Method and device for charging energy storage modules

Abstract

To provide a charging method and charging device of a power storage module which greatly improve the convenience when charging a charging module as a secondary battery as compared to a conventional technique.SOLUTION: There is provided a charging method of a power storage module equipped with multiple power storage elements that have different allowable power storage capacities or the variations in the allowable power storage capacities. The power storage module is designed to fully charge the power storage module by fully charging each power storage element. When charging the power storage module, if it is assumed that the power storage element that has the minimum allowable power storage capacity in the multiple power storage elements constitutes all of the multiple power storage elements first, the power storage module collectively performs charging at a time in such a state that the respective power storage elements are connected in series in a range that does not reach a full charge.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a charging device and a charging method for a secondary battery that can continue to be used for a long time by repeatedly charging a user, and more particularly to a charging method and a charging device for a power storage module that can be excellently used for an electric double layer capacitor as a physical secondary battery.

Background Art

[0002] In recent years, for example, chemical secondary batteries represented by lithium ion batteries have been rapidly spreading, and are essential as batteries for mobile phones, electric assist bicycles, electric wheelchairs, etc., which are indispensable tools for life. Furthermore, as part of global warming countermeasures, it is urgent to mass supply to the market by mass production in the future as a power source for EVs (electric vehicles) that use a motor that is rapidly spreading as a driving source instead of an engine as an internal combustion engine. Along with this, various forms of charging facilities for the above-mentioned EV batteries have also been proposed (for example, see Patent Document 1).

Prior Art Documents

Patent Documents

[0003] <用

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When charging the charging module rapidly, current is made to flow into the upstream side and the downstream side of each of the many arranged charging modules. However, since there are quality variations in the manufacturing process for each charging module, it is necessary to select charging modules with as little variation as possible and form these charging modules, for example, in a series arrangement as the overall charging module.

[0005] <用 However, this method necessitates selecting only high-quality charging modules with minimal variation. During this selection process, a significant percentage of charging modules with variations are deemed unsuitable and may be discarded entirely. This results in a lower yield and significantly higher manufacturing costs for the charging module units.

[0006] Specifically, when charging modules are rapidly charged, a large current is supplied all at once to a charging module unit, for example, that is arranged in series. If there are variations in the quality of the charging modules when they are fully charged, current will be forcibly supplied to some of the lower-quality charging modules as well.

[0007] Therefore, when the entire charging module is fully charged, a current exceeding the capacity of some of the lower-quality charging modules to withstand the current flow and reach full charge is supplied.

[0008] As a result, these inferior quality charging modules may be subjected to excessive stress, leading to their deterioration or damage. Furthermore, chemical changes and accelerated reaction rates due to temperature increases can cause the charging modules to overheat, potentially leading to a fire caused by the charging module itself in the worst-case scenario.

[0009] However, as mentioned above, if only high-spec charging modules that meet all stringent charging accuracy requirements are selected and combined in large numbers to form a charging module unit, the cost of the charging module unit itself will be extremely high, as described above. Furthermore, a large number of lower-quality charging modules that cannot be used will be discarded, significantly reducing production efficiency. In addition, this will exacerbate environmental problems due to waste and worsen the working environment on the manufacturing line.

[0010] Therefore, the inventors of this invention focused on the fact that if they could realize a charging module unit and a charging method for a charging module that can effectively utilize charging modules of slightly inferior quality, excluding charging modules of such poor quality that they are clearly unsuitable for use as charging modules, and which do not meet the strict performance specifications of conventional methods within a certain acceptable range, while ensuring safety, then the various problems described above could be solved.

[0011] The object of the present invention is to provide a charging device and charging method for a secondary battery that can be used for a long period of time by the user through repeated charging, and which is particularly excellent for use with electric double-layer capacitors as physical secondary batteries. [Means for solving the problem]

[0012] To solve the above-mentioned problems, the charging method for an energy storage module according to claim 1 of the present invention is: A charging method for an energy storage module equipped with multiple energy storage elements, each having different or varying allowable energy storage capacities, The energy storage module is configured to be fully charged by fully charging each of the energy storage elements. Even if we assume that, when charging the aforementioned energy storage module, the energy storage element having the minimum allowable energy storage capacity among these multiple energy storage elements constitutes part of the multiple energy storage elements, Electricity storage A first charging step involves simultaneously charging all energy storage elements at once while they are connected in series, within a range that prevents overcharging of the elements. The first charging step Electricity storage The system is characterized by having a second charging step in which, following the state in which the module is charged, each of the single or parallel-connected groups of energy storage elements is charged to the point where each parallel-connected unit is fully charged, thereby fully charging the energy storage module.

[0014] Furthermore, the method for charging the energy storage module according to claim 2 of the present invention is: A method for charging an energy storage module comprising one or more electric double-layer capacitors, each with different or varying allowable storage capacities, connected in parallel and then connected in series, The energy storage module is configured to be fully charged by fully charging each of the electric double-layer capacitors. In charging the aforementioned energy storage module, a first charging step is performed in which, assuming that the electric double layer capacitor with the smallest allowable energy storage capacity and the electric double layer capacitor with the largest allowable energy storage capacity constitute a part of the group of electric double layer capacitors, one or more electric double layer capacitors connected in parallel are connected in series and charged all at once, within a range that does not lead to overcharging. The first charging step Electricity storage The device is characterized by having a second charging step in which, following the charging of the module, each of the parallel-connected electric double-layer capacitor groups is individually charged until each parallel-connected unit is fully charged, thereby fully charging the energy storage module.

[0016] Furthermore, the charging device for the energy storage module according to claim 3 of the present invention is A charging device for an energy storage module, which has multiple energy storage elements, each with different or varying allowable energy storage capacities, The energy storage module is configured to be fully charged by fully charging each of the energy storage elements. When charging the aforementioned energy storage module, even assuming that the energy storage element with the minimum allowable energy storage capacity among these multiple energy storage elements constitutes a portion of the multiple energy storage elements, the elements are connected in series and charged all at once to a extent that does not result in full charge. The aforementioned Electricity storageWhile continuing to keep the module charged, the full charge of the power storage module is performed by charging each of the charging elements so that each of them is fully charged for each parallel connection unit.

[0018] Also, the charging device for the power storage module according to claim 4 of the present invention is A charging device for a power storage module including one or more electric double layer capacitors having different or varying allowable storage capacities connected in parallel and further connected in series, The power storage module is configured to fully charge the power storage module by fully charging each of the electric double layer capacitors. When charging the power storage module, assuming that the electric double layer capacitor having the minimum allowable storage capacity among these plurality of electric double layer capacitors constitutes a part of the plurality of electric double layer capacitors, the electric double layer capacitors are connected in series and charged all at once within a range where full charge cannot be achieved, and The Electricity storage While continuing to keep the module charged, the full charge of the power storage module is performed by charging each of the electric double layer capacitors individually so that each of them is fully charged for each stage where the electric double layer capacitors are connected in series.

Advantages of the Invention

[0020] According to the present invention, it is possible to provide a charging method and a charging device for a power storage module that greatly enhance the convenience when charging a charging module as a secondary battery as compared with the prior art.

Brief Description of the Drawings

[0021] [Figure 1] It is a block diagram showing the configuration of a control system provided in a charging device for a power storage module according to an embodiment of the present invention. [Figure 2] It is a flowchart for explaining a routine for implementing a charging method for a power storage module according to an embodiment of the present invention based on the configuration of the control system shown in FIG. 1. [Figure 3] An explanatory diagram showing a schematic image structure of a conventional secondary battery currently in use (Fig. 3(1)), and an explanatory diagram showing a schematic image structure of the secondary battery according to the present invention (Fig. 3(2)). [Figure 4] It is a diagram for explaining the rapid charging process when it is determined that rapid charging is required for step S10 explained in the text description related to Fig. 1 and the flowchart of Fig. 2 accompanying this. [Figure 5] It is a diagram showing a state where rapid charging is further performed from the state shown in Fig. 4, the rapid charging mode is completed, and then individual charging of each power storage element is started. [Figure 6] It shows a state where individual charging of each power storage element is advanced from the state shown in Fig. 5. [Figure 7] It is a diagram showing the process of flowing current into each power storage element that still has room for charging from the state shown in Fig. 6 until all power storage elements are fully charged. [Figure 8] It is a diagram for explaining the charging process when the individual charging mode of each power storage element is selected from the beginning. [Figure 9] It is a diagram showing the states of sequentially advancing the charging process shown in Fig. 8. [Figure 10] It is a diagram showing a state where the charging current is further individually flowed into each power storage element from the state shown in Fig. 9, and the charging of the entire secondary battery is progressing. [Figure 11] It is a diagram showing a state where current is further individually flowed into each power storage element following the state shown in Fig. 10 to advance the charging. [Figure 12] It is a diagram showing the process of further advancing the charging process from the state shown in Fig. 11 to fully charge all power storage elements of the secondary battery completely. [Figure 13] It is an explanatory diagram for promoting a further understanding of the present invention by conceptually comparing the time series of the charging required time in each of the rapid charging mode, combined charging mode, and individual charging mode shown in Figs. 4 to 12.

Embodiments for Carrying Out the Invention

[0022] Hereinafter, a charging device for an energy storage module according to an embodiment of the present invention will be described with reference to the drawings. Figure 1 is a block diagram showing the configuration of a control system provided in a charging device for an energy storage module according to an embodiment of the present invention.

[0023] The energy storage module 10 according to this embodiment is configured by sequentially connecting a total of N energy storage devices 101, 102, 103, ... 100 + N (where N is a natural number of 2 or more; hereafter, this will be referred to as the "energy storage element group 100" or simply "energy storage element 100" as appropriate in accordance with Figure 1) in series, from one to N, assuming that the allowable energy storage capacity of each device varies up or down within a predetermined range of specifications.

[0024] Furthermore, this energy storage module is equipped with input / output terminals 101ta, 102ta, 103ta, ... 100+Nta on the anode side of each of the energy storage element groups 1 to N, and each of the same energy storage element groups is also equipped with input / output terminals 101tb, 102tb, 103tb, ... 100+Ntb on the cathode side. In addition, each of the input / output terminals 101ta, 102ta, 103ta, ... 100+Nta for individual charging of the energy storage element groups is equipped with switches (hereinafter referred to as "SW" as appropriate in the text and drawings) H1 to Hn (where n is a natural number of 2 or more corresponding to N), and each of the input terminals 101tb, 102tb, 103tb, ... 100+Ntb for individual charging of the energy storage element groups is equipped with switches L1 to Ln. It should be noted that the positive electrode of energy storage element group K and the cathode of energy storage element K-1, and the positive electrode of energy storage element K+1 and the cathode of energy storage element K are interconnected.

[0025] Then, via switches H1 to Hn and switches L1 to Ln, the + and - sides of the individual charging terminals for each of the energy storage element groups 1 to N are connected. These individual charging input / output terminals for each of the energy storage element groups consist of a terminal group that connects switches H1 to Hn to the + side of each of the N energy storage elements, and a terminal group that connects switches L1 to Ln to the - side of each of the N energy storage elements. Each of these terminal groups has only one set connected to the charging current power supply 20 and the current detection unit 30 of the charging device 10, using n switches for the + and - sides.

[0026] The charging device 10 includes a charging power supply unit (current output unit) 20, a voltage / current detection unit 30, and a charging control unit 40. The charging power supply unit 20 transmits an output signal to the voltage / current detection unit 30 to control the system so that one pair of switches H1 to Hn and switches L1 to Ln are conductive, while the other switches remain non-conductive, and also receives detection signals from the voltage / current detection unit 30.

[0027] Furthermore, when the charging control unit 40 receives a detection signal from the voltage / current detection unit 30, it sends on / off control signals to switches H1 to Hn and switches L1 to Ln according to this information to control these switches on and off as appropriate. Therefore, if necessary, it is also possible to connect the + and - sides of a group of energy storage elements connected in series to the charging power supply unit and perform charging and other control operations, but this will not be explained here.

[0028] Next, we will explain the specific charging methods for the energy storage module based on the circuit block diagram shown in Figure 1, using the flowchart shown in Figure 2 to illustrate the specific control methods for each different operating mode.

[0029] Figure 2 is a flowchart illustrating the routine for implementing a charging method for an energy storage module according to an embodiment of the present invention, based on the configuration of the control system shown in Figure 1. First, the operating mode is selected. In selecting this operating mode, it is determined whether or not rapid charging is required (step S10).

[0030] If it is determined in step S10 that rapid charging is necessary, the rapid charging mode on the right side of the flowchart is started. In this rapid charging mode, the charging power supply is activated (step S100).

[0031] Next, SWH1 and SWLn are closed, and the other switches remain open (step S101). Then, it is determined whether the energy storage module is a capacitor (electric double-layer capacitor, hereinafter simply referred to as "capacitor") (step S102). If it is determined in step S102 that the energy storage module is a capacitor, the voltage value between SWH1 and SWLn is monitored (step S103).

[0032] In step S103, the monitoring operation is performed beforehand to set a module allowable voltage that does not exceed a set value, based on the individual capacitor specifications and capacitance deviation information, so that the voltage across the terminals of the minimum capacitance does not exceed a set value. Then, it is determined whether the voltage value exceeds the set value (step S104). If the voltage value does not exceed the set value, the process returns to step S103 and the routines of steps S103 and S104 are repeated.

[0033] On the other hand, if it is determined in step S104 that the voltage value has exceeded the set value, charging is considered complete, and switches SWH1 and SWLn are opened, and charging from the charging power supply is stopped (step S20).

[0034] Furthermore, if it is determined in step S102 that the energy storage module is not a capacitor, the total amount of charge supplied to the energy storage module is monitored (step S105). Then, the total amount of charge is calculated from the current detection information of the charging power supply (step S106). In this step, the total amount of charge is calculated by the cumulative sum of the current value and the duration. In this step, the minimum capacity is determined in advance from the capacity deviation of each battery specification, and the amount of charge that will not cause the battery to overcharge during charging is determined and set in advance.

[0035] Next, it is determined whether the total charge exceeds the set value (step S107). If it is determined that the total current does not exceed the set value, the process returns to step S106 and the routine of steps S106 and S107 is repeated. On the other hand, if the total current exceeds the set value in step S107, the switch is opened to indicate that charging is complete and charging from the charging power supply is stopped (step S20).

[0036] Next, if the rapid charging mode is not selected in step S10, it is determined whether or not to select the individual charging mode (step S11). If the individual charging mode is selected in step S11, the variable X is set to 1, all switches are opened, and the charging power supply is activated (step S201). Then SWHX and SWLX are closed (step S202).

[0037] Next, it is determined whether the energy storage module is a capacitor or not (step S203). If it is determined in step S203 that the energy storage module is a capacitor, the voltage value between SWHX and SWLX is monitored (step S204). In order to perform this step, the maximum voltage between the capacitor terminals of the energy storage element group is set in advance for this monitoring operation.

[0038] Next, it is determined whether the voltage value has exceeded the set value (step S205). If it is determined in this step that the voltage value has not exceeded the set value, the process returns to step S204, and the routines of steps S204 and S205 are repeated. On the other hand, if it is determined in step S205 that the voltage value has exceeded the set value, all switches are opened in step S206, and the variable X = X + 1.

[0039] Next, it is determined whether the variable X exceeds a predetermined value n (step S207). If the variable X does not exceed the predetermined value n in this step, the process returns to step S202, closing SWHX and SWLX. Then, in step S203, it is determined whether the energy storage module is a capacitor or not. If it is determined in this step that the energy storage module is a capacitor, the process proceeds to step S204 as described above, and the routine explained earlier is repeated.

[0040] If it is determined in step S207 that the variable X has exceeded a predetermined value n, the SW is opened to indicate that charging is complete and charging from the charging power supply is stopped (step S20).

[0041] On the other hand, if it is determined in step S203 that the energy storage module is not a capacitor, the total amount of charge supplied to the module is monitored (step S211). In this monitoring step, the minimum capacity is determined from the capacity deviation of the individual battery specifications, and the total amount of charge that does not cause overcharging is set in advance.

[0042] Next, it is determined whether the total charge amount exceeds the set value (step S212). If it is determined in this step that the set value has not been exceeded, the process returns to step S211 and this routine is repeated.

[0043] Then, if it is determined in step S212 that the total charge amount has exceeded the set value, all switches are opened and the variable X = X + 1 is set (step S213). Next, it is determined whether the variable X has exceeded a predetermined value n (step S214). If it is determined that X has exceeded n, the switches are opened to indicate that charging is complete and charging from the charging power supply is stopped (step S20).

[0044] On the other hand, if it is not determined that the variable X has exceeded a predetermined value n, SWHX and SWLX are closed and the process returns to step S202, and the routine from step S202 to step S214 is repeated.

[0045] Furthermore, in this invention, it is also possible to choose to perform a combined charging operation without selecting either the rapid charging or individual charging described above. In this case, by not selecting the individual charging mode in step S11, the system transitions to the combined charging operation mode (step S30). In this combined charging operation mode defined in step S30, the rapid charging operation performed in the series of routines in step S100 is performed (step S31).

[0046] Then, once the rapid charging operation is complete (step S32), the individual charging operation described in step S200 above is performed (step S33).

[0047] Next, once the individual charging operation is complete (step S34), the SW is opened in step S20 to indicate that charging is complete, and charging from the charging power supply is stopped.

[0048] In this way, the charging operation of the energy storage module according to the present invention is performed by selecting the optimal charging process that suits the time, place, and occasion, depending on various conditions for charging, namely, when there is not enough time for charging and the motor or other load to be operated by the energy storage module after charging does not need to be operated for a long time, for example when running errands in the neighborhood with an EV (electric vehicle) or electric bicycle, or when there is enough time to fully charge the energy storage module by performing an individual charging operation, or when it is desired to charge for a time that is about half the time required for both, the above-mentioned combined charging operation (step S30) or the combined charging specified in step S20 is performed.

[0049] Next, the above explanation will be explained more conceptually and clearly based on the diagrams shown in Figures 3 to 12, in relation to the flowchart shown in Figure 2. Figure 3 is an explanatory diagram showing the schematic structure of a conventional secondary battery currently in use (Figure 3(1)), and an explanatory diagram showing the schematic structure of a secondary battery according to the present invention (Figure 3(2)).

[0050] Furthermore, the specific displays and accompanying textual explanations in Figures 3 to 12 below are presented in accordance with equivalent explanatory diagrams of water tanks, water flow, on / off valves, etc., which are frequently used as conceptual explanations to facilitate the understanding of current, voltage, etc., in analog circuits and electrical circuits. In other words, the specific displays and accompanying textual explanations in Figures 3 to 12 are merely supplementary explanations to facilitate the understanding of the present invention, and it goes without saying that these contents and expressions themselves do not limit the scope of the rights of this patent application.

[0051] In the drawings from Figure 3 onward, the vertically elongated compartmentalized areas shown only with solid lines in Figure 3(1), and with a combination of solid and dotted lines (Figures 3(2) to (a-3)) in Figures 3(2) to 12 respectively, schematically represent the individual energy storage elements that constitute the energy storage module as a secondary battery (hereinafter simply referred to as "secondary battery").

[0052] Note that each of the "energy storage elements" referred to here corresponds to the "energy storage element group" or "energy storage module" shown in Figure 1, but for the sake of simplicity in explanation and ease of understanding the invention, the term "energy storage element" will be used.

[0053] Furthermore, the rightward-pointing arrows shown in the lower left of Figures 3 to 5 represent the current flowing into the secondary battery during rapid charging. The size of these rightward-pointing arrows also simultaneously represents the amount of current flowing into the secondary battery. Figure 3(1) shows that the current I for rapid charging, shown in Figures 3(2) to 5(a-3), is far greater than the current ia for conventional secondary battery charging.

[0054] Furthermore, the downward arrows shown appropriately above each of the vertically elongated energy storage elements in Figures 3(2) and 5(b-1) to 11(c-8) schematically represent the current i that is separately supplied to fully charge each energy storage element corresponding to that arrow.

[0055] In other words, the size (thickness) of the rightward-pointing arrow on the left side of the diagram above, which indicates rapid charging, and the thickness of the downward-pointing arrows indicating the current flowing separately into each energy storage element are quite different. This is because, during rapid charging, as indicated by the thick rightward-pointing horizontal arrow, a large amount of current is flowed into the secondary battery all at once, while the thinner downward-pointing arrows above each energy storage element indicate that an appropriate amount of current is flowed into each energy storage element to charge it.

[0056] In Figures 3 through 12, the diagrams where the thick rightward-pointing arrow on the left is not displayed indicate that the supply of rapid charging current to the secondary battery has been stopped. Also, the areas above each energy storage element where the thin downward-pointing arrow is not displayed indicate that no charging current is being supplied to the corresponding energy storage element.

[0057] Furthermore, the area enclosed by the upper and lower arrows on the left side of each drawing (range d (Figure 3) or D) indicates the permissible upper limit for enabling rapid charging of a secondary battery composed of a combination of these energy storage elements, taking into account the variations that occur in the manufacturing process of each energy storage element, i.e., the fact that each energy storage element can be charged individually. Specifically, the upper limit for rapid charging common to all energy storage elements is indicated by the horizontal dotted line dmin (Figure 3), Dmin, at the bottom.

[0058] On the other hand, the horizontal line portion dmax (Figure 3), corresponding to the portion indicated by the downward arrow above, represents the maximum charge capacity of each energy storage element, given the variations in their respective charge capacities.

[0059] The horizontal line C shown in Figures 3(2) to 12 indicates an example of the permissible rapid charging level for each energy storage element when the rapid charging mode is selected during charging of the secondary battery. In other words, it indicates the permissible rapid charging limit level at which charging will be forcibly terminated when the rapid charging mode described in step S10 of the flowchart in Figure 2 is selected and rapid charging of the secondary battery is performed. In rapid charging mode, if the secondary battery can be used as a power source afterward with a charge amount considerably less than this level without reaching it, for example, if the user decides to stop rapid charging when the charge amount reaches a level sufficient to drive to a nearby location using an electric vehicle (EV), run an errand, and return home in a short time.

[0060] As is clear from these drawings, in the current secondary battery shown in Figure 3(1), the allowable charge flow of each energy storage element is strictly controlled during the manufacturing process, resulting in a narrower width d and smaller deviations in the allowable charge amount between each energy storage element. In manufacturing such a secondary battery, variations in the manufacturing process of each energy storage element must be strictly controlled, and energy storage elements that do not meet the required stringent specifications must be discarded. As a result, as the product yield increases, the number of discarded energy storage elements increases, leading to higher overall costs for secondary batteries, and the environmental problems associated with the disposal of energy storage elements are currently a major issue.

[0061] Furthermore, according to the present invention, when a secondary battery is constructed by combining various energy storage elements and energy storage cells and other energy storage elements using them, it is possible to ensure a sufficient safety factor while taking into account the variations in the charge tolerance levels of each energy storage element.

[0062] In light of these circumstances, in the present invention, as shown in Figures 3(2) to 12, the relationship between the allowable charge amount based on manufacturing variations of each energy storage element is not strictly defined (see the relationship between the width of d in Figure 3(1) and the width of D in Figures 3(2) and thereafter), and only energy storage elements that hinder the function of a secondary battery are discarded as defective products. As a result, the present invention can avoid the aforementioned decrease in the manufacturing yield of each energy storage element, the increase in costs associated with discarding a large number of defective energy storage elements, and the environmental damage associated with disposal.

[0063] Manufacturers of energy storage cells, which are the smallest components that make up each energy storage element, or manufacturers who assemble energy storage elements and secondary batteries by combining these energy storage cells, can eliminate the troublesome process of strictly measuring and inspecting the allowable charge amount for the secondary battery itself, or for each energy storage element and the energy storage cells that make it up, and then classifying the allowable charge amount of each energy storage element into levels and separating them according to their allowable charge amount.

[0064] In other words, by combining energy storage elements that have a certain degree of variation in their allowable charge capacity, the energy storage elements themselves and the secondary batteries they combine can be manufactured uniquely without going through cumbersome measurement and inspection processes. This eliminates the need for the conventional level classification based on allowable charge capacity, making it possible to mass-produce and supply energy storage elements and secondary batteries to the market at low cost.

[0065] In Figure 3(1), each vertically elongated battery storage element is separated by a solid line, and its size has been deliberately depicted as smaller than it actually is. The reason for this is as follows: For example, in the case of a chemical secondary battery such as a lithium-ion secondary battery, the process of charging the secondary battery by flowing current through it always involves a chemical reaction.

[0066] The rate of this chemical reaction has an equivalent electrical resistance. Therefore, if a large current is applied at once during rapid charging, the heat generated by the resistance will increase the temperature, accelerating the rate of the chemical reaction. As a result, it is generally known that this can further accelerate the heating of the secondary battery, potentially leading to battery damage or fire. For this reason, the resistance of the secondary battery during charging due to such a chemical reaction, which has an equivalent electrical resistance, is represented by solid lines for each energy storage element in Figure 3(1) to facilitate understanding why a large current cannot be applied during rapid charging of such a chemical secondary battery.

[0067] On the other hand, the vertically elongated energy storage elements shown in Figures 3(2) to 5(a-3) are individually shown, with the upper part demarcated by a solid line and the lower part by a dotted line. Specifically, the lower part shown by the dotted line represents the common allowable charge amount during rapid charging, taking into account the variation in the allowable charge amount of each energy storage element, and the portion above that represents the allowable charge amount remaining after rapid charging for each energy storage element, corresponding to the length of the solid line.

[0068] In addition, the diagrams clearly show that each energy storage element constituting the secondary battery shown in Figures 3(2) to 12 is composed of an assembly of energy storage elements consisting of electric double-layer capacitors, which are so-called physical secondary batteries.

[0069] Let me explain the meaning of this. A secondary battery consisting of such an electric double-layer capacitor has a completely different charging principle and specific configuration from the chemical secondary batteries, such as the lithium-ion batteries commonly used as described above. Specifically, even when a large amount of current is supplied during rapid charging, it does not involve a chemical reaction like that of a chemical secondary battery; that is, this chemical reaction does not generate heat as resistance when current is supplied during rapid charging, allowing for instantaneous charging. This is illustrated in the diagram to make it visually easy to understand.

[0070] Furthermore, Figure 4 is an explanatory diagram that conceptually shows, in order from top to bottom, the process of rapid charging when it is determined that rapid charging is necessary, as described below in the embodiment and in step S10 shown in the flowchart of Figure 2. More specifically, Figure 4(a-1) shows the state in which the secondary battery has a charge level of zero.

[0071] Figure 13 is an explanatory diagram that conceptually compares the time series of charging times in each of the following modes: the rapid charging mode by step S10 (Figures 4(a-1) to 5(a-3)), the combined charging mode by step S30 (Figures 5(b-1) to 7(b-5)), and the individual charging mode by step S20 (Figures 8(c-1) to 12(c-9)), in order to further facilitate a better understanding of the present invention.

[0072] Figure 4(a-1) shows the state at the start of rapid charging in step S10 (t=0). Figure 4(a-2) shows the state after rapid charging has started in step S10.

[0073] Furthermore, Figure 5 is a conceptual diagram illustrating, in top and bottom order, the state in which the rapid charging of the secondary battery shown in Figure 4 has progressed further. More specifically, Figure 5(a-3) shows that the rapid charging has progressed further from the state shown in Figure 4(a-2), reaching the upper limit of the allowable rapid charging level for the secondary battery. In this state, each energy storage element has a sufficient margin of charge remaining relative to its allowable storage capacity, and Figure 5(a-3) shows the state in which the rapid charging mode has been completed. It should be noted that this control method also makes it possible to charge multiple points of series-connected energy storage elements simultaneously, but here we will only point out that this is also possible.

[0074] Then, in the process from Figure 5(a-3) to Figure 5(b-1), the rapid charging mode is completed and the system transitions to the fully charged mode shown in step S20, indicating that charging has progressed. This can be understood from the fact that, as shown in Figure 5(b-1), the charging current is indicated by a thin downward arrow for each energy storage element, and a charging current i, which is different from the current supplied to the secondary battery in the rapid charging process, is individually supplied to each energy storage element (the leftmost energy storage element in Figure 5(b-1)).

[0075] Here, the current flowing through each energy storage element should be within the allowable value of each element, regardless of whether it is fast charging. However, the allowable voltage applied to each energy storage element is currently low, around 3-5V, and it is thought that the power supply side losses will be greater during individual charging than during fast charging. Due to the constraints of the allowable power supply side losses, the temperature rise near the power supply's allowable power may increase. If it is necessary to suppress the temperature rise considering the lifespan of the device, it may be necessary to reduce the current near the power supply's allowable power value to suppress the temperature rise. Also, since it is expected that losses will increase at low voltage and high current when using energy storage elements in parallel compared to high voltage, the explanation here uses a current value lower than that used during fast charging. However, as long as the current value is kept within the allowable range of each energy storage element, there are no other constraints. Needless to say, when using energy storage elements in parallel, it is necessary to ensure that the charging current flows evenly through each element and that the current value is within the allowable range of each element.

[0076] Furthermore, Figure 5(b-1) is a conceptual diagram illustrating the state after the rapid charging mode of the secondary battery shown in Figure 5(a-3) has been completed and the combined charging described in step S30 of the flowchart in Figure 2 has been started. Note that when the rapid charging mode in step S10 of the flowchart in Figure 2 is selected, the charging operation of this embodiment is stopped and no further charging is performed once the rapid charging is completed in the state shown in Figure 5(a-3).

[0077] Furthermore, as described above, the permissible rapid charging limit level C of the rapid charging mode for the secondary battery shown in Figure 5(b-1) indicates the permissible rapid charging limit level at which charging is forcibly terminated when the rapid charging mode described in step S10 of the flowchart in Figure 2 is selected and rapid charging of the secondary battery is performed. Therefore, a notable feature of the present invention is that it is possible to stop the rapid charging mode at a freely chosen level depending on the usage of the secondary battery, before reaching this permissible rapid charging limit level C of the rapid charging mode, and to complete the rapid charging at any desired charge amount.

[0078] Specifically, in rapid charging mode, if the secondary battery can be used as a power source even with a significantly lower charge level without reaching this level, the user can decide to stop rapid charging once the charge level reaches a level sufficient to drive to a nearby location in an electric vehicle (EV), run an errand, and return home in a short time.

[0079] This allows the user to appropriately stop the rapid charging process midway through, while considering the balance between charging time and the power consumed by the secondary battery, and within the range that reaches the aforementioned acceptable limit level for rapid charging, according to the user's purpose.

[0080] Therefore, not only for secondary batteries used in electric vehicles, but also for electric bicycles and electric wheelchairs, the rapid charging time can be shortened to suit the travel area, allowing for quicker charging. For example, when you have a time-sensitive errand to run nearby, you can complete only the minimum necessary rapid charging operation to achieve your goal.

[0081] Similarly, even if a situation arises where reception robots, guidance robots, or assistance robots, which are expected to become widespread rapidly in the future, need to be used quickly and for only a short time, supplying only the minimum necessary amount of power to the secondary battery in rapid charging mode in a very short time will allow these robots to be used flexibly, significantly improving their usability.

[0082] Figure 6(b-2) shows the state after individual charging of each energy storage element has progressed from the state shown in Figure 5(b-1), where the energy storage has exceeded the rapid charging allowable energy storage level of all energy storage elements. From what is shown in Figure 6(b-2), it can be understood that after completing the individual charging in Figure 6(b-1) and fully charging the second energy storage element from the left, when individual charging of the third energy storage element from the left begins, a current i is started to flow to this energy storage element.

[0083] Furthermore, Figure 6(b-3) shows a state where individual charging of each energy storage element has progressed further than in Figure 6(b-2). In this figure, the first five energy storage elements from the left are sequentially fully charged through individual charging, and then the charging current i, indicated by the lower arrow, is started to flow into the sixth energy storage element from the left in order to begin charging this element.

[0084] Figure 7 is a conceptual diagram illustrating, in top and bottom order, the state in which the combined charging of the secondary batteries shown in Figure 6 has been further advanced. More specifically, Figure 7(b-4) shows the state in which the energy storage element that still has charge remaining, i.e., the second energy storage element from the right, is fully charged, starting from the state shown in Figure 6(b-3).

[0085] Furthermore, Figure 7(b-5) shows the state after the secondary battery has been fully charged by flowing current i into the rightmost energy storage element from the state shown in Figure 7(b-4), thereby fully charging all the energy storage elements. In other words, in this state, all the energy storage elements are fully charged and the secondary battery has been fully charged, so the downward current i flowing into each energy storage element is not shown.

[0086] Furthermore, Figure 8 is an explanatory diagram conceptually showing the charging process of a secondary battery in top-to-bottom order when the individual charging mode for each energy storage element is selected from the initial stage of charging, as described in the embodiment below and the flowchart in Figure 2. Specifically, Figure 8 is an explanatory diagram conceptually showing, in top-to-bottom order, the process of fully charging a secondary battery by selecting the individual charging mode for each energy storage element shown in Figure 2, S20, from the beginning, without selecting the rapid charging mode described above. Unlike rapid charging, which can be interrupted at any point, this method of charging a secondary battery by individual charging cannot be interrupted until charging is complete, so it is an effective charging method when there is sufficient time to spare for charging.

[0087] More specifically, Figure 8(c-1) shows the secondary battery itself in a state where its charge level is almost zero. Also, unlike the rapid charging case described above, this figure shows the state in which the leftmost energy storage element, which should be fully charged first, is supplied with the current indicated by the downward arrow i, that is, the current necessary and sufficient to charge each energy storage element.

[0088] Figure 8(c-2) shows the state in Figure 8(c-1) where the leftmost energy storage element has been fully charged, and individual charging of the second energy storage element from the left has begun. In other words, in the initial stage of this individual charging, the leftmost energy storage element has finished charging and is fully charged.

[0089] Furthermore, Figure 9 is a conceptual diagram illustrating the state in which the individual charging of the secondary batteries shown in Figure 8 is continued, in order from top to bottom. Specifically, Figure 9(c-3) shows that the first and second energy storage elements from the left in Figure 8(c-2) have been fully charged in order.

[0090] Furthermore, Figure 9(c-4) shows a further progression of the individual charging process compared to Figure (c-3), where the first to third energy storage elements from the left are fully charged in sequence, and then individual charging of the fourth energy storage element from the left begins.

[0091] Furthermore, Figure 10 is a conceptual diagram illustrating, in vertical order, the state in which the individual charging of the secondary battery shown in Figure 9 is further advanced. Specifically, Figure 10(c-5) shows the state in which, from the state shown in Figure 9, the individual charging of the energy storage elements is further advanced, and after the first to fifth energy storage elements from the left are sequentially fully charged, the individual charging of the sixth energy storage element from the left is started.

[0092] Furthermore, Figure 10(c-6) shows a state where, starting from the state shown in Figure 10(c-5), individual charging of the energy storage elements has progressed further, and after the seventh energy storage element from the right has been fully charged, individual charging of the sixth energy storage element from the right has begun.

[0093] Furthermore, Figure 11 is a conceptual diagram illustrating, in top-to-bottom order, the process of further individual charging of the energy storage elements following the state shown in Figure 10. Specifically, Figure 11(c-7) shows the state in which, after fully charging the fifth energy storage element from the right shown in Figure 10(c-6), individual charging of the fourth energy storage element from the right begins.

[0094] Furthermore, by advancing this charging process, as shown in Figure 11(c-8), the total charge of the secondary battery increases overall, approaching full charge, and the charging process begins only for the rightmost energy storage element, which is the last element to be charged.

[0095] Furthermore, Figure 12(c-9) is a conceptual diagram illustrating, in top and bottom order, the state in which the secondary battery has been fully charged by further advancing the charging process from the state shown in Figure 11 to completely fully charge all of its energy storage elements. Specifically, it shows the state in which the secondary battery has been fully charged by further advancing the charging process from the state shown in Figure 11 to completely fully charge all of its energy storage elements. In this state, it can be understood that the secondary battery is fully charged because all the downward arrows indicating the current flowing into each energy storage element have disappeared.

[0096] Figure 13 is an explanatory diagram that conceptually compares the time series of charging times in each of the following modes: the rapid charging mode by step S10 (Figures 4(a-1) to 5(a-3)), the combined charging mode by step S30 (Figures 5(b-1) to 7(b-5)), and the individual charging mode by step S20 (Figures 8(c-1) to 12(c-9)), in order to further facilitate a better understanding of the present invention.

[0097] Figure 13(a) shows the <Select rapid charging by step S10> mode. As shown in the figure, rapid charging is completed after the charging time TA has elapsed from the start of charging at T=0, and partial charging of the secondary battery is completed. It should be noted that in this rapid charging mode, it is possible to stop rapid charging even before time TA has elapsed. That is, for example, rapid charging can be stopped at any point along the arrow in Figure 13(a).

[0098] Furthermore, Figure 13(b) shows the <Select combination charging by step S30> mode, where the process progresses chronologically from completion of rapid charging to individual charging. That is, From the start of rapid charging at T=0, after TA has elapsed and rapid charging is complete, the process switches to separate charging, and after a charging time TB, individual charging is completed, resulting in a full charge of the secondary battery. In the diagram, TB = (tb1 + tb2 + ... tb(n-1) + tbn).

[0099] Furthermore, Figure 13(c) shows the mode where <individual charging by step S20 is selected>, where individual charging is completed after the charging time TC has elapsed from the start of individual charging at T=0, and the secondary battery is fully charged. Note that in the figure, TC = (tc1 + tc2 + tc3 + ... tc(n-2) + tc(n-1) + tcn).

[0100] As explained above, based on the differences between these three types of charging modes, the present invention can be visually easily understood from Figure 13 as it allows for appropriate charging of the secondary battery according to different circumstances (TPO) each time, taking into account whether there is sufficient charging time or not.

[0101] Next, the operation of the charging device and charging method for the charging module according to the above embodiment will be explained with specific examples. It should be noted that these examples are merely illustrative.

[0102] For example, in conventional secondary batteries currently in use, as can be seen from Figure 3(1) where a charging current i(A) is supplied from the left side of the figure, the secondary battery is charged to the minimum storage capacity of the storage cell that makes up the secondary battery, taking into account a safety factor so that this storage cell does not reach full charge, and this is referred to as a full charge.

[0103] In other words, with the structure of conventional secondary batteries and the charging methods based thereon, it was extremely difficult to fully charge all of the energy storage cells, even though this was referred to as "full charge" as described above.

[0104] On the other hand, according to the present invention, as is clear from the written description of the above-described embodiment, the block diagram of the present invention shown illustratively, the flowchart of the charging method, and the explanatory diagram showing the charging process in chronological order, it differs from the conventional secondary battery charging method described above.

[0105] The unique charging method of this invention enables "full charging of the secondary battery" by fully charging all storage cells, even if there is greater variation in the allowable charge amount of each storage cell that makes up the secondary battery compared to conventional storage cells.

[0106] In other words, compared to fully charging a secondary battery using conventional methods, even if there is a large variation in the charging capacity of each storage cell, by fully charging all storage cells, it is possible to increase the amount of stored energy using the same storage elements, resulting in a remarkable advantage over conventional technology in that the usable amount of stored energy in the secondary battery can be significantly improved.

[0107] Furthermore, if you try to use an electric bicycle to go shopping nearby, but the charge in the charging module is low and you can't use it even for a short shopping trip, you have to wait a long time for the charging module on the electric bicycle to fully charge, even if it's just a short trip. This disrupts your daily routine, for example, you might not make it in time to buy groceries for dinner, resulting in a significantly delayed dinner. However, the present invention can solve all of these problems at once.

[0108] Similarly, if you're driving an electric vehicle to run errands like shopping or going to the hospital nearby, and the charge module is almost depleted, you'll need to charge the electric vehicle's charge module before reaching your destination. In this case, the charge module is usually set to charge up to about 60% to ensure a certain driving range, and then additional charge is added as needed. However, even if you charge it to the initial setting of the charging station, it will still take a considerable amount of time, even without waiting for charging time, making it impossible to reach your destination and complete your errands on schedule, thus disrupting your daily routine.

[0109] For example, if you have a hospital appointment, you might have to go through the troublesome process of having to reschedule if you miss your appointment time, or it might take longer to take an elderly family member to a day care service.

[0110] Furthermore, if a family member's health suddenly deteriorates, though not to the point of requiring an ambulance, and the charging module needs to be charged at an inconvenient time, it could take a considerable amount of time to get to the hospital for a check-up, potentially leading to a further deterioration of their health. However, according to the present invention, these problems can be solved all at once.

[0111] It should be noted that this embodiment is merely an example of the present invention, and the present invention is not limited to this form. That is, the shape, number, and correlation of each component can be appropriately changed as long as the effects of the present invention can be achieved, and it goes without saying that the flowchart explaining the effects of this embodiment can also have its routine changed as long as the effects of the present invention can be achieved.

[0112] Furthermore, in the embodiments described above, we have explained a method for charging an energy storage module configured by connecting large-capacity capacitors, which are an example of charging elements, in parallel, and then connecting them in series, as well as a battery storage module that combines other forms of chemical secondary batteries, such as lithium-ion batteries, in an equivalent configuration to these capacitors. However, the present invention can also be applied when charging an energy storage device equipped with other equivalent physical secondary batteries instead of capacitors as physical secondary batteries, or when charging an energy storage device equipped with other equivalent chemical secondary batteries instead of lithium-ion batteries as chemical secondary batteries.

[0113] Similarly, in the above-described embodiment, a storage module consisting of a group of storage elements 1 to N, in which capacitors as energy storage elements are connected in parallel, was used. However, the present invention can also be applied to a storage module consisting of a single storage element 1 to N instead of these groups of storage elements.

[0114] Next, we will introduce the inventor's insights that support the advantages of this invention. Currently, various energy storage elements—batteries and capacitors—are charged by connecting modules in series and setting them to a predetermined voltage, and then connecting these modules in parallel. However, this method has problems, particularly due to the large individual variations in each battery and other component, such as self-discharge and leakage current.

[0115] Specifically, while it is possible to understand the characteristic variations of each component within a module and combine modules by performing evaluations and measurements in advance, it can be difficult to understand factors such as leakage current and internal self-consumption of the battery. In addition, it is difficult to realize methods that predict the increase or fluctuation of capacity, leakage current, and internal resistance, as well as the changes in self-consumption, due to the aging degradation of individual energy storage elements, and then combine modules accordingly. Therefore, the construction and prediction of degradation models for fundamental elements and modules have made virtually no progress and remain a challenge for the future.

[0116] Furthermore, regarding the measurement of deviations in leakage current and capacitance of each module component, the development of technology to accurately and quickly measure a large number of components remains in the same state as described above, and we are still far from resolving the long-standing issues.

[0117] As a countermeasure, in large-capacity capacitor modules, a method is still used in which the module is periodically completely discharged to empty the stored charge of all capacitors within the module, thereby eliminating the uneven distribution of stored charge caused by leakage current and fluctuations in capacitor capacity, and then the module is recharged to correct the unevenness of the stored charge of each capacitor.

[0118] Another method, used in some applications, involves connecting a resistor in parallel with the energy storage element to minimize the effects of leakage current and internal losses. This makes the current flowing through the resistor greater than the leakage current and internal losses, thus allowing the aforementioned losses to be ignored.

[0119] However, these methods inherently involve the problem of reducing the inherent capacity of the energy storage element and increasing losses, so there is a need for a new method to solve these problems. In light of these circumstances, the inventors of this invention have decided to propose the present invention, which can solve all of these problems at once.

[0120] In making such a proposal, the following four items (1) to (4) are essential charge control functions for realizing the highly convenient charging devices and charging methods for various energy storage elements, batteries, and capacitors, as conceived by the inventors of the present invention, particularly for large-capacity capacitor modules. (1) It must be capable of fast charging. (2) The device must be able to stop rapid charging at any point during rapid charging and start operating. (3) In addition to rapid charging, it is possible to charge each individual module and all modules until they are fully charged. (4) When charging individual modules, the charging operation will not be interrupted until the module is fully charged. However, in the event of unavoidable cancellation, we considered it necessary to ensure that the equipment could be restarted after the interruption and that charging of individual modules could be resumed thereafter.

[0121] To address all of these requirements, the present invention's apparatus and method are configured to require the connection of energy storage elements / batteries and capacitors individually or in parallel. Regarding a charging control device / method for an energy storage module with these connected in series, Figure 1 shows a schematic functional diagram of the charging device / method, and Figure 2 shows a schematic operation flow diagram of the charging control of the energy storage module, both conceived as examples of what the present invention aims to achieve.

[0122] More specifically, in terms of the type of charging operation, the charging control unit closes the necessary switches of the switch groups SWH1 to SWHn connected to the positive electrode side and SWL1 to Ln connected to the negative electrode side of each of the energy storage element groups 1 to N, activates the charging power supply, and starts charging. The charging power supply outputs charging power as a current output, within the power supply capacity range.

[0123] Furthermore, this charging device and method is designed to operate in three ways: (a) rapid charging, (b) individual charging, and (c) combined charging of (a) and (b). In this way, we have realized and proposed a novel charging device and method for various energy storage elements, batteries, and capacitors that possesses significant advantages not found in conventional secondary battery charging devices and methods.

[0124] Finally, we will explain how the charging method and charging device for the energy storage module according to the present invention can be combined with a physical secondary battery consisting of an electric double-layer capacitor and disseminated to various fields, thereby advancing a next-generation energy supply system globally.

[0125] In the case of lithium-ion batteries, which are currently the mainstream in various fields, it is necessary to manufacture them with strict specifications for the positive electrode active material, negative electrode active material, and the electrolyte between them in order to maintain consistent characteristics as a secondary battery. This is because, in the finished battery, variations in capacity, or deviations, mean that battery units with low capacity will determine the overall storage capacity of the energy storage device. Therefore, for use as a high-capacity secondary battery in electric vehicles (EVs), for example, the structure of the lithium-ion secondary battery must be quite large, and the manufacturing cost is high.

[0126] On the other hand, in such chemical batteries, if the specifications of the positive electrode active material, negative electrode active material, and the electrolyte between them are not strictly controlled to reduce the internal resistance of the battery, when a secondary battery is fully charged in a short time, the internal temperature of the battery itself may rise due to heat generated by the internal resistance, or temperature increases may vary between batteries and even within the battery due to various variations in the manufacturing process. This can cause some batteries to break down due to the rapid temperature increase, leading to an accelerating increase in the rate of chemical reactions and the resulting self-heating, which can cause damage or fire.

[0127] On the other hand, electric double-layer capacitors do not involve the chemical reactions or lithium ion movement (which are considered equivalent to electrical resistance) seen in chemical batteries such as the lithium-ion batteries mentioned above. Instead, only the movement of electrolyte ions in the electrolyte solution and adsorption and desorption to and from the electrodes occur. This eliminates changes in materials and ion movement between electrodes, resulting in advantages such as low electrical resistance and short reaction times.

[0128] Specifically, it has the characteristics of exhibiting almost no performance degradation even after repeated charging and discharging, reaching a cycle life of up to one million cycles, and also having a significantly faster charging speed compared to chemical batteries.

[0129] Therefore, such secondary batteries have a strong potential to become widespread rapidly in the future. The advantages of electric double-layer capacitors are that they store energy by the movement of ions in the electrolyte between electrodes, resulting in low internal resistance, very little heat generation even when current flows, minimal degradation of characteristics because there is no degradation associated with charging and discharging since it is not a chemical reaction, and the ability to instantaneously supply current up to the maximum allowable current due to the physical structure of the capacitor.

[0130] Furthermore, I will discuss the special circumstances that stand in the way of producing lithium-ion rechargeable batteries cheaply and in large quantities. One of these special circumstances is that, in obtaining lithium as a raw material for lithium-ion batteries from producing countries that produce it in large quantities, there are currently various complex constraints stemming from complex factors such as diplomatic ties, economic relations, and the balance of power between nations. This is because, like nickel and cobalt, which are rare metals used as raw materials for other chemical rechargeable batteries, it is difficult to obtain lithium cheaply, easily, and in large quantities.

[0131] On the other hand, for our country, an maritime nation surrounded by the sea, if lithium could be efficiently extracted from seawater, it would be possible to obtain an inexhaustible supply of lithium from seawater without being subject to the aforementioned constraints. However, unfortunately, there is no prospect of realizing technology to efficiently recover lithium, which is present in extremely small amounts in seawater, in the near future.

[0132] On the other hand, although unrelated to the difficulties in obtaining lithium, addressing the rapid changes (deterioration) in the global environment in recent years has become an urgent global issue. Specifically, this is as follows:

[0133] In recent years, climate change caused by global warming has become a serious global problem, and the adoption of electric vehicles (EVs) is being promoted worldwide to address these issues. Furthermore, with the increasing popularity of EVs, there are urgent challenges in rapidly and widely deploying them, such as extending the driving range per charge, deploying EVs in larger vehicles to handle greater logistics, and expanding their use in public transportation like buses.

[0134] Furthermore, the conventional basic idea of ​​electricity supply has been to install large-scale power plants such as nuclear power plants, thermal power plants, hydroelectric power plants, and other wind and tidal power plants in locations somewhat far from urban areas, and to supply electricity to urban areas from these power plants using equally large-scale transmission systems.

[0135] On the other hand, the existing system, which can only stably supply electricity if all such large-scale infrastructure facilities are operating without problems, is now facing various issues. For example, Japan's entire territory and surrounding sea area are located on various tectonic plates, including the Eurasian Plate, the North American Plate, the Pacific Plate, and the Philippine Sea Plate, making it impossible to predict when a major earthquake, a large-scale volcanic eruption, a major earthquake, a tsunami accompanying a major earthquake, or a fire may occur. And once such a disaster occurs, there is a risk that the aforementioned power generation infrastructure facilities will malfunction, causing a sudden decrease or even complete loss of power supply capacity to urban areas.

[0136] This can be caused not only by such natural phenomena, but also by damage to infrastructure, particularly power transmission systems, due to river flooding resulting from the arrival of massive typhoons and linear rainbands caused by large-scale low-pressure systems associated with global warming.

[0137] Similarly, the same applies to man-made disasters caused by unpredictable and sudden conflicts between nations, terrorist acts against power infrastructure, and other such events.

[0138] Furthermore, it is essential to establish evacuation sites in various locations for disaster victims in the event of major disasters or disasters caused by extreme weather, as described above, and to also install rescue systems in these disaster relief facilities to protect those who become seriously ill or injured.

[0139] As is clear from the above explanation, it is important to widely popularize the large-capacity electric double-layer capacitor, which was described as part of the gist of the present invention, as a secondary battery. Furthermore, by using the charging device and charging method of an energy storage device using the electric double-layer capacitor according to the present invention together, it is possible to fully demonstrate the various advantages of the large-capacity electric double-layer capacitor as a physical secondary battery, which differ from chemical secondary batteries.

[0140] It should be noted that the circuit block diagrams, flowcharts, and other explanatory drawings shown in each of the embodiments described above are merely examples, and it goes without saying that the structure, materials, circuit configuration, etc. can be appropriately modified within the scope that allows the effects of the present invention to be realized. [Explanation of symbols]

[0141] 10. Energy storage module (charging device) 20 Charging current power supply (charging power supply section) 30 Voltage / Current Detection Unit 40 Charging control unit 101, 102, 103, ... 100+N Energy Storage Devices 101ta, 102ta, 103ta, ... 100+Nta Input / Output Terminals for Individual Charging of Energy Storage Element Groups 101tb, 102tb, 103tb, ... 100+Ntb Input terminals for individual charging of energy storage element groups H1~Hn Switch L1~Ln switch

Claims

1. A charging method for an energy storage module equipped with multiple energy storage elements, each having different or varying allowable energy storage capacities, The energy storage module is configured to be fully charged by fully charging each of the energy storage elements. In charging the aforementioned energy storage module, a first charging step is performed in which, assuming that the energy storage element with the minimum allowable energy storage capacity among the plurality of energy storage elements constitutes a portion of the plurality of energy storage elements, the energy storage elements are connected in series and charged all at once within a range that does not lead to overcharging of the energy storage element; A method for charging an energy storage module, characterized by having a second charging step, which, following the state in which the energy storage module has been charged by the first charging step, charges each of the single or parallel-connected groups of energy storage elements so that each parallel-connected unit is fully charged, thereby fully charging the energy storage module.

2. A method for charging an energy storage module comprising one or more electric double-layer capacitors, each with different or varying allowable storage capacities, connected in parallel and then connected in series, The energy storage module is configured to be fully charged by fully charging each of the electric double-layer capacitors. In charging the aforementioned energy storage module, a first charging step is performed in which, assuming that the electric double layer capacitor with the smallest allowable energy storage capacity and the electric double layer capacitor with the largest allowable energy storage capacity constitute a part of the group of electric double layer capacitors, one or more electric double layer capacitors connected in parallel are connected in series and charged all at once, within a range that does not lead to overcharging. A method for charging an energy storage module, characterized by having a second charging step, which, following the state in which the energy storage module has been charged by the first charging step, individually charges each of the parallel-connected electric double-layer capacitor groups so that each parallel-connected unit is fully charged, thereby fully charging the energy storage module.

3. A charging device for an energy storage module, which has multiple energy storage elements, each with different or varying allowable energy storage capacities, The energy storage module is configured to be fully charged by fully charging each of the energy storage elements. When charging the aforementioned energy storage module, even assuming that the energy storage element with the minimum allowable energy storage capacity among these multiple energy storage elements constitutes a portion of the multiple energy storage elements, the elements are connected in series and charged all at once to a extent that does not result in full charge. A charging device for an energy storage module, characterized in that, after the energy storage module is in a charged state, each of the charging elements in parallel connection units is charged until each is fully charged, thereby fully charging the energy storage module.

4. A charging device for an electric double-layer capacitor comprising one or more electric double-layer capacitors, each with different or varying allowable storage capacities, connected in parallel and further connected in series, The energy storage module is configured to be fully charged by fully charging each of the electric double-layer capacitors. When charging the aforementioned energy storage module, even if we first assume that the electric double layer capacitor with the minimum allowable energy storage capacity among these multiple electric double layer capacitors constitutes a portion of the multiple electric double layer capacitors, the electric double layer capacitors are connected in series and charged all at once to a extent that does not reach full charge, A charging device for an energy storage module, characterized in that, after charging the energy storage module, each of the electric double-layer capacitors connected in series is individually charged until each stage is fully charged, thereby fully charging the energy storage module.

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