JP2023100560A - Secondary battery with power generation function - Google Patents

Abstract

To provide a secondary battery with a power generation function, capable of achieving stable power generation.SOLUTION: A secondary battery 100 of a power generation function using a heat power element 1, contains: the heat power element 1 that is contacted to a heat medium 3 that indicates a temperature being equal to a temperature of outer air or larger, and that is unnecessary a temperature difference between electrodes; and a secondary battery 2 that is electrically connected to the heat power element 1. The heat power element 1 contains a pair of electrodes 11 and 12 including a different work function different from each other. For example, the heat power element 1 contains an intermediate part that is provided between the pair of electrodes 11 and 12, and contains a non-conductor layer enveloping a fine particle. The non-conductor layer supports the pair of electrodes 11 and 12.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a secondary battery with a power generation function using a thermoelectric element.

In recent years, regarding charging of secondary batteries such as lithium ion secondary batteries, for example, a thermoelectric charger as disclosed in Patent Document 1 has been proposed.

The thermoelectric charger disclosed in Patent Document 1 includes a thermoelectric element in which a thermoelectric semiconductor is embedded in a ceramic substrate, electrodes are fixed to the thermoelectric semiconductor, and a second electrode provided on one side of the thermoelectric element. 1 heat exchange section, a second heat exchange section provided on the other side of the thermoelectric element, and means for extracting the output of the thermoelectric element to the outside.

In addition to thermoelectric elements using the Seebeck effect as in Patent Document 1, thermoelectric elements that do not require a temperature difference between electrodes, such as in Patent Document 2, have been developed as the above thermoelectric elements.

The power generation element disclosed in Patent Document 2 is a power generation element that converts thermal energy into electrical energy, and is provided with a first electrode facing the first electrode and having a higher potential than the first electrode. and an intermediate portion provided between said first electrode and said second electrode and containing a solvent in which nanoparticles are dispersed.

JP-A-11-284235 Japanese Patent No. 6942404

Here, when the thermoelectric element utilizing the Seebeck effect disclosed in Patent Document 1 is used, it is premised on providing a configuration for generating a temperature difference between the electrodes. In particular, it is necessary to maintain the temperature difference between the electrodes for a long time in order to continuously and stably generate power using the thermoelectric element. In this respect, Patent Document 1 assumes that a temperature difference between electrodes is generated by using metal, liquid, or the like. For this reason, since power generation is assumed under conditions where the temperature difference between the electrodes is likely to change, there is a concern that this may lead to unstable power generation.

In contrast, the thermoelectric element disclosed in Patent Document 2 does not need to generate a temperature difference between the electrodes. However, if the heat transferred to the thermoelectric element fluctuates over time, it may lead to unstable power generation, similar to the above thermoelectric element. This point is neither described nor suggested in Patent Document 2.

SUMMARY OF THE INVENTION Accordingly, the present invention has been devised in view of the problems described above, and an object of the present invention is to provide a secondary battery with a power generation function capable of achieving stable power generation.

A secondary battery with a power generation function according to a first invention is a secondary battery with a power generation function that uses a thermoelectric element, is in contact with a heat medium that exhibits a temperature higher than the outside air, and does not require a temperature difference between the electrodes. and a secondary battery electrically connected to the thermoelectric element, wherein the thermoelectric element includes a pair of electrodes having work functions different from each other.

A secondary battery with a power generation function according to a second invention is, in the first invention, wherein the thermoelectric element includes an intermediate portion provided between the pair of electrodes and containing a non-conductor layer containing fine particles, the non-conductor A layer is characterized by supporting the pair of electrodes.

A secondary battery with a power generation function according to a third invention is characterized in that in the first invention or the second invention, the pair of electrodes are sandwiched between the heat mediums.

A secondary battery with a power generation function according to a fourth invention is the secondary battery according to any one of the first to third inventions, wherein the heat medium includes a casing of the secondary battery, and the thermoelectric element includes the casing. It is characterized by being provided in contact with.

A secondary battery with a power generation function according to a fifth aspect of the invention is the secondary battery according to the fourth aspect, wherein the heat medium includes a heat storage section that stores heat energy, and the thermoelectric element is disposed between the housing section and the heat storage section. It is characterized by being provided in contact with.

A secondary battery with a power generation function according to a sixth invention is a secondary battery with a power generation function according to any one of the first to fourth inventions, wherein the heat medium includes a container in which the thermoelectric element and the secondary battery are installed, and the thermoelectric element is , in contact with the inner wall of the container.

A secondary battery with a power generation function according to a seventh invention is characterized in that, in any one of the first to third inventions, the heat medium includes a circuit board, and the thermoelectric element is in contact with the circuit board. .

A secondary battery with a power generation function according to an eighth invention is characterized in that, in the seventh invention, the thermoelectric element and the secondary battery are provided on the same main surface of the circuit board.

A secondary battery with a power generation function according to a ninth aspect of the present invention is the secondary battery in the seventh aspect, wherein the heat medium includes a casing of the secondary battery, and the thermoelectric element is formed between the circuit board and the casing. It is characterized by being provided in between.

A secondary battery with a power generation function according to a tenth aspect of the invention is, in any one of the first to fourth aspects of the invention, wherein the heat transfer medium includes a drive section to which electric power is supplied from the secondary battery, and the thermoelectric element is: It is characterized by being in contact with the drive section.

According to the first to tenth inventions, the thermoelectric element is in contact with the heat medium having a temperature higher than the outside air. Therefore, it is possible to suppress variation in heat transferred to the thermoelectric element over time. This makes it possible to achieve stable power generation.

In particular, according to the second invention, the intermediate portion includes a non-conductor layer containing fine particles. That is, the non-conductor layer suppresses movement of the fine particles between the electrodes. For this reason, it is possible to prevent the fine particles from becoming unevenly distributed on the one electrode side over time and reducing the amount of movement of electrons. This makes it possible to stabilize the power generation amount.

Moreover, according to the second invention, the non-conductor layer supports the pair of electrodes. Therefore, compared to the case where a solvent or the like is used instead of the non-conductive layer, there is no need to provide a support portion or the like for maintaining the distance (gap) between the electrodes, and the gap resulting from the formation accuracy of the support portion is eliminated. Distortion can be removed. This makes it possible to suppress variations in the amount of power generation.

In particular, according to the third invention, the pair of electrodes are sandwiched between the heat mediums. Therefore, it is possible to further suppress fluctuations in the heat transferred to the thermoelectric element over time. This makes it possible to achieve more stable power generation.

In particular, according to the fourth invention, the thermoelectric element is provided in contact with the casing. Therefore, thermal energy generated from the secondary battery can be converted into electrical energy via the thermoelectric element. This makes it possible to increase the amount of power generation. In addition, it is possible to effectively utilize exhaust heat generated by using the secondary battery.

In particular, according to the fifth invention, the thermoelectric element is provided in contact between the housing and the heat storage section. Therefore, it is possible to easily suppress the temporal change in the amount of thermal energy supplied to the thermoelectric element. This makes it possible to further stabilize the power generation amount.

In particular, according to the sixth invention, the thermoelectric element is in contact with the inner wall of the container. Therefore, thermal energy transferred to the container can be converted into electrical energy via the thermoelectric element. This makes it possible to increase the amount of power generation.

In particular, according to the seventh invention, the thermoelectric element is in contact with the circuit board. Therefore, thermal energy generated on the circuit board by arithmetic processing or the like can be converted into electrical energy via the thermoelectric element. This makes it possible to increase the amount of power generation. In addition, exhaust heat generated by arithmetic processing or the like can be effectively used.

In particular, according to the eighth invention, the thermoelectric element and the secondary battery are provided on the same main surface of the circuit board. Therefore, it is possible to prevent the heat energy generated from the secondary battery from being retained in the circuit board. This makes it possible to suppress quality degradation such as deterioration of the circuit board and a decrease in computation speed.

In particular, according to the ninth invention, the thermoelectric element is provided in contact between the circuit board and the casing. Therefore, it is possible to suppress direct transmission of heat energy generated from the secondary battery to the circuit board. This makes it possible to suppress quality degradation such as deterioration of the circuit board and a decrease in computation speed.

In particular, according to the tenth invention, the thermoelectric element is in contact with the drive section. Therefore, thermal energy generated from the drive section can be converted into electrical energy via the thermoelectric element. This makes it possible to increase the amount of power generation. In addition, exhaust heat generated from the driving section can be effectively used.

FIG. 1 is a schematic diagram showing an example of a secondary battery with a power generation function according to an embodiment. FIG. 2(a) is a schematic diagram showing a first modification of the secondary battery with power generation function in the embodiment, and FIG. 2(b) is a diagram showing a third modification of the secondary battery with power generation function in the embodiment. It is a schematic diagram showing. FIGS. 3A and 3B are schematic diagrams showing a fourth modification of the secondary battery with power generation function according to the embodiment. FIG. 4 is a conceptual diagram showing an example of the power generation system in the embodiment. FIG. 5(a) is a schematic cross-sectional view showing an example of a thermoelectric element in the embodiment, and FIG. 5(b) is a schematic cross-sectional view along AA in FIG. 5(a). FIG. 6 is a schematic cross-sectional view showing an example of the intermediate portion. FIG. 7A is a schematic cross-sectional view showing a first modification of the thermoelectric element according to the embodiment, and FIG. 7B is a schematic cross-sectional view showing a second modification of the thermoelectric element according to the embodiment. FIG. 8 is a schematic cross-sectional view showing a first modification of the intermediate portion. FIG. 9 is a schematic cross-sectional view showing a second modification of the intermediate portion.

Hereinafter, an example of a secondary battery with a power generation function and a power generation system as an embodiment of the present invention will be described with reference to the drawings. In each figure, the height direction in which each electrode of the thermoelectric element is stacked is defined as a first direction Z, and one planar direction that intersects, for example, is orthogonal to the first direction Z is defined as a second direction X, and the first direction Z A third direction Y is another plane direction that intersects, for example, is orthogonal to each of the second direction X and the second direction X. In addition, the configuration in each drawing is schematically described for explanation, and for example, the size of each configuration and the comparison of sizes for each configuration may differ from those in the drawings.

(Secondary battery 100 with power generation function)
FIG. 1 is a schematic diagram showing an example of a secondary battery 100 with a power generation function according to this embodiment.

The secondary battery 100 with power generation function is electrically connected to a known device that requires a power source, such as an electronic device, an electric vehicle, a self-contained sensor terminal, or the like. In addition to being used as a main power source, the secondary battery 100 with power generation function may also be used, for example, as an auxiliary power source.

A secondary battery 100 with power generation function includes a thermoelectric element 1 and a secondary battery 2 . The thermoelectric element 1 converts thermal energy into electrical energy. The secondary battery 2 is electrically connected to the thermoelectric element 1, and is electrically connected to, for example, a driving unit or the like that is driven by power supply. The driving section indicates a known driving device such as an arithmetic processing unit such as a CPU (Central Processing Unit) or a motor.

The thermoelectric element 1 includes a pair of electrodes 11, 12 having work functions different from each other. In this case, when converting thermal energy into electrical energy, a temperature difference between the electrodes becomes unnecessary. For example, the thermoelectric element 1 has a first surface 1f and a second surface 1s that intersect with the first direction Z, the first electrode 11 is provided on the first surface 1f side, and the second electrode 12 is provided on the second surface 1s. provided on the side. Between the first electrode 11 and the first surface 1f, and between the second electrode 12 and the second surface 1s, a member such as a substrate or a housing may be provided, or a cavity may be provided. good. In addition to the above, for example, the thermoelectric element 1 may have the surface of the first electrode 11 as the first surface 1f and the surface of the second electrode 12 as the second surface 1s.

Here, when the secondary battery 2 is charged using a conventional thermoelectric element whose power generation is unstable, there is a possibility of causing an unexpected problem such as an overcharged state, and there is concern about early deterioration of the secondary battery 2. It is mentioned as. On the other hand, in the secondary battery 100 with power generation function according to the present embodiment, the thermoelectric element 1 is in contact with the heat medium 3 having a temperature higher than the outside air. Therefore, it is possible to suppress fluctuations in the heat transferred to the thermoelectric element 1 over time. This makes it possible to achieve stable power generation. Therefore, it is possible to suppress early deterioration of the secondary battery 2, for example. For example, as shown in FIG. 1, the first surface 1f and the second surface 1s of the thermoelectric element 1 are in contact with the heat medium 3, and at least one of the first surface 1f, the second surface 1s, and the side surface is It may be in contact with the heat medium 3 .

For example, the pair of electrodes 11 and 12 may be sandwiched between the heat mediums 3 . In this case, fluctuations in heat transferred to the thermoelectric element 1 over time can be further suppressed. In particular, variations in the heat transferred to the electrodes 11 and 12 are suppressed, making it difficult for variations in temperature difference to occur between the electrodes 11 and 12 . This makes it possible to achieve more stable power generation. For example, as shown in FIG. 1, the entire thermoelectric element 1 may be sandwiched between the heat mediums 3, or at least a portion of the thermoelectric element 1 may be sandwiched between the heat mediums 3. Note that the pair of electrodes 11, 12, etc. being “sandwiched” by the heat medium 3 indicates a state in which the pair of electrodes 11, 12, etc. are in contact with the heat medium 3, and may also indicate a state in which they are separated from each other.

The pair of electrodes 11 and 12 are sandwiched between the first heat medium 3f and the second heat medium 3s, for example, along the first direction Z in which the main surfaces face each other. The pair of electrodes 11 and 12 may be sandwiched between the first heat medium 3f and the second heat medium 3s, for example, along the second direction X or the third direction Y parallel to the main surface. In either case, thermal energy can be continuously supplied to the electrodes 11 and 12 from the heat mediums 3f and 3s. In particular, by using the thermoelectric element 1 that does not require a temperature difference between the electrodes, there is no need to consider the degree of thermal energy supplied from each heat medium 3f, 3s, and it is easy to realize continuous and stable power generation. It becomes possible to Details of the thermoelectric element 1 will be described later.

The secondary battery 2 indicates a known chargeable/dischargeable battery such as a lithium ion secondary battery. The secondary battery 2 can be charged based on electric power generated by the thermoelectric element 1, for example. The type, performance, etc. of the secondary battery 2 can be arbitrarily selected according to the application.

The heat medium 3 may be any structure as long as it exhibits a temperature higher than the outside air, and may be, for example, a heat source that generates thermal energy. The heat medium 3 includes the first heat medium 3f and the second heat medium 3s provided separately, and may also include the first heat medium 3f and the second heat medium 3s provided integrally, for example.

Examples of heat sources include electronic parts of electronic devices such as CPUs, light-emitting elements such as LEDs (Light Emitting Diodes), engines of automobiles, production equipment in factories, human bodies, sunlight, and ambient temperature. Examples of the heat medium 3 include, in addition to the heat sources described above, structures capable of storing heat, such as housings of electronic devices, exhaust heat pipes, glass and frames of solar panels, and car bodies.

The secondary battery 100 with power generation function includes a charging circuit 5 as shown in FIG. 4, for example. As the charging circuit 5, for example, a known circuit that is used when charging the secondary battery 2 using energy generation such as the thermoelectric element 1 is used. The charging circuit 5 includes a rectifying circuit 51, a smoothing circuit 52, and a voltage limiter 53, for example. The charging circuit 5 may include, for example, a booster circuit.

The rectifier circuit 51 is used, for example, when the polarity of the voltage output from the thermoelectric element 1 changes. The smoothing circuit 52 is used, for example, when smoothing the DC voltage output from the thermoelectric element 1 or the rectifier circuit 51 . The voltage limiter 53 is used, for example, to prevent excessive voltage from being applied to the secondary battery 2 .

<First Modification: Heat Transfer Medium 3 Includes Casing Part 21 of Secondary Battery 2>
For example, the heat medium 3 may include the housing portion 21 of the secondary battery 2 . In this case, the thermoelectric element 1 may be provided in contact with the casing 21, as shown in FIG. That is, the pair of electrodes 11 and 12 are sandwiched between the arbitrary first heat medium 3f and the housing portion 21 corresponding to the second heat medium 3s. Therefore, thermal energy generated from the secondary battery 2 can be converted into electrical energy via the thermoelectric element 1 . This makes it possible to increase the amount of power generation. In addition, exhaust heat generated with the use of the secondary battery 2 can be effectively used.

Note that the temperature of the housing 21 increases as the secondary battery 2 is charged and discharged, and the temperature of the housing 21 tends to be continuously higher than that of the outside air. Therefore, by using the housing portion 21 as the heat medium 3, it is possible to stably supply thermal energy to the thermoelectric elements 1. FIG.

As the housing part 21, a known secondary battery housing is used, and for example, a material with high thermal conductivity is used. The container 31 contains the electrodes and the active material of the secondary battery 2, and may contain, for example, arbitrary electronic members, sealing materials, and the like.

Note that, for example, the thermoelectric element 1 may be provided between a pair of secondary batteries 2 . That is, the pair of electrodes 11 and 12 are connected to the housing portion 21 of one secondary battery 2 corresponding to the first heat medium 3f and the housing portion 21 of the other secondary battery 2 corresponding to the second heat medium 3s. may be sandwiched between Also in this case, thermal energy generated from the secondary battery 2 can be converted into electrical energy via the thermoelectric element 1 . This makes it possible to increase the amount of power generation.

<Second Modification: Heat Transfer Medium 3 Includes a Heat Storage Unit>
For example, the heat medium 3 may include a heat storage unit that stores heat energy. In this case, the thermoelectric element 1 is provided in contact between the heat storage section and the housing section 21 . That is, the pair of electrodes 11 and 12 are sandwiched between the heat storage portion corresponding to the first heat medium 3f and the housing portion 21 corresponding to the second heat medium 3s. Therefore, it is possible to easily suppress the temporal change in the amount of thermal energy supplied to the thermoelectric element 1 . This makes it possible to further stabilize the power generation amount.

The heat storage unit has, for example, a known sensible heat storage material that utilizes the specific heat of a substance. As the sensible heat storage material, for example, airgel, bricks, etc. are used. Airgel has nano-sized porosity smaller than the mean free path of air molecules, and is made of silica, carbon, alumina, or the like. As the sensible heat storage material, for example, a material exhibiting a specific heat higher than that of glass (for example, 0.67 J/g·K at 10 to 50° C.) is used. For the value of specific heat, reference can be made to literature values, or measurement results according to JIS K 7123 may be used.

The heat storage unit may have a latent heat storage material that utilizes transition heat (latent heat) associated with phase change or transition of a substance, for example. As the latent heat storage material, a known material utilizing phase change such as water or sodium chloride is used. The heat storage unit may have, for example, a chemical heat storage material that utilizes endothermic heat generated during a chemical reaction. For example, a known material is used as the chemical heat storage material.

Note that, for example, the thermoelectric element 1 may be provided in contact with a pair of heat storage units. That is, the pair of electrodes 11 and 12 may be sandwiched between one heat storage portion corresponding to the first heat medium 3f and the other heat storage portion corresponding to the second heat medium 3s. Also in this case, it is possible to easily suppress the temporal change in the amount of thermal energy supplied to the thermoelectric element 1 . This makes it possible to further stabilize the power generation amount.

In addition to the above, for example, the thermoelectric element 1 may be provided in a state of being included in the heat storage section. Also in this case, it is possible to easily suppress the temporal change in the amount of thermal energy supplied to the thermoelectric element 1 . This makes it possible to further stabilize the power generation amount. In particular, the temperature difference is less likely to occur in the region where the thermoelectric element 1 is included in the heat storage section. Therefore, it is difficult for a temperature difference to occur between the electrodes 11 and 12, and it is possible to suppress variation in power generation due to a temperature difference between the electrodes.

<Third Modification: Heat Transfer Medium 3 Includes Container 31>
For example, the heat medium 3 may include a container 31 in which the thermoelectric element 1 and the secondary battery 2 are installed. In this case, the thermoelectric element 1 contacts the inner wall of the container 31 . That is, the pair of electrodes 11 and 12 are sandwiched between the inner walls of the container 31 corresponding to the heat medium 3 . Therefore, the thermal energy transmitted to the container 31 can be converted into electrical energy via the thermoelectric element 1 . This makes it possible to increase the amount of power generation.

Note that the thermoelectric element 1 may be in contact with the inner wall of the container 31 and the housing portion 21, as shown in FIG. 2(b), for example. That is, the pair of electrodes 11 and 12 may be sandwiched between the inner wall of the container 31 corresponding to the first heat medium 3f and the housing portion 21 corresponding to the second heat medium 3s. Also in this case, the thermal energy transmitted to the container 31 and the housing portion 21 can be converted into electrical energy via the thermoelectric element 1 . This makes it possible to increase the amount of power generation.

As the container 31, a known material that protects electronic components and the like is used, for example, a material with high thermal conductivity is used. The container 31 may contain, for example, the thermoelectric element 1 and the secondary battery 2, as well as any electronic member, sealing material, and the like.

<Fourth Modification: Heat Medium 3 Includes Circuit Board 4>
For example, the heat medium 3 may contain a circuit board 4 . In this case, the thermoelectric element 1 is in contact with the circuit board 4, for example, as shown in FIG. 3(a). That is, the pair of electrodes 11 and 12 are sandwiched between the arbitrary first heat medium 3f and the circuit board 4 corresponding to the second heat medium 3s. Therefore, thermal energy generated on the circuit board 4 by arithmetic processing or the like can be converted into electrical energy via the thermoelectric element 1 . This makes it possible to increase the amount of power generation. In addition, exhaust heat generated by arithmetic processing or the like can be effectively used.

In addition, for example, the thermoelectric element 1 and the secondary battery 2 may be provided on the same main surface of the circuit board 4 . In this case, the heat energy generated from the secondary battery 2 can be easily supplied to the thermoelectric element 1 via the circuit board 4, and the heat energy can be suppressed from being retained in the circuit board 4. . This makes it possible to suppress deterioration of the circuit board 4 and degradation of quality such as a decrease in computation speed.

Alternatively, the thermoelectric element 1 may be provided in contact between the circuit board 4 and the casing 21, as shown in FIG. 3(b), for example. That is, the pair of electrodes 11 and 12 are sandwiched between the housing portion 21 corresponding to the first heat medium 3f and the circuit board 4 corresponding to the second heat medium 3s. Therefore, direct transmission of thermal energy generated from the secondary battery 2 to the circuit board 4 can be suppressed. This makes it possible to suppress deterioration of the circuit board 4 and degradation of quality such as a decrease in computation speed.

The circuit board 4 indicates a known wiring board on which electronic components such as a CPU and a transistor are mounted. The size and type of the circuit board 4 can be arbitrarily set according to the application. For example, the above-described charging circuit 5 may be arranged on the circuit board 4 .

(power generation system)
Next, an example of the power generation system according to this embodiment will be described. FIG. 4 is a conceptual diagram showing an example of the power generation system in this embodiment.

The power generation system includes, for example, a secondary battery 100 with a power generation function and a control unit 6, as shown in FIG. The secondary battery 100 with power generation function may include, for example, a plurality of thermoelectric elements 1 or a plurality of secondary batteries 2 .

The control unit 6 includes a known arithmetic processing device such as a CPU, and is mounted in an electronic device such as a personal computer or a smart phone. The control unit 6 may include sensors such as a current measuring sensor, a voltage measuring sensor, and a temperature sensor, and measure measured values. The control unit 6 may include a storage unit that stores preset threshold values, for example.

The control unit 6 controls charging conditions for the secondary battery 2 charged via the thermoelectric element 1 . Therefore, the charging condition can be controlled based on the charge/discharge state of the secondary battery 2 and the power generation state of the thermoelectric element 1 . This makes it possible to suppress early deterioration of the secondary battery 2 .

The control unit 6 acquires, for example, at least one of voltage and current based on the power generation of the thermoelectric element 1 as a measured value. The control unit 6 may, for example, acquire a corresponding measured value for each of the plurality of thermoelectric elements 1 .

The control unit 6 controls charging conditions for the secondary battery 2 based on the measured value. The control unit 6 may control the control conditions for each of one or more secondary batteries 2, for example, based on one or more measured values. The charging conditions can be arbitrarily set in advance, for example, and can be arbitrarily set as long as the conditions affect the charging of the secondary battery 2 .

For example, if the charging circuit 5 includes a plurality of voltage limiters 53, the charging conditions include conditions for connecting to the voltage limiters 53 according to the measured values. That is, the control unit 6 electrically connects a specific voltage limiter 53 to the secondary battery 2 and electrically separates the other voltage limiters 53 from the secondary battery 2 based on the measured value, thereby adjusting the charging condition. can be controlled.

For example, the control unit 6 may acquire the temperature of the thermoelectric element 1 during power generation as a measured value. In this case, for example, the controller 6 may control the temperature of the thermoelectric element 1 based on the result of comparing a preset temperature threshold value with the measured value. By controlling the temperature of the thermoelectric element 1, the power generation amount of the thermoelectric element 1 can be changed, so the charging condition of the secondary battery 2 can be controlled.

For example, when the temperature of the thermoelectric element 1 during power generation is acquired as a measured value, the control unit 6 may calculate an estimated amount of power generation corresponding to the measured value and control the charging conditions based on the calculation result. In addition to the above, for example, the control unit 6 may acquire changes in temperature over time during power generation of the thermoelectric element 1 as measured values. In this case, the control unit 6 may control charging conditions for interrupting charging of the secondary battery 2 when a temperature change exceeding a threshold occurs.

For example, the thermoelectric element 1 may include a plurality of elements electrically connected to the secondary battery 2 independently of each other. In this case, the control unit 6 may control the electrical connection relationship between the secondary battery 2 and the plurality of elements as the charging condition. For example, the control unit 6 acquires voltages as measured values for each of the plurality of elements. After that, the control unit 6 selects an element capable of outputting a voltage suitable for the state of charge of the secondary battery 2 based on the measured value, and electrically connects the selected element and the secondary battery 2 .

For example, the control unit 6 uses the discharge rate characteristics of the secondary battery 2 acquired in advance to calculate a voltage suitable for the charge rate of the secondary battery 2 . After that, the control unit 6 identifies an element capable of outputting the calculated voltage from the measured values obtained from the plurality of elements, and electrically connects the element and the secondary battery 2 . Note that the control unit 6 may connect, for example, a plurality of elements in parallel or in series.

For example, the secondary battery 2 may be electrically connected to, for example, the driving section, and the thermoelectric element 1 may be electrically separated from the driving section. In this case, the control unit 6 may control the conditions of power supplied from the secondary battery 2 to the driving unit. The control unit 6 acquires supply information (for example, voltage and current) regarding power supplied from the secondary battery 2 to the driving unit, for example, via the sensor described above. Based on the supply information, the control unit 6 controls the conditions of power supplied from the secondary battery 2 to the drive unit in the same manner as the charging conditions described above.

For example, the secondary battery 2 and the thermoelectric element 1 may be electrically connected to the drive section. In this case, similarly to the above, for example, the control section 6 may control the conditions of electric power supplied from the thermoelectric element 1 to the driving section. Further, for example, the control unit 6 may control conditions of power supplied from the secondary battery 2 and the thermoelectric element 1 to the driving unit. Even in this case, similarly to the method described above, the control unit 6 acquires supply information regarding power supplied to the driving unit from the thermoelectric element 1 and the secondary battery 2, and controls the power conditions based on the supply information. can be done.

(Thermoelectric element 1)
FIG. 5(a) is a schematic cross-sectional view showing an example of the thermoelectric element 1 in this embodiment, and FIG. 5(b) is a schematic cross-sectional view taken along line AA in FIG. 5(a).

The thermoelectric element 1 includes, for example, a first electrode 11, a second electrode 12, and an intermediate portion 14, as shown in FIG. 5(a). The thermoelectric element 1 may comprise at least one of the first substrate 15 and the second substrate 16, for example.

The first electrode 11 and the second electrode 12 are provided facing each other. The first electrode 11 and the second electrode 12 have different work functions. The intermediate portion 14 is provided in a space 140 including a gap G between the first electrode 11 and the second electrode 12, as shown in FIG. 6, for example. The intermediate portion 14 includes fine particles 141 .

The particles 141 may include, for example, a first particle 141f and a second particle 141s. For example, the median diameter D50s of the second fine particles 141s is smaller than the median diameter D50f of the first fine particles 141f. In this case, for example, it is possible to increase the possibility that the second particles 141s enter between the particles of the first particles 141f. At this time, compared to the case where only one of the fine particles 141f and 141s is included in the intermediate portion 14, the variable range is narrower. Therefore, fluctuation of the fine particles 141 can be suppressed. As a result, it is possible to suppress a decrease in the power generation amount.

Further, for example, by including the particles 141f and 141s in the particles 141, the area of the particles 141 in contact with the electrodes 11 and 12 can be increased compared to the case where only the first particles 141f having a large median diameter D50f are included. can be done. Therefore, the amount of electrons moving between the electrodes 11 and 12 can be increased. This makes it possible to increase the amount of power generation.

In addition, for example, by including the particles 141f and 141s in the particles 141, the filling degree of the particles 141 in the intermediate portion 14 can be easily improved compared to the case where only the second particles 141s having a small median diameter D50s are included. be able to. Thereby, the movement of electrons between the fine particles 141 can be facilitated. In this respect as well, it is possible to increase the amount of power generation.

Details of each configuration will be described below.

<First Electrode 11, Second Electrode 12>
The first electrode 11 and the second electrode 12 are spaced apart in the first direction Z, as shown in FIG. 5(a), for example. Each of the electrodes 11 and 12 may extend in the second direction X and the third direction Y, for example, and may be provided in plurality. For example, one second electrode 12 may be provided facing the plurality of first electrodes 11 at different positions. Also, for example, one first electrode 11 may be provided facing the plurality of second electrodes 12 at different positions.

A conductive material is used as the material of the first electrode 11 and the second electrode 12 . As materials for the first electrode 11 and the second electrode 12, for example, materials having different work functions are used. The electrodes 11 and 12 may be made of the same material, in which case they may have different work functions.

As the material of the electrodes 11 and 12, for example, a material composed of a single element such as iron, aluminum, or copper may be used, or an alloy material composed of, for example, two or more elements may be used. A non-metallic conductor, for example, may be used as the material of the electrodes 11 and 12 . Examples of nonmetallic conductors include silicon (Si: for example, p-type Si or n-type Si) and carbon-based materials such as graphene.

The thickness of the first electrode 11 and the second electrode 12 along the first direction Z is, for example, 4 nm or more and 1 μm or less. The thickness of the first electrode 11 and the second electrode 12 along the first direction Z may be, for example, 4 nm or more and 500 nm or less.

A gap G, which indicates the distance between the first electrode 11 and the second electrode 12, can be arbitrarily set by changing the thickness of the non-conductor layer 142, for example. For example, by narrowing the gap G, the electric field generated between the electrodes 11 and 12 can be increased, so that the amount of power generated by the thermoelectric element 1 can be increased. Also, by narrowing the gap G, for example, the thickness of the thermoelectric element 1 along the first direction Z can be reduced.

Gap G is a finite value of, for example, 500 μm or less. The gap G is, for example, 10 nm or more and 1 μm or less. For example, when the gap G is 200 nm or less, the possibility of contact between the first electrode 11 and the second electrode 12 increases. Also, if the gap G is larger than 1 μm, the electric field generated between the electrodes 11 and 12 may weaken. For these reasons, the gap G is preferably larger than 200 nm and 1 μm or less.

<Intermediate part 14>
The intermediate portion 14 includes, for example, fine particles 141 and a non-conductor layer 142 . The non-conductor layer 142 contains the fine particles 141 and supports the first electrode 11 and the second electrode 12 . In this case, movement of the particles 141 in the gap G is suppressed by the non-conductor layer 142 . Therefore, it is possible to prevent the fine particles 141 from becoming unevenly distributed on the side of one of the electrodes 11 and 12 over time and reducing the amount of movement of electrons. This makes it possible to stabilize the power generation amount.

The non-conductor layer 142 is formed, for example, by curing a non-conductor material. The non-conductor layer 142 exhibits a solid, for example. The non-conducting layer 142 may include, for example, diluent residue and uncured portions of the non-conducting material. In this case as well, it is possible to stabilize the power generation amount in the same manner as described above. Also, the fine particles 141 are fixed in a dispersed state in the non-conductor layer 142, for example. In this case as well, it is possible to stabilize the power generation amount in the same manner as described above.

The intermediate portion 14 is provided on the first electrode 11 . Also, the second electrode 12 is provided on the non-conductor layer 142 . Here, in the thermoelectric element 1 that does not require a temperature difference between the electrodes when converting thermal energy into electrical energy, by suppressing variations in the gap G on the surfaces along the second direction X and the third direction Y, For example, it is possible to increase the amount of power generation. In this regard, when a liquid such as a solvent is used as the intermediate portion, it is necessary to provide a support portion or the like for maintaining the gap G. However, there has been a concern that the gap G may vary greatly with the formation of the supporting portion and the like. On the other hand, in the thermoelectric element 1 according to the present embodiment, the second electrode 12 is provided on the non-conductor layer 142, so that there is no need to provide a support or the like for maintaining the gap G, and the support or the like is not required. It is possible to eliminate gap variations due to formation accuracy. This makes it possible to suppress variations in the amount of power generation.

Further, when a support portion or the like is provided to maintain the gap, there is a concern that the fine particles 141 may come into contact with the support portion and agglomerate around the support portion. On the other hand, in the thermoelectric element 1 according to the present embodiment, it is possible to eliminate the state in which the fine particles 141 aggregate due to the supporting portion. This makes it possible to maintain a stable power generation amount.

The intermediate portion 14 extends on a plane along the second direction X and the third direction Y, as shown in FIG. 5B, for example. The intermediate portion 14 is provided within a space 140 formed between the electrodes 11 , 12 . The intermediate portion 14 may be in contact with the main surfaces of the electrodes 11 and 12 facing each other, and may also be in contact with the side surfaces of the electrodes 11 and 12, for example.

The fine particles 141 may be dispersed in the non-conductor layer 142 and partially exposed from the non-conductor layer 142, for example. The particles 141 may be filled in the gap G, for example, and the non-conductor layer 142 may be provided in the gaps between the particles 141 . The particle diameter of the fine particles 141 is smaller than the gap G, for example. The particle diameter of the fine particles 141 is set to a finite value of 1/10 or less of the gap G, for example. If the particle diameter of the fine particles 141 is set to 1/10 or less of the gap G, it becomes easier to form the intermediate portion 14 containing the fine particles 141 in the space 140 . Thereby, when the thermoelectric element 1 is produced, workability can be improved.

Here, "fine particles" refer to those containing a plurality of particles. The fine particles 141 include particles having a particle diameter of, for example, 2 nm or more and 1000 nm or less. The fine particles 141 may include, for example, particles having a median diameter (median diameter: D50) of 3 nm or more and 20 nm or less, or particles having an average particle diameter of 3 nm or more and 20 nm or less. . The particle number concentration of the fine particles 141 may be, for example, about 1.0×10 ⁶ to 1.0×10 ¹² /ml, and can be arbitrarily set according to the application. The median diameter or average particle diameter and particle number concentration can be measured, for example, by using a particle size distribution analyzer. As the particle size distribution measuring instrument, for example, a particle size distribution measuring instrument using a dynamic light scattering method (eg, Zetasizer Ultra manufactured by Malvern Panalytical, etc.) may be used.

Note that the first fine particles 141f and the second fine particles 141s included in the fine particles 141 can be arbitrarily selected, for example, as long as the particle diameter is within the range described above. Also, the difference between the median diameter D50f of the first fine particles 141f and the median diameter D50s of the second fine particles 141s is arbitrary.

For example, the particle number concentration of the first fine particles 141f is lower than the particle number concentration of the second fine particles 141s. Here, when the particle number concentration of the first fine particles 141f is higher than the particle number concentration of the second fine particles 141s, the possibility of the second fine particles 141s entering between the particles of the first fine particles 141f becomes low. For this reason, the degree of filling of the particles 141 between the electrodes 11 and 12 cannot be increased, and there is a concern that the particles 141 may be unevenly distributed. In contrast, according to the present embodiment, for example, the particle number concentration of the first fine particles 141f is lower than the particle number concentration of the second fine particles 141s. In this case, the filling degree of the fine particles 141 between the electrodes 11 and 12 can be increased. Therefore, it is possible to suppress uneven distribution of the fine particles 141 and the like.

For example, the work function of the first fine particles 141f is lower than the work function of the second fine particles 141s. In this case, electrons tend to move from the first electrode 11 and the first fine particles 141f toward the second fine particles 141s. In addition, since the inter-particle distance of the second fine particles 141s tends to be shorter than the inter-particle distance of the first fine particles 141f, an electron transfer path is easily formed in the intermediate portion 14 . Therefore, electrons are easily supplied from the first electrode 11 to the intermediate portion 14 via the second fine particles 141s. Thereby, the transmission of electrons between the electrodes 11 and 12 can proceed smoothly. Therefore, it is possible to increase the amount of power generation.

The fine particles 141 include, for example, a conductive material, and any material is used depending on the application. The fine particles 141 may contain one type of material, or may contain a plurality of materials depending on the application.

The fine particles 141 contain, for example, metal. As the fine particles 141, for example, in addition to particles containing one kind of material such as gold or silver, particles of an alloy containing two or more kinds of materials may be used.

Fine particles 141 contain, for example, a metal oxide. Examples of fine particles 141 containing metal oxides include zirconia (ZrO ₂ ), titania (TiO ₂ ), silica (SiO ₂ ), alumina (Al ₂ O ₃ ), iron oxides (Fe ₂ O ₃ , Fe ₂ O ₅ ), Copper oxide (CuO ₎ , zinc oxide (ZnO), yttria ( _Y2O3 ), niobium _oxide ( _Nb2O5 ) _, molybdenum oxide ( _MoO3 ), indium oxide ( _In2O3 ), tin oxide ( _SnO2 ), tantalum oxide (Ta ₂ O ₅ ), tungsten oxide (WO ₃ ), lead oxide (PbO), bismuth oxide (Bi ₂ O ₃ ), ceria (CeO ₂ ), antimony oxide (Sb ₂ O ₅ , Sb ₂ O ₃ ), a metal oxide of at least one element selected from the group consisting of metals and Si is used. Particulate 141 may include, for example, a dielectric.

The fine particles 141 may contain, for example, metal oxides other than magnetic substances. For example, when the fine particles 141 contain a metal oxide exhibiting a magnetic substance, movement of the fine particles 141 can be restricted by a magnetic field generated due to the environment in which the thermoelectric element 1 is installed. Therefore, by including a metal oxide other than a magnetic material, the fine particles 141 are not affected by the magnetic field caused by the external environment, and it is possible to suppress the decrease in the power generation amount over time.

The fine particle 141 includes, for example, a coating 141a on its surface. The thickness of the coating 141a is, for example, a finite value of 20 nm or less. By providing such a film 141 a on the surface of the fine particles 141 , it is possible to suppress aggregation when dispersed in the non-conductor layer 142 , for example. In addition, by providing such coating 141 a on the surface of the particles 141 , it is possible to prevent the particles 141 from directly contacting at least one of the first electrode 11 and the second electrode 12 .

A material having, for example, a thiol group or a disulfide group is used as the coating 141a. Alkanethiol such as dodecanethiol is used as the material having a thiol group. As a material having a disulfide group, for example, an alkane disulfide or the like is used.

The non-conductor layer 142 is provided between the electrodes 11 and 12 and is in contact with the electrodes 11 and 12, for example. The thickness of the non-conductor layer 142 is, for example, a finite value of 500 μm or less. The thickness of the non-conductor layer 142 affects the value and variation of the gap G described above. Therefore, for example, when the thickness of the non-conductor layer 142 is 200 nm or less, the possibility of contact between the first electrode 11 and the second electrode 12 increases. Also, if the thickness of the non-conductor layer 142 is greater than 1 μm, the electric field generated between the electrodes 11 and 12 may weaken. For these reasons, the thickness of the non-conductor layer 142 is preferably greater than 200 nm and equal to or less than 1 μm.

The non-conductor layer 142 may contain, for example, one type of material, or may contain a plurality of materials depending on the application. Materials described in ISO1043-1 or JIS K 6899-1, for example, may be used as the non-conductor layer 142 . The non-conductor layer 142 may include a plurality of layers containing different materials, for example, and may include a structure in which each layer is laminated. When the non-conductor layer 142 includes a plurality of layers, for example, particles 141 containing different materials may be included (eg, dispersed) in each layer.

The non-conductor layer 142 has insulating properties, for example. The material used for the non-conductor layer 142 is arbitrary as long as it is a non-conductor material that can fix the fine particles 141 in a dispersed state, but an organic polymer compound is preferable. When the non-conductor layer 142 contains an organic polymer compound, the non-conductor layer 142 can be formed flexibly, so that the thermoelectric element 1 can be formed in a shape such as curved or bent depending on the application.

Examples of organic polymer compounds include polyimides, polyamides, polyesters, polycarbonates, poly(meth)acrylates, radically polymerizable photo- or thermosetting resins, photo-cationically polymerizable photo- or thermosetting resins, epoxy resins, and acrylonitrile components. can be used, such as copolymers containing

An inorganic substance may be used as the non-conductor layer 142, for example. Examples of inorganic substances include porous inorganic substances such as zeolite and diatomaceous earth, as well as cage-like molecules.

<First Substrate 15, Second Substrate 16>
The first substrate 15 and the second substrate 16 are spaced apart in the first direction Z with the electrodes 11 and 12 and the intermediate portion 14 interposed therebetween, as shown in FIG. 5A, for example. The first substrate 15 is, for example, in contact with the first electrode 11 and separated from the second electrode 12 . The first substrate 15 fixes the first electrode 11 . The second substrate 16 is in contact with the second electrode 12 and separated from the first electrode 11 . A second substrate 16 fixes the second electrode 12 .

The thickness of each of the substrates 15 and 16 along the first direction Z is, for example, 10 μm or more and 2 mm or less. The thickness of each substrate 15, 16 can be set arbitrarily. The shape of each of the substrates 15 and 16 may be, for example, square, rectangular, or disk-like, and can be arbitrarily set according to the application.

As the substrates 15 and 16, for example, a plate-like member having insulating properties can be used, and known members such as silicon, quartz, and Pyrex (registered trademark) can be used. The substrates 15 and 16 may be, for example, film-shaped members, and known film-shaped members such as PET (polyethylene terephthalate), PC (polycarbonate), and polyimide may be used.

For each of the substrates 15 and 16, for example, a conductive member can be used, such as iron, aluminum, copper, or an alloy of aluminum and copper. Further, as the substrates 15 and 16, a member such as a conductive polymer may be used in addition to a conductive semiconductor such as Si or GaN. If conductive members are used for the substrates 15 and 16, wiring for connecting to the electrodes 11 and 12 becomes unnecessary.

For example, if the first substrate 15 is a semiconductor, it may have a degenerate portion that contacts the first electrode 11 . In this case, the contact resistance between the first electrode 11 and the first substrate 15 can be reduced as compared with the case without the degenerate portion. Also, the first substrate 15 may have a recessed portion on a surface different from the surface in contact with the first electrode 11 . In this case, the contact resistance between the wiring (for example, the first wiring 101) electrically connected to the first substrate 15 can be reduced.

For example, when stacking a plurality of thermoelectric elements 1 shown in FIG. In this case, contact resistance can be reduced by providing degenerate portions on the contact surfaces of the substrates 15 and 16 that are in contact with each other as the thermoelectric elements 1 are stacked.

The above-described degenerate portion is generated by, for example, ion-implanting an n-type dopant into a semiconductor at a high concentration, coating the semiconductor with a material such as glass containing an n-type dopant, and performing heat treatment after coating.

As impurities to be doped into the semiconductor first substrate 15, known impurities such as P, As, Sb, etc. for n-type, and B, Ba, Al, etc. for p-type are mentioned. Also, if the concentration of the impurity in the degenerate portion is, for example, 1×10 ¹⁹ ions/cm ³ , electrons can be efficiently emitted.

For example, when the first substrate 15 is a semiconductor, the specific resistance value of the first substrate 15 may be, for example, 1×10 ⁻⁶ Ω·cm or more and 1×10 ⁶ Ω·cm or less. If the resistivity value of the first substrate 15 is less than 1×10 ⁻⁶ Ω·cm, it is difficult to select the material. Also, if the specific resistance value of the first substrate 15 is greater than 1×10 ⁶ Ω·cm, there is a concern that current loss may increase.

In addition, although the case where the 1st board|substrate 15 is a semiconductor was demonstrated above, the 2nd board|substrate 16 may be a semiconductor. In this case, the description is omitted because it is the same as the above.

The thermoelectric element 1 may include only the first substrate 15 as shown in FIG. 7A, or may include only the second substrate 16, for example. Further, as shown in FIG. 7B, the thermoelectric element 1 has a laminated structure in which a plurality of the first electrodes 11, the intermediate portions 14, and the second electrodes 12 are laminated in this order without the respective substrates 15 and 16. (e.g. 1a, 1b, 1c, etc.), for example, a laminated structure comprising at least one of the substrates 15, 16 may be indicated.

Note that the intermediate portion 14 may contain a solvent 142s instead of the non-conductor layer 142, as shown in FIG. 8, for example. In this case, the fine particles 141 are dispersed in the solvent 142s. Further, each of the electrodes 11 and 12 is supported by a supporting portion (not shown). A known liquid such as water or toluene is used as the solvent 142s. Even in this case, it is possible to suppress a decrease in the power generation amount by including the above-described first fine particles 141f and second fine particles 141s.

Note that the intermediate portion 14 may not include the non-conductor layer 142, as shown in FIG. 9, for example. In this case, the gap G is filled with the fine particles 141 . Further, each of the electrodes 11 and 12 is supported by a supporting portion (not shown). Even in this case, it is possible to suppress a decrease in the power generation amount by including the above-described first fine particles 141f and second fine particles 141s.

<Example of operation of thermoelectric element 1>
For example, when thermal energy is applied to the thermoelectric element 1, a current is generated between the first electrode 11 and the second electrode 12, converting the thermal energy into electrical energy. The amount of current generated between the first electrode 11 and the second electrode 12 depends on thermal energy and also depends on the difference between the work function of the second electrode 12 and the work function of the first electrode 11 .

The amount of current generated can be increased by increasing the work function difference between the first electrode 11 and the second electrode 12 and by decreasing the gap G, for example. For example, the amount of electrical energy generated by the thermoelectric element 1 can be increased by considering at least one of increasing the work function difference and decreasing the gap G. Further, by providing the fine particles 141 between the electrodes 11 and 12, the amount of electrons moving between the electrodes 11 and 12 can be increased, which can lead to an increase in the amount of current.

Note that the "work function" indicates the minimum energy required to extract electrons in a solid into a vacuum. The work function is measured using, for example, ultraviolet photoelectron spectroscopy (UPS), X-ray photoelectron spectroscopy (XPS), or Auger electron spectroscopy (AES). can be done. As the “work function”, in addition to using actual measurement values for each configuration of the thermoelectric element 1, for example, known values measured for materials may be used.

According to this embodiment, the thermoelectric element 1 is in contact with the heat medium 3 exhibiting a temperature higher than the outside air. Therefore, it is possible to suppress fluctuations in the heat transferred to the thermoelectric element 1 over time. This makes it possible to achieve stable power generation.

Further, according to the present embodiment, the intermediate portion 14 includes the non-conductor layer 142 encapsulating the fine particles 141 . That is, the non-conductor layer 142 suppresses movement of the fine particles 141 between the electrodes. Therefore, it is possible to prevent the fine particles 141 from becoming unevenly distributed on the one electrode side over time and reducing the amount of movement of electrons. This makes it possible to stabilize the power generation amount.

Also, according to this embodiment, the non-conductor layer 142 supports the pair of electrodes 11 and 12 . Therefore, compared to the case where a solvent or the like is used instead of the non-conductor layer 142, there is no need to provide a supporting portion or the like for maintaining the distance (gap G) between the electrodes, and the accuracy of forming the supporting portion is reduced. Variation in the gap G can be eliminated. This makes it possible to suppress variations in the amount of power generation.

Further, according to this embodiment, the pair of electrodes 11 and 12 are sandwiched between the heat mediums 3 . Therefore, it is possible to further suppress fluctuations in the heat transferred to the thermoelectric element 1 over time. This makes it possible to achieve more stable power generation.

Moreover, according to the present embodiment, the thermoelectric element 1 is provided in contact with the housing portion 21 . Therefore, thermal energy generated from the secondary battery 2 can be converted into electrical energy via the thermoelectric element 1 . This makes it possible to increase the amount of power generation. In addition, exhaust heat generated with the use of the secondary battery 2 can be effectively used.

Further, according to this embodiment, the thermoelectric element 1 is provided in contact between the housing portion 21 and the heat storage portion. Therefore, it is possible to easily suppress the temporal change in the amount of thermal energy supplied to the thermoelectric element 1 . This makes it possible to further stabilize the power generation amount.

Further, according to this embodiment, the thermoelectric element 1 is in contact with the inner wall of the container 31 . Therefore, the thermal energy transmitted to the container 31 can be converted into electrical energy via the thermoelectric element 1 . This makes it possible to increase the amount of power generation.

Moreover, according to this embodiment, the thermoelectric element 1 is in contact with the circuit board 4 . Therefore, thermal energy generated on the circuit board 4 by arithmetic processing or the like can be converted into electrical energy via the thermoelectric element 1 . This makes it possible to increase the amount of power generation. In addition, exhaust heat generated by arithmetic processing or the like can be effectively used.

Further, according to this embodiment, the thermoelectric element 1 and the secondary battery 2 are provided on the same main surface of the circuit board 4 . Therefore, it is possible to prevent the heat energy generated from the secondary battery 2 from being retained in the circuit board 4 . This makes it possible to suppress deterioration of the circuit board 4 and degradation of quality such as a decrease in computation speed.

Further, according to this embodiment, the thermoelectric element 1 is provided in contact between the circuit board 4 and the housing portion 21 . Therefore, direct transmission of thermal energy generated from the secondary battery 2 to the circuit board 4 can be suppressed. This makes it possible to suppress deterioration of the circuit board 4 and degradation of quality such as a decrease in computation speed.

Moreover, according to the present embodiment, the thermoelectric element 1 is in contact with the drive section. Therefore, thermal energy generated from the drive section can be converted into electrical energy via the thermoelectric element 1 . This makes it possible to increase the amount of power generation. In addition, exhaust heat generated from the driving section can be effectively used.

Further, according to this embodiment, for example, the thermoelectric element 1 may be electrically connected to the secondary battery 2 via a booster circuit. In this case, when charging the secondary battery 2 using the power generation of the thermoelectric element 1, it is possible to shorten the charging time.

Further, according to the present embodiment, for example, the control unit 6 may control charging conditions for the secondary battery 2 charged via the thermoelectric element 1 . In this case, the charging conditions can be controlled based on the charge/discharge state of the secondary battery 2 and the power generation state of the thermoelectric element 1 . This makes it possible to suppress early deterioration of the secondary battery 2 .

Further, according to this embodiment, for example, the secondary battery 2 may be electrically connected to the driving section, and the thermoelectric element 1 may be electrically separated from the driving section. In this case, the power generation system can be used without changing the conventional connection relationship between the secondary battery 2 and the drive unit. This makes it possible to improve the convenience of the power generation system.

Further, according to the present embodiment, for example, the control unit 6 may control conditions of power supplied from the secondary battery 2 to the drive unit. In this case, the electric power supplied from the secondary battery 2 can be controlled according to variations in power generation of the thermoelectric element 1 . This makes it possible to achieve stable power supply.

Further, according to the present embodiment, for example, the control unit 6 may control the electrical connection relationship between the secondary battery 2 and a plurality of elements as a charging condition. In this case, charging conditions that impose a load on the secondary battery 2 can be avoided, and charging suitable for the state of the secondary battery 2 can be performed. This makes it possible to further suppress early deterioration of the secondary battery 2 .

Further, according to the present embodiment, for example, the particles 141 may include first particles 141f and second particles 141s having a smaller median diameter D50s than the first particles 141f. In this case, it is possible to increase the possibility that the second fine particles 141s enter between the particles of the first fine particles 141f, and it is possible to suppress fluctuations in the dispersed state of the fine particles 141. FIG. As a result, it is possible to suppress a decrease in the power generation amount.

Further, according to the present embodiment, for example, the particle number concentration of the first fine particles 141f may be lower than the particle number concentration of the second fine particles 141s. That is, the filling degree of the fine particles 141 between the electrodes 11 and 12 can be increased. Therefore, it is possible to further suppress fluctuations in the dispersed state of the fine particles 141 . As a result, it is possible to further suppress the decrease in the power generation amount.

Also, according to this embodiment, for example, the non-conductor layer 142 may include an organic polymer compound. In this case, the non-conductor layer 142 can be formed flexibly. Thereby, it is possible to form the thermoelectric element 1 having a shape according to the application.

Further, according to the present embodiment, for example, the intermediate portion 14 is provided on the first electrode 11 and includes a solid non-conductor layer 142 and fine particles 141 dispersed and fixed in the non-conductor layer 142. may contain. That is, the non-conductor layer 142 suppresses movement of the fine particles 141 between the electrodes (the first electrode 11 and the second electrode 12). In this case, it is possible to prevent the fine particles 141 from becoming unevenly distributed on one electrode side over time and reducing the amount of movement of electrons. This makes it possible to stabilize the power generation amount.

Also according to this embodiment, for example, the intermediate portion 14 is provided on the first electrode 11 and may include a solid non-conducting layer 142 . Also, the second electrode 12 may be provided on the non-conductor layer 142 and have a work function different from that of the first electrode 11 . In this case, compared to the case where a solvent or the like is used instead of the non-conductor layer 142, there is no need to provide a support or the like for maintaining the distance (gap G) between the electrodes. Therefore, it is possible to eliminate the variation of the gap G to be applied. This makes it possible to suppress variations in the amount of power generation.

While several embodiments of the invention have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and equivalents thereof.

Reference Signs List 1: thermoelectric element 11: first electrode 12: second electrode 14: intermediate portion 15: first substrate 16: second substrate 17: sealing material 2: secondary battery 3: heat medium 3f: first heat medium 3s: Second heat medium 4 : Circuit board 5 : Charging circuit 51 : Rectifying circuit 52 : Smoothing circuit 53 : Voltage limiter 6 : Control unit 100 : Secondary battery with power generation function 140 : Space 141 : Particles 141a : Coating 142 : Non-conductor layer 142s: solvent G: gap R: load Z: first direction X: second direction Y: third direction

A secondary battery with a power generation function according to a first invention is a secondary battery with a power generation function that uses a thermoelectric element, is in contact with a heat medium that exhibits a temperature higher than the outside air, and does not require a temperature difference between the electrodes. and a secondary battery electrically connected to the thermoelectric element, wherein the thermoelectric element comprises a pair of electrodes having work functions different from each other and provided between the pair of electrodes to disperse fine particles. and a middle portion including a non-conducting layer, wherein the non-conducting layer supports the pair of electrodes .

A secondary battery with a power generation function according to a second invention is characterized in that, in the first invention , the non-conductor layer exhibits a solid state .

Further, according to the first to tenth inventions, the intermediate portion includes a non-conductor layer containing fine particles. That is, the non-conductor layer suppresses movement of the fine particles between the electrodes. For this reason, it is possible to prevent the fine particles from becoming unevenly distributed on the one electrode side over time and reducing the amount of movement of electrons. This makes it possible to stabilize the power generation amount.

Further, according to the first to tenth inventions, the non-conductor layer supports the pair of electrodes. Therefore, compared to the case where a solvent or the like is used instead of the non-conductive layer, there is no need to provide a support portion or the like for maintaining the distance (gap) between the electrodes, and the gap resulting from the formation accuracy of the support portion is eliminated. Distortion can be removed. This makes it possible to suppress variations in the amount of power generation.

A secondary battery with a power generation function according to a first invention is a secondary battery with a power generation function that uses a thermoelectric element, is in contact with a heat medium that exhibits a temperature higher than the outside air, and does not require a temperature difference between the electrodes. and a secondary battery electrically connected to the thermoelectric element, wherein the thermoelectric element comprises a pair of electrodes having work functions different from each other and provided between the pair of electrodes to disperse fine particles. and a middle portion including a non-conducting layer that is curved, the non-conducting layer supporting the pair of electrodes , and the thickness of the non-conducting layer being greater than 200 nm .

A secondary battery with a power generating function according to a second invention is characterized in that, in the first invention, the non-conductor layer is solid , and the thickness of the non-conductor layer is 1 μm or less .

Claims (10)

A secondary battery with a power generation function using a thermoelectric element,
The thermoelectric element that is in contact with a heat medium exhibiting a temperature higher than the outside air and does not require a temperature difference between electrodes;
a secondary battery electrically connected to the thermoelectric element;
with
A secondary battery with a power generation function, wherein the thermoelectric element includes a pair of electrodes having work functions different from each other. The thermoelectric element includes an intermediate portion provided between the pair of electrodes and including a non-conductor layer containing fine particles,
The secondary battery with power generation function according to claim 1, wherein the non-conductor layer supports the pair of electrodes. 3. The secondary battery with power generation function according to claim 1, wherein the pair of electrodes are sandwiched between the heat mediums. The heat medium includes a casing of the secondary battery,
The secondary battery with power generation function according to any one of claims 1 to 3, wherein the thermoelectric element is provided in contact with the housing. The heat medium includes a heat storage unit that stores thermal energy,
5. The secondary battery with power generation function according to claim 4, wherein the thermoelectric element is provided in contact between the housing portion and the heat storage portion. The heat medium includes a container in which the thermoelectric element and the secondary battery are installed,
The secondary battery with power generation function according to any one of claims 1 to 4, wherein the thermoelectric element is in contact with the inner wall of the container. The heat medium includes a circuit board,
The secondary battery with power generation function according to any one of claims 1 to 3, wherein the thermoelectric element is in contact with the circuit board. 8. The secondary battery with power generation function according to claim 7, wherein the thermoelectric element and the secondary battery are provided on the same main surface of the circuit board. The heat medium includes a casing of the secondary battery,
The secondary battery with power generation function according to claim 7, wherein the thermoelectric element is provided in contact between the circuit board and the casing. The heat medium includes a drive unit supplied with power from the secondary battery,
The secondary battery with power generation function according to any one of claims 1 to 4, wherein the thermoelectric element is in contact with the drive section.

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