Battery pack, energy storage device and energy storage system

Abstract

The embodiment of the utility model discloses a battery pack, an energy storage device and an energy storage system, and relates to the technical field of batteries, and structural adhesive with conductivity is arranged between an insulating layer of each battery and the bottom of a first shell. When the battery pack is under the condition of high electric field intensity, even if bubbles exist in the structural adhesive, due to the fact that the structural adhesive has conductivity, charges in the structural adhesive move under the high electric field intensity, voltages in all positions in the structural adhesive are balanced, and high voltage difference cannot be formed at the bubbles of the structural adhesive, so that the battery pack is prevented from being damaged. When the battery pack is used, partial discharge cannot be formed in bubbles of the structural adhesive, the insulation layer on the outer surface of the battery is prevented from losing the insulation effect due to aging under the long-term effect of the partial discharge, thermal runaway caused by short circuit of the battery and the first shell of the battery pack is further avoided, and meanwhile, the battery pack can be put into use after passing a partial discharge test.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and in particular to a battery pack, an energy storage device and an energy storage system. Background Art

[0002] The battery pack is composed of multiple batteries connected in series, parallel or series-parallel, and a single battery is fixed to the bottom of the battery pack shell by structural adhesive. The structural adhesive has the dual functions of fixing the battery and insulating it from the ground.

[0003] Due to the characteristics of structural adhesives and process limitations, it is difficult to eliminate the presence of bubbles inside the structural adhesive after it is cured. When the battery pack is under high electric field strength, the bubbles inside the structural adhesive may become the starting point of local discharge. The structural adhesive and even the insulating layer on the outer surface of the battery are easily aged due to local discharge, which may cause the insulation performance between the battery and the battery pack shell to deteriorate, and eventually a short circuit may occur, leading to thermal runaway. It may also cause the battery pack to fail the local discharge test and the battery pack cannot be put into use. Utility Model Content

[0004] The embodiments of the utility model provide a battery pack, an energy storage device and an energy storage system, which are intended to solve the problem of thermal runaway caused by a short circuit between the battery and the battery pack shell due to partial discharge of the battery pack structural adhesive, and the problem of the battery pack failing a partial discharge test.

[0005] In a first aspect, an embodiment of the present application proposes a battery pack, comprising: a first shell, a plurality of batteries and a structural adhesive, wherein the plurality of batteries are arranged in the first shell, an insulating layer is arranged on the outer surface of each battery, the structural adhesive is arranged between the insulating layer of each battery and the bottom of the first shell, and the structural adhesive is conductive.

[0006] This embodiment proposes a battery pack, in which a conductive structural adhesive is arranged between the insulating layer of each battery and the bottom of the first shell. When the battery pack is in a high electric field strength, even if there are bubbles inside the structural adhesive, due to the conductivity of the structural adhesive, under high electric field strength, the charges in the structural adhesive move, so that the voltages at various locations in the structural adhesive are balanced, and no high voltage difference is formed at the bubbles in the structural adhesive. Therefore, no local discharge is formed in the bubbles in the structural adhesive, and the insulating layer on the outer surface of the battery is prevented from losing its insulating function due to aging under the long-term effect of local discharge, thereby avoiding thermal runaway caused by a short circuit between the battery and the first shell of the battery pack, and also ensuring that the battery pack can pass the local discharge test and be put into use.

[0007] In some embodiments, the material of the structural adhesive is an insulating material doped with a conductive medium.

[0008] In this embodiment, the structural adhesive is made of at least a conductive medium and an insulating material. Bubbles will still be generated during the mixing process and the reaction process. Bubbles will still exist inside the structural adhesive after it is cured. However, since the structural adhesive is conductive, under high electric field strength, the charges in the structural adhesive will move, so that the voltage at various locations in the structural adhesive reaches a balance, and a high voltage difference will not be formed at the bubbles in the structural adhesive. Therefore, local discharge will not be formed in the bubbles of the structural adhesive.

[0009] In some embodiments, the conductive medium is a conductor material or a semiconductor material.

[0010] In this embodiment, the conductive medium doped in the insulating material can be selected according to the strength of the electric field strength in which the battery pack is located. If the electric field strength in which the battery pack is located is relatively large, a conductive material can be doped in the insulating material to prepare a structural adhesive; if the electric field strength in which the battery pack is located is relatively small, a semiconductor material can be doped in the insulating material to prepare a structural adhesive.

[0011] In some embodiments, the electrical conductivity of the structural adhesive is greater than or equal to 10 −6 S / m.

[0012] In this embodiment, this conductivity level is considered to be the minimum requirement for structural adhesive to be used in battery packs in power grids. The higher the total voltage of the power grid, the greater the electric field strength. To avoid partial discharge of the battery pack, the conductivity of the structural adhesive in the battery pack is also required to be higher. In practical applications, structural adhesives with different conductivities can be selected according to the total voltage of the power grid, so that the battery pack will not be partially discharged under different electric field strengths.

[0013] In some embodiments, the thickness of the insulating layer is greater than 80 microns.

[0014] In this embodiment, the thickness of the insulating layer is increased, thereby improving the dielectric strength of the insulating layer, so that the voltage of the electric field can be reliably borne without insulation breakdown and thus causing safety accidents.

[0015] In some embodiments, the insulating layer includes at least two sub-insulating layers. In this embodiment, multiple sub-insulating layers are provided to increase the thickness of the insulating layer.

[0016] In a second aspect, an embodiment of the present application proposes an energy storage device, comprising: a second shell; a plurality of battery packs as described in the first aspect and any embodiment of the first aspect, wherein the plurality of battery packs are arranged in the second shell; and a first insulating support member, wherein the first insulating support member is arranged between the plurality of battery packs and the bottom of the second shell.

[0017] In a third aspect, an embodiment of the present application proposes an energy storage system, comprising a plurality of energy storage devices as described in the second aspect.

[0018] The above description is only an overview of the technical solution of the utility model. In order to more clearly understand the technical means of the utility model, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the utility model more obvious and easy to understand, the specific implementation methods of the utility model are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0020] Figure 1 It is a schematic diagram of the structure of the current battery pack;

[0021] FIG2 (a) is a schematic diagram of the gas inside the bubble of the structural adhesive proposed in the embodiment of the present utility model being ionized under the action of an electric field;

[0022] FIG2 (b) is a schematic diagram of partial discharge in a structural adhesive according to an embodiment of the present utility model;

[0023] FIG2 (c) is a schematic diagram of carbonization after partial discharge in the structural adhesive proposed in an embodiment of the utility model;

[0024] Figure 3 A schematic diagram of the structure of a battery pack proposed in an embodiment of the utility model;

[0025] Figure 4 A schematic diagram of the structure of the energy storage device proposed in the embodiment of the utility model;

[0026] Figure 5 for Figure 1 A schematic diagram of a portion of the structure of a battery pack shown in FIG. 1 is applied to an energy storage device;

[0027] Figure 6 for Figure 5 A schematic diagram of insulation of the energy storage device to ground is shown;

[0028] Figure 7 for Figure 4 A partial structural schematic diagram of the energy storage device shown;

[0029] Figure 8 for Figure 7 Schematic diagram of insulation of the energy storage device to ground.

[0030] The realization of the purpose, functional features and advantages of the utility model will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0031] The following embodiments of the technical solution of the utility model are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the utility model, and are therefore only used as examples, and cannot be used to limit the protection scope of the utility model.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as those commonly understood by technicians in the technical field to which the present invention belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention; the terms "including" and "having" in the specification and claims of the present invention and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0033] In the description of the embodiments of the present utility model, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present utility model, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0034] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0035] In the description of the embodiments of the present utility model, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships, for example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0036] In the description of the embodiments of the present invention, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0037] In the description of the embodiments of the present invention, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present invention.

[0038] In the description of the embodiments of the present utility model, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present utility model can be understood according to specific circumstances.

[0039] The battery pack is composed of multiple batteries connected in series, parallel or series-parallel, and a single battery is fixed to the bottom of the battery pack shell by structural adhesive. The structural adhesive has the dual functions of fixing the battery and insulating it from the ground.

[0040] Due to the characteristics of structural adhesives and process limitations, it is difficult to eliminate the presence of bubbles inside the structural adhesive after it is cured. When the battery pack is under high electric field strength, the bubbles inside the structural adhesive may become the starting point of local discharge. The structural adhesive and even the insulating layer on the outer surface of the battery are easily aged due to local discharge, which may cause the insulation performance between the battery and the battery pack shell to deteriorate, and eventually a short circuit may occur, leading to thermal runaway. It may also cause the battery pack to fail the local discharge test and the battery pack cannot be put into use.

[0041] To this end, an embodiment of the present application proposes a battery pack, including: a first shell, multiple batteries and structural adhesive, the multiple batteries are arranged in the first shell, the outer surface of each battery is provided with an insulating layer, the structural adhesive is arranged between the insulating layer of each battery and the bottom of the first shell, and the structural adhesive is conductive.

[0042] In the embodiment of the present application, a conductive structural adhesive is disposed between the insulating layer of each battery and the bottom of the first shell. When the battery pack is in a high electric field strength, even if there are bubbles inside the structural adhesive, the charges in the structural adhesive move under high electric field strength because the structural adhesive is conductive, so that the voltages at various locations in the structural adhesive are balanced, and a high voltage difference will not be formed at the bubbles in the structural adhesive. Therefore, local discharge will not be formed in the bubbles in the structural adhesive, and the insulating layer on the outer surface of the battery will not lose its insulating function due to aging under the long-term effect of local discharge, thereby avoiding thermal runaway caused by a short circuit between the battery and the first shell of the battery pack, and also ensuring that the battery pack can pass the local discharge test and be put into use.

[0043] In order to better understand the embodiments of the present application, the battery pack, energy storage device and energy storage system provided in the embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0044] Figure 1 The figure shows a schematic diagram of the structure of a battery pack 10, which includes: a first shell 101, a plurality of batteries 102 arranged in the first shell 101, an insulating layer 103 arranged on the outer surface of each battery 102, and an insulating structural adhesive 104 arranged between the insulating layer 103 of each battery 102 and the bottom of the first shell 101. The insulating structural adhesive 104 has the dual functions of fixing the battery 102 and insulating it from the ground.

[0045] The components of the insulating structural adhesive 104 generally include resin and curing agent, and may also include fillers for improving the thermal conductivity of the insulating structural adhesive 104. Since the insulating structural adhesive 104 is prepared by mixing multiple materials, bubbles 1040 are easily formed during the mixing and reaction processes. Therefore, it is difficult to eliminate the existence of bubbles 1040 inside the insulating structural adhesive 104 after it is cured. Figure 1 There are a plurality of bubbles 1040 inside the middle insulating structural adhesive 104 .

[0046] According to research, the battery pack 10 can be applied to electric vehicles, electric bicycles, etc. The total voltage of the battery pack 10 is generally several hundred volts, and the electric field strength of the battery pack 10 is not high, so there will be no partial discharge of the insulating structural adhesive 104. However, when the battery pack 10 is applied to the power grid, the total voltage of the battery pack 10 is generally at the kilovolt level, or even as high as several hundred kilovolts, and the electric field strength of the battery pack 10 is relatively high.

[0047] When the battery pack 10 is under high electric field strength, the bubbles 1040 inside the insulating structural glue 104 may become the starting point of local discharge. This is because the dielectric constant of the bubbles 1040 in the insulating structural glue 104 is much lower than the dielectric constant of the surrounding insulating material, and the bubble 1040 area will show a lower dielectric strength. Under high electric fields, the electric field strength near the bubbles 1040 is much higher than the electric field strength in the insulating material. The gas in the bubble 1040 is ionized under the action of the electric field to form electrons and positive ions, as shown in Figure 2 (a). These charged particles are accelerated under the action of the electric field and may further ionize the gas molecules to form a chain reaction. The space charge generated by ionization will form a local electric field in the bubble 1040, and this local electric field will be superimposed with the external electric field, resulting in further enhancement of the electric field in the bubble 1040, thereby promoting more ionization. Once the voltage difference of the local electric field in the bubble 1040 reaches a certain level, a local discharge will be formed, as shown in Figure 2 (b). This discharge usually manifests as tiny electric sparks, which will cause the gas temperature in the bubble 1040 to rise, further intensifying the ionization process. At the same time, the tiny electric sparks will also burn the insulating structural glue 104 and even the insulating layer 103 on the outer surface of the battery 102 to carbonize it. As shown in Figure 2 (c), the carbonization process can be regarded as an aging process of the insulating structural glue 104 and the insulating layer 103, which will lead to a decrease in the insulation performance between the battery 102 and the battery pack 10 shell, and eventually a short circuit may occur, leading to thermal runaway, and may also cause the partial discharge test of the battery pack 10 to fail, and the battery pack 10 cannot be put into use.

[0048] To address this, a battery pack 10 is provided in this embodiment. Figure 3 As shown, it includes: a first shell 101, a plurality of batteries 102 are arranged in the first shell 101, an insulating layer 103 is arranged on the outer surface of each battery 102, a structural adhesive 105 is arranged between the insulating layer 103 of each battery 102 and the bottom of the first shell 101, and the structural adhesive 105 is conductive.

[0049] Figure 3 The number of batteries 102 in the battery pack 10 is three, which is only an example. The number of batteries 102 in the battery pack 10 can be set according to actual needs. Figure 3 The multiple batteries 102 shown are connected in series, which is only an example. In practice, the multiple batteries 102 may be connected in series, in parallel, or in series and parallel.

[0050] An insulating layer 103 is disposed on the outer surface of each battery 102 . The insulating layer 103 is directly disposed on the outer surface of the battery 102 to provide insulation between the batteries 102 . The insulating layer 103 can be made of a single insulating material (such as polyimide) without adding other materials. Therefore, there are no bubbles 1040 in the insulating layer 103 .

[0051] Use conductive structural adhesive 105 instead Figure 1 The insulating structural adhesive 104 shown, and the conductive structural adhesive 105 are arranged between the insulating layer 103 of each battery 102 and the bottom of the first shell 101, which plays the role of fixing the battery 102 and conducting electricity. When the battery pack 10 is used in the power grid, the battery pack 10 is in the case of high electric field strength. Even if there are bubbles 1040 inside the structural adhesive 105, because the structural adhesive 105 is conductive, under high electric field strength, the charge in the structural adhesive 105 moves, so that the voltage at various locations in the structural adhesive 105 reaches a balance, and a high voltage difference will not be formed at the bubbles 1040 of the structural adhesive 105. Therefore, local discharge will not be formed in the bubbles 1040 of the structural adhesive 105, and the insulating layer 103 on the outer surface of the battery 102 will not lose its insulating function due to aging under the long-term effect of local discharge, thereby avoiding thermal runaway caused by the short circuit between the battery 102 and the first shell 101 of the battery pack 10, and also ensuring that the battery pack 10 can pass the local discharge test and then be put into use.

[0052] The conductive structural adhesive 105 is described in detail below.

[0053] In some embodiments, the structural adhesive 105 is made of an insulating material doped with a conductive medium.

[0054] The structural adhesive 105 can use an insulating material as a base material, that is, a non-conductive adhesive, such as epoxy resin, silicone rubber, polyurethane, etc. In order to make these insulating materials conductive, a conductive medium is doped therein. In addition, if the insulating material is epoxy resin or polyurethane, a curing agent needs to be added to the insulating material in order to cure the structural adhesive 105. If the insulating material is silicone rubber, there is no need to add a curing agent to the insulating material.

[0055] In this embodiment, the structural adhesive 105 is made of at least a conductive medium and an insulating material. Bubbles are still generated during the mixing process and the reaction process. Bubbles are still present inside the structural adhesive 105 after it is cured (not shown in the figure). However, since the structural adhesive 105 is conductive, under high electric field strength, the charges in the structural adhesive 105 move, so that the voltages at various locations in the structural adhesive 105 are balanced, and a high voltage difference will not be formed at the bubbles (not shown in the figure) of the structural adhesive 105. Therefore, local discharge will not be formed in the bubbles (not shown in the figure) of the structural adhesive 105.

[0056] In some embodiments, the conductive medium is a conductor material or a semiconductor material.

[0057] Conductive materials include: metal powder (such as silver, copper, nickel, aluminum, etc.), metal fiber (such as copper fiber, nickel fiber, etc.), carbon material (such as carbon black, graphite, carbon nanotubes, graphene, etc.), conductive polymer (such as polyaniline, polythiophene, etc.). The structural adhesive 105 using conductive materials as conductive medium has the performance of a conductor, and its conductivity can reach 10 4 S / m (Siemens / meter) and above.

[0058] Semiconductor materials include: silicon (usually added to the adhesive in the form of silicon particles or silicon wafers), zinc oxide, and other semiconductor materials (such as gallium arsenide, indium phosphide, etc.). Structural adhesive 105 using semiconductor materials as conductive media has semiconductor properties, and its conductivity can be between 10 −6 S / m to 10 3 S / m (Siemens / meter).

[0059] In practical applications, the conductive medium doped in the insulating material can be selected according to the strength of the electric field where the battery pack 10 is located. If the electric field strength where the battery pack 10 is located is relatively strong, a conductive material can be doped in the insulating material to prepare the structural adhesive 105; if the electric field strength where the battery pack 10 is located is relatively weak, a semiconductor material can be doped in the insulating material to prepare the structural adhesive 105.

[0060] In some embodiments, the electrical conductivity of the structural adhesive 105 is greater than or equal to 10 −6 S / m.

[0061] The electrical conductivity of structural adhesive 105 is greater than or equal to 10 −6 S / m (Siemens / meter) means that the electrical conductivity of the structural adhesive 105 is relatively good. This conductivity level is considered to be the minimum requirement for the structural adhesive 105 to be used in the battery pack 10 in the power grid. The higher the total voltage of the power grid, the greater the electric field strength. To avoid partial discharge of the battery pack 10, the conductivity of the structural adhesive 105 in the battery pack 10 is also required to be higher. In practical applications, structural adhesives 105 with different conductivities can be selected according to the total voltage of the power grid, so that the battery pack 10 will not be partially discharged under different electric field strengths.

[0062] The material of the structural adhesive 105 in the above embodiment is only an example. In practical applications, other materials can also be used to prepare the conductive structural adhesive 105, as long as the conductivity of the structural adhesive 105 can meet the requirement of avoiding partial discharge. This embodiment will not be repeated one by one.

[0063] The insulating layer 103 disposed on the outer surface of the battery 102 is described in detail below.

[0064] like Figure 1 As shown, in the electric field, the insulating layer 103 and the insulating structural glue 104 on the outer surface of the battery 102 jointly bear the voltage of the electric field; Figure 3 The battery pack 10 in the embodiment shown uses a conductive structural adhesive 105. In the electric field, the conductive structural adhesive 105 bears part or almost no voltage, and most of the voltage is borne by the insulating layer 103 on the outer surface of the battery 102. Therefore, in the same electric field, Figure 3 The voltage borne by the insulating layer 103 on the outer surface of the battery 102 is greater than Figure 1 The voltage borne by the insulating layer 103 on the outer surface of the battery 102 is shown, so that Figure 3 The insulating layer 103 on the outer surface of the battery 102 can reliably bear the voltage of the electric field without insulation breakdown and thus causing safety accidents. Figure 3 The dielectric strength of the insulating layer 103 on the outer surface of the battery 102 must be greater than Figure 1 The dielectric strength of the insulating layer 103 on the outer surface of the battery 102 is shown.

[0065] In some embodiments, the thickness of the insulating layer 103 is greater than 80 microns.

[0066] Figure 1 The thickness of the insulating layer 103 shown in FIG. 1 is generally less than or equal to 80 microns. Figure 3 The insulating layer 103 with a thickness greater than 80 microns can be used by increasing Figure 3 The thickness of the insulating layer 103 is increased, thereby improving the dielectric strength of the insulating layer 103.

[0067] Achievable, Figure 3 The thickness of the middle insulating layer 103 can also be 90 microns, 100 microns, etc. Insulating layers 103 of different thicknesses can be selected according to the size of the electric field voltage borne by the insulating layer 103. The greater the electric field voltage borne by the insulating layer 103, the thicker the insulating layer 103 needs to be.

[0068] In some embodiments, the insulating layer 103 includes at least two sub-insulating layers.

[0069] The thickness of the insulating layer 103 can be increased by providing multiple sub-insulating layers. Figure 1 The insulating layer 103 is shown as Figure 3 The sub-insulating layer in the insulating layer 103 in the insulating layer is provided with multiple sub-insulating layers to improve Figure 3 The insulating properties of the insulating layer 103 in FIG.

[0070] In some embodiments, the electrical conductivity of the insulating layer 103 in this embodiment is less than or equal to 10 −16 S / m.

[0071] Figure 1 The conductivity of the insulating layer 103 shown in FIG. −14S / m (Siemens / meter), in this embodiment Figure 3 The conductivity of the insulating layer 103 is less than or equal to 10 −16 S / m (Siemens / meter) has better insulation performance and better dielectric strength. Therefore, it can reliably withstand the voltage of the electric field without insulation breakdown and causing safety accidents.

[0072] In practical applications, insulating layers 103 with different conductivity can be selected according to the magnitude of the electric field voltage borne by the insulating layer 103. The greater the electric field voltage borne by the insulating layer 103, the better the insulation performance of the insulating layer 103 needs to be and the smaller the conductivity of the insulating layer 103 needs to be.

[0073] Achievable, Figure 3 The insulating layer 103 in the Figure 1 The insulating layer 103 in the insulating layer is made of a material with better insulating properties. For example, Figure 1 The insulating layer 103 shown in FIG. 1 is made of polyimide. The electrical conductivity of polyimide is usually about 10 -15 Up to 10 -13 In the range of S / m (Siemens / meter); Figure 3 The insulating layer 103 shown in the figure can be made of materials with better insulation properties than polyimide, such as polytetrafluoroethylene, epoxy resin, polyethylene, and polypropylene. The electrical conductivity of polytetrafluoroethylene is usually 10 -22 S / m to 10 -20 S / m, the conductivity of epoxy resin is usually 10 -16 S / m to 10 -15 S / m, the conductivity of polyethylene is usually 10 -17 S / m to 10 -16 S / m, the conductivity of polypropylene is usually 10 -16 S / m to 10 -15 S / m. Made by using materials with better insulation performance Figure 3 The insulating layer 103 in the Figure 3 The conductivity of the insulating layer 103.

[0074] Achievable, Figure 3 The insulating layer 103 in the Figure 1 The insulating layer 103 is made of the same insulating material, but Figure 3 The thickness of the insulating layer 103 is greater than Figure 1 The thickness of the insulating layer 103 in .

[0075] For example, Figure 1 The thickness of the insulating layer 103 shown in FIG. 1 is generally less than or equal to 80 microns. Figure 3The insulating layer 103 may have a thickness greater than 80 microns, for example, 90 microns, 100 microns, etc. By increasing Figure 3 The thickness of the insulating layer 103 is reduced Figure 3 The conductivity of the insulating layer 103.

[0076] To achieve the above purpose, the present utility model embodiment also provides an energy storage device 20, such as Figure 4 As shown, the energy storage device 20 includes: a second shell 201, a plurality of battery packs 10 as described in the above embodiment, and the plurality of battery packs 10 are arranged in the second shell 201; a first insulating support 202, and the first insulating support 202 is arranged between the plurality of battery packs 10 and the bottom of the second shell 201.

[0077] Figure 4 The number of battery packs 10 in the energy storage device 20 is 2, which is only an example. The number of battery packs 10 in the energy storage device 20 can be set according to actual needs. Figure 4 The multiple battery packs 10 shown are connected in series, which is only an example. In practice, the multiple battery packs 10 may be connected in series, in parallel, or in series and parallel.

[0078] The first insulating support member 202 is disposed between the plurality of battery packs 10 and the bottom of the second shell 201 , and plays the role of insulating and fixing the battery packs 10 .

[0079] It is worth noting that the energy storage device 20 is not placed directly on the ground 40 , but is fixed on the ground 40 via the second insulating support member 30 .

[0080] Figure 1 A partial structural diagram of the energy storage device 20 composed of the battery pack 10 shown in FIG. Figure 5 As shown, the resistance of the insulating layer 103 on the outer surface of the battery 102 is R1, and the capacitance is C1, the resistance of the insulating structural glue 104 is R2, and the capacitance is C2, the resistance of the first shell 101 and the first insulating support 202 is R3, and the capacitance is C3, the resistance of the second shell 201 and the second insulating support 30 is R4, and the capacitance of the second shell 201 to the ground is C4, and the resistance of the first shell 101 to the ground is R5.

[0081] Figure 5 The schematic diagram of the insulation of the energy storage device 20 to the ground is shown in FIG. Figure 6 As shown, in the electric field, the resistance R1 and capacitance C1 of the insulating layer 103 on the outer surface of the battery 102, the resistance R2 and capacitance C2 of the insulating structural adhesive 104, the resistance R3 and capacitance C3 of the first shell 101 and the first insulating support 202, the resistance R4 of the second shell 201 and the second insulating support 30, the capacitance C4 of the second shell 201 to the ground, and the resistance R5 of the first shell 101 to the ground jointly bear the voltage in the electric field.

[0082] Figure 7 Shown Figure 4 A partial structural diagram of the energy storage device 20, wherein the battery pack 10 uses a conductive structural adhesive 105. Assuming that the conductive structural adhesive 105 has good conductivity and does not bear voltage, then Figure 7 The schematic diagram of the insulation of the energy storage device 20 to the ground is shown in FIG. Figure 8 As shown, the resistance R1 and capacitance C1 of the insulating layer 103 on the outer surface of the battery 102, the resistance R3 and capacitance C3 of the first shell 101 and the first insulating support 202, the resistance R4 of the second shell 201 and the second insulating support 30, the capacitance C4 of the second shell 201 to the ground, and the resistance R5 of the first shell 101 to the ground jointly bear the voltage in the electric field. Assuming that the voltage of the electric field remains unchanged, then, originally Figure 6 The voltage borne by the resistor R2 and the capacitor C2 of the insulating structural glue 104 is transferred to other parts. Therefore, in practical applications, the insulation performance of at least one of the insulating layer 103 on the outer surface of the battery 102, the first shell 101, the first insulating support 202, and the second insulating support 30 can be appropriately enhanced to ensure that the energy storage device 20 can reliably bear the voltage of the electric field without being damaged.

[0083] To achieve the above objectives, an embodiment of the present utility model further provides an energy storage system, which includes a plurality of energy storage devices 20 as described in the above embodiments.

[0084] The output of a single energy storage device 20 is connected to a power conversion system, and the power conversion system is connected to the power grid. The output of a single energy storage device 20 is direct current, which is converted into alternating current by the power conversion system and then connected to the power grid to supply power to the power grid; or, the power grid converts alternating current into direct current through the power conversion system and then charges the energy storage device 20.

[0085] The above are only preferred embodiments of the present invention, and do not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A battery pack, characterized in that: include: a first shell; A plurality of batteries, each of which has an insulating layer disposed on its outer surface, and the plurality of batteries are disposed in the first housing; The structural adhesive is arranged between the insulating layer of each battery and the bottom of the first shell, and the structural adhesive has conductivity.

2. The battery pack according to claim 1, characterized in that: The structural adhesive is made of an insulating material doped with a conductive medium.

3. The battery pack according to claim 2, characterized in that: The conductive medium is a conductor material or a semiconductor material.

4. The battery pack according to any one of claims 1 to 3, characterized in that: The electrical conductivity of the structural adhesive is greater than or equal to 10 −6 S / m.

5. The battery pack according to any one of claims 1 to 3, characterized in that: The thickness of the insulating layer is greater than 80 microns.

6. The battery pack according to claim 5, characterized in that: The insulating layer includes at least two sub-insulating layers.

7. The battery pack according to any one of claims 1 to 3, characterized in that: The electrical conductivity of the insulating layer is less than or equal to 10 −16 S / m.

8. An energy storage device, characterized in that: include: a second shell; A plurality of battery packs according to any one of claims 1 to 7, wherein the plurality of battery packs are disposed in the second housing; A first insulating support member is disposed between the plurality of battery packs and a bottom of the second shell.

9. An energy storage system, characterized in that: Comprising a plurality of energy storage devices as claimed in claim 8.

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