Electric storage module

An electric storage module includes an electric storage cell, a voltage detection board, and a spacer. The electric storage cell has an electric storage element, as well as terminals electrically connected to the positive or negative electrodes of the electric storage element. The voltage detection board has a land and wiring provided on it. The spacer has electrical conductivity and contacts the terminal and the land.

BACKGROUND

Field of the Invention

The present invention relates to an electric storage module constituted by electric storage cells.

Description of the Related Art

Electric storage cells such as lithium ion capacitors are expected to be used within the range between their upper-limit voltage and lower-limit voltage, and once outside this range, they generate gas and can no longer be charged and discharged in a stable manner with ease. For this reason, electric storage modules with built-in electric storage cells are constituted so that the voltages of the electric storage cells are monitored and controlled (refer to Patent Literature 1, for example).

To be specific, electric storage modules constituted by electric storage cells whose terminals are connected to a control board via cables to monitor and control the voltages of the electric storage cells, are common.

BACKGROUND ART LITERATURES

SUMMARY

According to this constitution, however, an increase in the number of electric storage cells installed in the electric storage module increases the number of cables and makes the storing of cables complicated. In addition, while it is possible to press-fit pins into a bus bar which is connected to the electric storage cells and then solder these pins in contact with a control board, this approach requires accuracy of parts and presents a problem in that the pins press-fit into the bus bar make unstable contact.

In light of the aforementioned situations, an object of the present invention is to provide an electric storage module that allows for stable voltage detection and features a simple voltage detection structure.

Any discussion of problems and solutions involved in the related art has been included in this disclosure solely for the purposes of providing a context for the present invention, and should not be taken as an admission that any or all of the discussion were known at the time the invention was made.

To achieve the aforementioned object, the electric storage module pertaining to a mode of the present invention comprises an electric storage cell, a voltage detection board, and a spacer.

The electric storage cell has an electric storage element, as well as terminals electrically connected to the positive or negative electrodes of the electric storage element.

The voltage detection board has a land and wiring provided on it.

The spacer has electrical conductivity and contacts the terminal and the land.

According to this constitution, the terminals of the electric storage cell are electrically connected to the land via the spacer, to allow for voltage detection via the voltage detection board. Since the terminals of the electric storage cell need not be connected to wiring, etc., or soldered, voltage detection is possible based on a simple structure.

The electric storage module may further have a voltage detection board holder that has insulation property, is placed between the terminal and the voltage detection board, and has an opening, and the spacer may contact the terminal and land via the opening.

The electric storage module may have a screw that is inserted through the voltage detection board, spacer, voltage detection board holder, and terminal, to jointly secure the voltage detection board, spacer, voltage detection board holder, and terminal.

The electric storage module may have multiple electric storage cells, and multiple spacers may respectively contact the terminals provided in the electric storage cells as well as multiple lands.

The electric storage cell may be a lithium ion capacitor.

As described above, an electric storage module can be provided, according to the present invention, that allows for stable voltage detection and features a simple voltage detection structure.

DESCRIPTION OF THE SYMBOLS

145- - - Voltage detection board holder cover

DETAILED DESCRIPTION OF EMBODIMENTS

The electric storage module pertaining to an embodiment of the present invention is explained.

[Constitution of Electric Storage Module]

FIG. 1is a perspective view of the electric storage module100pertaining to this embodiment, whileFIG. 2is an exploded perspective view of the electric storage module100. As shown in these figures, the electric storage module100comprises a housing110, electric storage cells120, a first voltage detection unit140, and a second voltage detection unit150. It should be noted that, in each of the figures below, the three directions that are crossing at right angles to each other represent the X direction, Y direction, and Z direction, respectively.

The housing110is constituted by a frame member111, a first sheet member112, and a second sheet member113, as shown inFIG. 2.

The frame member111is a frame-shaped member made of synthetic resin, etc. Mounted on the frame member111are, for example, connectors that are electrically connected to the positive-electrode terminals and negative-electrode terminals of the electric storage cells120, and a board on which control circuits for the electric storage cells120are installed.

The first sheet member112and second sheet member113are sheet-shaped members made of aluminum or other metal. As the first sheet member112and second sheet member113sandwich the frame member111, a housing space R enclosed by the frame member111, first sheet member112, and second sheet member113is formed. The first sheet member112and second sheet member113are secured to the frame member111with screws, etc.

The housing110is not limited to the constitution illustrated herein; instead, it may be constituted in any way so long as a housing space in which the electric storage cells120can be housed is formed.

The electric storage cells120are cells that can be charged and discharged.FIG. 3is a perspective view of an electric storage cell120.FIG. 4is a cross-sectional view of an electric storage cell120, showing a cross-section along line A-A inFIG. 3. As shown in these figures, the electric storage cell120has an electric storage element121, exterior members122, a positive-electrode terminal123, and a negative-electrode terminal124.

The electric storage element121is constituted by positive electrodes125, negative electrodes126and separators127that are layered, as shown inFIG. 4.

The positive electrodes125are each a sheet-shaped member that contains positive electrode material, being a current-collecting foil layered with a positive-electrode material, for example. The current-collecting foil is a porous aluminum foil, for example, and the positive-electrode material is a mixture of activated carbon or other positive-electrode active material and binder resin, etc., for example.

The negative electrodes126are each a sheet-shaped member that contains negative-electrode material, being a current-collecting foil layered with a negative-electrode material, for example. The current-collecting foil is a porous copper foil, for example, and the negative-electrode material is a mixture of graphite or other negative-electrode active material and binder resin, etc., for example.

The separators127are each a sheet-shaped member made of a woven fabric, non-woven fabric, synthetic microporous resin membrane, etc., insulating a positive electrode125and a negative electrode126.

The positive electrodes125and negative electrodes126are layered via the separators127in between, to constitute the electric storage element121. The numbers of positive electrode125and negative electrode126layers are not limited in any way. The electric storage element121is housed inside the exterior members122together with any electrolyte solution.

The exterior members122seal the electric storage element121. The exterior members122may each be a laminate film constituted by a metal foil whose top side and bottom side are both coated with a synthetic resin, where the synthetic resin is thermally fused along the periphery of the electric storage element121.

It should be noted that the exterior members122need not be laminate films, and any members may be used so long as they can seal the electric storage element121.

The positive-electrode terminal123is electrically connected to the positive electrodes125, and led out from between the exterior members122to the outside. The positive-electrode terminal123may be a metal foil or metal sheet made of aluminum, etc. The positive-electrode terminal123has a hole123aprovided in it.

The negative-electrode terminal124is electrically connected to the negative electrodes126, and led out from between the exterior members122to the outside of the exterior members122. The negative-electrode terminal124may be a metal foil or metal sheet made of copper, etc. The negative-electrode terminal124has a hole124aprovided in it.

The electric storage cell120has the constitution described above. However, the electric storage cell120is not limited to the constitution illustrated herein; instead, it may be constituted as a lithium ion capacitor, lithium ion secondary battery, electrical double-layer capacitor, or the like, so long as it can be charged and discharged.

The housing space R can house two sets of electric storage cells120, where each set consists of two stacked electric storage cells120. Additionally, the number of electric storage cells120housed inside the housing space R is not limited, and only one electric storage cell120may be housed in it.

The first voltage detection unit140is a unit for detecting the voltages of the electric storage cells120.FIGS. 5 and 6are exploded perspective views of the first voltage detection unit140, whereFIG. 5is a perspective view of the first voltage detection unit140from the top side, whileFIG. 6is a perspective view of the first voltage detection unit140from the bottom side.

As shown in these figures, the first voltage detection unit140comprises a voltage detection board141, a voltage detection board holder142, spacers143, screws144, and a voltage detection board holder cover145.

The voltage detection board141electrically connects the positive-electrode terminals123and negative-electrode terminals124of the electric storage cells120, and a control board provided in the electric storage module100but not illustrated.FIG. 7is a perspective view of the voltage detection board141. As shown in this figure, the voltage detection board141has holes141aas well as lands141baround them. The lands141bare made of a metal or other conductive material.

Wiring141cis provided on the top and bottom sides of the voltage detection board141. The wiring141celectrically connects the lands141band board terminals141d(refer toFIG. 5).

The voltage detection board holder142is made of an insulation material and supports the voltage detection board141. As shown inFIG. 6, the voltage detection board holder142has openings142aprovided in it.

The spacers143are made of aluminum or other conductive material, and electrically connect the positive-electrode terminal123and the lands141bor electrically connect the negative-electrode terminal124and the lands141b. The spacers143may have a ring-like shape.

The screws144are each inserted through the voltage detection board141, spacer143, voltage detection board holder142, and positive-electrode terminal123, or through the voltage detection board141, spacer143, voltage detection board holder142, and negative-electrode terminal124, to jointly secure them. The screws144may be made of a conductive material or insulation material.

The voltage detection board141, voltage detection board holder142, spacers143, screws144and voltage detection board holder cover145are combined to constitute the first voltage detection unit140.FIGS. 8 and 9are perspective views of the first voltage detection unit140, whereFIG. 8is a perspective view of the first voltage detection unit140from the top side, whileFIG. 9is a perspective view of the first voltage detection unit140from the bottom side.

The spacers143contact the lands141bvia the openings142a(refer toFIG. 7), and the screws144are inserted through the holes141aand the spacers143. In this condition, these members are installed on the electric storage cells120, after which the voltage detection board holder cover145is fitted into the voltage detection board holder142.

The second voltage detection unit150has the same constitution as the first voltage detection unit140; specifically, it comprises a voltage detection board141, a voltage detection board holder142, spacers143, screws144, and a voltage detection board holder cover145.

[Mounting of Voltage Detection Boards]

FIG. 10is a schematic view showing a mode in which the voltage detection boards141are mounted. As shown inFIG. 2, the first voltage detection unit140and second voltage detection unit150are placed over the positive-electrode terminals123and negative-electrode terminals124of the electric storage cells120.

As shown inFIG. 10, bus bars146are provided in the frame member111. The bus bars146are each constituted by a sheet-shaped member made of an insulation material, to which a metal member is fixed. The electric storage cells120are placed in a manner allowing their positive-electrode terminals123and negative-electrode terminals124to contact the metal parts of the bus bars146, respectively, and are thus electrically connected to the positive-electrode terminal and negative-electrode terminal of the electric storage module100via the bus bars146.

Over the positive-electrode terminals123and negative-electrode terminals124, the voltage detection board holder142is placed via the spacers143. The spacers143contact the lands141bon the voltage detection board141via the openings142aprovided in the voltage detection board holder142.

This way, the positive-electrode terminals123and negative-electrode terminals124are electrically connected to the voltage detection board141via the spacers143, and also electrically connected to the board terminals141dvia the wiring141c(refer toFIG. 7). The board terminals141dare connected to a control board which is not illustrated, to detect the voltage of each electric storage cell120.

At the positive electrode, the screw144is inserted through the hole141ain the voltage detection board141, the spacer143, the hole123ain the positive-electrode terminal123, and the hole146ain the bus bar146, to secure the members. At the negative electrode, the screw144is inserted through the hole141ain the voltage detection board141, the spacer143, the hole124ain the negative-electrode terminal124, and the hole146ain the bus bar146, to jointly secure the members.

In other words, the first voltage detection unit140, second voltage detection unit150, electric storage cells120, and bus bars146, are jointly secured by the screws144. Since the components are connected by the screws144, no high machining accuracy is required of each component. In addition, there is no need to connect the voltage detection board141by soldering, etc., which can prevent the reliability from dropping due to the heat from soldering.

In the present disclosure where conditions and/or structures are not specified, a skilled artisan in the art can readily provide such conditions and/or structures, in view of the present disclosure, as a matter of routine experimentation. Also, in the present disclosure including the examples described above, any ranges applied in some embodiments may include or exclude the lower and/or upper endpoints, and any values of variables indicated may refer to precise values or approximate values and include equivalents, and may refer to average, median, representative, majority, etc. in some embodiments. Further, in this disclosure, “a” may refer to a species or a genus including multiple species, and “the invention” or “the present invention” may refer to at least one of the embodiments or aspects explicitly, necessarily, or inherently disclosed herein. The terms “constituted by” and “having” refer independently to “typically or broadly comprising”, “comprising”, “consisting essentially of”, or “consisting of” in some embodiments. In this disclosure, any defined meanings do not necessarily exclude ordinary and customary meanings in some embodiments.

The present application claims priority to Japanese Patent Application No. 2017-197446, filed Oct. 11, 2017, the disclosure of which is incorporated herein by reference in its entirety including any and all particular combinations of the features disclosed therein.