to the other side of the unit cell 12. Spacers 15 are affixed to the double-sided adhesive tape 13. The spacer 15 includes an end surface contact portion 15a and a substrate contact portion 15b arranged on one end surface side, and a through hole 15c through which the negative electrode terminal 12a passes is provided at the center of the end surface contact portion 15a.

A protective circuit portion 16 is attached to the spacer 15. On the protection circuit board 16a of the protection circuit unit 16, positive and negative electrode terminals 16b are provided by gold plating, and a PTC element 16c is provided. In addition, lead plate portions 16d and 16e disposed on both end surface sides of the unit cell 12 are provided at both end portions of the protection circuit board 16a.
Ribs 15 d and 15 e extending in the longitudinal direction are provided at the upper and lower ends of the end surface contact portion 15 a of the spacer 15.

The first exterior case 17 includes a substrate covering portion 17a that covers the protection circuit substrate 16a, an end surface covering portion 17b that covers approximately half of the one end surface, and an other end surface covering portion 17c that covers approximately half of the other end surface. The substrate covering portion 17a is formed with a window portion 17d for exposing the electrode terminal 16b of the protection circuit substrate 16a. The one end surface covering portion 17b is provided with a locking concave portion 17e, and the other end surface covering portion 17c is provided with a locking convex portion 17f.
Protrusions extending in the longitudinal direction of the end surface covering portion 17b are provided at positions spaced from the upper and lower ends of the one end surface covering portion 17b of the first exterior case 17 by a predetermined distance. A groove portion (not shown) is formed between the ribs 15d and 15e so that the ribs 15d and 15e are smoothly fitted with no play.

The second outer case 18 includes an other side surface covering portion 18 a that covers the other side surface of the unit cell 12, one end surface covering portion 18 b that covers the one end surface, and another end surface covering portion 18 c that covers the other end surface. The one end surface covering portion 18b is provided with a locking convex portion 18d, and the other end surface covering portion 18c is provided with a locking concave portion 18e.
The second exterior case 18 is provided with protrusions 18f and 18h extending in the longitudinal direction of the one end face covering portion 18b at a position spaced from the upper and lower ends of the one end face covering portion 18b by a predetermined distance. Groove portions 18g and 18i are formed between the portions 18f and 18h and both ends so that the ribs 15d and 15e are fitted.

When the battery pack 11 is assembled, the double-sided adhesive tapes 13 and 14 are affixed along the side surfaces of the unit cell 12, and the spacer 15 is affixed with the negative electrode terminal 12a penetrating the through hole 15c. Further, it disposed a protection circuit portion 16 on the outside of the spacer 15, you spot welding the lead plate portion 16d and 16e to the negative electrode terminal 12a and the lead mounting plate, respectively.

And the board | substrate coating | coated part 17a of the 1st exterior case 17 is distribute | arranged to the outer side of the protection circuit board 16a, and the one end surface coating | coated part 17b is attached so that the ribs 15d and 15e of the spacer 15 may fit in the groove part.
The other side surface covering portion 18a of the second exterior case 18 is disposed on the other side surface of the unit cell 12, and the one end surface covering portion 18b is attached and fitted to the groove portions 18g and 18i so that the ribs 15d and 15e of the spacer 15 are fitted. The mating convex portion 18 d is fitted into the fitting concave portion 17 e of the first outer case 17. Then, the fitting concave portion 18 e of the other end surface covering portion 18 c is fitted into the fitting convex portion 17 f of the first outer case 17.

In the present embodiment, it is difficult to secure the adhesive area of the double-sided adhesive tapes 13, 14, and the spacer 15 is arranged on the end surface side of the side where the negative electrode terminal 12 a is provided, which protrudes outward. and a second outer case 18 a spacer 15 ribs 15d, so engaged to 15e, the unit cell 12, even under tension to the label 20 when the first case 17 and second case member 18 wrapped with a label 20 The battery pack 11 can be assembled without the first exterior case 17 and the second exterior case 18 being dragged and without the first exterior case 17 and the second exterior case 18 being displaced from the proper positions.
On the other end surface side, since the deviation is suppressed by the adhesive force of the double-sided adhesive tapes 13 and 14, the spacer 15 can be made substantially L-shaped, the cost of the mold for manufacturing the spacer 15, and the spacer 15 itself. The unit price of can be lowered.

Embodiment 3 FIG.
Figure 7 shows a state of attaching the second outer case 27 in the unit cell 22 of the battery pack according to a third embodiment of the present invention, it is a longitudinal sectional view of the longitudinal of the unit cell 22.
A negative electrode terminal 22 a is provided on one end surface of the unit cell 22. A double-sided adhesive tape 23, a spacer 24, and a second outer case 27 are provided on the end face with the negative electrode terminal 22 a penetrating therethrough. A lead plate portion 25 is spot-welded to the negative electrode terminal 22a.

Above and below the spacer 24, groove portions 24a and 24b extending in the direction in which the spacer 24 extends are provided, and the second exterior case 27 is provided with ribs 27a and 27b fitted into the groove portions 24a and 24b. ing. Similarly, the first outer case is provided with a pair of ribs (not shown) that are fitted into the grooves 24a and 24b.
In the present embodiment, the unit cell 22, a label without dragged first external case and the second case member 27 even if a tension when winding the label the first external case and the second case member 27, the second covering The battery pack can be assembled without the case 27 being displaced from the proper position.

In the first to third embodiments, ribs or grooves are provided on the upper and lower ends of the spacer, and grooves or ribs are provided on the upper and lower ends of the first outer case and the second outer case. Although described, the present invention is not limited to this, and may be provided on at least one end side. Further, the first exterior case and the second exterior case are not limited to the case where the protrusion is provided and the groove is formed between the protrusion and the end.
And the exterior case is not limited to what is divided into two (the exterior case has two divided parts), but one part of the exterior case is divided, and the opposite ends of the divided parts are fitted together. It may be configured to match.
Further, the unit cell is not limited to a case where a negative electrode terminal is provided on one end surface, and a portion other than the portion where the negative electrode terminal is provided is a positive electrode terminal.

It is a perspective view which shows the battery pack which concerns on Embodiment 1 of this invention. It is a disassembled perspective view of a battery pack. It is an expansion perspective view which shows a spacer, a 1st exterior case, and a 2nd exterior case. It shows a state of attaching the second outer case to Motoden pond is a longitudinal sectional view of the longitudinal of the unit cell. It is a disassembled perspective view which shows the battery pack which concerns on Embodiment 2 of this invention. It is an expansion perspective view which shows a spacer, a 1st exterior case, and a 2nd exterior case. Shows a state of attaching the second outer case to the unit cell of a battery pack according to the third embodiment of the present invention, it is a longitudinal sectional view of the longitudinal of the unit cell. It is a disassembled perspective view which shows the conventional battery pack. It is a longitudinal sectional view of the longitudinal of the unit cell of the battery pack of FIG.

Explanation of symbols

1, 11, Battery pack 2, 12, 22 Unit cell 3, 13, 14, 23 Double-sided adhesive tape 4, 15, 24 Spacer 4e, 4f, 4g, 4h, 15d, 15e Rib 5, 16 Protection circuit part 6, 17 1st exterior case 7, 18, 27 2nd exterior case 6h, 6j, 7g, 7i, 7k, 7n Groove 6e, 7e, 17e, 18e Fitting recess 6f, 7d, 17f, 18d Fitting projection 10, 20 Label 24a, 24b Groove 27a, 27b Rib

Claims (7)

A flat battery having two planes and four side surfaces, and a unit cell with electrode terminals protruding on one side surface;
Disposed on the outside of either side of the unit cell, a protection circuit board having an external output terminal,
A lead plate for connecting the protection circuit board , the electrode terminal , and a side surface other than the one side surface of the unit cell, which is a terminal having a different polarity from the electrode terminal;
An exterior frame that covers the four side surfaces of the unit cell, the protection circuit board, and the lead plate ;
In the battery pack, the exterior frame has at least one divided portion formed in a portion different from the portion covering the protective circuit board, and the opposite ends of the divided portion are fitted to each other.
Said segmented portion, between the side surface of the unit cell facing converting said cross section, extends along the side surface comprises a spacer having a locking portion,
The battery pack, wherein the locking portion is locked to the exterior frame . The locking portion is composed of a rib extending in the extending direction of the spacer,
The battery pack according to claim 1, further comprising a recessed groove that fits into the rib in the vicinity of an end portion in a short direction of the exterior frame. The locking portion comprises a concave groove extending in the extending direction of the spacer,
The battery pack according to claim 1, further comprising a rib that fits into the concave groove in the vicinity of an end portion in a short direction of the exterior frame. 4. The battery pack according to claim 1, wherein the spacer insulates between the lead plate and a side surface of the unit cell on which the spacer is disposed . 5. Before SL spacers battery pack according to any one of claims 1 to 4 are arranged in at least the one side surface of the unit cell.   The battery pack according to any one of claims 1 to 5, wherein a longitudinal end portion of a side surface of the unit cell on which the spacer is disposed forms a curved surface, and a curvature radius of the curved surface is 1.0 or less. The spacer, battery pack according to any one of claims 1 to 6 having a substrate contact portion interposed between the side surface and the protective circuit board to dispose the protection circuit board of the unit cell.

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