JP2013201358A - Power storage cell and abnormality detecting method for power storage cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power storage cell whose abnormality can be easily detected during use.SOLUTION: A power storage container houses a power storage structure including a nonaqueous electrolyte, a positive electrode, and a negative electrode. A positive electrode terminal connected to the positive electrode is led out of the power storage container. A negative electrode terminal connected to the negative electrode is led out of the power storage container. In the power storage cell, a reference electrode is arranged which is electrically connected to neither the positive electrode nor the negative electrode. A reference terminal is connected to the reference electrode and led out of the power storage container.

Description

  The present invention relates to a storage cell using a non-aqueous electrolyte and an abnormality detection method thereof.

  When manufacturing a storage cell using a non-aqueous electrolyte such as an electric double layer capacitor or a lithium ion secondary battery, defective products are detected by evaluating a voltage drop due to internal resistance, a voltage holding test, or the like. Even if the storage cell is determined to be a non-defective product, the product life varies depending on the product. For this reason, it is desirable to detect a storage cell that has reached the end of its life as a result of use. In particular, when moisture is contained in the storage cell, the capacity of the storage cell and charge / discharge characteristics are reduced due to the reaction between the electrolytic solution and moisture.

  A storage cell in which a positive electrode plate, a negative electrode plate, and a separator are laminated and wound, and then wound with an adhesive winding stopper is known. A pH-responsive polymer is contained in the adhesive layer of the anti-winding tape. When moisture enters the storage cell, the acidity of the electrolytic solution increases and the pH-responsive polymer contracts. Accordingly, the anti-winding tape is peeled off from the laminated structure of the positive electrode plate, the negative electrode plate, and the separator, and the distance between the electrodes is increased. As the distance between the electrodes increases, the internal resistance of the storage cell increases. By detecting this increase in internal resistance, it is possible to determine whether moisture has entered.

JP 2009-16199 A

In the conventional method, it is possible to determine the quality of the storage cell at the time of product shipment, but it is not suitable for determining the deterioration state of the storage cell in the usage state. A technique for determining a deterioration state of a storage cell in a use state is desired.
An object of the present invention is to provide a power storage cell and a power storage module that can easily detect an abnormality during use.

According to one aspect of the invention,
A storage container;
A power storage structure housed in the power storage container and including a non-aqueous electrolyte, a positive electrode, and a negative electrode;
A positive electrode terminal connected to the positive electrode and led out to the outside of the storage container;
A negative electrode terminal connected to the negative electrode and led out to the outside of the storage container;
A reference electrode housed in the storage container and not electrically connected to either the positive electrode or the negative electrode;
There is provided a power storage cell having a reference terminal connected to the reference electrode and led out to the outside of the power storage container.

According to another aspect of the invention,
A storage container;
A power storage structure housed in the power storage container and including a non-aqueous electrolyte, a positive electrode, and a negative electrode;
A positive electrode terminal connected to the positive electrode and led out to the outside of the storage container;
A negative electrode terminal connected to the negative electrode and led out to the outside of the storage container;
A pair of reference electrodes housed in the storage container and not electrically connected to either the positive electrode or the negative electrode;
Measuring a voltage between the pair of reference electrodes of a storage cell having a reference terminal connected to the reference electrode and led to the outside of the storage container;
Comparing a voltage between the pair of reference electrodes and a determination threshold;
When the voltage between the pair of reference electrodes exceeds the determination threshold, the storage cell is determined to be abnormal, and when the voltage between the pair of reference electrodes is equal to or less than the determination threshold, the storage cell is determined to be normal. There is provided a method for determining abnormality of a power storage cell having a determining step.

According to yet another aspect of the invention,
A storage container;
A power storage structure housed in the power storage container and including a non-aqueous electrolyte, a positive electrode, and a negative electrode;
A positive electrode terminal connected to the positive electrode and led out to the outside of the storage container;
A negative electrode terminal connected to the negative electrode and led out to the outside of the storage container;
A reference electrode housed in the storage container and not electrically connected to either the positive electrode or the negative electrode;
Measuring the potential of the positive electrode or the negative electrode with reference to the reference electrode of a storage cell having a reference terminal connected to the reference electrode and led to the outside of the storage container;
Comparing the measured potential with a determination threshold;
A storage cell having a step of determining that the storage cell is abnormal when the measured potential exceeds the determination threshold, and determining that the storage cell is normal when the measured potential is less than or equal to the determination threshold An abnormality determination method is provided.

  By measuring the voltage between the pair of reference terminals or the potential of the positive electrode or the negative electrode with reference to the reference terminal, it is possible to detect the occurrence of an abnormality in the storage cell.

1A is a perspective view of components in a power storage container of a power storage cell according to the first embodiment, and FIG. 1B is a plan view of the power storage cell according to the first embodiment. 2A is a cross-sectional view taken along one-dot chain line 2A-2A in FIG. 1B, and FIG. 2B is a cross-sectional view of the power storage structure and the reference electrode. FIG. 3 is a graph showing temporal variation in normalized capacitance of an evaluation sample having the structure of a storage cell according to Example 1. FIG. 4 is a graph showing the time variation of the voltage between the reference electrodes measured in a state where a voltage of 2.7 V is applied between the positive electrode and the negative electrode of the evaluation sample having the structure of the storage cell according to Example 1. FIG. 5 is a graph showing the time variation of the voltage between the reference electrodes measured in a state where the evaluation sample having the structure of the storage cell according to Example 1 was discharged. FIG. 6 is a cross-sectional view of a power storage module using the power storage cell according to the first embodiment. 7A and 7B are plan views of a storage cell according to a modification of the first embodiment. FIG. 8 is a plan view of a storage cell according to a modification of the first embodiment. FIG. 9 is a perspective view of the components in the storage container of the storage cell according to the modification of the first embodiment. FIG. 10A is a perspective view of components in the storage container of the storage cell according to the second embodiment, and FIG. 10B is a plan view of the storage cell according to the second embodiment. FIG. 11 shows the results of measuring the potentials of the positive electrode and the negative electrode of a sample having the same structure as that of the electricity storage cell according to Example 2, with a voltage of 2.5 V applied between them as a reference. It is a graph. FIG. 12 shows the results of measuring the potentials of the positive electrode and the negative electrode of a sample having the same structure as that of the electricity storage cell according to Example 2, with a voltage of 2.7 V being applied between them as a reference. It is a graph.

[Example 1]
FIG. 1A is a perspective view of components in a storage container of a storage cell according to the first embodiment. The electricity storage structure 20 and the reference electrode 30 are accommodated in the electricity storage container. The power storage structure 20 includes a plurality of plate-like positive electrodes 22 and a plurality of negative electrodes 23 that are alternately stacked. A separator 21 is inserted between the positive electrode 22 and the negative electrode 23. An xyz orthogonal coordinate system in which the stacking direction is the z direction is defined.

  A region where the positive electrode 22 and the negative electrode 23 overlap each other in a virtual plane (xy plane) orthogonal to the stacking direction (z direction) is referred to as a power storage region 27. In the xy in-plane direction, the separator 21 includes the power storage region 27. Each of the positive electrodes 22 includes an interconnection 24 that extends from the power storage region 27 to the outside of the separator 21. Similarly, each negative electrode 23 includes an interconnect 25. Interconnections 24 and 25 are led out from power storage region 27 in the same direction (positive direction of the y-axis). The interconnect parts 24 of the plurality of positive electrodes 22 are arranged at the same position in the x direction. The interconnecting portions 25 of the plurality of negative electrodes 23 are also arranged at the same position in the x direction. The interconnect part 24 and the interconnect part 25 are arranged at different positions in the x direction. The interconnect portions 24 of the positive electrode 22 overlap each other outside the separator 21, and the interconnect portions 25 of the negative electrode 23 overlap each other outside the separator 21.

  The reference electrode 30 includes a pair of reference electrode plates 30A and 30B. The reference electrode plates 30A and 30B are arranged at positions that sandwich the power storage structure 20 in the z direction. That is, the reference electrode plates 30A and 30B are arranged at one end and the other end of the electricity storage structure 20, respectively. Part of the reference electrode plates 30 </ b> A and 30 </ b> B overlaps with the power storage region 27 of the positive electrode 22 and the negative electrode 23. Separator 21 is disposed between one reference electrode plate 30A and power storage structure 20 and between the other reference electrode plate 30A and power storage structure 20.

  Reference electrode plates 30A and 30B include connection portions 31A and 31B, respectively. Connection portions 31A and 31B are led out from power storage region 27 in a direction opposite to interconnection portions 24 and 25 (a negative direction of the y-axis). Further, the connecting portions 31A and 31B are arranged at different positions in the x direction.

  FIG. 1B shows a plan view of the storage cell according to the first embodiment. A positive electrode 22, a negative electrode 23, a separator 21, and a reference electrode 30 are accommodated in the electricity storage container 33. The electricity storage region 27 where the positive electrode 22 and the negative electrode 23 overlap is included in the separator 21 in the xy plane. A positive terminal 35 is connected to the interconnect 24 of the positive electrode 22. A negative terminal 36 is connected to the interconnect 25 of the negative electrode 23. Reference terminals 37A and 37B are connected to connection portions 31A and 31B of reference electrode plates 30A and 30B, respectively. The positive terminal 35, the negative terminal 36, and the reference terminals 37 </ b> A and 37 </ b> B are led out to the outside of the storage container 33. The positive electrode terminal 35 and the negative electrode terminal 36 are led out in the same direction (positive direction of the y axis). The reference terminal 37A and the reference terminal 37B are also led out in the same direction (the negative direction of the y axis).

2A is a cross-sectional view taken along one-dot chain line 2A-2A in FIG. 1B. A power storage container 33 is constituted by the aluminum laminate films 33A and 33B. The power storage structure 20 and the reference electrode 30 are sandwiched between aluminum laminate films 33A and 33B. The reference electrode 30 is electrically separated from both the positive electrode 22 and the negative electrode 23. Aluminum laminate films 33A and 33B are heat-welded to each other at the outer peripheral portion. The positive electrodes 22 and the negative electrodes 23 are alternately stacked. In FIG. 2A, the description of the separator 21 (FIGS. 1A and 1B) is omitted.

  The interconnections 24 of the positive electrode 22 are stacked in the z direction and connected to the positive electrode terminal 35. For example, ultrasonic welding is used to connect the interconnecting portion 24 and the positive terminal 35. The connection portion 31B of the reference electrode plate 30B is ultrasonically welded to the reference terminal 37B. The positive electrode terminal 35 and the reference terminal 37 </ b> B are drawn to the outside of the electricity storage container 33 through between the aluminum laminate films 33 </ b> A and 33 </ b> B.

  FIG. 2B shows a cross-sectional view of the power storage structure 20 and the reference electrode 30. The positive electrode 22 includes a positive electrode current collector 40 and a polarizable electrode 41 for a positive electrode disposed on both surfaces thereof. The negative electrode 23 includes a negative electrode current collector 45 and polarizable electrodes 46 for the negative electrode disposed on both surfaces thereof. For the positive electrode current collector 40 and the negative electrode current collector 45, for example, an aluminum foil is used. The polarizable electrode 41 for the positive electrode is formed, for example, by applying a slurry containing a binder kneaded with activated carbon particles to the surface of the positive electrode current collector 40 and then heating and fixing the slurry. The polarizable electrode 46 for the negative electrode is formed by the same method.

A separator 21 is disposed between the positive electrode 22 and the negative electrode 23. For the separator 21, for example, cellulose paper is used. This cellulose paper is impregnated with a non-aqueous electrolyte. As the solvent for the non-aqueous electrolyte, a polarizable organic solvent such as propylene carbonate, ethylene carbonate, ethyl methyl carbonate or the like is used. As the electrolyte (supporting salt), a quaternary ammonium salt such as TEABF ₄ (tetraethylammonium tetrafluoroborate), TEMABF ₄ (triethylmethylammonium tetrafluoroborate), SBPBF ₄ (spirobipyrrolidinium tetrafluoroborate) or the like is used. . The separator 21 prevents a short circuit between the polarizable electrode 41 for the positive electrode and the polarizable electrode 46 for the negative electrode, and a short circuit between the positive electrode current collector 40 and the negative electrode current collector 45. The positive electrode 22, the negative electrode 23, and the non-aqueous electrolyte constitute an electric double layer capacitor.

  Each of the reference electrode plates 30A and 30B also has the same layer structure as the positive electrode 22 and the negative electrode 23. That is, it includes a current collector 48 and polarizable electrodes 49 arranged on both sides thereof.

  With reference to FIGS. 3-5, the method to determine the deterioration state of the electrical storage cell by Example 1 is demonstrated. In order to conduct a deterioration test of the storage cell, four evaluation samples having the same structure as the storage cell according to Example 1 were prepared.

  FIG. 3 shows the time variation of the capacitance of the four evaluation samples. The atmospheric temperature in the deterioration test was 70 ° C., and a voltage of 2.7 V was applied between the positive electrode 22 and the negative electrode 23. The horizontal axis represents the elapsed time of the degradation test in the unit “time”. The vertical axis represents C / Ci where the initial value of capacitance is Ci and the current value is C, that is, the ratio of the current value to the initial value of capacitance. The triangle symbol, square symbol, rhombus symbol, and circle symbol in FIG. 3 indicate the measurement results of the samples S1, S2, S3, and S4, respectively. The electrostatic capacities of the samples S3 and S4 are rapidly decreased after 400 hours and 600 hours, respectively. It is considered that some abnormality occurred when the capacitance began to drop rapidly. However, it is difficult to measure the capacitance during operation of the storage cell.

4 and 5 show the time variation of the voltage between the reference electrodes of the four evaluation samples. FIG. 4 shows a measurement result when a deterioration test is performed by applying a voltage of 2.7 V between the positive electrode 22 and the negative electrode 23 at an atmospheric temperature of 70 ° C., and FIG. 5 shows a measurement result at the time of discharge. Indicates. The horizontal axis represents the elapsed time of the deterioration test in the unit “time”, and the vertical axis represents the voltage between the reference electrodes in the unit “V”. The triangle symbol, square symbol, rhombus symbol, and circle symbol in FIGS. 4 and 5 indicate the measurement results of the samples S1, S2, S3, and S4, respectively.

  When no abnormality occurs in the evaluation sample, the voltage between the reference electrodes is 0.2 V or less. When an abnormality occurs in the samples S3 and S4, the voltage between the reference electrodes rises exceeding 0.2. The time when the voltage between the reference electrodes rises overlaps with the time when the capacitance suddenly drops. Further, the voltage fluctuation between the reference electrodes shows almost the same tendency in the state in which a voltage of 2.7 V is applied between the positive electrode 22 and the negative electrode 23 and in the discharge state. Since the reference electrode 30 is not electrically connected to either the positive electrode 22 or the negative electrode 23, the voltage between the reference electrodes can be measured even during the operation of the storage cell.

  If the voltage between the reference electrodes exceeds 0.2V, it is highly likely that some abnormality has occurred. Note that the determination threshold for the presence or absence of abnormality can be determined by performing an evaluation experiment on a plurality of samples in the same product group. By measuring the voltage between the reference electrodes of the storage cell in operation, an abnormality of the storage cell can be detected. When the measured voltage exceeds the determination threshold value, it is determined that the storage cell is abnormal. When the measured voltage is less than or equal to the determination threshold, it is determined that the storage cell is normal.

  In the first embodiment, the reference electrode 30 is disposed outside the power storage structure 20 (FIG. 2A), and therefore the reference electrode 30 does not affect the charge / discharge characteristics of the power storage cell.

  FIG. 6 shows a cross-sectional view of a power storage module using the power storage cell according to the first embodiment. The storage cells 50 and the heat transfer plates 51 are alternately stacked. Pressure plates 52 are disposed at both ends in the stacking direction. A plurality of tie rods 53 are bridged from one pressure plate 52 to the other pressure plate 52. A compression force in the stacking direction is applied to the storage cell 50 and the heat transfer plate 51 by the tie rod 53 and the pressure plate 52. By connecting the positive electrode terminal 35 and the negative electrode terminal 36 of the energy storage cells 50 adjacent to each other, the plurality of energy storage cells 50 are connected in series. The heat transfer plate 51 serves as a heat transfer path for cooling the storage cell 50.

  Each reference terminal 37 </ b> A, 37 </ b> B of the storage cell 50 is connected to the abnormality detection circuit 54. The abnormality detection circuit 54 compares the voltage between the reference terminals 37 </ b> A and 37 </ b> B with a predetermined determination threshold for each power storage cell 50. When the voltage between the reference terminals 37A and 37B exceeds the determination threshold, an alarm is issued.

  7A, 7B, and 8 are plan views of power storage cells according to modifications of the first embodiment. In the modification shown in FIG. 7A, the positive electrode terminal 35, the negative electrode terminal 36, and the reference terminals 37A and 37B are led out from the storage container 33 in the same direction (positive direction of the y axis). In this modification, when the storage cells are stacked as shown in FIG. 6, electrical connection only needs to be made from one side surface of the stacked body. The reference terminals 37A and 37B are smaller than the positive terminal 35 and the negative terminal 36. For this reason, the operator can easily distinguish the positive terminal 22 and the negative terminal 23 from the reference terminals 37A and 37B at the time of manufacture.

  In the modification shown in FIG. 7B, the shapes of the reference terminals 37 </ b> A and 37 </ b> B outside the electricity storage container 33 are different from the shapes of the positive electrode terminal 35 and the negative electrode terminal 36 outside the electricity storage container 33. An operator can clearly distinguish the positive terminal 22 and the negative terminal 23 from the reference terminals 37A and 37B. For this reason, it is possible to reduce the frequency of erroneous connection.

In the modification shown in FIG. 8, the positive terminal 35 and the negative terminal 36 are led out from the storage container 33 in opposite directions. Furthermore, one reference terminal 37A and the other reference terminal 37B are led out in directions opposite to each other. In this way, the reference electrode 30 can also be arranged in a storage cell having a terminal arrangement in which the positive electrode terminal 35 and the negative electrode terminal 36 are led out from the storage container 33 in opposite directions.

  In FIG. 9, the perspective view of the component in the electrical storage container of the electrical storage cell by the other modification of Example 1 is shown. Hereinafter, differences from the first embodiment shown in FIG. 1A will be described, and description of the same configuration will be omitted. In the first embodiment, the reference electrode plates 30 </ b> A and 30 </ b> B are disposed outside the power storage structure 20.

  In the modification shown in FIG. 9, the reference electrode plate 30 </ b> A and the reference electrode plate 30 </ b> B are inserted between the positive electrode 22 and the negative electrode 23. Also in this modification, the reference electrode plates 30 </ b> A and 30 </ b> B are electrically separated from both the positive electrode 22 and the negative electrode 23. Specifically, the separators 21 are respectively inserted between the reference electrode plate 30A and the positive electrode 22 and the negative electrode 23 on both sides thereof. Further, separators 21 are inserted between the reference electrode plate 30B and the positive electrode 22 and the negative electrode 23 on both sides thereof.

  When the capacitance of the storage cell is rapidly reduced, an abnormality occurs at the interface between the polarizable electrode 41 (FIG. 2B) of the positive electrode 22 and the polarizable electrode 46 (FIG. 2B) of the negative electrode 23 and the electrolyte. It is thought that. At this time, it is considered that the abnormality occurs in the voltage between the reference electrodes because the same abnormality occurs at the interface between the polarizable electrode 49 (FIG. 2B) of the reference electrode 30 and the electrolytic solution. . When the reference electrode plates 30 </ b> A and 30 </ b> B are inserted into the electricity storage structure 20, the same abnormality as that generated in the polarizable electrodes 41 and 46 of the positive electrode 22 and the negative electrode 23 occurs in the polarizable electrode 49 of the reference electrode 30. Cheap. For this reason, abnormality of an electrical storage cell can be detected earlier.

[Example 2]
FIG. 10A is a perspective view of components in the storage container of the storage cell according to the second embodiment. Hereinafter, differences from the first embodiment shown in FIG. 1A will be described, and description of the same configuration will be omitted. In the first embodiment, the reference electrode 30 includes a pair of reference electrode plates 30A and 30B. In Example 2, the reference electrode 30 includes only one reference electrode plate. One reference electrode 30 is disposed outside the power storage structure 20. The reference electrode 30 includes a connection portion 31 derived from the power storage region 27 with respect to the xy plane. Note that, as illustrated in FIG. 9, the reference electrode 30 may be inserted into the power storage structure 20.

  FIG. 10B is a plan view of the storage cell according to the second embodiment. One reference electrode 30 includes a connection portion 31. A reference terminal 37 is connected to the connection portion 31. The reference terminal 37 is pulled out to the outside of the electricity storage container 33. In Example 2, since only one reference electrode 30 is arranged, the voltage between the reference electrodes cannot be defined. With reference to FIG.11 and FIG.12, the abnormality determination method of the electrical storage cell by Example 2 is demonstrated. As evaluation samples, the four evaluation samples S1, S2, S3, and S4 shown in FIGS. 3 to 5 were used. By not using one reference electrode of the evaluation sample, the abnormality determination of the storage cell having the substantially same structure as the structure according to Example 2 was performed.

  11 and 12 show temporal fluctuations of the potentials of the positive electrode 22 and the negative electrode 23 with respect to the potential of the reference electrode 30. FIG. In any case, the atmospheric temperature of the deterioration test was set to 70 ° C. 11 and 12 show the potentials of the positive electrode 22 and the negative electrode 23 when voltages of 2.5 V and 2.7 V are applied between the positive electrode 22 and the negative electrode 23, respectively. The triangular symbol, square symbol, rhombus symbol, and circle symbol in FIGS. 11 and 12 indicate the measurement results of the samples S1, S2, S3, and S4, respectively.

In the samples S3 and S4, the potentials of the positive electrode 22 and the negative electrode 23 are increased with respect to the potential of the reference electrode 30 almost simultaneously with the time when the capacitance shown in FIG. The occurrence of abnormality can be detected by setting a determination threshold between the potential of the positive electrode 22 and the negative electrode 23 before the occurrence of abnormality and the potential of the positive electrode 22 and the negative electrode 23 after occurrence of abnormality. Since the reference electrode 30 is not electrically connected to any of the positive electrode 22 and the negative electrode 23, it is possible to determine abnormality even during operation of the storage cell.

  By measuring the potential of the positive electrode 22 or the negative electrode 23 of the operating storage cell with the reference electrode 30 as a reference, an abnormality of the storage cell can be detected. When the measured potential exceeds the determination threshold value, it is determined that the storage cell is abnormal. When the measured potential is equal to or lower than the determination threshold, the power storage cell is determined to be normal.

  In Example 1 and Example 2 described above, the storage cell is configured with an electric double layer capacitor. However, the reference electrode is also used for determining the abnormality of other storage structures such as lithium ion capacitors and lithium ion secondary batteries. Can do. Moreover, in the said Example 1 and Example 2, the electrical storage structure 20 was demonstrated about the laminated | stacked electrical storage cell which sealed the aluminum laminate films 33A and 33B (FIG. 2A). In addition, the reference electrode of Example 1 and Example 2 can also be applied to a can-type storage cell in which a positive electrode and a negative electrode are housed in a metallic can.

  Although the present invention has been described with reference to the embodiments, the present invention is not limited thereto. It will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like can be made.

20 Power Storage Structure 21 Separator 22 Positive Electrode 23 Negative Electrode Interconnection 25 Positive Electrode Interconnection 27 Negative Electrode Interconnection 27 Electricity Storage Area 30 Reference Electrode 30A, 30B Reference Electrode Plate 31A, 31B Connection 33 Electricity Storage Container 35 Positive Electrode Terminal 36 Negative Electrode 37A, 37B Reference terminal 40 Positive electrode current collector 41 Positive electrode polarizable electrode 45 Negative electrode current collector 46 Negative electrode polarizable electrode 48 Current collector 49 Polarized electrode 50 Storage cell 51 Heat transfer plate 52 Pressure plate 53 Tie rod 54 Abnormality detection circuit

Claims (12)

A storage container;
A power storage structure housed in the power storage container and including a non-aqueous electrolyte, a positive electrode, and a negative electrode;
A positive electrode terminal connected to the positive electrode and led out to the outside of the storage container;
A negative electrode terminal connected to the negative electrode and led out to the outside of the storage container;
A reference electrode housed in the storage container and not electrically connected to either the positive electrode or the negative electrode;
A storage cell having a reference terminal connected to the reference electrode and led out to the outside of the storage container. Each of the positive electrode and the negative electrode has a plate shape,
The electrical storage cell according to claim 1, wherein the electrical storage structure includes the positive electrode and the negative electrode that are alternately stacked.   The power storage cell according to claim 2, wherein the reference electrode is disposed outside the power storage structure in a stacking direction of the positive electrode and the negative electrode. The reference electrode is disposed between a positive electrode and a negative electrode adjacent to each other that constitute the power storage structure,
Furthermore, the electrical storage cell of Claim 2 which has a separator each arrange | positioned between the said reference electrode and the said positive electrode, and between the said reference electrode and the said negative electrode.   5. The reference electrode according to claim 2, wherein the reference electrode includes a pair of reference electrode plates electrically separated from each other, and the reference terminal is connected to each of the reference electrode plates. 6. Power storage cell.   The power storage cell according to claim 5, wherein the pair of reference electrode plates are arranged so as to sandwich the power storage structure in a stacking direction of the positive electrode and the negative electrode.   The electricity storage according to any one of claims 2 to 6, wherein a shape of an outer portion of the reference terminal of the electricity storage container is different from a shape of an outer portion of the electricity storage container of the positive electrode terminal and the negative electrode terminal. cell.   The power storage cell according to any one of claims 2 to 7, wherein the positive terminal, the negative terminal, and the reference terminal are led out from the power storage container in the same direction.   8. The direction in which the positive electrode terminal and the negative electrode terminal are led out from the power storage container and the direction in which the reference terminal is led out from the power storage container are opposite to each other. The electricity storage cell according to item. Each of the positive electrode and the negative electrode has a layer structure including a current collector and polarizable electrodes disposed on both surfaces of the current collector,
The electrical storage cell according to claim 1, wherein the reference electrode has the same layer structure as the positive electrode and the negative electrode. A storage container;
A power storage structure housed in the power storage container and including a non-aqueous electrolyte, a positive electrode, and a negative electrode;
A positive electrode terminal connected to the positive electrode and led out to the outside of the storage container;
A negative electrode terminal connected to the negative electrode and led out to the outside of the storage container;
A pair of reference electrodes housed in the storage container and not electrically connected to either the positive electrode or the negative electrode;
Measuring a voltage between the pair of reference electrodes of a storage cell having a reference terminal connected to the reference electrode and led to the outside of the storage container;
Comparing a voltage between the pair of reference electrodes and a determination threshold;
When the voltage between the pair of reference electrodes exceeds the determination threshold, the storage cell is determined to be abnormal, and when the voltage between the pair of reference electrodes is equal to or less than the determination threshold, the storage cell is determined to be normal. An abnormality determination method for a power storage cell including a step of determining. A storage container;
A power storage structure housed in the power storage container and including a non-aqueous electrolyte, a positive electrode, and a negative electrode;
A positive electrode terminal connected to the positive electrode and led out to the outside of the storage container;
A negative electrode terminal connected to the negative electrode and led out to the outside of the storage container;
A reference electrode housed in the storage container and not electrically connected to either the positive electrode or the negative electrode;
Measuring the potential of the positive electrode or the negative electrode with reference to the reference electrode of a storage cell having a reference terminal connected to the reference electrode and led to the outside of the storage container;
Comparing the measured potential with a determination threshold;
A storage cell having a step of determining that the storage cell is abnormal when the measured potential exceeds the determination threshold, and determining that the storage cell is normal when the measured potential is less than or equal to the determination threshold Anomaly judgment method.

Images