JP2012181971A - Method of manufacturing battery cell, battery cell, power supply device, and vehicle having the power supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery cell that is waterproofed and protected by coating the battery cell with an insulation thermal contraction sheet, and to provide a method of manufacturing the battery cell, and a power supply device.SOLUTION: In a battery cell having a waterproofing and insulating thermal contraction sheet coating an outer can, a bonded part adhered and sealed so as to be in a bag shape for inserting the outer can therein. The outer can is inserted into the bag shape of the thermal contraction sheet, and heating is performed to tightly adhere the thermal contraction sheet to the outer can. The bonded part of the thermal contraction sheet is melted and compressed in a direction parallel to a mating surface to obtain a substantially planar structure in which a protruding length of the bonded part is shortened. Thereby, an external dimension of the battery cell having insulation property and waterproofness can be standardized, and leakage between the battery cells and a risk of entering of water caused by condensation can be reduced effectively.

Description

  TECHNICAL FIELD The present invention relates to a battery cell manufacturing method, a battery cell, a power supply device, and a vehicle including the battery cell used as a power source of a motor for driving a hybrid vehicle, an electric vehicle, and the like. The present invention relates to a battery cell manufacturing method, a battery cell, a power supply device, and a vehicle including the same.

  An automobile such as an electric vehicle that runs with a motor or a hybrid car that runs with both a motor and an engine is equipped with a power supply device in which battery cells are housed in an outer case. As shown in FIGS. 22 and 23, this power supply device is a battery block in which a large number of battery cells 10X are connected in series to increase the output voltage in order to obtain an output for driving the automobile with a motor. An insulating separator 51 is interposed between the battery cells to insulate the battery cells. Further, the outer peripheral surface of the battery cell is protected by sandwiching both surfaces of the battery cell between the separators and accommodating the battery cell between the separators.

  As shown in FIG. 24, each battery cell has a rectangular outer can 12 and is provided with positive and negative electrode terminals 13 at the upper end. The battery cell 10X often uses a high-power lithium ion secondary battery. Since the outer can 12 of the lithium ion secondary battery has an intermediate potential, the battery cell surface has a high potential, and it is necessary to insulate it from the ground of the outer case 55. For this reason, many measures are taken to insulate the outer can of the battery cell with an insulating cover or an insulating sheet.

  In general, as shown in FIG. 25, the battery cell is covered with a bag-shaped heat shrinkable sheet 20 </ b> X leaving the upper surface of the battery cell so that the electrode terminal on the upper part of the battery cell is exposed. Specifically, the heat-shrinkable sheet 20X having a cylindrical opening at the top and the bottom is cut with an appropriate length, and the battery cell 10X is inserted from one opening end as shown in FIG. As shown in b), the heat-shrinkable sheet 20X is heat-shrinked to adhere to the surface of the outer can. At this time, the heat-shrinkable sheets 20X were thermally welded to each other on the bottom surface of the battery cell 10X to close the opening, and the blank portion was further cut to cover the surface of the battery cell 10X with the heat-shrinkable sheet.

  However, it is difficult to completely remove the blank portion by cutting, in order to avoid a situation in which the heat shrink sheet is damaged at the bottom surface of the battery cell due to the cutting and the surface of the outer can is partially exposed. It is necessary to cut with some margin. As a result, as shown in FIG. 25 (b) and FIG. 27 (b), the joining surface between the heat welding sheets protrudes from the heat welding wire HL on the bottom surface of the battery cell 10X.

  In particular, in the shrinking process in which the heat-shrinkable sheet is thermally shrunk, the welded portion on the bottom surface of the outer can is not shrunk, so that it is folded into a pleated shape. Since the pleated portion has a considerable strength, it is difficult to fold, and as a result, the hard protrusion protrudes from the bottom surface of the battery cell. If such a protrusion is large, there is a possibility of interference with the bottom surface of the separator when the battery cell is stored in the separator.

  On the other hand, although a cooling method has been proposed in which a battery cell is placed on a cooling plate and the bottom surface of the battery cell is thermally coupled to the cooling plate to dissipate the battery cell through the cooling plate, the bottom surface of the battery cell If there is a protrusion on the surface, the surface contact between the battery cell and the cooling plate is hindered, and there is a problem that heat conduction is lowered. In particular, the pleated shape varies for each battery cell, and the amount of protrusion is not constant, so that the contact state becomes unstable. In addition, since the storage in the separator described above is hindered, there is a problem that individual differences occur between the battery cells and the yield of the battery cells deteriorates.

Japanese Patent Laid-Open No. 2003-223872 JP 2002-184364 A

  The present invention has been made for the purpose of solving the conventional problems. A main object of the present invention is to provide a battery cell, a manufacturing method, a power supply device, and a vehicle including the same, in which the battery cell is covered with a heat-shrink sheet and the protrusion of the joint surface is suppressed and the reliability of heat dissipation is improved. There is to do.

Means for Solving the Problems and Effects of the Invention

  In order to achieve the above object, according to the battery cell of the first aspect of the present invention, an outer can and a heat-shrinkable thermal contraction having a waterproof and insulating property covering the outer peripheral surface of the outer can. A process for preparing the heat-shrinkable sheet in a fixed size capable of covering the outer peripheral surface of the outer can, and the outer peripheral surface of the outer can with the heat-shrinkable sheet The heat-shrinkable sheet is heated at a first temperature to adhere to the surface of the outer can, and the heat-shrinkable sheets are joined together at the edges to form a joining surface, or the heat-shrinkable sheets are edged Forming a bonding surface, covering the outer peripheral surface of the outer can with the heat-shrinkable sheet, and heating the heat-shrinkable sheet at a first temperature to adhere to the surface of the outer can; and the bonding Heat the projecting part of the surface at the second temperature to obtain a substantially flat surface Forming, it can contain. As a result, the situation where the joint surface protrudes from the surface of the battery cell covered with the heat shrink sheet can be suppressed, and when stacking a plurality of battery cells, the joint surface protrudes and it is difficult to arrange them on the same plane. Can be avoided.

  Moreover, according to the manufacturing method of a 2nd battery cell, said 2nd temperature can be set to high temperature rather than said 1st temperature. Thereby, it melts at a temperature higher than the temperature at which the heat-shrinkable sheet is thermally shrunk, and a flat surface can be reliably formed on the joint surface.

  Further, according to the third battery cell manufacturing method, in forming the substantially flat surface, one surface of the heat-resistant spacer having a slit into which the joint can be inserted is applied to the surface of the outer can. Contacting, projecting the joint from the slit, pressing the other surface of the spacer against the heating plate in this state, melting the projecting portion of the joint surface with the heating plate, forming a substantially flat surface, Alternatively, in forming the substantially flat surface, the spacer can be placed on the heating plate, and a protruding portion of the joining surface can be inserted into a slit opened in the spacer and melted by the heating plate, thereby forming a substantially flat surface. . Thereby, while protecting the surface of the heat shrink sheet | seat which coat | covers the surface of a battery cell with a heat resistant spacer, the advantage which can selectively heat only the protrusion part of a joint surface and can form a flat surface is acquired. In addition, since the protruding amount of the joint surface can be uniformly suppressed to a certain amount defined by the thickness of the spacer, individual differences and variations in the protruding amount for each battery cell are also suppressed, and there is an advantage that a certain quality is guaranteed. It is done.

  Furthermore, according to the fourth method of manufacturing a battery cell, the joint surface can be extended at a substantially central position along the longitudinal direction of the surface of the battery cell. Thereby, a battery cell can be coat | covered uniformly with a heat-shrink sheet | seat, and reliability can be improved.

  Furthermore, according to the fifth battery cell manufacturing method, the joint surface can be formed on the bottom surface of the battery cell. Thereby, the situation where a joint surface protrudes from the bottom face of a battery cell can be avoided, the battery cell can be easily made independent, and the thermal coupling state when joining the cooling plate on the bottom face of the battery cell can be improved.

  Furthermore, according to the sixth method of manufacturing a battery cell, the slit formed in the spacer can be formed with an inner diameter wider than the width of the joint surface in the width direction. Thereby, a joining surface can be reliably guided in a slit, and all the front-end | tips of a joining surface can be formed in a flat surface.

  Furthermore, according to the seventh battery cell manufacturing method, the thickness of the spacer can be made thinner than the protruding length of the protruding portion of the joint surface. Thereby, the protrusion part of a joint surface can be reliably exposed from a slit, and a flat surface can be formed by making it contact with a heating plate.

  Furthermore, according to the eighth method for producing a battery cell, the outer can can be formed into a square shape whose appearance is substantially rectangular. Thereby, it can be set as the stable shape which suppressed the protrusion of the bottom face, coat | covering the bottom face and side face of a square-shaped exterior can with a heat-shrink sheet.

  Furthermore, according to the ninth method for producing a battery cell, the heat shrinkable sheet when the outer peripheral surface of the outer can is covered with the heat shrinkable sheet can be chamfered at the corner on the bottom side of the outer can. it can. As a result, it is possible to avoid the situation where the joining surface protrudes to the side on the bottom surface side of the outer can, and to easily fit in the slit.

  Furthermore, according to the tenth battery cell, a battery cell comprising an outer can and a heat-shrinkable sheet having waterproofness and insulation covering the outer peripheral surface of the outer can, wherein the heat-shrinkable sheet comprises: The surface of the outer can has a joint part to which a part of the heat-shrinkable sheet is adhered, and the joint part can be formed with a substantially flat flat surface at the tip. Thereby, the situation where a joint surface protrudes from the surface of the outer can of the battery cell covered with the heat shrink sheet can be avoided, and the surface can be easily aligned on the same surface particularly when a plurality of battery cells are stacked.

  Furthermore, according to the eleventh battery cell, the flat surface can be formed wider in cross-sectional view than the joint portion.

  Furthermore, according to the twelfth battery cell, the battery pack further includes a sealing plate provided on the outer can and an electrode terminal provided on the sealing plate, and the heat shrink sheet removes the sealing plate of the outer can. The surface can be coated. Thus, the portion of the outer can other than the sealing plate is insulated by the heat shrink sheet, and the electrode terminals provided on the sealing plate are exposed to the outside so that the output of the battery cell can be taken out.

  Furthermore, according to the thirteenth battery device, the battery cells can be stacked.

  Furthermore, according to the fourteenth vehicle, the power supply device can be mounted.

It is the perspective view which made the battery cell which concerns on Example 1, and the heat-shrink sheet into the bag shape. FIG. 3 is a three-side view in which the battery cell shown in FIG. 1 is covered with a heat shrink sheet. 3 is a three-side view showing a battery cell coated with a heat-shrinkable sheet according to Example 1. FIG. It is the front view of the process of melt-compressing the joining surface made to the battery cell of Example 1 of this invention, and the expansion perspective view of the part melt-compressed. FIG. 5A is a schematic view of the heat shrinkable sheet used in Example 1, and FIG. 5B is a perspective view showing a state in which the heat shrinkable sheet of FIG. 5A is cut. It is a perspective view which shows the state which coat | covered the battery cell of Fig.1 (a) with the heat-shrink sheet | seat of FIG.5 (b). It is a perspective view which shows a mode that a joining surface heats with a heating plate through a spacer. It is a schematic cross section which shows the state which made the spacer contact | abut to the exterior can bottom in FIG. It is a schematic cross section which shows the state which crushed protrusion in FIG. It is a perspective view which shows the spacer which concerns on a modification. It is a perspective view which shows the spacer which concerns on another modification. It is a front view of the heat-shrink sheet used in Example 3 of this invention and the heat-shrink sheet made into the bag shape. It is the perspective view which coat | covered the heat-shrink sheet | seat made into the bag shape used in Example 3 of this invention, and a battery cell. It is a front view of the process of melt-compressing the joint surface made to the battery cell of Example 3 of this invention. It is the top view and side view showing the heating plate and spacer which are used by this invention. It is the front view of the process using a spacer in Example 3 of this invention, and the expansion perspective view of the part melt-compressed. It is a side view of the power supply unit which laminated | stacked the battery cell of this invention. FIG. 18 is a plan view of the power supply unit shown in FIG. 17. It is a block diagram which shows the example which mounts a power supply device in the hybrid car which an engine and a motor drive | work. It is a block diagram which shows the example which mounts a power supply device in the electric vehicle which drive | works only with a motor. It is a block diagram which shows the example applied to the power supply device for electrical storage. It is a top view which shows the power supply device which laminated | stacked the battery cell. It is a side view of the power supply device of FIG. It is a perspective view of the battery cell of FIG. FIG. 25 is a trihedral view showing a state in which the battery cell of FIG. 24 is covered with a conventional waterproof sheet. It is a perspective view which shows a mode that the battery cell of FIG. 24 is coat | covered with the conventional waterproof sheet. It is a perspective view which shows a mode that a heat-shrink sheet is heat-shrinked from the state of FIG. FIG. 28A is a front view of the heat-shrinkable sheet used in Example 1, FIG. 28B is a front view showing a state where battery cells are inserted into the heat-shrinkable sheet of FIG. 28A, and FIG. ) Is a schematic view showing a state where the heat-shrinkable sheet of FIG. 28B is heat-shrinked. FIG. 29A is a front view of the heat-shrinkable sheet used in Example 2, FIG. 29B is a front view of a state in which the corners of the heat-shrinkable sheet of FIG. 29A are cut, and FIG. Fig. 29 (b) is a front view of a state in which the bottom surface of the heat shrinkable sheet of Fig. 29 (b) is thermally welded to form a bag, and Fig. 29 (d) is a perspective view of a state in which battery cells are housed in the heat shrinkable sheet of Fig. 29 (c). FIG. 29 (e) is a front view of the heat-shrinkable sheet of FIG. 29 (d) after heat shrinkage, and FIG. 29 (f) is a bottom view of FIG. 29 (e).

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiment described below exemplifies a battery cell and a manufacturing method, a power supply device, and a vehicle including the same for embodying the technical idea of the present invention, and the present invention is a battery cell and a manufacturing method. The power supply device and the vehicle including the same are not specified as follows. Further, the present specification by no means specifies the members shown in the claims to the members of the embodiments. In particular, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in the embodiments are not intended to limit the scope of the present invention unless otherwise specified, and are merely explanations. It is just an example. Note that the size, positional relationship, and the like of the members shown in each drawing may be exaggerated for clarity of explanation. Further, in the following description, the same name and reference numeral indicate the same or the same members, and detailed description will be omitted as appropriate. Furthermore, each element constituting the present invention may be configured such that a plurality of elements are constituted by the same member and the plurality of elements are shared by one member, and conversely, the function of one member is constituted by a plurality of members. It can also be realized by sharing.
Example 1

  The battery cell which concerns on Example 1 of this invention is shown in FIGS. The battery cell 10 shown in these figures is a lithium ion secondary battery (Li-ion). However, the battery cell is not specified as a lithium ion secondary battery. The present invention can be applied to the manufacture of all batteries that cover the surface of the outer can with a heat-shrinkable sheet, regardless of whether it is a secondary battery or a primary battery. For example, the battery cell may be a secondary battery such as a nickel metal hydride battery (NiCd) or a nickel cadmium battery (Ni-MH), or a primary battery such as a manganese battery or an alkaline battery. Furthermore, the battery cell is not limited to a prismatic battery, and may be a columnar battery cell whose cross-sectional shape is circular, oval, or elliptical.

Example 1 shown in FIG. 1A is a prismatic battery having a rectangular outer can. Specifically, the outer can 12 of the battery cell 10 has a rectangular shape whose outer shape is thinner than the width. Furthermore, it is a bottomed box shape having a width L, a thickness d and a height H, and the upper surface is closed by a sealing plate 11. An electrode terminal 13 is attached to the sealing plate 11 via an insulating member 15. The outer can is made of aluminum having excellent thermal conductivity, but is not limited to this, and may be iron, magnesium-aluminum alloy, or the like.
(Heat shrink sheet)

  Since the surface of the outer can has a high potential, it needs to be insulated. Therefore, as shown in FIG. 1, the outer peripheral surface of the outer can 12 excluding the sealing plate 11 on the upper surface is covered with an insulating heat shrink sheet 20. In addition, when water accumulates inside the power supply device due to condensation or the like, the heat shrinkable sheet 20 is waterproof to prevent short circuit and rust. Further, welding is performed so that pinholes and the like are not generated at the joint surfaces between the heat shrink sheets.

  In the example of FIG. 1, the battery cell 10 has a heat-shrinkable sheet 20 in a bag shape and has an outer can 12 inserted therein. Here, as the heat-shrinkable sheet, a product made of PET (polyethylene terephthalate) having insulating properties and waterproof properties is used. However, the present invention is not limited to this, and a heat-shrinkable sheet having insulating properties and waterproof properties such as PVC (polyvinyl chloride), PP (polypropylene), PE (polyethylene), and PO (polyolefin) can also be used.

  The heat-shrinkable sheet 20 has an inner diameter and a depth at which the outer can 12 of the battery cell 10 can be inserted, and is formed in a size that can cover the outer surface. In Example 1, the bag-like shape formed by the heat-shrinkable sheet 20 shown in FIG. 1B is set such that the lateral width W is 1.05 to 1.3 times the width L of the outer can 12, and the gusset width t is The thickness d of the outer can 12 is set to 1.0 to 1.2 times, and the depth D is set to 1.05 to 1.2 times the height H of the outer can 12. The shrinkage temperature is 50 to 120 ° C. However, it has a uniaxial stretching characteristic or a biaxial stretching characteristic depending on the specifications of the heat shrinkable sheet, and the shrinkage rate and the heat shrink temperature differ depending on the material used.

  Furthermore, by placing a heat-resistant spacer 40 on the heating plate 30 as shown in FIG. 4 and inserting the joining surface GL into the slit 41 opened in the spacer 40, a quantitative compression ratio is maintained. A melt compression part FL is formed. As a result, the battery cell with the heat-shrinkable sheet can be made to have a standard size, can be stably fixed to the separator or the like, and can heat the heating plate 30 to the outer can 12 itself through the spacer 40. Conduction can be suppressed, and furthermore, the stress at the time of pressing the bonding surface GL with the heating plate 30 can be dispersed, so that the outer can 12 and the battery cell 10 can be prevented from being damaged.

Hereinafter, a procedure for coating the surface of the battery cell with the heat shrinkable sheet will be described. First, a heat shrinkable sheet 20A capable of covering the outer peripheral surface of the outer can 12 is prepared. Here, a cylindrical heat-shrink sheet 20A shown in FIG. 5A is prepared in advance. The cylindrical inner diameter is set to a size that allows the outer can 12 to be inserted. This cylindrical heat-shrink sheet 20A is cut to a standard size according to the height of the outer can 12 as shown in FIG. Then, the outer can 12 is inserted into the cylindrical heat-shrinkable sheet 20A cut as shown in FIG. 6, and the heat-shrinkable sheet 20A is heated at the first temperature to adhere to the surface of the outer can 12, and further the outer can 12, the edge of the heat-shrinkable sheet 20 </ b> A is thermally welded to form the joint surface GL. The first temperature for thermally shrinking the heat-shrinkable sheet 20A is, for example, 50 to 120 ° C. In this state, the heat-shrinkable sheet 20A is in close contact with the outer can 12, but on the bottom surface, the heat-welded joint surface GL does not shrink and protrudes in a pleated shape as shown in FIG. This part is hardened and difficult to fold. In particular, the folds tend to be denser toward the end face side. Since such protrusions are not fixed in shape and are different for each battery cell, and are on the bottom surface of the outer can 12, when the plurality of battery cells are stacked and placed on the plate, the heights are uneven. Cause. In particular, in a system in which the battery cell is cooled by the cooling plate by being placed in a thermally coupled state on a cooling plate containing a refrigerant circulation path, the contact state between the bottom surface of the battery cell and the cooling plate is not constant, Causes thermal binding to be inhibited. Moreover, it is difficult to fold the protruding portion because the protruding portion is melted and has strength, and if it is bent forcibly, the heat shrinkable sheet may be torn or the bottom surface of the outer can may be damaged.
(Spacer)

  Therefore, in the present embodiment, the protruding portion of the joint surface is heated at the second temperature to form a substantially flat surface. A heated heating plate 30 is used for heating. Here, a spacer 40 is used as shown in the exploded perspective view of FIG. 7 so as to selectively heat only the protruding portion. The spacer 40 is formed to be approximately the same size or larger than the bottom surface of the battery cell so as to cover the bottom surface of the battery cell. The spacer 40 has a slit 41 at the center thereof. The slit 41 is formed to have a width that is longer than the joint surface GL and can accommodate the pleated fluctuations of the joint surface GL so that the joint surface GL can be inserted.

  While the spacer 40 is brought into contact with the bottom surface of the outer can 12, the joining surface GL is inserted into the slit 41, and the joining surface GL penetrating the slit 41 is protruded downward as shown in the sectional view of FIG. 8. . In this state, the bottom surface of the battery cell is pressed against the heating plate 30 with the slit 41 interposed, and the tip of the protrusion is melted. At this time, the second temperature for heating the protrusions is set to a temperature at which the cured heat-shrinkable sheet can be melted. Preferably, the temperature is higher than the first temperature, for example, 200 ° C to 250 ° C. As a result, as shown in FIG. 9, the tip of the protrusion is melted and crushed to form a flat surface. In addition, by further heating and crushing the portion where the heat-shrinkable sheets are melted together, the bonding between the heat-shrinkable sheets can be further strengthened. In particular, as a result of the protrusions being crushed by the heating plate 30 and expanded in the lateral direction, the width of the joint surface GL is expanded and the stability is increased. In addition, even if a pinhole is formed in the joint portion, it can be expected to eliminate this by melting at a higher temperature.

  The spacer 40 is preferably thin so that the protruding portion of the joint surface GL becomes small. In particular, since the protrusion amount of the protrusion after heating is defined by the thickness of the spacer 40, it is set according to the required protrusion amount. As the spacer material, a heat-resistant member such as heat-resistant polypropylene can be used.

  In the example of FIG. 7, the slit 41 is formed to have a constant width over the length direction, but the width can be partially changed. In particular, the pleated shape becomes more intense at the edge of the battery cell and is relatively small at the middle part. Therefore, as shown in FIG. 10, the slit is opened in a shape in which the width of the central part is narrowed and the width of the edge is widened. The spacer 40A can also be used. Alternatively, as shown in FIG. 11, the spacer 40 </ b> B may be formed in a shape in which the slit is penetrated by one wall surface and the plate is bifurcated. The spacer 40B having this shape makes the branched plates substantially parallel to each other and uses the separated portion as a slit. The spacer having this shape can be formed so that the area of the spacer is smaller than the bottom surface of the battery cell.

  According to this method, the joining surface GL is pressed against the heating plate 30 to be thermally compressed, and wasteful protruding portions can be easily reduced. In particular, since the parts other than the protruding parts can be protected with spacers, it is possible to avoid accidental damage to the heat-shrink sheet on the bottom of the outer can, which is superior in terms of safety and reliability, and selectively removes only necessary parts. it can. Further, it is possible to easily define the protrusion of the joint surface to a certain amount, and there is an advantage that individual differences between the battery cells can be easily reduced. However, it is possible to form the flat portion by individually heating the protruding portion of the joint surface GL using a heated hand or the like. However, this method is troublesome and it is not easy to regulate the amount of protrusion to a certain amount.

  The battery cell 10A having a flat projection on the bottom surface of the outer can 12 is more stable when placed on a plate, and particularly when a plurality of battery cells are stacked, the height can be easily aligned on the same surface. it can.

In the above example, the bottom surface of the tubular heat-shrinkable sheet is closed on the bottom surface of the battery cell in a state where the cut tubular heat-shrinkable sheet is coated on the battery cell, but the present invention is limited to this method. Not. For example, the cut cylindrical heat-shrinkable sheet may be configured such that the bottom side is first closed to form a bag, and the battery cell is stored in the bag-shaped heat-shrinkable sheet. With this method, the bottom surface of the battery cell can be reliably closed by making it into a bag shape beforehand, so when performing simultaneously with the coating of the side surface and the bottom surface of the battery cell outer can, for example, the blank portion of the heat shrink sheet is the bottom surface of the battery cell. It is possible to avoid a situation where a part of the bottom surface is exposed due to shortage on the side.
(Example 2)

  Further, in Example 1, as shown in the perspective view of FIG. 5B and the front view of FIG. 28A, the heat-shrinkable sheet 20A is cut into a substantially rectangular shape in plan view. In this configuration, when the battery cell 10 is inserted into the heat shrinkable sheet 20A and thermally contracted as shown in the front view of FIG. 28 (b), the heat shrinkable sheet 20A as shown in the bottom view of FIG. 28 (c). The joint surface GL may protrude laterally from the bottom surface of the battery cell 10. If there is such a protrusion from the bottom surface, it is necessary to make a slit provided in the spacer larger, and the size of the spacer must be made larger than the bottom surface of the battery cell. In addition, when the slit becomes large, the possibility that the battery cell is placed on the spacer up to the portion without the joint surface GL is increased, and handling becomes worse.

  Therefore, it is preferable to chamfer the corners at the bottom of the heat shrink sheet to reduce the extra parts of the heat shrink sheet, that is, the parts that cause wrinkles and twists, and suppress such wrinkles and twists. it can. This example is shown in FIGS. 29A to 29F as Example 2. FIG. Here, as shown in FIG. 29 (a), the corners on the bottom side of the heat-shrinkable sheet 20C once cut into a rectangular shape are cut into hexagonal shapes as shown in FIG. 29 (b).

Further, as shown in FIG. 29 (c), the bottom surface of the heat-shrinkable sheet 20C is thermally welded and closed to form a bag, and then the battery cell 10C is inserted as shown in FIG. 29 (d). In addition, the heat-shrink sheet 20C which cut the corner part beforehand and made it into a bag shape can also be prepared. In this state, the heat-shrinkable sheet 20C is heat-shrinked at the first temperature and is brought into close contact with the side and bottom surfaces of the outer can as shown in FIG. If it is this structure, as shown in FIG.29 (f), in the bottom face of an exterior can, the joining surface GL used as the hook will be settled in the bottom face of the battery cell 10C. This is because, as shown in FIG. 29 (d), the surplus portion of the joint surface GL before the heat shrinkage is reduced in the vicinity of the end portion of the battery cell. As a result, the corner portion of the joint surface GL, which has been severely twisted, can be prevented from jumping out laterally on the bottom surface of the battery cell 10C, eliminating the need to open the slit larger than necessary, and improving the handling of the spacer. it can.
(Example 3)

  In Example 1 described above, the example in which the battery cell is covered with the heat shrinkable sheet 20 </ b> A so that the bonding surface is located on the bottom surface of the battery cell has been described. However, the present invention is not limited to this example, and in the configuration in which the joining surface is provided on the side surface of the battery cell, the protrusion can be similarly eliminated by heating. Such an example is shown in FIGS. 12 to 16 as a third embodiment. In this battery cell, as shown in FIG. 13, the heat shrinkable sheet 20B is bent into a U shape, and is thermally welded on both sides to form a bag. Specifically, as shown in FIG. 12 (a), the heat-shrinkable sheet 20B is cut into a rectangular size, folded at a rectangular folding line CL, and both side surfaces orthogonal to the folding line CL are bonded with adhesive or heat welding. A joint portion GL is created. Thus, a bag shape as shown in FIG. 12 (b) can be obtained. As shown in FIG. 13 (a), the battery cell 10B is inserted into the bag shape and thermally contracted by heating to heat the battery cell 10B. The battery cell 10B is created by closely contacting the shrinkable sheet 20B. As a result, as shown in FIG. 13 (b), joint portions GL are formed on both side surfaces of the battery cell 10B. For the joint GL, a hot melt adhesive, a thermosetting adhesive, an ultraviolet curable adhesive, or the like can be used.

  Furthermore, since the heat-shrinkable sheet is made of resin, the joint GL to be created can be heat-welded by heating such as a heating method, a high-frequency application method, or an ultrasonic application method. In this embodiment, heat welding is performed at 180 to 210 ° C. using a heating method. However, the heat welding temperature differs depending on the specifications of the heat shrinkable sheet.

  However, when the adhesive or heat-welded joint GL is heat-shrinked by heat-shrinking the heat-shrinkable sheet and brought into close contact with the battery cell, it forms a meandering deformed solid piece, as shown in FIG. By compressing the mating surface of the joint portion GL in parallel with the heating plate 30, the joint portion GL is melted and re-fused to form a substantially flat melt-compressed portion FL, and the protrusion length of the joint portion GL is reduced to ½. Compressed to １ ／. In this embodiment, it is melt-compressed at 200 to 270 ° C. using a heating method. However, the melt compression temperature varies depending on the specifications of the heat shrinkable sheet.

  Furthermore, the melt compression part FL places the spacer 40 which is heat-resistant on the heating plate 30 as shown in FIG. 16, and inserts the junction part GL in the slit 41 opened there, and quantitative compression rate Can keep. Thereby, it is possible to make the battery cell 10B with the heat-shrinkable sheet into a fixed size, and it is possible to stably fix the battery cell 10B to the separator or the like, and heat the heating plate 30 through the spacer 40 to heat the outer can 12 itself. The conduction can be suppressed, and furthermore, the joint portion GL can disperse the stress when being pressed by the heating plate 30, so that the outer can 12 and the battery cell 10 can be prevented from being damaged.

By further melting and compressing the joint portion thus welded and sealed, the joint surface of the heat shrinkable sheet is melted and re-fused, so that the appearance of cracks and pinholes can be effectively reduced, such as water The risk of entering the outer can can be prevented. Furthermore, the joint protrusion length of the heat-shrinkable sheet can be shortened, and the installation and fixing of the battery cells can be stabilized even when the battery cells in the power supply device are installed in the separator by making it substantially flat. Since the outer diameter can be constant, it is possible to improve the adhesion with the separator.
(Power supply)

A plurality of the battery cells 10A or 10B described above are stacked via an insulating separator 51, and the power supply device 50 connected as shown in FIGS. 17 to 18 can be configured. The power supply device 50 is provided in an outer case 55 by disposing an insulating sheet 54 below a battery stack in which a plurality of rectangular battery cells 10A or 10B are stacked via separators 51. In the example of FIGS. 17 to 18, 12 rectangular battery cells 10 are stacked. Further, end plates 52 are arranged on both end faces of the battery stack. The end plates 52 are fixed by a bind bar 53 disposed on the side surface of the battery stack. Thus, the battery stack is fixed between the end plates 52 so as to be sandwiched. The bind bar 53 is bent at both ends to form a bent piece, and the whole is U-shaped. By providing a screw hole in the bent piece and the end plate 52, the bind bar 53 is screwed and fixed to the end plate 52. Needless to say, the number of battery cells can be changed depending on the specification voltage and current of the power supply device.
(vehicle)

  Moreover, this power supply device can be used as an in-vehicle battery system. As a vehicle equipped with a power supply device, an electric vehicle such as a hybrid car or a plug-in hybrid car that runs with both an engine and a motor, or an electric car that runs only with a motor can be used, and it is used as a power source for these vehicles. .

  FIG. 19 shows an example in which a power supply device is mounted on a hybrid car that runs with both an engine and a motor. A vehicle HV equipped with the power supply device shown in this figure includes an engine 96 and a travel motor 93 that travel the vehicle HV, a power supply device 100 that supplies power to the motor 93, and a generator that charges a battery of the power supply device 100. 94. The power supply apparatus 100 is connected to a motor 93 and a generator 94 via a DC / AC inverter 95. The vehicle HV travels by both the motor 93 and the engine 96 while charging / discharging the battery of the power supply device 100. The motor 93 is driven to drive the vehicle when the engine efficiency is low, for example, during acceleration or low-speed driving. The motor 93 is driven by power supplied from the power supply device 100. The generator 94 is driven by the engine 96 or is driven by regenerative braking when the vehicle is braked to charge the battery of the power supply device 100.

FIG. 20 shows an example in which a power supply device is mounted on an electric vehicle that runs only with a motor. A vehicle EV equipped with the power supply device shown in this figure includes a traveling motor 93 for traveling the vehicle EV, a power supply device 100 that supplies power to the motor 93, and a generator 94 that charges a battery of the power supply device 100. And. The motor 93 is driven by power supplied from the power supply device 100. The generator 94 is driven by energy when regeneratively braking the vehicle EV and charges the battery of the power supply device 100.
(Power storage device for power storage)

  Furthermore, this power supply device can be used not only as a power source for a moving body such as a vehicle, but also as a stationary power storage facility. For example, as a power source for households and factories, a power supply system that is charged with solar power or midnight power and discharged when necessary, or a street light that is charged with solar power during the day and discharged at night It can also be used as a backup power source for traffic lights that are driven in the event of a power failure. Such an example is shown in FIG. The power supply apparatus 100 shown in this figure forms a battery unit 82 by connecting a plurality of battery packs 81 in a unit shape. Each battery pack 81 has a plurality of battery cells connected in series and / or in parallel. Each battery pack 81 is controlled by a power controller 84. The power supply apparatus 100 drives the load LD after charging the battery unit 82 with the charging power supply CP. For this reason, the power supply apparatus 100 includes a charging mode and a discharging mode. The load LD and the charging power source CP are connected to the power supply device 100 via the discharging switch DS and the charging switch CS, respectively. ON / OFF of the discharge switch DS and the charge switch CS is switched by the power supply controller 84 of the power supply apparatus 100. In the charging mode, the power supply controller 84 switches the charging switch CS to ON and the discharging switch DS to OFF to permit charging from the charging power supply CP to the power supply apparatus 100. Further, when the charging is completed and the battery is fully charged, or in response to a request from the load LD in a state where a capacity of a predetermined value or more is charged, the power controller 84 turns off the charging switch CS and turns on the discharging switch DS to discharge. The mode is switched to permit discharge from the power supply apparatus 100 to the load LD. Further, if necessary, the charge switch CS can be turned on and the discharge switch DS can be turned on to supply power to the load LD and charge the power supply device 100 at the same time.

  A load LD driven by the power supply apparatus 100 is connected to the power supply apparatus 100 via a discharge switch DS. In the discharge mode of the power supply apparatus 100, the power supply controller 84 switches the discharge switch DS to ON, connects to the load LD, and drives the load LD with the power from the power supply apparatus 100. As the discharge switch DS, a switching element such as an FET can be used. ON / OFF of the discharge switch DS is controlled by the power supply controller 84 of the power supply apparatus 100. The power controller 84 also includes a communication interface for communicating with external devices. In the example of FIG. 21, it is connected to the host device HT according to an existing communication protocol such as UART or RS-232C. Further, if necessary, a user interface for the user to operate the power supply system can be provided.

  Each battery pack 81 includes a signal terminal and a power supply terminal. The signal terminals include a pack input / output terminal DI, a pack abnormality output terminal DA, and a pack connection terminal DO. The pack input / output terminal DI is a terminal for inputting / outputting signals from other pack batteries and the power supply controller 84, and the pack connection terminal DO is for inputting / outputting signals to / from other pack batteries which are child packs. Terminal. The pack abnormality output terminal DA is a terminal for outputting the abnormality of the battery pack to the outside. Furthermore, the power supply terminal is a terminal for connecting the battery packs 81 in series and in parallel. The battery units 82 are connected to the output line OL via the parallel connection switch 85 and are connected in parallel to each other.

  A battery cell, a manufacturing method, a power supply device, and a vehicle including the battery cell according to the present invention are used as a power supply device for a plug-in hybrid electric vehicle, a hybrid electric vehicle, an electric vehicle, or the like that can switch between an EV traveling mode and an HEV traveling mode. It can be suitably used. Also, a backup power supply device that can be mounted on a rack of a computer server, a backup power supply device for a wireless base station such as a mobile phone, a power storage device for home use and a factory, a power supply for a street light, etc. Also, it can be used as appropriate for applications such as a backup power source such as a traffic light.

DESCRIPTION OF SYMBOLS 10, 10A, 10B, 10C, 10X ... Battery cell 11 ... Sealing plate 12 ... Exterior can 13 ... Electrode terminal 15 ... Insulating member 20, 20A, 20B, 20C, 20X ... Heat-shrink sheet 30 ... Heating plate 40, 40A, 40B ... Spacer 41 ... Slit 50, 100 ... Power supply 51 ... Separator 52 ... End plate 53 ... Bind bar 54 ... Insulating sheet 55 ... Exterior case 81 ... Battery pack 82 ... Battery unit 84 ... Power supply controller 85 ... Parallel connection switch 93 ... Motor 94 ... Generator 95 ... DC / AC inverter 96 ... Engine CL ... Folding curve HL ... Thermal welding line GL ... Joining surface FL ... Melt compression part HV, EV ... Vehicle CP ... Charging power supply LD ... Load DS ... Discharge switch CS ... Charge switch DI ... Pack input / output terminal DA ... Pack abnormal output terminal DO ... Pack connection terminal HT ... E Capital equipment OL ... output line

Claims (14)

An outer can,
A heat-shrinkable heat-shrink sheet having waterproof and insulating properties covering the outer peripheral surface of the outer can;
A method for producing a battery cell comprising:
Preparing the heat-shrinkable sheet in a fixed size capable of covering the outer peripheral surface of the outer can;
Covering the outer peripheral surface of the outer can with the heat shrinkable sheet, heating the heat shrinkable sheet at a first temperature to adhere to the surface of the outer can, and joining the heat shrinkable sheets to each other at the edge Forming or joining the heat-shrinkable sheets at the edges to form a bonding surface, covering the outer peripheral surface of the outer can with the heat-shrinkable sheet, and heating the heat-shrinkable sheet at a first temperature to form the outer package A process of adhering to the surface of the can;
Heating the protruding portion of the joining surface at a second temperature to form a substantially flat surface;
The manufacturing method of the battery cell characterized by including. It is a manufacturing method of the battery cell according to claim 1,
The method for producing a battery cell, wherein the second temperature is set higher than the first temperature. It is a manufacturing method of the battery cell according to claim 1 or 2,
In the formation of the substantially flat surface, one surface of a heat-resistant spacer having a slit into which the joint can be inserted is brought into contact with the surface of the outer can, and the joint is inserted into the other of the spacer through the slit. The other surface is pressed against a heated heating plate, and the protruding portion of the joining surface is melted with the heating plate to form a substantially flat surface, or the substantially flat surface In the formation, the spacer is placed on the heating plate, and a protruding portion of the joint surface is inserted into a slit opened in the spacer and melted by the heating plate, thereby forming a substantially flat surface. A method for manufacturing a battery cell. It is a manufacturing method of the battery cell according to any one of claims 1 to 3,
The method for manufacturing a battery cell, wherein the joining surface is extended at a substantially central position along the longitudinal direction of the surface of the battery cell. It is a manufacturing method of the battery cell as described in any one of Claim 1 to 4, Comprising:
The method for manufacturing a battery cell, wherein the joining surface is formed on a bottom surface of the battery cell. It is a manufacturing method of the battery cell according to any one of claims 1 to 5,
The method of manufacturing a battery cell, wherein the slit formed in the spacer is formed to have an inner diameter wider than the width of the joint surface in the width direction. It is a manufacturing method of the battery cell according to any one of claims 1 to 6,
The method of manufacturing a battery cell, wherein the spacer is formed thinner than the protruding length of the protruding portion of the joint surface. It is a manufacturing method of the battery cell according to any one of claims 1 to 7,
The method of manufacturing a battery cell, wherein the outer can is formed in a square shape having an outer appearance of a substantially rectangular shape. A method for producing a battery cell according to any one of claims 3 to 8,
The battery cell, wherein the heat-shrinkable sheet when the outer peripheral surface of the outer can is covered with the heat-shrinkable sheet has its corners chamfered on the bottom surface side of the outer can. An outer can,
A heat-shrink sheet having waterproofness and insulating properties covering the outer peripheral surface of the outer can;
A battery cell comprising:
The heat-shrinkable sheet has a joint part to which a part of the heat-shrinkable sheet is adhered on the surface of the outer can.
The junction part is formed by forming a tip of the joint part into a substantially flat flat surface. The battery cell according to claim 10,
The battery cell, wherein the flat surface is formed wider than the joint portion in a cross-sectional view. The battery cell according to claim 10 or 11, further comprising:
A sealing plate provided on the outer can;
An electrode terminal provided on the sealing plate;
With
A battery cell, wherein the heat-shrink sheet covers a surface of the outer can excluding a sealing plate.   The power supply device formed by laminating | stacking the battery cell as described in any one of Claims 10-12.   A vehicle comprising the power supply device according to claim 13.

Images