Solar cell and storage battery integrated electrical storage device

Abstract

The utility model discloses a solar battery and storage battery integrated electrical storage device, which comprises a plurality of solar battery modules and a plurality of storage battery units which are stacked and have different internal resistances, and each storage battery unit is electrically connected with the corresponding solar battery module to form an independent electrical storage assembly. When light of different intensity ranges irradiates the corresponding solar cell modules, the internal resistance of at least one storage battery unit is located in the load resistance range corresponding to the maximum generated power generated by the corresponding solar cell module. According to the invention, at least one solar cell module with the optimal power generation efficiency can always exist for different light intensities, so that the storage battery unit can be efficiently charged. A control circuit is not specially arranged between the solar cell module and the storage battery unit, power supply for the control circuit is not needed, and extra electric energy loss can be reduced.

Description

Technical Field

[0001] The utility model relates to the field of solar power generation, in particular to a power storage device integrating a solar cell and a storage battery. Background Art

[0002] The power generation capacity of solar cells that convert sunlight and other light energy into electricity is generally as follows Figure 1 The current / voltage characteristics shown. When the resistance of the connected load is large, the output voltage of the solar cell is large, but the current is small; when the connected load resistance is small, the current of the solar cell is large, but the required output voltage cannot be obtained. Therefore, there is a connection load resistance range in the solar cell for the most efficient acquisition of power generation. And the optimal connection load range changes according to the power generation of the solar cell, that is, the intensity of light irradiated to the solar cell. In the case of connecting a storage battery to a solar cell to charge the storage battery, the load resistance of the solar cell becomes the internal resistance of the storage battery, so this characteristic also needs to be considered when charging the storage battery with a solar cell. Therefore, in the case of charging the storage battery with a solar cell, the solar cell is generally not directly connected to the storage battery, but a charging circuit for controlling current / voltage is set between them. For example, Japanese Patent Laid-Open No. 2000-132251 discloses a charging control circuit for suppressing the low power generation efficiency of the solar cell when the internal resistance of the storage battery is small relative to the power generation capacity of the solar cell and the input voltage of the storage battery is lower than the optimal output voltage region of the solar cell.

[0003] In addition, WO2005 / 109599 describes a method of directly charging a solar cell and a storage battery without the above-mentioned charging control circuit. When the intensity of light irradiating the solar cell changes from very strong to weak according to the sunshine conditions, there is no storage battery solution that effectively generates sunshine energy in a solar cell integrated storage battery. Therefore, when used indoors and when used outdoors under sunshine, the standard power generation is greatly different, so the same storage device cannot be shared.

[0004] In the method of charging the connected storage battery without compromising the power generation efficiency of the solar cell even when the solar cell is used both outdoors and indoors under the changing conditions of seasons, weather, and sunshine from sunrise to sunset, as described above, a circuit or device for controlling the current and voltage between the solar cell and the storage battery load is always required, and no solution capable of directly connecting the solar cell and the storage battery has been proposed. Moreover, the charging control circuit or device requires a power supply for the control operation, and the method is not composed of only the solar cell and the storage battery. Utility Model Content

[0005] The purpose of the utility model is to overcome the shortcomings of the prior art and provide a power storage device integrating a solar cell and a storage battery.

[0006] In order to achieve the above objectives, the technical solution of the utility model is:

[0007] A power storage device integrating a solar cell and a storage battery comprises a plurality of solar cell modules and a plurality of stacked storage battery units having different internal resistances, wherein each of the storage battery units is electrically connected to a corresponding solar cell module to form an independent power storage assembly. When light of different intensity ranges is irradiated on the corresponding solar cell module, the internal resistance of at least one storage battery unit is within the load resistance range corresponding to the maximum power generation generated by the corresponding solar cell module.

[0008] Preferably, no circuit for controlling current and / or voltage is provided between the battery unit and the corresponding solar cell module.

[0009] Preferably, a diode is provided between the battery unit and the corresponding solar cell module, so that the current of the solar cell module flows unidirectionally to the battery unit.

[0010] Preferably, the battery unit is a thin sheet structure with a thickness ranging from 0.1 mm to 0.5 mm.

[0011] Preferably, a plurality of the battery cells are stacked along the thickness direction of the thin sheet structure.

[0012] Preferably, a plurality of the solar cell modules are spaced apart on the top surface of a plurality of the stacked battery units, and each of the solar cell modules extends from a side of the plurality of the stacked battery units and is connected to a corresponding battery unit.

[0013] Preferably, the positive electrode of each battery unit is connected to one end of the corresponding solar cell, and the negative electrode of each battery unit is connected to the other end of the corresponding solar cell.

[0014] Preferably, the output voltage of each of the battery cells is the same.

[0015] Preferably, the battery unit comprises a plurality of thin-film lithium-ion batteries connected in series.

[0016] Preferably, the lithium ion salt concentrations contained in the polymer solid electrolyte of the thin film lithium ion battery in the battery cells with different internal resistances are different.

[0017] Compared with the prior art, the utility model has the following beneficial effects:

[0018] (1) The energy storage device integrating solar cells and storage batteries proposed by the present invention does not need to specially set up a control circuit between the solar cell module and the storage battery unit, and does not need to provide a power supply to the control circuit, which can reduce additional power loss. A device with autonomous and effective power generation and storage functions can be realized only by solar cell units and storage battery units.

[0019] (2) The integrated solar cell and storage battery power storage device proposed by the present invention can always have at least one solar cell module with the best power generation efficiency in response to the ever-changing light intensity, so as to efficiently charge the storage battery unit.

[0020] (3) The battery unit in the integrated solar cell and battery storage device proposed in the present invention is a thin sheet structure, which is convenient for stacking and laying of solar cell modules, thereby achieving structural optimization. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings are included to provide a further understanding of the embodiments and are incorporated into and constitute a part of this specification. The accompanying drawings illustrate the embodiments and together with the description are used to explain the principles of the utility model. It will be easy to recognize other embodiments and many expected advantages of the embodiments as they become better understood by reference to the following detailed description.

[0022] Figure 1 A schematic diagram of voltage / current characteristics of a solar cell module in a power storage device integrating a solar cell and a storage battery according to an embodiment of the present application;

[0023] Figure 2 A schematic diagram of a power storage device integrating a solar cell and a storage battery according to an embodiment of the present application;

[0024] Figure 3 A schematic cross-sectional view of a power storage device integrating a solar cell and a storage battery according to an embodiment of the present application, taken on plane A;

[0025] Figure 4 A schematic cross-sectional view of a power storage device integrating a solar cell and a storage battery according to an embodiment of the present application, taken on plane B;

[0026] Figure 5 It is a cross-sectional schematic diagram of a power storage device integrating a solar cell and a storage battery in an embodiment of the present application on the C plane;

[0027] Figure 6 A schematic cross-sectional view of a power storage device integrating a solar cell and a storage battery according to an embodiment of the present application on a D plane;

[0028] Figure 7A schematic diagram of the internal circuit structure of a battery unit of a power storage device integrating a solar cell and a battery according to an embodiment of the present application;

[0029] Figure 8 A schematic cross-sectional view of a battery unit according to an embodiment of the present application;

[0030] Figure numerals: 11, first battery cell; 12, second battery cell; 13, third battery cell; 14, fourth battery cell; 21, first solar cell module; 22, second solar cell module; 23, third solar cell module; 24, fourth solar cell module; 25, thin-film lithium-ion battery; 1, negative electrode active material layer; 2, positive electrode active material layer; 3, isolation layer; 4, negative electrode; 5, positive electrode; 6, laminated sealing material. DETAILED DESCRIPTION

[0031] The present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant utility model, rather than to limit the utility model. It is also necessary to explain that, for ease of description, only the parts related to the relevant utility model are shown in the accompanying drawings.

[0032] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0033] refer to Figure 1-8In the embodiment of the present application, a storage device integrating a solar cell and a storage battery is proposed, comprising a plurality of solar cell modules and a plurality of storage battery units arranged in layers and having different internal resistances, that is, different storage battery units have different internal resistances, and a plurality of storage battery units are stacked in sequence. Each storage battery unit is electrically connected to a corresponding solar cell module to form an independent storage assembly. No control circuit is specially arranged between the storage battery unit and the solar cell module, so that the solar cell module can always have the best power generation efficiency for the power generation of solar energy or indoor illumination that changes moment by moment, thereby charging the storage battery unit. As the intensity of light irradiated on the solar cell module changes, the sizes of different internal resistances of a plurality of storage battery units are respectively located within the load resistance range corresponding to the maximum power generation power generated by light of different intensity ranges irradiated on the corresponding solar cell module. Therefore, when light of different intensity ranges irradiates on the solar cell module, at least one storage battery unit has an internal resistance within the load resistance range corresponding to the maximum power generation power generated by the corresponding solar cell module, so that the solar cell module charges the storage battery unit with the maximum power generation power, thereby effectively improving the charging efficiency of the storage battery unit. Specifically, different intensity ranges can be divided according to specific requirements, such as dividing the intensity of light by thresholds. Taking a threshold as an example, when the intensity of light is a first intensity, if the first intensity is lower than the threshold, there is a battery unit whose internal resistance is within the load resistance range corresponding to the maximum power generation generated by the first intensity of light irradiating the solar cell module connected to it; when the intensity of light is a second intensity, if the second intensity is higher than the threshold, there is another battery unit whose internal resistance is within the load resistance range corresponding to the maximum power generation generated by the second intensity of light irradiating the solar cell module connected to it, and so on. By using battery units with different internal resistances, it is possible to cover light of different intensities irradiating the solar cell module and generate the maximum power generation, so as to effectively improve the power generation efficiency of the solar cell module.

[0034] The solar cell module used in the embodiment of the present application has the following features: Figure 1 The voltage / current characteristics shown in the figure are that there is a connection load resistance range in the solar cell module for most effectively obtaining the maximum power generation, that is, there is an optimal connection load resistance range, so that the solar cell module has the maximum power generation. And the optimal connection load resistance range changes according to the power generation of the solar cell module or the intensity of the light irradiated to the solar cell. When the solar cell module is irradiated with strong light, the solar cell module generates more power. If the internal resistance of the battery unit connected to the solar cell module is small ( Figure 1On the other hand, when the light is weak indoors or in the shade, the amount of power generated by the solar cell module is small, and if the internal resistance of the battery cell connected to it is large ( Figure 1 In the example of FIG. 1 , the internal resistance of the solar cell module is about 50Ω, and the internal resistance of the solar cell module is about 50Ω. The power generation efficiency of the solar cell module is high. Therefore, the embodiment of the present application connects a number of battery cells with different internal resistances to the corresponding solar cell modules as a whole. The battery cells with internal resistances as low as about 5Ω and the battery cells with internal resistances as high as about 50Ω can be electrically connected to the corresponding solar cell modules respectively to receive the input voltage of the corresponding solar cell module to the greatest extent. When the light is strong, the solar cell module connected to the battery cell on the 5Ω side can generate electricity effectively. On the contrary, when the light is weak, the current is effectively taken from the solar cell module connected to the 50Ω battery cell into the battery cell. Therefore, whether the light is strong or weak, there is a solar cell module with the highest power generation efficiency, which can supply the generated power to the corresponding battery cell.

[0035] In a specific embodiment, no circuit for controlling current and / or voltage is provided between the battery unit and the corresponding solar cell module. Therefore, the power storage device proposed in the embodiment of the present application does not need to outsource the circuit or device for controlling current and / or voltage, nor does it need to provide power supply for the circuit or device for controlling current and / or voltage, thereby reducing additional power loss.

[0036] In a specific embodiment, a diode is provided between the storage battery unit and the corresponding solar cell module so that the current of the solar cell module flows unidirectionally to the storage battery unit. By inserting a diode between the solar cell module and the storage battery unit to prevent the current from flowing back from the storage battery unit to the solar cell module, the reverse flow of the storage current can be avoided.

[0037] In a specific embodiment, the battery cell is a thin sheet structure with a thickness ranging from 0.1 mm to 0.5 mm. A plurality of solar cell modules are arranged at intervals on the top surface of a plurality of stacked battery cells, each solar cell module extends from the side of a plurality of stacked battery cells and is connected to a corresponding battery cell, the positive electrode of each battery cell is connected to one end of its corresponding solar cell, and the negative electrode of each battery cell is connected to the other end of its corresponding solar cell. By making the battery cell into a thin sheet structure, it is easy to stack battery cells with different internal resistances, and by adopting a structure in which the solar cell module is arranged on the top surface, an integrated power storage device is realized. Since the battery cell is a thin sheet structure with a thickness of 0.1 mm to 0.5 mm, a plurality of battery cells with different internal resistances can be prepared according to the range of light intensity, that is, a battery cell with a capacity corresponding to the power generation of the solar cell module. For example, by increasing the number of stacked thin-sheet battery cells with low internal resistance, it is possible to design the system to fully store power when the light is strong, and conversely, the number of stacked battery cells with high internal resistance that work effectively when the light is weak can be reduced according to the power generation. When using the stored electricity, by cutting off the connection between the solar cell module and the battery cell and connecting each battery cell in parallel, the previously stored power can be used in total. That is, the power generation energy can be fully utilized without wasting it under any sunshine conditions.

[0038] In one embodiment, reference Figure 2-6, taking 4 thin-sheet battery cells with a thickness of 0.14 mm as an example, the 4 battery cells are stacked in sequence, and the 4 battery cells are respectively set as the first battery cell 11, the second battery cell 12, the third battery cell 13 and the fourth battery cell 14, and the solar cell modules connected thereto are respectively the first solar cell module 21, the second solar cell module 22, the third solar cell module 23 and the fourth solar cell module 24, and the internal resistances are 5Ω, 10Ω, 20Ω and 40Ω respectively. The first solar cell cell 11, the second solar cell cell 12, the third solar cell cell 13, the fourth solar cell cell 14, the first solar cell module 21, the second solar cell module 22, the third solar cell module 23 and the fourth solar cell module 24 stacked as the battery assembly are arranged on the top of the battery assembly at intervals in sequence, and extend from the side to be connected to the corresponding first battery cell 11, the second battery cell 12, the third battery cell 13 and the fourth battery cell 14 respectively. When the intensity of light irradiated on the solar cell module on the top surface of the battery assembly is within the first intensity range, since the internal resistance of the first battery unit 11 is 5Ω, the magnitude of the internal resistance is within the load resistance range corresponding to the maximum power generated by the first solar cell module 21 when the light within the first intensity range is irradiated, so the power output of the first solar cell module 21 is maximum at this time; when the intensity of light is within the second intensity range, since the internal resistance of the second battery unit 12 is 10Ω, the magnitude of the internal resistance is within the load resistance range corresponding to the maximum power generated by the second solar cell module 22 when the light within the second intensity range is irradiated, so the second solar cell module 2 2 output power is the maximum; when the light intensity is in the third intensity range, since the internal resistance of the third battery unit 13 is 20Ω, the magnitude of the internal resistance is within the load resistance range corresponding to the maximum power generated by the third solar cell module 23 when the light in the third intensity range is irradiated, so the power output of the third solar cell module 23 is the maximum; when the light intensity is in the fourth intensity range, since the internal resistance of the fourth battery unit 14 is 40Ω, the magnitude of the internal resistance is within the load resistance range corresponding to the maximum power generated by the fourth solar cell module 24 when the light in the fourth intensity range is irradiated, so the power output of the fourth solar cell module 24 is the maximum. The values ​​of the first intensity range, the second intensity range, the third intensity range and the fourth intensity range decrease in sequence. In the remaining embodiments, the number of battery units and the magnitude of the internal resistance can be set according to specific needs.

[0039] In a specific embodiment, the battery cell includes a plurality of thin-film lithium-ion batteries 25 connected in series. The output voltage of each battery cell is the same. Figure 7, the internal structure of each battery unit is composed of three thin-film lithium-ion batteries 25 with an open circuit voltage of 3.6V connected in series. In other embodiments, the internal structure of the battery unit can also be composed of other numbers of thin-film lithium-ion batteries 25, thin-film lithium-ion batteries 25 with other open circuit voltages, or batteries made of other materials, according to actual needs.

[0040] Furthermore, the concentration of lithium ion salt contained in the polymer solid electrolyte of the thin film lithium ion battery 25 in the battery cells with different internal resistances is different. In one embodiment, the battery cell proposed in the embodiment of the present application can use a thin film lithium ion battery 25 to set different internal resistances. For example, the thin film lithium ion battery 25 produced by the invention patent with the publication number CN110998951A and the name of the electrode sheet manufacturing method, the all-solid-state battery and the all-solid-state battery manufacturing method can be used to adjust the internal resistance of each battery cell by the concentration of lithium ion salt contained in the polymer solid electrolyte. In other embodiments, other methods can also be used to make battery cells.

[0041] The battery cell of the embodiment of the present application is a thin sheet structure, and the internal resistance of the battery cell can be adjusted according to the composition, and it is necessary to be a safe battery cell without battery degradation or heat caused by overcharging or overdischarging. By using the positive electrode active material layer 2, the negative electrode active material layer 1, and the isolation layer 3 of a general lithium ion battery as the constituent materials, and using a polymer solid electrolyte composed of lithium ion salts, ionic liquids, and polymers instead of a flammable electrolyte, a safe and thin sheet battery with a variety of internal resistances and battery capacities can be constructed.

[0042] Here, the ionic liquid in the polymer solid electrolyte is a solvent for transferring lithium ions, and by dissolving lithium ion salts, it constitutes a non-aqueous electrolyte together with the lithium ion salts. In addition, by using a polymer solid electrolyte containing lithium ion salts, ionic liquids and polymers, it is possible to achieve smooth movement of lithium ions in the polymer solid electrolyte, maintain lithium ion conductivity at a high level, and increase the amount of power generated by solar cells, that is, for a storage battery cell, good charging performance can be obtained even at a high charging rate, and it has high safety. In addition, since the interfaces of each particle in the electrode layer are filled and bonded by the polymer solid electrolyte, even in high-output charging and discharging, a thin-film lithium ion battery 25 with good output characteristics that are no less than those of previous batteries using general liquid electrolytes can be achieved.

[0043] The ionic liquid used here is generally composed of a cationic component and an anionic component, is liquid at room temperature (25°C), and has the characteristics of being non-volatile and having a relatively high decomposition temperature. By using an ionic liquid in the electrolyte that constitutes the polymer solid electrolyte, the heat resistance and safety of the electrolyte are excellent compared to the case of using a general flammable organic solvent (such as a cyclic carbonate, a chain carbonate, etc.). In addition, by increasing the concentration of the lithium ion salt in the ionic liquid, it has high performance even during high-output charging and discharging, and a high-energy-density, high-voltage thin-film lithium-ion battery 25 can be obtained. For example, in a polymer solid electrolyte, by adjusting the content of the lithium ion salt between 1 mol / kg and 6 mol / kg relative to the sum of the contents of the ionic liquid and the polymer, the conductivity of the movable lithium ions can be changed by more than one order of magnitude, and the internal resistance of the battery cell can be appropriately designed. In addition, by making the content of lithium ion salt less than 6 mol / kg, the viscosity increase of the non-aqueous electrolyte formed by dissolving the lithium ion salt in the ionic liquid can be suppressed, and the particle interfaces or partitions in the bonding electrode layer can be well filled with the polymer solid electrolyte. As the anion component contained in the ionic liquid, general (FSO2)2N- (i.e., FSI anion) or (CF3SO2)2N- (i.e., TFSI anion) can be used. The electrolyte of the thin film lithium ion battery 25 in the embodiment of the present application is not limited to a polymer solid electrolyte containing an ionic liquid.

[0044] The battery cell in the embodiment of the present application is preferably used when the output characteristics of the solar cell module are high, that is, when the amount of power supply current is large, the internal resistance of the battery is low and the storage capacity of the battery cell is large. As a method of constructing such a battery cell, Figure 8 As shown, a positive electrode active material layer 2 is formed on the back surface side relative to the negative electrode active material layer 1, and the negative electrode active material layer 1 and the positive electrode active material layer 2 are separated by a separator 3. A negative electrode 4 is formed on the front surface of the negative electrode active material layer 1, and a positive electrode 5 is formed on the surface of the positive electrode active material layer 2 to form a thin film lithium ion battery 25 with a bipolar structure. The internal structure of the battery cell is set to a plurality of stacked thin film lithium ion batteries 25 with a bipolar structure, and the battery cell is formed by coating with a laminated sealing material 6, which can provide a battery cell with improved storage capacity and low internal resistance of the battery. In the method of using a polymer solid electrolyte containing an ionic liquid for the separator 3, the thickness of the battery cell can be set to be less than 0.5 mm.

[0045] On the contrary, when the output characteristics of the solar cell are low, that is, when the amount of power generation supply current is small, the internal resistance of the battery cell is preferably high accordingly. Such a battery cell can also be designed with a thickness of 0.1 mm or more and the best power generation efficiency by adjusting the thickness and composition method of the electrode active material layer and the concentration of the lithium ion salt in the ionic liquid according to the above-mentioned production method.

[0046] The above describes the specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A power storage device integrating a solar cell and a storage battery, characterized in that: The invention comprises a plurality of solar cell modules and a plurality of stacked battery cells with different internal resistances. Each of the battery cells is electrically connected to the corresponding solar cell module to form an independent storage component. When light of different intensity ranges is irradiated on the corresponding solar cell module, the internal resistance of at least one battery cell is within the load resistance range corresponding to the maximum power generation generated by the corresponding solar cell module.

2. The solar cell and battery integrated power storage device according to claim 1, characterized in that: No circuit for controlling current and / or voltage is provided between the battery unit and the corresponding solar cell module.

3. The solar cell and battery integrated power storage device according to claim 1, characterized in that: A diode is arranged between the battery unit and the corresponding solar cell module, so that the current of the solar cell module flows unidirectionally to the battery unit.

4. The solar cell and battery integrated power storage device according to claim 1, characterized in that: The battery unit is a thin sheet structure with a thickness ranging from 0.1 mm to 0.5 mm.

5. The solar cell and storage battery integrated power storage device according to claim 4, characterized in that: A plurality of the battery cells are stacked along the thickness direction of the thin sheet structure.

6. The solar cell and storage battery integrated power storage device according to claim 5, characterized in that: A plurality of solar cell modules are arranged at intervals on the top surfaces of a plurality of stacked battery units, and each of the solar cell modules extends from a side of the plurality of stacked battery units and is connected to a corresponding battery unit.

7. The solar cell and battery integrated power storage device according to claim 1, characterized in that: The positive electrode of each storage battery unit is connected to one end of the corresponding solar cell, and the negative electrode of each storage battery unit is connected to the other end of the corresponding solar cell.

8. The solar cell and battery integrated power storage device according to claim 1, characterized in that: The output voltage of each of the battery cells is the same.

9. The solar cell and storage battery integrated power storage device according to claim 1, characterized in that: The battery unit includes a plurality of thin-film lithium-ion batteries connected in series.

10. The solar cell and storage battery integrated power storage device according to claim 9, characterized in that: The lithium ion salt concentrations contained in the polymer solid electrolyte of the thin film lithium ion battery in the battery cells with different internal resistances are different.

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