Energy storage apparatus and energy storage apparatus checking method

An energy storage apparatus provided with an energy storage device is provided with an electrode terminal disposed on the energy storage device, and a bus bar placed on a surface of the electrode terminal and connected to the electrode terminal. The bus bar includes a plurality of opening portions formed such that the surface of the electrode terminal is exposed.

TECHNICAL FIELD

The present invention relates to an energy storage apparatus provided with an energy storage device, and an energy storage apparatus checking method.

BACKGROUND ART

In an energy storage apparatus provided with an energy storage device, a configuration is known in which a bus bar is connected to the energy storage device. In the energy storage apparatus, the bus bar is typically bonded to electrode terminals of the energy storage device by welding the bus bar to the electrode terminals (see Patent Document 1, for example).

PRIOR ART DOCUMENTS

Patent Documents

SUMMARY OF THE INVENTION

Problems to be Solved by the Invention

However, in the typical energy storage apparatus, there is the problem that bonding failures may be caused during the bonding of the electrode terminals of the energy storage device and the bus bar.

The present invention has been made to solve the problem, and an object of the present invention is to provide an energy storage apparatus and an energy storage apparatus checking method with which the occurrence of bonding failures during the bonding of an electrode terminal of an energy storage device and a bus bar can be reduced.

Means for Solving the Problems

In order to achieve the object, according to an aspect of the present invention, an energy storage apparatus provided with an energy storage device includes an electrode terminal disposed on the energy storage device, and a bus bar which is disposed on a surface of the electrode terminal and which is connected to the electrode terminal. The bus bar includes a plurality of opening portions which is formed such that the surface of the electrode terminal is exposed.

The present invention may be implemented not only as the energy storage apparatus but also as an energy storage apparatus checking method for reducing the occurrence of bonding failures, or as a bus bar with which the energy storage apparatus is provided.

In addition, the present invention may be implemented not only as the energy storage apparatus checking method but also as an checking device provided with a processing unit for performing a characteristic process included in the energy storage apparatus checking method. It is also possible to implement the present invention as a program or an integrated circuit for causing a computer to execute the characteristic process included in the energy storage apparatus checking method. The program may be distributed via storage media such as a CD-ROM, or transmission media such as the internet.

Advantages of the Invention

According to the energy storage apparatus of the present invention, the occurrence of bonding failures during the bonding of an electrode terminal of an energy storage device and a bus bar can be reduced.

MODE FOR CARRYING OUT THE INVENTION

In the typical energy storage apparatus, there is the problem that bonding failures may occur during the bonding of the electrode terminal of the energy storage device and the bus bar if there is a gap between the electrode terminal and the bus bar. In particular, in the configuration in which the bus bar is welded to the surface of the electrode terminal, welding failures may be caused during the welding if the bus bar is separated from the surface of the electrode terminal.

The present invention has been made to solve the problem, and has the object of providing an energy storage apparatus and energy storage apparatus checking method with which the occurrence of bonding failures can be reduced during the bonding of the electrode terminal of the energy storage device and the bus bar.

In order to achieve the object, according to an aspect of the present invention, an energy storage apparatus provided with an energy storage device includes an electrode terminal disposed on the energy storage device; and a bus bar placed on a surface of the electrode terminal and connected to the electrode terminal. The bus bar includes a plurality of opening portions which is formed such that the surface of the electrode terminal is exposed.

In this case, the energy storage apparatus is provided with the bus bar which is disposed on the surface of the electrode terminal of the energy storage device, and which is connected to the electrode terminal. The bus bar includes the plurality of opening portions formed such that the surface of the electrode terminal is exposed. That is, the surface of the electrode terminal of the energy storage device is exposed from the plurality of opening portions formed in the bus bar. Accordingly, by measuring the height of the exposed portion of the surface of the electrode terminal, a clearance between the electrode terminal and the bus bar can be measured. Thus, the energy storage apparatus makes it possible to bond the electrode terminal and the bus bar while monitoring the clearance between the electrode terminal of the energy storage device and the bus bar, whereby the occurrence of bonding failures during the bonding of the electrode terminal and the bus bar can be reduced.

The energy storage apparatus may include a plurality of energy storage devices each having an electrode terminal. The bus bar may include three or more opening portions formed such that the surface of the electrode terminal of each of the plurality of energy storage devices is exposed.

In this case, the bus bar includes three or more opening portions formed such that the surface of each of the electrode terminals is exposed. That is, three or more surface portions of the electrode terminal are exposed from the three or more opening portions, so that the height of the three or more exposed portions can be measured. Accordingly, the height and inclination of the surface of the electrode terminal can be calculated from the height of the three or more exposed portions of the electrode terminal. Thus, the clearance between the electrode terminal and the bus bar can be calculated, and the occurrence of the bonding failure during the bonding of the electrode terminal and the bus bar can be reduced.

The three or more opening portions may be formed such that the exposed portions of the surface of the electrode terminal are nonlinearly arranged.

In this case, the three or more opening portions are formed such that the exposed portions of the surface of the electrode terminal are nonlinearly arranged. Accordingly, using the height of the three or more exposed portions that are nonlinearly arranged, the height and inclination of the surface of the electrode terminal can be accurately calculated. Thus, the clearance between the electrode terminal and the bus bar can be accurately calculated, and the occurrence of the bonding failure during the bonding of the electrode terminal and the bus bar can be reduced.

The plurality of opening portions may be formed such that an outer periphery portion of the surface of the electrode terminal is exposed.

In this case, the plurality of opening portions formed in the bus bar is formed such that the outer periphery portion of the surface of the electrode terminal is exposed, and the height of the outer periphery portion of the surface of the electrode terminal can be measured. The height of the surface of the electrode terminal can be calculated more accurately from the height of a plurality of locations in the outer periphery portion of the surface of the electrode terminal than from the height of a plurality of locations in a center portion of the surface of the electrode terminal. Accordingly, since the height of the surface of the electrode terminal can be calculated from the height of the outer periphery portion of the surface of the electrode terminal, the height of the surface of the electrode terminal can be more accurately calculated.

The plurality of opening portions may be cut-outs formed in the outer edge portion of the bus bar.

In this case, the plurality of opening portions is formed in the bus bar by forming the cut-outs in the outer edge portion of the bus bar. If through-holes are formed in a center portion of the bus bar as a plurality of opening portions, the bus bar may become warped due to burrs and the like, for example. Accordingly, by forming the cut-outs in the outer edge portion of the bus bar, the warping of the bus bar over the electrode terminal can be reduced. Thus, the occurrence of the bonding failure during the bonding of the electrode terminal and the bus bar can be reduced.

The plurality of opening portions may be formed such that exposed portions of the surface of the electrode terminal are linearly arranged.

In this case, the plurality of opening portions formed in the bus bar is formed such that the exposed portions of the surface of the electrode terminal are linearly arranged. Accordingly, when measuring the height of the plurality of exposed portions exposed from the plurality of opening portions, the height of the plurality of exposed portions can be measured by moving the measurement device linearly with respect to the electrode terminal. That is, by the simple operation of moving the measurement device linearly with respect to the electrode terminal, the height of the plurality of exposed portions can be easily measured.

The bus bar may have an electrode terminal side surface bonded to the surface of the electrode terminal.

In this case, because the electrode terminal side surface of the bus bar and the surface of the electrode terminal are bonded, the bus bar and the electrode terminal can be strongly bonded via a face-to-face bonding.

The plurality of opening portions may be disposed outside a bonded portion of the bus bar and the electrode terminal.

In this case, because the plurality of opening portions formed in the bus bar is disposed outside the bonded portion between the bus bar and the electrode terminal, the plurality of opening portions can be disposed without interfering with the bonding of the bus bar and the electrode terminal.

In the surface of the electrode terminal, an uneven portion which is a recess portion or a convex portion may be formed, and the plurality of opening portions may be formed such that a portion of the surface of the electrode terminal which is different from the uneven portion is exposed.

In this case, the plurality of opening portions formed in the bus bar is formed such that the portion different from the uneven portion in the surface of the electrode terminal. Accordingly, the height of the portion different from the uneven portion can be measured. Thus, even when the uneven portion is formed in the surface of the electrode terminal, the height of the surface of the electrode terminal can be calculated without being affected by the influence of the uneven portion.

In order to achieve the object, according to an aspect of the present invention, an checking method for an energy storage apparatus provided with an energy storage device includes measuring a height of a surface of an electrode terminal disposed on the energy storage device by measuring a height of an exposed portion of the surface of the electrode terminal, the exposed portion being exposed from an opening portion formed in a bus bar placed on the surface of the electrode terminal.

In this case, the energy storage apparatus checking method includes measuring the height of the surface of the electrode terminal by measuring the height of the exposed portion of the surface of the electrode terminal of the energy storage device, the exposed portion being exposed from the opening portion formed in the bus bar. In this way, the clearance between the electrode terminal and the bus bar can be checked before or after the electrode terminal and the bus bar are bonded. Accordingly, the occurrence of bonding failures during the bonding of the electrode terminal and the bus bar can be reduced.

Further, the height of a surface of the bus bar may be measured.

In this case, by measuring the height of the surface of the bus bar, the height of the bus bar and the height of the electrode terminal of the energy storage device can be compared, whereby the clearance between the electrode terminal and the bus bar can be checked.

The measuring the heights of the exposed portion and the surface of the bus bar may include simultaneously measuring the heights of a plurality of the exposed portions which is linearly arranged and the surface of the bus bar.

In this case, by simultaneously measuring the heights of the plurality of the exposed portions and the surface of the bus bar, the heights can be easily measured.

In addition, it may be determined whether a difference between the height of the exposed portion and the height of the surface of the bus bar is within a predetermined range.

In this way, by determining whether the difference between the height of the exposed portion of the electrode terminal and the height of the surface of the bas bar is in the predetermined range, it can be checked whether the clearance between the electrode terminal and the bus bar is within an allowable range.

During the measuring of the height of the exposed portion, the height of the surface of the electrode terminal may be measured by measuring the heights of three or more exposed portions.

In this case, by measuring the heights of three or more exposed portions of the electrode terminal, the height and inclination of the surface of the electrode terminal can be measured. Accordingly, the clearance between the electrode terminal and the bus bar can be accurately checked.

In the following, the energy storage apparatus according to an embodiment of the present invention will be described with reference to the drawings. The embodiments which will be described below illustrate preferred examples of the present invention. The numerical values, shapes, materials, constituent elements, located positions and manners of connection of constituent elements, steps (method processes), order of steps and the like which may be indicated in the embodiments are exemplary, and are not to be taken as limiting the present invention. Of constituent elements in the following embodiments, the constituent elements that are not recited in the independent claims setting forth the broadest concepts may be described as being optional constituent elements. In the respective figures, dimensions and the like may not reflect precise dimensions and the like.

EMBODIMENTS

The configuration of an energy storage apparatus1will be described.

FIG. 1is a perspective view illustrating an exterior view of the energy storage apparatus1according to an embodiment of the present invention.FIG. 2is an exploded perspective view illustrating constituent elements of the energy storage apparatus1according to the embodiment of the present invention as disassembled.

In the figures, a Z-axis direction is shown as a vertical direction, and the Z-axis direction will be hereafter described as being the vertical direction. However, depending on the mode of use, the Z-axis direction may not correspond to the vertical direction. Accordingly, the Z-axis direction is not limited to the vertical direction.

The energy storage apparatus1is a device that can be charged with electricity from the outside and discharge electricity to the outside. For example, the energy storage apparatus1is a battery module used for electric power storage purpose or power supply purpose.

As illustrated in the figures, the energy storage apparatus1is provided with an outer case10including a first outer case11and a second outer case12; and an energy storage unit30and an electric device40which are housed in the outer case10.

The outer case10is a rectangular (box-shaped) container (module case) which is disposed outside the energy storage unit30and the electric device40, and which constitutes an outer case of the energy storage apparatus1. Specifically, the outer case10locates the energy storage unit30and the electric device40at predetermined positions, and protects the energy storage unit30and the electric device40from shocks and the like. The outer case10is made from an insulating resin and the like, such as polycarbonate or polypropylene (PP), thus preventing the energy storage unit30and the electric device40from contacting external metal members and the like.

The outer case10includes the first outer case11and the second outer case12. The first outer case11constitutes a lid of the outer case10. The second outer case12constitutes a body of the outer case10. The first outer case11is a flat rectangular cover member closing an opening of the second outer case12, and is fitted with a positive electrode external terminal21and a negative electrode external terminal22. The energy storage apparatus1is charged with electricity from the outside, or discharges electricity to the outside, via the positive electrode external terminal21and the negative electrode external terminal22. The second outer case12is a rectangular cylindrical housing having a bottom and formed with an opening, and houses the energy storage unit30and the electric device40.

The first outer case11and the second outer case12may be formed from members of the same material, or members of different materials.

The energy storage unit30includes a plurality of energy storage devices, and is connected to the positive electrode external terminal21and the negative electrode external terminal22on the first outer case11. In the present embodiment, as illustrated inFIG. 2, the energy storage unit30is disposed in the second outer case12with the plurality of energy storage devices laterally laid and stacked in the Z-axis direction. The energy storage unit30is housed in the outer case10with the first outer case11covering the same from above. The detailed description of the configuration of the energy storage unit30will be made later.

The electric device40is a rectangular device in which a circuit board, a relay and the like are disposed. The electric device40is disposed to a side of the energy storage unit30(on the plus side in the X-axis direction). In the present embodiment, as illustrated inFIG. 2, the electric device40is disposed upright in the Z-axis direction in the second outer case12, with the circuit board vertically arranged. The electric device40is housed in the outer case10with the first outer case11covering the same from above.

The circuit board provided in the electric device40is connected by wiring (leading wire) to the positive electrode terminal or the negative electrode terminal of each of the energy storage devices in the energy storage unit30. For example, the circuit board acquires a charge state and discharge state (battery state such as voltage and temperature) of the energy storage device for monitoring and control purposes.

The configuration of the energy storage unit30will be described in detail.

FIGS. 3 and 4are perspective views illustrating the configuration of the energy storage unit30according to an embodiment of the present invention. Specifically,FIG. 3is the exploded perspective view illustrating the configuration in which a bus bar frame500and a bus bar600are separated from the energy storage unit30.FIG. 4is the exploded perspective view illustrating constituent elements obtained by disassembling the constituent elements that remain after the bus bar frame500and the bus bar600have been separated from the energy storage unit30.

In these and subsequent figures, for convenience of description, a Y-axis direction is shown as a vertical direction. While the Y-axis direction may be described as being the vertical direction in some parts, the Y-axis direction may not necessarily correspond to the vertical direction in an actual mode of use.

As illustrated in the figures, the energy storage unit30is provided with a plurality of energy storage devices100(in the present embodiment, eight energy storage devices100); a plurality of spacers200(in the present embodiment, seven spacers200); a pair of sandwiching members300; a plurality of restraining members400(in the present embodiment, four restraining members410to440); a bus bar frame500; and a plurality of bus bar600(in the present embodiment, five bus bars610to650).

The energy storage devices100are secondary batteries (batteries) that can be charged with electricity and can discharge electricity. More specifically, the energy storage devices100are nonaqueous electrolyte secondary batteries, such as lithium ion secondary batteries. The energy storage devices100have a flat rectangular shape, and are disposed adjacent to the spacers200. That is, the plurality of energy storage devices100is respectively alternately disposed with the respective plurality of spacers200, and is arranged in the Z-axis direction.

In the present embodiment, the energy storage devices100are disposed laterally in the outer case10(seeFIG. 2). In the figure, however, the energy storage devices100are illustrated as being disposed with the electrode terminals thereof facing upward for convenience of description. The energy storage devices100are not limited to the nonaqueous electrolyte secondary batteries. The energy storage devices100may be secondary batteries other than nonaqueous electrolyte secondary batteries, or may be capacitors. The detailed description of the configuration of the energy storage devices100will be made later.

The spacers200are disposed between two adjacent energy storage devices100, and are insulating plate-like members formed from a resin and the like for providing insulation between the two energy storage devices100. In the present embodiment, between the eight energy storage devices100, seven spacers200are disposed. The spacers200are formed from an insulating resin, such as polycarbonate, polypropylene (PP) or the like, for example. The spacers200may be formed from any material as long as the members have insulating property.

The spacers200are formed so as to cover substantially half (substantially half when divided into two in the Z-axis direction) of the front side or rear side of the energy storage devices100. Specifically, in both surfaces (both surfaces in the Z-axis direction) on the front side or rear side of the spacers200, recess portions are formed. In the recess portions, substantially half of the energy storage devices100are inserted. In this configuration, the two spacers200sandwiching an energy storage device100cover most of the energy storage device100. Accordingly, increased insulating property is achieved by the spacers200between the energy storage devices100and the other conductive members.

The sandwiching members300include sandwiching members310and320which are a pair of planar members. The sandwiching members300sandwich and hold the plurality of energy storage devices100from both sides in the arranged direction (Z-axis direction) of the plurality of energy storage devices100.

Specifically, the sandwiching member310is the planar member which is disposed on the plus side in the Z-axis direction with respect to the energy storage device100disposed on the most-plus side in the Z-axis direction among the plurality of energy storage devices100. The sandwiching member320is the planar member which is disposed on the minus side in the Z-axis direction with respect to the energy storage device100disposed on the most minus side in the Z-axis direction among the plurality of energy storage devices100. With the sandwiching member310and the sandwiching member320, the plurality of energy storage devices100and the plurality of spacers200are sandwiched and held from both sides in the arranged direction (Z-axis direction) of the plurality of energy storage devices100and the plurality of spacers200.

From the viewpoint of strength and the like, the sandwiching members300(sandwiching members310,320) are formed of metal (conductive) members of stainless steel or aluminum, for example. Insulation from the energy storage devices100is ensured by the insulating members disposed between the adjacent energy storage devices100. The sandwiching members300are not limited to metal (conductive) members, and may be formed of insulating members having high strength, for example. The sandwiching member310and the sandwiching member320may be formed of members of the same material or members of different materials.

The restraining members400are members of which both ends are attached to the sandwiching members300to restrain the plurality of energy storage devices100. Specifically, the restraining members400are disposed so as to straddle the plurality of energy storage devices100, thereby providing the plurality of energy storage devices100with restraining force in the arranged direction (Z-axis direction) of the plurality of energy storage devices. Preferably, the restraining members400are formed of metal members of stainless steel or aluminum, for example, as in the case of the sandwiching members300. The restraining members400, however, may be formed of non-metal members, for example.

Specifically, the restraining members400have one end attached to the sandwiching member310, and the other end attached to the sandwiching member320. The restraining members400provide the plurality of energy storage devices100and the plurality of spacers200with restraining force in the arranged direction of the plurality of energy storage devices100and the plurality of spacers200.

The restraining members400include the restraining members410to440. The restraining members410and420are disposed on both sides in the vertical direction (both sides in the Y-axis direction) of the plurality of energy storage devices100, thereby sandwiching and restraining the plurality of energy storage devices100from the both sides. The restraining members430and440are disposed on both sides of the plurality of energy storage devices100(both sides in the X-axis direction), thereby sandwiching and restraining the plurality of energy storage devices100from the both sides.

Specifically, the restraining member410and the restraining member420are a pair of elongated and planar members disposed on the plus side and minus side in the Y-axis direction of the plurality of energy storage devices100. The restraining member430and the restraining member440are a pair of elongated and planar members disposed on the plus side and minus side in the X-axis direction of the plurality of energy storage devices100.

The bus bar frame500is a member that can provide insulation between the bus bar600and the other members, protect various wiring and the like disposed in the energy storage apparatus1, and regulate the position of the bus bar600. In particular, the bus bar frame500positions the bus bar600with respect to the plurality of energy storage devices100.

Specifically, the bus bar frame500is placed over the plurality of energy storage devices100(on the plus side in the Y-axis direction), and is positioned with respect to the plurality of energy storage devices100. On the bus bar frame500, the bus bar600is placed. As protruding portions of the bus bar frame500are inserted into opening portions formed in the bus bar600, the bus bar600is positioned with respect to the bus bar frame500. In this way, the bus bar600is positioned with respect to the plurality of energy storage devices100, and bonded to the respective electrode terminals of the plurality of energy storage devices100.

While the bus bar frame500is formed from insulating resin such as polycarbonate or polypropylene (PP), for example, the bus bar frame500may be formed from any material as long as the member has insulating property. The detailed configuration of the bus bar frame500, and the detailed configuration in which the bus bar frame500positions the bus bar600will be described later.

The bus bar600is bus bars that are electrically connected to the respective plurality of energy storage devices100. Specifically, the bus bar600is conductive members electrically connected to the respective electrode terminals of the plurality of energy storage devices100. The bus bar600electrically connects some of the electrode terminals of the plurality of energy storage devices100. Specifically, the bus bar600is disposed on the surface of the electrode terminals of the plurality of energy storage devices100, and connected (bonded) to the electrode terminals.

The bus bar600includes the bus bars610to650. The bus bars610to630are bus bars connected to the positive electrode terminals and negative electrode terminals of different energy storage devices100among the plurality of energy storage devices100. The bus bar640is a bus bar connected to the positive electrode terminal of an energy storage device100among the plurality of energy storage devices100, and to the positive electrode external terminal21disposed on the first outer case11. The bus bar650is a bus bar connected to the negative electrode terminal of an energy storage device100among the plurality of energy storage devices100, and to the negative electrode external terminal22disposed on the first outer case11.

Specifically, the bus bars610to630have one ends connected to the positive electrode terminals of two energy storage devices100, and the other ends connected to the negative electrode terminals of other two energy storage devices100different from the two earlier-mentioned energy storage devices100. The bus bar640has one end electrically connected to the positive electrode terminals of two energy storage devices100, and the other end connected to the positive electrode external terminal21. The bus bar650has one end connected to the negative electrode terminals of two energy storage devices100, and the other end electrically connected to the negative electrode external terminal22. In this configuration, the plurality of energy storage devices100has a series connection of every two energy storage devices100connected in parallel by the bus bars610to650(seeFIG. 10).

While the bus bar600(bus bars610to650) are formed from aluminum conductive member, for example, the material of the bus bar600is not particularly limited. All of the bus bars610to650may be formed of members of the same material, or some of the bus bars may be formed of members of different materials.

The configuration of the energy storage devices100will be described in detail.

FIG. 5is a perspective view illustrating the configuration of the energy storage devices100according to an embodiment of the present invention. Specifically, the figure is a perspective view illustrating the inside of the energy storage devices100as viewed through the container110of the energy storage devices100.

As illustrated in the figure, the energy storage device100is provided with the container110, a positive electrode terminal120, and a negative electrode terminal130. The container110houses an electrode assembly140, a positive electrode current collector150, and a negative electrode current collector160. While the container110encapsulates a liquid, such as an electrolyte solution, depiction of the liquid is omitted.

The container110is configured from a rectangular and cylindrical body made of metal with a bottom, and a metal lid portion closing an opening of the body. The inside of the container110can be sealed by, e.g., welding the lid portion and the body after the electrode assembly140and the like are housed therein.

The electrode assembly140is a power generating element which is provided with a positive electrode, a negative electrode, and a separator, and which can store electricity. Specifically, electrode assembly140is a wound electrode assembly formed by winding layers of the positive electrode and the negative electrode with the separator sandwiched between the electrodes. The electrode assembly140may be a stacked electrode assembly including a stack of planar electrode plates.

The positive electrode is an electrode plate of an elongated band-like conductive positive electrode current collector foil of aluminum, aluminum alloy, or the like, on a surface of which a positive active material layer is formed. The negative electrode is an electrode plate of an elongated band-like conductive negative electrode current collector foil of copper, copper alloy, or the like, on a surface of which a negative active material layer is formed. The separator is a microporous sheet. The positive electrode, the negative electrode, and the separator used in the energy storage devices100are not particularly different from those that have been used, and may use known materials as appropriate, unless the performance of the energy storage devices100would be adversely affected. The electrolyte solution (nonaqueous electrolyte) encapsulated in the container110is also not particularly limited, and may use various types unless the performance of the energy storage devices100is adversely affected.

The positive electrode current collector150is a conductive and rigid member which is disposed between the positive electrode of the electrode assembly140and a side wall of the container110, and which is electrically connected to the positive electrode terminal120and the positive electrode. The positive electrode current collector150is formed from aluminum, aluminum alloy, or the like, as is the positive electrode current collector foil of the positive electrode. The negative electrode current collector160is a conductive and rigid member which is disposed between the negative electrode of the electrode assembly140and the side wall of the container110, and which is electrically connected to the negative electrode terminal130and the negative electrode of the electrode assembly140. The negative electrode current collector160is formed from copper, copper alloy, or the like, as is the negative electrode current collector foil of the negative electrode.

The positive electrode terminal120is an electrode terminal electrically connected to the positive electrode of the electrode assembly140via the positive electrode current collector150. The negative electrode terminal130is an electrode terminal electrically connected to the negative electrode of the electrode assembly140via the negative electrode current collector160. Specifically, the positive electrode terminal120and the negative electrode terminal130are metal electrode terminals for outputting the electricity stored in the electrode assembly140to an external space of the energy storage devices100, and for introducing electricity into the energy storage devices100in order to stored electricity in the electrode assembly140.

Specifically, the positive electrode terminal120and the negative electrode terminal130are formed from aluminum, aluminum alloy, or the like. The negative electrode current collector160is formed from copper, copper alloy, or the like which is different from the material of the negative electrode terminal130. Accordingly, the negative electrode terminal130and the negative electrode current collector160are connected via a rivet170formed from copper, copper alloy, or the like. The rivet170is a member for connecting the negative electrode terminal130and the negative electrode current collector160, and for attaching (fixing) the negative electrode terminal130and the negative electrode current collector160to a lid plate of the container110.

The negative electrode terminal130is configured such that a rivet surface171, which is an upper surface (surface on the plus side in the Y-axis direction) of the rivet170, is exposed from a negative electrode terminal surface131, which is an upper surface (a surface on the plus side in the Y-axis direction) of the negative electrode terminal130. Specifically, the rivet170is disposed so as to be exposed from the negative electrode terminal surface131, whereby an recess/convex portion which is a recess portion or a convex portion is formed on the surface of the negative electrode terminal130. In the present embodiment, the rivet surface171is formed so as not to protrude from the negative electrode terminal surface131, and the uneven portion has a recessed shape.

The positive electrode current collector150is formed from the same material as that of the positive electrode terminal120. Accordingly, the positive electrode terminal120has a shape integrally including a rivet with the same function as the rivet170. Thus, from a positive electrode terminal surface121which is an upper surface (a surface on the plus side in the Y-axis direction) of the positive electrode terminal120, the rivet is not exposed, and the positive electrode terminal surface121is a flat surface.

The configuration of the bus bar600(bus bars610to650) will be described in detail. Because the bus bars610to630have similar configurations, the configuration of the bus bar610will be described in detail, and a description of the configurations of the bus bars620and630will be simplified or omitted. Also, a description of the configurations of the bus bars640and650will be simplified or omitted because they are partly similar to that of the bus bar610.

FIG. 6is a perspective view illustrating the configuration of the bus bar610according to the embodiment of the present invention.FIG. 7is a plan view illustrating the configuration of the bus bar610according to the embodiment of the present invention. Specifically,FIG. 7is a plan view illustrating the configuration of the bus bar610as viewed from the plus side in the Y-axis direction.

As illustrated in the figures, the bus bar610includes a plurality of terminal connecting portions (in the present embodiment, four terminal connecting portions611to614); a plurality of parallel connecting portions (in the present embodiment, two parallel connecting portions615and616); and a series connecting portion617.

The terminal connecting portions611to614are rectangular and planar connecting portions connected to the respective electrode terminals (the positive electrode terminal120or the negative electrode terminal130) of the plurality of energy storage devices100. Specifically, the terminal connecting portions611to614are plate-like regions extending on an X-Z plane, and are arranged in the Z-axis direction.

In the terminal connecting portion611, four opening portions611ato611dare formed as a plurality of opening portions. The opening portions611ato611dare cut-outs (recess portions) formed in outer edge portions of the terminal connecting portion611, and are formed such that the surface of the electrode terminal of the energy storage devices100is exposed.

The surface of the electrode terminal being exposed from the opening portions refers to a state in which, the opening portions are formed in positions close to the surface of the electrode terminal, and the surface of the electrode terminal is visible from the opening portion as viewed from the outside of the opening portions (and in a direction perpendicular to the surface of the electrode terminal).

Specifically, the opening portion611ais a substantially rectangular cut-out formed in an end portion of the terminal connecting portion611on the minus side in the X-axis direction and on the minus side in the Z-axis direction. The opening portion611bis a substantially semicircular cut-out formed in an outer edge portion of the terminal connecting portion611on the minus side in the X-axis direction and on the plus side in the Z-axis direction. The opening portion611cis a substantially rectangular cut-out formed in the end portion of the terminal connecting portion611on the plus side in the X-axis direction and on the minus side in the Z-axis direction. The opening portion611dis a substantially semicircular cut-out formed in the outer edge portion of the terminal connecting portion611on the plus side in the X-axis direction and on the plus side in the Z-axis direction.

In the terminal connecting portion612, as a plurality of opening portions, four opening portions612ato612dare formed. The opening portions612ato612dare cut-outs (recess portions) formed in the outer edge portion of the terminal connecting portion612, and are formed such that the surface of the electrode terminal of the energy storage devices100is exposed.

Specifically, the opening portion612ais a substantially semicircular cut-out formed in the outer edge portion of the terminal connecting portion612on the minus side in the X-axis direction and on the minus side in the Z-axis direction. The opening portion612bis a substantially semicircular cut-out formed in the outer edge portion of the terminal connecting portion612on the minus side in the X-axis direction and on the plus side in the Z-axis direction. The opening portion612cis a substantially semicircular cut-out formed in the outer edge portion of the terminal connecting portion612on the plus side in the X-axis direction and on the minus side in the Z-axis direction. The opening portion612dis a substantially semicircular cut-out formed in the outer edge portion of the terminal connecting portion612on the plus side in the X-axis direction and on the plus side in the Z-axis direction.

In the terminal connecting portion613, as a plurality of opening portions, three opening portions613ato613care formed. The opening portions613aand613bare cut-outs (recess portions) formed in an outer edge portion of the terminal connecting portion613. The opening portion613cis a through-hole formed in the terminal connecting portion613. The opening portions613ato613care formed such that the surface of the electrode terminal of the energy storage devices100is exposed.

Specifically, the opening portion613ais a substantially semicircular cut-out formed in the outer edge portion of the terminal connecting portion613on the minus side in the X-axis direction and on the minus side in the Z-axis direction. The opening portion613bis a substantially semicircular cut-out formed in the outer edge portion of the terminal connecting portion613on the minus side in the X-axis direction and on the plus side in the Z-axis direction. The opening portion613cis a circular through-hole formed in the terminal connecting portion613on the plus side in the X-axis direction and in the center portion in the Z-axis direction, cutting through the terminal connecting portion613in the Y-axis direction.

In the end portion on the plus side in the X-axis direction of the terminal connecting portion613, a wiring connecting portion613dfor connecting a wire for monitoring the state of the bus bar610in terms of voltage and the like is formed. For this reason, the opening portion613cis formed not as a cut-out but as a through-hole on the plus side in the X-axis direction of in the terminal connecting portion613. In an alternative configuration, the terminal connecting portion613may not include the wiring connecting portion613d, and a cut-out may also be formed on the plus side in the X-axis direction of the terminal connecting portion613.

In the terminal connecting portion614, as a plurality of opening portions, four opening portions614ato614dare formed. The opening portions614ato614dare cut-outs (recess portions) formed in an outer edge portion of the terminal connecting portion614such that the surface of the electrode terminal of the energy storage devices100is exposed.

Specifically, the opening portion614ais a substantially semicircular cut-out formed in the outer edge portion on the minus side in the X-axis direction and on the minus side in the Z-axis direction of the terminal connecting portion614. The opening portion614bis a substantially rectangular cut-out formed in the end portion on the minus side in the X-axis direction and on the plus side in the Z-axis direction of the terminal connecting portion614. The opening portion614cis a substantially semicircular cut-out formed in the outer edge portion on the plus side in the X-axis direction and the minus side in the Z-axis direction of the terminal connecting portion614. The opening portion614dis a substantially rectangular cut-out formed in the end portion on the plus side in the X-axis direction and on the plus side in the Z-axis direction of the terminal connecting portion614.

The plurality of opening portions611a,611b,612a,612b,613a,613b,614a, and614bis formed so as to be linearly arranged in the arranged direction of the terminal connecting portions611to614. Similarly, the plurality of opening portions611c,611d,612c,612d,613c,614c, and614dis formed so as to be linearly arranged in the arranged direction of the terminal connecting portions611to614.

The shape of the opening portions611ato611d,612ato612d,613ato613c, and614ato614dis not limited to the shapes described above, and may be any shape. The size of the openings of the opening portions is not particularly limited; preferably, however, the size is a minimum size allowing the measurement of the height of exposed portions of the electrode terminals of the energy storage devices100which are exposed from the opening portions, as will be described later.

The parallel connecting portions615and616are bent-plate shaped regions which are disposed between the terminal connecting portions611to614, and which are formed so as to protrude in a curve on the plus side in the Y-axis direction. Specifically, the parallel connecting portion615is a portion disposed between the terminal connecting portions611and612. The parallel connecting portion616is a portion disposed between the terminal connecting portions613and614.

The series connecting portion617is a portion disposed between the terminal connecting portions612and613, and is a bent-plate shaped region formed so as to protrude in a curve on the plus side in the Y-axis direction. The series connecting portion617has an outer shape similar to the terminal connecting portions613and614. The terminal connecting portions611to614, the parallel connecting portions615and616, and the series connecting portion617are disposed so as to be linearly arranged in the Z-axis direction.

In each of the parallel connecting portions615and616, a plurality of opening portions is formed. Specifically, in the parallel connecting portion615, two opening portions615aand615barranged in the X-axis direction are formed. In the parallel connecting portion616, two opening portions616aand616barranged in the X-axis direction are formed. The opening portions615aand615bare circular through-holes penetrating through the parallel connecting portion615in the Y-axis direction. The opening portions616aand616bare circular through-holes penetrating through the parallel connecting portion616in the Y-axis direction.

The shape of the opening portions615a,615b,616a, and616bmay not be circular, and may instead be rectangular and the like. The opening portions615a,615b,616a, and616bmay not be through-holes, and may instead be cut-outs (recess portions) and the like formed in the outer edges of the parallel connecting portions615or616.

The configuration of the bus bar frame500will be described in detail.

FIG. 8is a perspective view illustrating the configuration of the bus bar frame500according to the embodiment of the present invention.FIG. 9is a perspective view illustrating the configuration of the bus bar frame500according to the embodiment of the present invention, with the bus bar600(bus bars610,640, and650) disposed thereon.

As illustrated inFIG. 8, the bus bar frame500includes a rectangular and planar bus bar frame body portion510. The bus bar frame body portion510is a region which constitutes the body of the bus bar frame500. The bus bar frame body portion510includes eight support portions511to518for placing and supporting the bus bar600.

The support portions511to518are elongated (bar-like) regions for placing and supporting the bus bars610to650. Specifically, the support portions511to514are disposed in the portion on the plus side in the X-axis direction of the bus bar frame body portion510, and are arranged in the Z-axis direction in order from the minus side in the Z-axis direction. The support portions515to518are disposed in the portion on the minus side in the X-axis direction of the bus bar frame body portion510, and arranged in the Z-axis direction in order from the minus side in the Z-axis direction.

In this way, the support portion511supports the bus bar640; the support portions512and513support the bus bar610; and the support portion514supports the bus bar650. The support portions515and516support the bus bar620, and the support portions517and518support the bus bar630.

Each of the support portions511to518includes two protruding portions for positioning the bus bars610to650with respect to the plurality of energy storage devices100. Specifically, the support portions511to518include protruding portions521to528. The protruding portions521to528are disposed in the opening portions formed in the bus bars610to650, thus positioning the bus bars610to650with respect to the plurality of energy storage devices100.

In this configuration, as illustrated inFIG. 9, for example, the protruding portions522and523of the bus bar frame500are disposed in the opening portions615a,615b,616a, and616bformed in the parallel connecting portions615and616of the bus bar610, whereby the bus bar610is disposed on the bus bar frame500.

Specifically, the support portions512and513of the bus bar frame500are disposed in the curved recess portions of the parallel connecting portions615and616, whereby the parallel connecting portions615and616are disposed on the support portions512and513of the bus bar frame500. In this case, the protruding portions522and523of the bus bar frame500are inserted into the opening portions615a,615b,616a, and616bof the bus bar610. In this way, the bus bar610is positioned on the bus bar frame500, and is therefore positioned with respect to the plurality of energy storage devices100. The same applies to the other bus bars.

FIGS. 10 to 12illustrate the bus bar600thus positioned and disposed with respect to the plurality of energy storage devices100.

FIG. 10is a perspective view illustrating the configuration in which the bus bar600(bus bars610to650) are disposed on the plurality of energy storage devices100(energy storage devices101to108) according to the embodiment of the present invention.FIG. 11is a plan view illustrating the configuration in which the bus bar610is disposed on the plurality of energy storage devices100(energy storage devices103to106) according to the embodiment of the present invention.

FIG. 12is a plan view illustrating the configuration in which the bus bar610is disposed on and bonded to the plurality of energy storage devices100(energy storage devices103to106) according to the embodiment of the present invention. In the figure, the terminal connecting portions612and613of the bus bar610are omitted, and only the terminal connecting portions611and614are illustrated.

These figures illustrate the configuration in which the bus bar600is disposed on the energy storage devices100, while omitting the bus bar frame500for convenience of description. In addition, in these figures, the eight energy storage devices100arranged in the Z-axis direction are illustrated as being the energy storage devices101to108in order from the minus side in the Z-axis direction. While only the bus bar610may be illustrated or described in some parts of the following descriptions, the other bus bars may be similar to the bus bar610.

As illustrated in the figures, the terminal connecting portion611is connected to the negative electrode terminal130of the energy storage device103, and the terminal connecting portion612is connected to the negative electrode terminal130of the energy storage device104. The terminal connecting portion613is connected to the positive electrode terminal120of the energy storage device105, and the terminal connecting portion614is connected to the positive electrode terminal120of the energy storage device106.

Specifically, the terminal connecting portion611is placed on the negative electrode terminal surface131so as to cover substantially the entire surface of the negative electrode terminal surface131of the negative electrode terminal130of the energy storage device103, and has the lower surface (the surface on the minus side in the Y-axis direction) bonded to the negative electrode terminal surface131. The terminal connecting portion612is placed on the negative electrode terminal surface131so as to cover substantially the entire surface of the negative electrode terminal surface131of the negative electrode terminal130of the energy storage device104, and has the lower surface (the surface on the minus side in the Y-axis direction) bonded to the negative electrode terminal surface131.

The terminal connecting portion613is placed on the positive electrode terminal surface121so as to cover substantially the entire surface of the positive electrode terminal surface121of the positive electrode terminal120of the energy storage device105, and has the lower surface (the surface on the minus side in the Y-axis direction) bonded to the positive electrode terminal surface121. The terminal connecting portion614is placed on the positive electrode terminal surface121so as to cover substantially the entire surface of the positive electrode terminal surface121of the positive electrode terminal120of the energy storage device106, and has the lower surface (the surface on the minus side in the Y-axis direction) bonded to the positive electrode terminal surface121.

Thus, the energy storage device103and the energy storage device104are connected in parallel, and the energy storage device105and the energy storage device106are also connected in parallel. The energy storage device103and energy storage device104and the energy storage device105and energy storage device106are connected in series.

The plurality of opening portions formed in the terminal connecting portions of the bus bar610is formed such that the surfaces of the electrode terminals of the energy storage devices100are exposed. Specifically, the plurality of opening portions is formed such that the outer periphery portions of the surfaces of the electrode terminals are exposed.

That is, the opening portions611ato611dformed in the terminal connecting portion611are formed such that respective exposed portions131ato131din the outer periphery portion of the negative electrode terminal surface131of the negative electrode terminal130of the energy storage device103are exposed. The opening portions612ato612dformed in the terminal connecting portion612are formed such that respective exposed portions132ato132din the outer periphery portion of the negative electrode terminal surface131of the negative electrode terminal130of the energy storage device104is exposed.

Similarly, the opening portions613ato613cformed in the terminal connecting portion613are formed such that respective exposed portions121ato121cin the outer periphery portion of the positive electrode terminal surface121of the positive electrode terminal120of the energy storage device105is exposed. The opening portions614ato614dformed in the terminal connecting portion614are formed such that respective exposed portions122ato122din the outer periphery portion of the positive electrode terminal surface121of the positive electrode terminal120of the energy storage device106is exposed.

Thus, the bus bar610is placed on the electrode terminals so as to cover substantially the entire surfaces of the electrode terminal surfaces in order to ensure a large contact area with the electrode terminals of the energy storage devices100. However, some of the electrode terminal surfaces are exposed from the opening portions. Specifically, the bus bar610, with respect to each of the electrode terminals of the plurality of energy storage devices100, has three or more opening portions that are formed such that the surface of the electrode terminal is exposed. The three or more opening portions are formed such that the exposed portions of the surface of the electrode terminal are nonlinearly arranged. That is, because the three or more opening portions are formed so as to be nonlinearly arranged, the exposed portions are nonlinearly arranged. For example, the opening portions611ato611dare formed at the four corners of the terminal connecting portion611such that the exposed portions131ato131dare nonlinearly arranged.

The plurality of opening portions formed in the terminal connecting portions of the bus bar610is formed such that the exposed portions of the surfaces of the electrode terminals of the energy storage devices100are linearly arranged. That is, the plurality of opening portions is formed such that the exposed portions are linearly arranged in a plurality of lines (in the present embodiment, two lines).

Specifically, the opening portions611a,611b,612a,612b,613a,613b,614a, and614bare formed such that the exposed portions131a,131b,132a,132b,121a,121b,122a, and122bare linearly arranged. Similarly, the opening portions611c,611d,612c,612d,613c,614c, and614dare formed such that the exposed portions131c,131d,132c,132d,121c,122c, and122dare linearly arranged.

As illustrated inFIG. 10, the plurality of opening portions formed in the terminal connecting portions of the bus bars640,610, and650is formed such that the exposed portions of the surfaces of the electrode terminals are linearly arranged. Similarly, the plurality of opening portions formed in the terminal connecting portions of the bus bars620and630is formed such that the exposed portions of the surfaces of the electrode terminals of the energy storage devices100are linearly arranged.

As illustrated inFIG. 12, the terminal connecting portions611to614of the bus bar610are bonded to the respective electrode terminals by laser welding and the like.

The plurality of opening portions formed in the terminal connecting portions611to614is disposed outside the portions where the bus bar610and the electrode terminals are bonded. The bus bar610has an electrode terminal side surface bonded to the surfaces of the electrode terminals.

Specifically, the opening portions611ato611dformed in the terminal connecting portion611is disposed outside bonding portions611eand611fwhere the bus bar610and the negative electrode terminal130of the energy storage device103are bonded. That is, the opening portions611aand611bare disposed on the minus side in the X-axis direction of the bonding portion611e, and the opening portions611cand611dare disposed on the plus side in the X-axis direction of the bonding portion611f.

The bonding portions611eand611fare portions where the terminal connecting portion611of the bus bar610is bonded to the negative electrode terminal130of the energy storage device103. Specifically, the bonding portions611eand611fof the terminal connecting portion611are irradiated with laser light and thereby laser welded (penetration welded), for example, whereby the surface of the terminal connecting portion611on the negative electrode terminal130side is bonded to the negative electrode terminal surface131of the negative electrode terminal130.

Similarly, the opening portions614ato614dformed in the terminal connecting portion614are disposed outside bonding portions614eand614fwhere the bus bar610and the positive electrode terminal120of the energy storage device106are bonded. That is, the opening portions614aand614bare disposed on the minus side in the X-axis direction of the bonding portion614e, and the opening portions614cand614dare disposed on the plus side in the X-axis direction of the bonding portion614f. The bonding portions614eand614fof the terminal connecting portion614are laser welded, for example, whereby the surface of the terminal connecting portion614on the positive electrode terminal120side is bonded to the positive electrode terminal surface121of the positive electrode terminal120. The same applies to the terminal connecting portions612and613.

The plurality of opening portions formed in the terminal connecting portions611to614is formed such that portions different from the uneven portions in the surfaces of the electrode terminals. Specifically, the opening portions611ato611dformed in the terminal connecting portion611are formed such that portions of the negative electrode terminal surface131of the negative electrode terminal130of the energy storage device103that are different from the uneven portion (where the rivet170is exposed). The same applies to the terminal connecting portion612.

With regard to the terminal connecting portions613and614, the above configuration is not present because of the absence of the uneven portion in the positive electrode terminal surfaces121. When the uneven portion is formed in the positive electrode terminal surface121, the plurality of opening portions is formed such that portions of the positive electrode terminal surface121different from the uneven portion are exposed.

By checking the clearance between the bus bars610to650and the respective electrode terminals of the energy storage devices100, bonding failures during the bonding of the bus bars610to650and the electrode terminal can be reduced. For this purpose, the checking is preferably implemented before and/or after bonding the bus bars610to650to the respective electrode terminals of the energy storage devices100. In the following, a method for checking the energy storage apparatus1will be described in detail.

FIG. 13is a flowchart for describing the checking method for the energy storage apparatus1according to the embodiment of the present invention.FIGS. 14 and 15are figures for describing the checking method for the energy storage apparatus1according to the embodiment of the present invention.

Specifically,FIG. 14is a plan view illustrating the configuration in which the bus bar600is placed on the electrode terminals of the energy storage devices100. That is, the figure is a top plan ofFIG. 10as viewed from above (on the plus side in the Y-axis direction).FIG. 15is a cross sectional view taken at the position of the opening portions formed in the terminal connecting portions of the bus bar600, with the bus bar600placed on the electrode terminals of the energy storage devices100. Specifically, the figure is a figure for describing the measurement of the height of the surfaces of the electrode terminals of the energy storage devices100and the bus bar600, using a measurement device2. In these figures, constituent elements other than the bus bar600and the energy storage devices100, such as the bus bar frame500, are omitted.

First, as illustrated inFIG. 13, the height of the exposed portions of the surfaces of the electrode terminals of the energy storage devices100, and the height of the surface of the bus bar600is measured (S102).

Specifically, as illustrated inFIG. 14, the height of the exposed portions of the surfaces of the electrode terminals that are exposed from the opening portions formed in the terminal connecting portions of the bus bar600placed on the surfaces of the electrode terminals of the energy storage devices100, and the height of the surface of the bus bar600are measured. For example, in row L1, of the exposed portions of the surfaces of the electrode terminals exposed from the plurality of the opening portions of the bus bars640,610, and650, the height of each of the linearly arranged plurality of the exposed portions, and the height of the surface of the bus bar600on the same line as the exposed portions are measured.

In the present embodiment, the linearly arranged plurality of the exposed portions and the surface of the bus bar600are irradiated with light (for example, laser light) simultaneously, using the measurement device, so as to simultaneously measure the height of the linearly arranged plurality of the exposed portions and the height of the surface of the bus bar600. Specifically, in row L1, the height of the plurality of the exposed portions and the height of the surface of the bus bar600are simultaneously measured, and then the height of the plurality of the exposed portions and the height of the surface of the bus bar600are simultaneously measured in the order of rows L2, L3, and L4. Accordingly, by moving the measurement device four times, the height of the exposed portions of the electrode terminals of all energy storage devices100included in the energy storage apparatus1, and the height of the surface of the bus bar600can be measured.

With reference toFIG. 15, the measurement of the height of the plurality of the exposed portions and the height of the surface of the bus bar600using the measurement device will be further described in detail. FIG.15is a figure for describing, as an example of the height measurement, the measurement of the height of the surfaces of the electrode terminals and the bus bar610using the measurement device2, with the bus bar610illustrated inFIG. 14being disposed on the electrode terminals of the energy storage devices103to106.

As illustrated inFIG. 15, the measurement device2is disposed at a certain interval from the bus bar610and in parallel with the bus bar610. As described above, in order to simultaneously measure the height of the plurality of the exposed portions and the height of the surface of the bus bar600in row L1illustrated inFIG. 14, for example, the measurement device2is disposed throughout the bus bars640,610, and650, and at a certain interval from and in parallel with the bus bars640,610, and650. As the measurement device2, for example, a laser displacement sensor (such as a two-dimensional laser displacement sensor from Keyence Corporation) may be used. A laser displacement sensor is a sensor for measuring the amount of displacement from a reference position to an object to be measured by irradiating the object to be measured with laser light. By using a two-dimensional laser displacement sensor, a surface shape of a predetermined width on the object to be measured can be measured.

The measurement device2simultaneously measures the height at the locations of, e.g., points P11to P14, P21to P24, P31, P32, and P41to P44inFIG. 15. The points P11, P14, P21, P24, P32, P41, and P44are measurement points on the exposed portions of the surfaces of the negative electrode terminals130or positive electrode terminals120of the energy storage devices103to106. The points P12, P13, P22, P23, P31, P42, and P43are measurement points on the surface of the bus bar610. For example, the measurement device2measures height h11from the reference surface as the height at point P11. Similarly, the measurement device2measures heights h12to h14from the reference surface as the heights at points P12to P14. The position of the reference surface is not particularly limited.

In this way, the measurement device2measures the height of the plurality of exposed portions of the surfaces of the electrode terminals of all energy storage devices100included in the energy storage apparatus1, and the height of the surface of the bus bar600. While the measurement device2simultaneously measures a plurality of locations, “simultaneous” means the same timing, where it is not necessary that the measurement times for the plurality of locations be completely in alignment, and more or less time displacement may be permitted. The area that the measurement device2can measure at once is not limited to the above, and the height of a single linearly formed exposed portions and the height of the surface of the bus bar600may be measured separately over a plurality of times. The measurement device2may be configured to measure using an infrared sensor or a measurement pin, for example.

Referring back toFIG. 13, it is then determined whether the difference between the height of the exposed portions of the electrode terminals of the energy storage devices100and the height of the surface of the bus bar600is within a predetermined range (S104). Specifically, the clearance between the bus bar600and the electrode terminals of the energy storage devices100is calculated, and it is determined whether the clearance is in an allowable range.

For example, it is determined whether the difference between height h11of the surface of the electrode terminal of the energy storage device100and height h12of the surface of the bus bar600is in the predetermined range. The predetermined range refers to, for example, a range on the order of t±0.1 mm where t is the plate thickness of the bus bar600(i.e., a range of not less than t−0.1 mm and not more than t+0.1 mm). Specifically, it is determined whether the value obtained by subtracting height h11and the plate thickness t of the bus bar600from height h12is in the prescribed range (such as on the order of ±0.1 mm; i.e., the range of not less than −0.1 mm and not more than 0.1 mm). The value obtained by subtracting height h11and the plate thickness t from height h12should theoretically be “0.” However, in light of the processing accuracy of the bus bar600and the measurement accuracy of the measurement device2, for example, it is determined whether the value is a value close to 0.

Similarly, with respect to the other locations, it is determined, e.g., whether the difference between height h14and height h13is within a predetermined range; i.e., whether the value obtained by subtracting height h14and the plate thickness t from height h13is in the prescribed range. The value of the prescribed range is not particularly limited and may be determined by the user as appropriate, such as, for example, a numerical value other than 0.1 mm; within ±several % of the plate thickness t; only an upper limit value; or only a lower limit value.

Referring back toFIG. 13, if the difference between the height of the surface of the electrode terminal of the energy storage device100and the height of the surface of the bus bar600is in the predetermined range (Yes in S104), it is determined that no bonding failure will be caused (S106). That is, if it is determined that the value obtained by subtracting the height of the surface of the electrode terminal and the plate thickness t of the bus bar600from the height of the surface of the bus bar600is in the prescribed range, it is determined that no bonding failure will be caused.

If it is determined that the difference between the height of the surface of the electrode terminal of the energy storage device100and the height of the surface of the bus bar600is outside the predetermined range (No in S104), it is determined that a bonding failure will be caused (S108). That is, if it is determined that the value obtained by subtracting the height of the surface of the electrode terminal and the plate thickness t of the bus bar600from the height of the surface of the bus bar600is not in the prescribed range, it is determined that a bonding failure will be caused.

Preferably, the checking is implemented before bonding the bus bar600and the electrode terminals of the energy storage devices100. When the checking is implemented after the bonding, it may be determined after the fact that no bonding failure has been caused (S106), or a bonding failure has been caused (S108), for example.

By performing the determination as to whether a bonding failure will be caused (has been caused), it becomes possible to correct the positional relation between the energy storage devices100and the bus bar600, or to distinguish the defective product, in response to the result of the determination.

In the present embodiment, the height of the surface of the electrode terminal is calculated using the height of a plurality of exposed portions of the surface of the electrode terminal measured with the measurement device2. That is, the height of the surface of the electrode terminal is measured by measuring the height of three or more exposed portions with respect to one electrode terminal. Specifically, using the measurement device2, by measuring the height of three or more exposed portions that are not on the same line (i.e., disposed so as to be nonlinearly arranged) with respect to one electrode terminal, the height and inclination (surface flatness) of the surface of the electrode terminal of the energy storage device100are calculated.

Also, with regard to the bus bar600, by similarly measuring the height of a plurality of locations (three or more positions disposed so as to be nonlinearly arranged) with respect to one bus bar, the height and inclination (surface flatness) of each bus bar are calculated. During the calculation of the height and inclination of the surfaces of the electrode terminal and the bus bar600, the height and inclination may be more accurately calculated using three or more measurement points. However, the height and inclination may be calculated using one or two measurement points.

Using at least one of the height and inclination of the surface of the electrode terminal of the energy storage device100and the height and inclination of the surface of the bus bar600thus calculated, it may be determined that no bonding failure will be caused (S106), or that a bonding failure will be caused (S108). In addition, using the data of the height and inclination of the surfaces of the electrode terminal and the bus bar600, it becomes possible, when it is determined that a bonding failure will be caused, to estimate a cause of the bonding failure (whether the problem is in the electrode terminal or the bus bar600).

As described above, the energy storage apparatus1according to the embodiment of the present invention is provided with the bus bar600placed on the surfaces of the electrode terminals of the energy storage devices100and connected to the electrode terminals. The bus bar600includes a plurality of opening portions formed such that the surfaces of the electrode terminals are exposed. That is, the surfaces of the electrode terminals of the energy storage devices100are exposed from the plurality of opening portions formed in the bus bar600. Accordingly, by measuring the height of the exposed portions of the surfaces of the electrode terminals, the clearance between the electrode terminals and the bus bar600can be measured. Thus, according to the energy storage apparatus1, the electrode terminals and the bus bar600can be bonded while monitoring the clearance between the electrode terminals of the energy storage devices100and the bus bar600. Accordingly, the occurrence of bonding failures during the bonding of the electrode terminals and the bus bar600can be reduced.

The bus bar600has three or more opening portions formed such that the surfaces of the electrode terminals with respect to each of the electrode terminals are exposed. That is, three or more surface portions of the electrode terminal are exposed from the three or more opening portions, and therefore the height of the three or more exposed portions can be measured. Accordingly, the height and inclination of the surface of the electrode terminal can be calculated from the height of three or more exposed portions of the electrode terminal. Consequently, the clearance between the electrode terminals and the bus bar600can be calculated, whereby the occurrence of bonding failures during the bonding of the electrode terminals and the bus bar600can be reduced.

In addition, the three or more opening portions are formed such that the exposed portions of the surface of the electrode terminal are nonlinearly arranged. Accordingly, the height and inclination of the surface of the electrode terminal can be accurately calculated using the height of the three or more exposed portions that are nonlinearly arranged. Thus, the clearance between the electrode terminal and the bus bar600can be accurately calculated, whereby the occurrence of bonding failures during the bonding of the electrode terminals and the bus bar600can be reduced.

Because the plurality of opening portions formed in the bus bar600is formed such that the outer periphery portion of the surface of the electrode terminal is exposed, the height of the outer periphery portion of the surface of the electrode terminal can be measured. The height of the surface of the electrode terminal can be more accurately calculated from the height of the plurality of locations in the outer periphery portion of the surface of the electrode terminal than from the height of the plurality of locations in the center portion of the surface of the electrode terminal. Accordingly, because the height of the surface of the electrode terminal can be calculated from the height of the outer periphery portion of the surface of the electrode terminal, the height of the surface of the electrode terminal can be more accurately calculated.

In addition, because the plurality of opening portions formed in the bus bar600is formed such that the portions different from the uneven portion in the surface of the electrode terminal are exposed, the height of the portion different from the uneven portion can be measured. Accordingly, even when an uneven portion is formed in the surface of the electrode terminal, the height of the surface of the electrode terminal can be calculated without being affected by the influence of the uneven portion.

By forming cut-outs in the outer edge portion of the bus bar600, a plurality of opening portions is formed in the bus bar600. If through-holes are formed in the center portion of the bus bar600as a plurality of opening portions, the bus bar600may become warped by burrs and the like. Accordingly, by forming cut-outs in the outer edge portion of the bus bar600, warping of the bus bar600on the electrode terminal can be reduced, and the occurrence of bonding failures during the bonding of the electrode terminals and the bus bar600can be reduced.

The plurality of opening portions formed in the bus bar600is formed such that the exposed portions of the surface of the electrode terminal are linearly arranged. Accordingly, when the height of the plurality of exposed portions exposed from the plurality of opening portions is measured, the height of the plurality of exposed portions can be measured by moving the measurement device linearly with respect to the electrode terminal. That is, by the simple operation of moving the measurement device linearly with respect to the electrode terminal, the height of the plurality of exposed portions can be easily measured.

Because the surface of the bus bar600on the electrode terminal side and the surface of the electrode terminal are bonded, the bus bar600and the electrode terminal can be strongly bonded via the face-to-face bonding.

The plurality of opening portions formed in the bus bar600is disposed outside the bonded portion of the bus bar600and the electrode terminal. Accordingly, the plurality of opening portions can be disposed without interfering with the bonding of the bus bar600and the electrode terminal.

In addition, by an checking method for the energy storage apparatus1according to an embodiment of the present invention, the height of the surface of the electrode terminal is measured by measuring the height of the plurality of exposed portions in the surface of the electrode terminal of the energy storage device100that are exposed from the plurality of opening portions formed in the bus bar600. In this way, the clearance between the electrode terminal and the bus bar600can be checked before or after bonding the electrode terminal and the bus bar600. Accordingly, the occurrence of bonding failures during the bonding of the electrode terminal and the bus bar600can be reduced.

By measuring the height of the surface of the bus bar600, the height of the bus bar600and the height of the electrode terminal of the energy storage device100can be compared. Accordingly, the clearance between the electrode terminal and the bus bar600can be checked.

By simultaneously measuring the height of the plurality of exposed portions of the electrode terminal of the energy storage device100and the height of the surface of the bus bar600, the height of the surface of the electrode terminal and the height of the surface of the bus bar600can be easily measured.

By determining whether the difference between the height of the exposed portion of the electrode terminal of the energy storage device100and the height of the surface of the bus bar600is within a predetermined range, it can be checked whether the clearance between the electrode terminal and the bus bar600is in an allowable range.

By measuring the height of three or more exposed portions of the electrode terminal of the energy storage device100, the height and inclination of the surface of the electrode terminal can be measured. Accordingly, the clearance between the electrode terminal and the bus bar600can be accurately checked.

While the energy storage apparatus1according to an embodiment of the present invention has been described, the present invention is not limited to the embodiment. The presently disclosed embodiment is to be taken as exemplary in all aspects rather than restrictive. The scope of the present invention is indicated by the claims rather than by the foregoing description, and is intended to include all modifications within the appended claims and their equivalents.

For example, in the embodiment, the plurality of opening portions (for example, opening portions611ato611d) formed in the terminal connecting portion of the bus bar600is described as being cut-outs (recess portions) formed in the outer edge portion. However, the plurality of opening portions formed in the terminal connecting portion of the bus bar600is not limited to cut-outs, and may be through-holes and the like.

In the embodiment, in the terminal connecting portion of the bus bar600, four opening portion are formed by way of example. However, the number of the opening portions formed in the terminal connecting portion of the bus bar600is not particularly limited. Preferably, however, three or more opening portions may be formed in the terminal connecting portion of the bus bar600in order to measure the height of the plane of bus bar600.

In the embodiment, the plurality of opening portions formed in the terminal connecting portion of the bus bar600is formed such that the outer periphery portion of the surface of the electrode terminal of the energy storage device100is exposed. However, the plurality of opening portions may be formed such that the center portion of the surface of the electrode terminal of the energy storage device100is exposed. In this case, while accuracy may be decreased, the height of the electrode terminal can be measured.

In the embodiment, the plurality of opening portions formed in the terminal connecting portion of the bus bar600is formed such that a portion of the surface of the electrode terminal of the energy storage device100that is different from the uneven portion is exposed. However, the plurality of opening portions may be formed such that the uneven portion is exposed. In this case, the measurement device may measure the height of the exposed portion while avoiding the uneven portion.

In the embodiment, the plurality of opening portions formed in the terminal connecting portion of the bus bar600is disposed outside the bonded portion of the bus bar600and the electrode terminal of the energy storage device100. However, the bonded portion may be disposed outside the plurality of opening portions. In this way, the bus bar600can be bonded to the electrode terminal.

The present invention may be implemented not only as the checking method for the energy storage apparatus1as described above, but also as a checking device provided with a processing unit for performing the characteristic processes included in the checking method for the energy storage apparatus1. In addition, the present invention may be implemented as a program or integrated circuit for causing a computer to execute the characteristic processes included in the checking method for the energy storage apparatus1. The present invention may also be implemented as a computer-readable non-transitory storage medium having the program recorded therein, such as a flexible disc, a hard disk, a CD-ROM, an MO, a DVD, a DVD ROM, a DVD-RAM, a Blu-ray (registered trademark) Disc (BD), or a semiconductor memory. The program may be distributed via storage media such as CD-ROM, and transmission media such as the internet.

The present invention may be implemented not only as the energy storage apparatus1, but also as the bus bar600with which the energy storage apparatus1is provided.

Embodiments combining the constituent elements of the above-described embodiment as desired are also included in the scope of the present invention.

INDUSTRIAL APPLICABILITY

The present invention can be applied to an energy storage apparatus provided with an energy storage device, for example.

DESCRIPTION OF REFERENCE SIGNS