Battery cell, energy storage device and electric equipment

Abstract

The utility model discloses a battery cell, an energy storage device and electric equipment, the battery cell comprises a naked battery cell, first adhesive paper and second adhesive paper, and the first adhesive paper and the second adhesive paper are both adhered to the naked battery cell; the number of the second gummed paper is at least two, and the two second gummed paper are respectively arranged on two opposite sides of the first gummed paper along the first direction of the naked battery cell; and the length of the first gummed paper is greater than that of the second gummed paper along the second direction of the naked battery cell. According to the utility model, the first gummed paper and the second gummed paper are adhered to the naked battery cell, and the first gummed paper adhered to the middle part of the naked battery cell is longer in the second direction, so that the first gummed paper can provide a larger binding surface, and the expansive force in the middle area of the large surface of the naked battery cell is more uniform, so as to improve the performance consistency of the battery cell; and meanwhile, the second gummed paper adhered to the two sides is short, so that the gummed paper can be saved, and the cost is reduced while the interface performance of the bare cell is ensured.

Description

Technical Field

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

[0002] The bare cell (JR, or Jellyroll) is a crucial component in the battery assembly process. It is typically made by tightly winding or folding the positive and negative electrode sheets and separators. The bare cell plays a crucial role in the battery industry, as it is the core component for storing and releasing energy. The manufacturing quality of the bare cell directly affects the performance and safety of the battery, so its design and production process require strict control and testing.

[0003] The bonding between the bare cell interfaces obtained after the positive and negative electrodes and separators are alternately laminated is weak, so the edges of the bare cells are usually glued. This is done by applying glue to both sides of the edges to secure the bare cells, both to secure the electrodes and to limit their expansion. However, existing glue-fixed bare cells often suffer from uneven binding strength and poor air permeability, leading to internal lithium deposition, black spots, and insufficient electrolyte infiltration during battery use. Utility Model Content

[0004] The purpose of the utility model is to provide a battery core, an energy storage device and an electrical device that can improve safety performance.

[0005] In order to achieve the purpose of the present invention, the present invention provides the following technical solutions:

[0006] In a first aspect, the present invention provides a battery cell, comprising a bare battery cell, a first adhesive tape and a second adhesive tape, wherein the first adhesive tape and the second adhesive tape are both pasted on the bare battery cell; there are at least two second adhesive tapes, and along the first direction of the bare battery cell, the two second adhesive tapes are respectively arranged on two sides opposite to each other of the first adhesive tape; along the second direction of the bare battery cell, the length of the first adhesive tape is greater than the length of the second adhesive tape.

[0007] The utility model sticks the first adhesive tape and the second adhesive tape on the bare battery cell, and the first adhesive tape stuck on the middle of the bare battery cell is longer in the second direction, so the first adhesive tape can provide a larger binding surface, thereby making the expansion force in the middle area of ​​the large surface of the bare battery cell more uniform, thereby improving the consistency of the battery cell performance; at the same time, the second adhesive tape stuck on both sides is shorter, which can save adhesive tape and reduce costs while ensuring the interface performance of the bare battery cell.

[0008] In one embodiment, along a first direction of the bare cell, the first adhesive tape includes a first adhesive section and two second adhesive sections, the first adhesive section being located between the two second adhesive sections, and along a third direction of the bare cell, the thickness of the first adhesive section is greater than the thickness of the second adhesive section. By setting the thickness of the first adhesive section to be greater than the thickness of the second adhesive section, the adhesive force of the first adhesive tape is adapted to the expansion force of the bare cell. The first adhesive section can provide greater adhesive force to restrain the central area of ​​the bare cell, preventing the first adhesive tape from restraining the bare cell too tightly and preventing the expansion force from being released. It can also prevent the gap between the electrodes in the bare cell from being too large due to excessive expansion, thereby lengthening the lithium ion transmission path and avoiding problems such as lithium plating or black spots on the interface.

[0009] In one embodiment, the first adhesive tape satisfies the relationship: 0.2 ≤ A1 / A ≤ 0.5, where A1 is the width of the first adhesive section and A is the width of the first adhesive tape along a first direction of the bare cell. By adjusting the ratio of the first adhesive section's width to the first adhesive tape, the adhesive force provided by the first adhesive tape in the first adhesive section can be controlled, thereby counteracting the expansion force of the bare cell through the adhesive force.

[0010] In one embodiment, the thickness of the first adhesive tape is greater than the thickness of the second adhesive tape. By making the first adhesive tape thicker than the second adhesive tape, the expansion force on both sides (around the periphery) of the bare cell can be accommodated, thereby preventing excessive gaps between the electrodes around the bare cell.

[0011] In one embodiment, the first adhesive tape is provided with through holes along the third direction thereof. Punching the holes in the first adhesive tape can improve the wettability of the first adhesive tape to the electrolyte, thereby allowing the electrolyte to penetrate into the bare battery cell through the first adhesive tape.

[0012] In one embodiment, the battery cell includes a first large surface, a second large surface, and a first side surface. The first large surface and the second large surface are opposite to each other. The two opposite sides of the first side surface are respectively connected to the first large surface and the second large surface. The first adhesive tape is affixed to the first large surface, the first side surface, and the second large surface. The orthographic projection of the through hole on the battery cell is located on the first side surface. After the energy storage device is filled with liquid, since the electrolyte is mainly concentrated around the bare battery cell, that is, the electrolyte is concentrated in the positions from the first side surface to the fourth side surface, and the four side surfaces are also the gaps between multiple electrode units, holes are punched in the first adhesive tape corresponding to the first side surface to allow the electrolyte to quickly infiltrate and ensure that there is still electrolyte on the side surface in the later stages of the cycle.

[0013] In one embodiment, there are multiple through holes, and along the third direction of the bare cell, the center distance L1 between two adjacent through holes is 20 mm to 30 mm. The distance between the through holes is set to meet the above relationship to ensure that the electrolyte can penetrate evenly through the through holes, avoiding the concentration of electrode liquid at the edge of the bare cell.

[0014] In one embodiment, the diameter D of the through hole is 6 mm to 10 mm. The diameter of the through hole is set within the above range to ensure the infiltration efficiency of the electrode liquid and the structural strength of the first adhesive tape.

[0015] In one embodiment, along the second direction of the bare cell on either the first or second large surface, the length L21 of the first adhesive tape is 25 mm to 70 mm, and the length L22 of the second adhesive tape is 25 mm to 40 mm. Setting the length L21 of the first adhesive tape and the length L22 of the second adhesive tape within these ranges ensures a relatively uniform expansion force in the central region of the bare cell's large surface, thereby improving cell performance consistency. Furthermore, controlling adhesive tape usage saves costs and improves efficiency.

[0016] In one embodiment, two pieces of the second adhesive tape are attached to the same edge of the bare cell as the first adhesive tape, and along a first direction of the bare cell, the width of the first adhesive tape is greater than the width of the second adhesive tape. Attaching the second adhesive tape to the corners of the bare cell (near the corners) can solve the problem of lithium deposition in the corners of the bare cell. Furthermore, because the second adhesive tape is narrower than the first adhesive tape, its adhesion to the bare cell is slightly weaker than that of the first adhesive tape, thereby preventing excessive binding force on the bare cell and preventing poor electrode corner wetting and wrinkling caused by limited electrode expansion.

[0017] In one embodiment, along the second direction of the bare cell, the bare cell includes a first side surface and a second side surface facing each other, and the number of second adhesive tapes is greater than or equal to four, two of which are affixed to the first side surface, and the other two are affixed to the second side surface. The two second adhesive tapes located on the outermost sides of the first side surface and the two second adhesive tapes located on the outermost sides of the second side surface are arranged rotationally symmetrically. By arranging at least four second adhesive tapes in a rotationally symmetrical arrangement at the four corners of the bare cell, the viscosity of the second adhesive tapes is moderate, and the four second adhesive tapes can prevent lithium deposition at the four corners of the bare cell and prevent incomplete coverage of the corners of the bare cell. Moreover, since the second adhesive tapes are relatively short, the electrolyte around the bare cell can be more easily absorbed and infiltrated.

[0018] In one embodiment, the number of the first adhesive tapes is greater than or equal to two, one of the first adhesive tapes is attached to the first side surface and is located between the two second adhesive tapes on the first side surface, the other first adhesive tape is attached to the second side surface and is located between the two second adhesive tapes on the second side surface, and the first adhesive tape located on the first side surface and the first adhesive tape located on the second side surface are arranged axially symmetrically. The adhesive tapes on the bare battery cell are arranged in the above manner, so that the battery cell can mainly be used in scenarios where liquid is injected on both sides and explosion-proof valves are on two sides. The explosion-proof valves of the energy storage device can be set on the third and fourth sides of the bare battery cell, and the energy storage device can also be injected from the third and fourth sides during the installation process. In this way, the first adhesive strip can be avoided, and the bare battery cell can be restrained to make the expansion force uniform without affecting the safe exhaust.

[0019] In one embodiment, the number of the second adhesive tapes is greater than or equal to six, of which two second adhesive tapes are pasted on the first side, and the other four second adhesive tapes are pasted on the second side, and the first adhesive tape is pasted on the first side and is located between the two second adhesive tapes on the first side. The adhesive tape on the bare battery cell is set in the above manner, so that the battery cell can be mainly used in the scenario of top (second edge) injection. Because the energy storage device is top-injected, the exhaust channel in the energy storage device is also at the top. If the top is glued too much and too densely, it will affect the exhaust during the injection process, so the adhesive tape at the second edge needs to be optimized. In this way, the exhaust capacity of the energy storage device during the injection process can be guaranteed, and the number of second adhesive tapes at the second edge can be adjusted according to the expansion force.

[0020] In one embodiment, the width L3 of the first adhesive tape along the first direction of the bare cell is 100 mm to 400 mm. Keeping the width of the first adhesive tape within the above range ensures that the first adhesive tape can suppress edge expansion of the bare cell and effectively restrain the bare cell.

[0021] In one embodiment, the width L4 of the second adhesive tape along the first direction of the bare cell is 25 mm to 50 mm. Keeping the width of the second adhesive tape within this range ensures that the second adhesive tape has a good binding effect on the corners of the bare cell, thereby solving the problem of lithium deposition at the corners.

[0022] In one embodiment, a gap is defined between the first and second adhesive tapes along a first direction of the bare cell, and the width L5 of the gap is 2 mm to 6 mm. The gap between the first and second adhesive tapes allows for electrolyte infiltration and controls the width of the first and second adhesive tapes, preventing them from overlapping too closely or from being too far apart, thereby reducing the restraining effect.

[0023] In a second aspect, the present invention provides an energy storage device comprising a housing and the battery cell described in the first aspect, wherein the battery cell is accommodated in the housing.

[0024] In a third aspect, the present invention provides an electrical device, comprising the energy storage device described in the second aspect, wherein the energy storage device supplies power to the electrical device. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the implementation methods or the description of the prior art. Obviously, the drawings described below are only some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 is a schematic diagram of an energy storage device in a household energy storage location according to an embodiment;

[0027] Figure 2 is a schematic diagram of an energy storage device according to an embodiment;

[0028] Figure 3 is a schematic diagram of a battery cell according to an embodiment;

[0029] Figure 4 is a top view of a bare battery cell according to an embodiment;

[0030] Figure 5 This is a schematic diagram of the cross-sectional structure of a first adhesive tape and a bare battery cell according to an embodiment;

[0031] Figure 6 is a side view of a battery cell according to an embodiment;

[0032] Figure 7 is a top view of a battery cell according to an embodiment;

[0033] Figure 8 1 is a top view of a battery cell according to another embodiment.

[0034] Description of reference numerals:

[0035] 100-energy storage device, 10-battery cell, 20-housing, 30-explosion-proof valve;

[0036] 11-bare cell, 111-first large surface, 112-second large surface, 113-first side surface, 114-second side surface, 115-third side surface, 116-fourth side surface, 11a-first edge, 11b-second edge, 11c-third edge, 11d-fourth edge;

[0037] 12-first adhesive tape, 121-adhesive layer, 122-insulating layer, 123-through hole, 12a-first section, 12b-second section, 12c-third section, 12d-first adhesive section, 12e-second adhesive section;

[0038] 13- second adhesive tape;

[0039] Y-first direction, Z-second direction, X-third direction, M-first axis of symmetry, N-second axis of symmetry;

[0040] 200-photovoltaic panels, 300-wind turbines, 400-grid. DETAILED DESCRIPTION

[0041] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0042] It should be noted that when a component is referred to as being "fixed to" another component, it may be directly on the other component or there may be an intermediate component. When a component is referred to as being "connected to" another component, it may be directly connected to the other component or there may be an intermediate component.

[0043] Unless otherwise defined, all technical and scientific terms used in this utility model have the same meanings as commonly understood by those skilled in the art to which this utility model belongs. The terms used in this utility model specification are only for the purpose of describing specific embodiments and are not intended to limit this utility model. The term "and / or" used in this utility model includes any and all combinations of one or more of the relevant listed items.

[0044] The following embodiments of the present invention are described in detail with reference to the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments may be combined with each other.

[0045] Because the energy people need is highly temporal and spatially dependent, rational energy utilization and improved efficiency require a medium or device that can store one form of energy in the same form or convert it into another, allowing it to be released in a specific form based on future application needs. As we all know, the primary method for generating green electricity currently is to develop green energy sources such as photovoltaics and wind power to replace fossil fuels. Currently, green electricity generation generally relies on photovoltaics, wind power, and hydropower. However, wind and solar power suffer from significant intermittent and fluctuating output, leading to grid instability, insufficient peak power consumption, and excessive off-peak power consumption. Unstable voltage can also damage power supply. Consequently, insufficient electricity demand or insufficient grid capacity can lead to "wind and solar curtailment." Addressing these issues requires energy storage. This involves converting electrical energy into other forms of energy through physical or chemical means and storing them, converting the energy back into electricity when needed. Simply put, energy storage is like a large "power bank," storing electricity when photovoltaic and wind power are plentiful and releasing it when needed.

[0046] Taking electrochemical energy storage as an example, this solution provides an energy storage device with a group of chemical batteries inside. The energy storage device mainly uses the chemical elements in the chemical batteries as energy storage media. The charging and discharging process is accompanied by chemical reactions or changes in the energy storage medium. Simply put, the electricity generated by wind and solar energy is stored in the chemical batteries. When the use of external electricity reaches its peak, the stored electricity is released for use, or transferred to places where electricity is scarce for use.

[0047] Currently, energy storage (i.e., energy storage) has a wide range of application scenarios, including (wind and solar) power generation-side energy storage, grid-side energy storage, base station-side energy storage, and user-side energy storage. The corresponding energy storage device types include:

[0048] (1) Large energy storage containers used in grid-side energy storage scenarios can serve as high-quality active and reactive power regulation power sources in the grid, achieving load matching of electricity in time and space, enhancing the ability to absorb renewable energy, and are of great significance in grid system backup, alleviating peak load power supply pressure, and peak and frequency regulation.

[0049] (2) Small and medium-sized energy storage cabinets used in industrial and commercial energy storage scenarios (banks, shopping malls, etc.) on the user side mainly operate in the "peak shaving and valley filling" mode. Since there is a large price difference in electricity prices at peak and valley locations according to electricity demand, after users have energy storage equipment, in order to reduce costs, they usually charge the energy storage cabinets / boxes during the low electricity price period; during the peak electricity price period, they release the electricity in the energy storage equipment for use, thereby saving electricity costs.

[0050] Please refer to Figure 1The energy storage device 100 provided in the embodiment of the present invention is applied to an energy storage system, which includes an electric energy conversion device (photovoltaic panel 200), a wind energy conversion device (wind turbine 300), a power grid 400 and an energy storage device 100. The energy storage device 100 can be used as an energy storage cabinet and can be installed outdoors. Specifically, the photovoltaic panel 200 can convert solar energy into electric energy during periods of low electricity prices. The energy storage device 100 is used to store the electric energy and supply it to the power grid 400 during peak hours of electricity consumption, or to supply power when the power grid 400 is out of power / power outage. The wind energy conversion device (wind turbine 300) can convert wind energy into electric energy. The energy storage device 100 is used to store the electric energy and supply it to the power grid 400 during peak hours of electricity consumption, or to supply power when the power grid 400 is out of power / power outage. The transmission of electric energy can be carried out using high-voltage cables.

[0051] The number of energy storage devices 100 can be multiple, and multiple energy storage devices 100 can be connected in series or in parallel. Multiple energy storage devices 100 are supported and electrically connected using isolation plates (not shown). In this embodiment, "multiple" refers to two or more. An energy storage box can also be provided outside the energy storage device 100 to accommodate the energy storage device 100.

[0052] It is understandable that the energy storage device 100 may include but is not limited to single cells, battery modules, battery packs, battery systems, etc. The actual application form of the energy storage device 100 provided in the embodiment of the present invention may be, but is not limited to, the products listed above, and may also be other application forms. The embodiment of the present invention does not strictly limit the application form of the energy storage device 100. The embodiment of the present invention only takes the energy storage device 100 as a multi-core battery as an example for explanation. Please refer to Figure 2 The energy storage device 100 includes a housing 20 and a battery cell 10 , and the battery cell 10 is accommodated in the housing 20 .

[0053] Please refer to Figure 3 and Figure 7 The utility model provides a battery cell 10, which includes a bare battery cell 11, a first adhesive tape 12 and a second adhesive tape 13. The first adhesive tape 12 and the second adhesive tape 13 are both pasted on the bare battery cell 11; there are at least two second adhesive tapes 13, and along the first direction Y of the bare battery cell 11, the two second adhesive tapes 13 are respectively arranged on two sides opposite to each other of the first adhesive tape 12; along the second direction Z of the bare battery cell 11, the length of the first adhesive tape 12 is greater than the length of the second adhesive tape 13.

[0054] Specifically, the bare cell 11 is the main power generating component of the lithium-ion cell 10, which generally includes one or more electrode units. Each electrode unit is composed of a positive electrode sheet, a negative electrode sheet and a diaphragm. The positive electrode sheet and the negative electrode sheet are separated by a diaphragm, so that the two can undergo electrochemical reaction under the action of the electrolyte.

[0055] like Figure 3and Figure 4 As shown, the bare cell 11 can be a rectangular parallelepiped, and the bare cell 11 includes a third direction X, a first direction Y, and a second direction Z, wherein the third direction X is the stacking direction of the above-mentioned positive electrode sheet, negative electrode sheet, and diaphragm, and the first direction Y, the second direction Z, and the third direction are perpendicular to each other. The bare cell 11 includes a first large surface 111 and a second large surface 112 opposite to each other in the third direction X, a first side surface 113 and a second side surface 114 opposite to each other in the second direction Z, and a third side surface 115 and a fourth side surface 116 opposite to each other in the first direction Y. The tabs are connected to the opposite ends of the bare cell 11 in the first direction Y, that is, the third side surface 115 and the fourth side surface 116 are both connected to tabs.

[0056] Among them, the bare cell 11 includes four edges connected in sequence, namely the first edge 11a and the second edge 11b facing each other, the third edge 11c and the fourth edge 11d facing each other, and the first edge 11a, the third edge 11c, the second edge 11b and the fourth edge 11d are connected in sequence. It should be explained that the edge is composed of its corresponding side surface and the part of the first large surface 111 and the second large surface 112 connected to the side surface. For example, the first edge 11a includes the first side surface 113, and the part of the first large surface 111 and the second large surface 112 connected to the first side surface 113 (such as Figure 3 and Figure 4 shown).

[0057] Furthermore, the first adhesive tape 12 is a sticky fixed structure attached to the bare cell 11. The first adhesive tape 12 is attached to the edge of the bare cell 11, that is, one end of the adhesive tape is attached to the first large surface 111, and the other end is attached to the second large surface 112 through the side of the third direction X. Figure 3 As shown, in this embodiment, the first adhesive tape 12 is attached to the first edge 11a, that is, from the first large surface 111 through the first side surface 113 to the second large surface 112. It is understood that the function of the first adhesive tape 12 is to secure the stacked bare cells 11, so that the multiple electrode units are relatively fixed. Therefore, the first adhesive tape 12 should be attached to the bare cells 11 in the third direction X to secure them.

[0058] The second adhesive tape 13 can be applied to the edge of the bare cell 11, near the corner. In a specific embodiment, both the first adhesive tape 12 and the second adhesive tape 13 are applied to the first edge 11a, with the first adhesive tape 12 applied to the middle of the first edge 11a and the second adhesive tape 13 applied to the end of the first edge 11a near the third edge 11c. Optionally, the second adhesive tape 13 serves as a finishing tape, which can be applied using a cutting and laminating device and has moderate viscosity.

[0059] The present invention adheres a first adhesive tape 12 and a second adhesive tape 13 to the bare battery cell 11, and the first adhesive tape 12 adhered to the middle of the bare battery cell 11 is relatively long in the second direction Z, so the first adhesive tape 12 can provide a larger binding surface, thereby making the expansion force in the middle area of ​​the large surface of the bare battery cell 11 more uniform, thereby improving the performance consistency of the battery cell 10; at the same time, the second adhesive tape 13 adhered on both sides is shorter, which can save adhesive tape, and reduce costs while ensuring the interface performance of the bare battery cell 11.

[0060] In one embodiment, please refer to Figure 8 , along the first direction Y of the bare cell 11, the first adhesive tape 12 includes a first adhesive section 12d ( Figure 8 The first adhesive section 12d is located between the two second adhesive sections 12e, and the adhesive force of the first adhesive section 12d is greater than the adhesive force of the second adhesive section 12e. By providing the first adhesive tape 12 with two adhesive sections with different adhesive forces, the adhesive force of the first adhesive tape 12 is adapted to the expansion force of the bare battery cell 11, thereby preventing the first adhesive tape 12 from being too tightly bound to the bare battery cell 11 and preventing the expansion force from being released. It also prevents excessive expansion from causing the gap between the electrodes in the bare battery cell 11 to become too large, thereby lengthening the lithium ion transmission path and avoiding problems such as lithium plating or black spots on the interface.

[0061] In one embodiment, the thickness of the first adhesive section 12d is greater than the thickness of the second adhesive section 12e along the third direction X of the bare cell 11. By setting the thickness of the first adhesive section 12d greater than the thickness of the second adhesive section 12e, the first adhesive section 12d can provide greater adhesive force to restrain the central region of the bare cell 11, thereby preventing the problem of excessive expansion force in the central region of the bare cell 11, which may lead to excessive gaps between the electrode pieces in the bare cell 11.

[0062] In one embodiment, the first adhesive tape 12 satisfies the relationship: 0.2 ≤ A1 / A ≤ 0.5, where A1 is the width of the first adhesive section 12d along the first direction of the bare cell 11, and A is the width of the first adhesive tape 12. Optionally, the value of A1 / A can be 1 / 2, 1 / 3, 1 / 4, or 1 / 5. By adjusting the ratio of the width of the first adhesive section 12d to the width of the first adhesive tape 12, the adhesive force provided by the first adhesive tape 12 in the first adhesive section 12d can be controlled, thereby counteracting the expansion force of the bare cell 11 through the adhesive force.

[0063] In one embodiment, the adhesive force of the second adhesive tape 13 is greater than that of the second adhesive section 12e. By setting the adhesive force of the second adhesive tape 13 to be greater than that of the second adhesive section 12e, the expansion force on both sides (around the periphery) of the bare cell 11 can be accommodated, thereby preventing excessive gaps between the electrodes around the bare cell 11.

[0064] In one embodiment, please refer to Figure 5 , the first adhesive tape 12 is pasted on the edge of the bare battery cell 11; the first adhesive tape 12 includes an adhesive layer 121 and an insulating layer 122, the adhesive layer 121 is connected to the bare battery cell 11, and the insulating layer 122 is connected to the side of the adhesive layer 121 facing away from the bare battery cell 11.

[0065] Specifically, the first adhesive tape 12 is a two-layer composite structure, including an adhesive layer 121 and an insulating layer 122, wherein the adhesive layer 121 is located in the inner layer and is directly connected to the bare battery cell 11, and the insulating layer 122 is located in the outer layer. The adhesive layer 121 plays the role of restraining and fixing the bare battery cell 11, and the insulating layer 122 plays the role of ventilation and infiltration of the electrolyte. It can be understood that based on the different functions of the adhesive layer 121 and the insulating layer 122, the adhesive layer 121 and the insulating layer 122 can be made of two different materials to achieve the corresponding effect. The first adhesive tape 12 can restrain and fix the bare battery cell 11, and the adhesive layer 121 can evenly distribute the expansion force of the bare battery cell 11; the first adhesive tape 12 pasted on the bare battery cell 11 can not only solve the problem of lithium deposition at the edge of the bare battery cell 11, but also has supporting capacity, and the bottom support sheet can be eliminated, and the overall load-bearing capacity of the bare battery cell 11 is not affected.

[0066] In one embodiment, as the bare cell 11 expands and its thickness increases, the adhesive force of the adhesive layer 121 is positively correlated with the expansion force of the bare cell 11 , and the adhesive force of the adhesive layer 121 changes in a gradient.

[0067] Specifically, during use of the energy storage device 100, the battery cells 10 will swell as the number of charge and discharge cycles increases, particularly at the edges of the bare battery cells 11. The adhesive strength of the adhesive layer 121 reflects the ability of the first adhesive tape 12 to bind the bare battery cells 11. When the adhesive strength is low, the second adhesive tape 13 will have a weaker bond to the bare battery cells 11. When the adhesive strength is high, the second adhesive tape 13 will have a stronger bond to the bare battery cells 11.

[0068] It is understandable that when the bare cell 11 does not expand, that is, the expansion force of the bare cell 11 is small, and the gap between the pole pieces of the bare cell 11 is appropriate, there is no need for the adhesive layer 121 to give the bare cell 11 too much adhesive force, so as to avoid poor pole piece infiltration and limited pole piece expansion leading to wrinkles. When the bare cell 11 expands, that is, the expansion force of the bare cell 11 is large, and the gap between the pole pieces of the bare cell 11 becomes larger, so the adhesive layer 121 is needed to give the bare cell 11 a greater adhesive force, so as to avoid the lithium ion transmission path becoming longer and avoid lithium deposition and black spots on the interface of the bare cell 11.

[0069] In one embodiment, please refer to Figure 3 and Figure 6The first adhesive tape 12 is provided with a through hole 123 that penetrates the adhesive layer 121 and the insulating layer 122. Specifically, the through hole 123 extends from the side of the first adhesive tape 12 facing away from the bare cell 11 to the side facing the bare cell 11. Punching holes in the first adhesive tape 12 improves the wettability of the first adhesive tape 12 to the electrolyte, allowing the electrolyte to penetrate into the bare cell 11 through the first adhesive tape 12.

[0070] In one embodiment, please refer to Figure 6 The orthographic projection of the through hole 123 on the battery cell 10 is located on the first side surface 113. Specifically, the first adhesive tape 12 attached to the first edge 11a includes a first section 12a, a second section 12b, and a third section 12c. The first section 12a is attached to the first large surface 111, the second section 12b is attached to the second large surface 112, and the third section 12c is attached to the first side surface 113. The through hole 123 is formed in the third section 12c.

[0071] It is understandable that after the energy storage device 100 is filled with liquid, since the electrolyte is mainly concentrated around the bare battery cell 11, that is, the electrolyte is concentrated in the positions from the first side surface 113 to the fourth side surface 116, and the four sides are also the gaps between the multiple electrode units, holes are punched in the first adhesive tape 12 corresponding to the first side surface 113, so that the electrolyte can quickly infiltrate and ensure that there is still electrolyte on the side surface in the later stage of the cycle.

[0072] In one embodiment, please refer to Figure 6 , there are multiple through holes 123, and along the third direction X of the bare cell 11, the center distance L1 between two adjacent through holes 123 is 20mm to 30mm. The distance between the through holes 123 is set to meet the above relationship in order to ensure that the electrolyte can be evenly infiltrated through the through holes 123, and to avoid part of the electrode liquid being concentrated at the edge of the bare cell 11 and unable to infiltrate. Optionally, the center distance L1 between two adjacent through holes 123 can be 20mm, 21mm, 22mm, 23mm, 24mm, 25mm, 26mm, 27mm, 28mm, 29mm, or 30mm.

[0073] In one embodiment, please refer to Figure 6 The diameter D of the through hole 123 is 6 mm to 10 mm. The diameter of the through hole 123 is set within the above range to ensure the infiltration efficiency of the electrode liquid and the structural strength of the first adhesive tape 12. Optionally, the diameter D of the through hole 123 can be 6 mm, 7 mm, 8 mm, 9 mm, or 10 mm.

[0074] In one embodiment, please refer to Figure 7, on the first large surface 111 or the second large surface 112, along the second direction Z of the bare cell 11, the length L21 of the first adhesive tape 12 is 25mm to 70mm, and the length L22 of the second adhesive tape 13 is 25mm to 40mm. Specifically, the length of the portion of the first adhesive tape 12 pasted on the first large surface 111 (the first section 12a) and the portion of the first adhesive tape 12 pasted on the second large surface 112 (the second section 12b) along the second direction Z are within the above range, which can ensure the adhesion of the first adhesive tape 12 to the bare cell 11 and fully utilize the expansion force of the first adhesive tape 12 on the bare cell 11. Optionally, the length L21 of the first adhesive tape 12 can be 25mm, 30mm, 35mm, 40mm, 45mm, 50mm, 55mm, 60mm, 65mm, or 70mm. Optionally, the length L22 of the second adhesive tape 13 can be 25mm, 30mm, 35mm, or 40mm.

[0075] In one embodiment, please refer to Figure 3 The two second adhesive tapes 13 and the first adhesive tape 12 are pasted on the same side edge of the bare battery cell 11 on the same side. Along the first direction Y of the bare battery cell 11, the width of the first adhesive tape 12 is greater than the width of the second adhesive tape 13.

[0076] By setting a second adhesive tape 13 and sticking the second adhesive tape 13 on the corner of the bare battery cell 11 (near the corner), the problem of lithium deposition at the corner of the bare battery cell 11 can be solved; and because the width of the second adhesive tape 13 is smaller than that of the first adhesive tape 12, the second adhesive tape 13 can avoid excessive binding force on the bare battery cell 11, thereby avoiding poor wetting at the corner of the electrode and wrinkling caused by limited expansion of the electrode.

[0077] In one embodiment, please refer to Figure 7 and Figure 8 Along the second direction Z of the bare battery cell 11, the number of the second adhesive tapes 13 is greater than or equal to four, two of which are pasted on the first side surface 113, and the other two second adhesive tapes 13 are pasted on the second side surface 114. The two second adhesive tapes 13 located on the outermost side surface 113 and the two second adhesive tapes 13 located on the outermost side surface 114 are rotationally symmetrically arranged.

[0078] Specifically, the number of second adhesive strips 13 can be four, with two of the second adhesive strips 13 attached to the first edge 11a and the other second adhesive strips 13 attached to the second edge 11b. The two second adhesive strips 13 attached to the first edge 11a are respectively located at two corners of the first edge 11a, that is, one of the two second adhesive strips 13 is attached to the end of the first edge 11a near the third edge 11c, and the other is attached to the end of the first edge 11a near the fourth edge 11d. The two second adhesive strips 13 attached to the second edge 11b are respectively located at two corners of the second edge 11b, that is, one of the two second adhesive strips 13 is attached to the end of the second edge 11b near the third edge 11c, and the other is attached to the end of the second edge 11b near the fourth edge 11d.

[0079] Furthermore, as shown in FIG7 , since the bare cell 11 is a rectangular parallelepiped, the bare cell 11 has a first symmetry axis M and a second symmetry axis N. The first symmetry axis M and the second symmetry axis N are orthogonal, the first symmetry axis M is parallel to the second direction Z, and the second symmetry axis N is parallel to the first direction Y. The four second adhesive strips 13 are arranged rotationally symmetrically about the intersection of the two symmetry axes, that is, the two second adhesive strips 13 on the first edge 11a (second edge 11b) are axially symmetrical about the first symmetry axis M, and the four second adhesive strips 13 on the first edge 11a and the second edge 11b are axially symmetrical about the second symmetry axis N.

[0080] By setting at least four second adhesive tapes 13 in rotationally symmetrical arrangement at the four corners of the bare battery cell 11, the viscosity of the second adhesive tapes 13 is moderate. The four second adhesive tapes 13 can prevent lithium deposition at the four corners of the bare battery cell 11 and avoid incomplete coverage of the corners of the bare battery cell 11. Moreover, since the width of the second adhesive tapes 13 is relatively short, the electrolyte around the bare battery cell 11 can be more easily absorbed and infiltrated.

[0081] In one embodiment, please refer to Figure 7 The number of first adhesive tapes 12 is greater than or equal to two, one of the first adhesive tapes 12 is pasted on the first side surface 113 and is located between the two second adhesive tapes 13 on the first side surface 113, and the other first adhesive tape 12 is pasted on the second side surface 114 and is located between the two second adhesive tapes 13 on the second side surface 114. The first adhesive tape 12 located on the first side surface 113 and the first adhesive tape 12 located on the second side surface 114 are arranged axially symmetrically.

[0082] Specifically, based on the above embodiment, two first adhesive tapes 12 and four second adhesive tapes 13 are attached to the bare cell 11. Specifically, on the first edge 11a, two second adhesive tapes 13 and one first adhesive tape 12 are attached, with the first adhesive tape 12 located between the two second adhesive tapes 13; and on the second edge 11b, two second adhesive tapes 13 and one first adhesive tape 12 are attached, with the first adhesive tape 12 located between the two second adhesive tapes 13.

[0083] Further, such as Figure 7 As shown, the two first adhesive tapes 12 are arranged axially symmetrically. Optionally, the two first adhesive tapes 12 are axially symmetrical about the second symmetry axis N; and any first adhesive tape 12 itself is axially symmetrical about the first symmetry axis M.

[0084] The adhesive tape on the bare cell 11 is arranged in the above manner, so that the cell 10 can be mainly used in scenarios where liquid is injected on both sides and explosion-proof valves 30 are on both sides. Figure 2 As shown, the explosion-proof valve 30 of the energy storage device 100 can be installed on the third side 115 and the fourth side 116 of the bare cell 11. During installation, the energy storage device 100 can also be injected from the third side 115 and the fourth side 116. This avoids the first rubber strip and constrains the bare cell 11 to ensure uniform expansion force without affecting safe exhaust.

[0085] By setting at least two first adhesive tapes 12 in an axially symmetrical arrangement on the two opposite edges of the bare battery cell 11, the top and bottom of the bare battery cell 11 can be affixed with two layers of composite adhesive tape, so that the expansion force at both ends of the bare battery cell 11 is uniform after expansion; and in the application scenario where the energy storage device 100 is injected with liquid on both sides and the explosion-proof valves 30 are on both sides, the second adhesive strips at the bottom and the bottom do not affect safe exhaust, and the symmetrical second adhesive strips can make the expansion force more uniform and the interface condition better.

[0086] In one embodiment, please refer to Figure 8 The number of the second adhesive tapes 13 is greater than or equal to six, two of which are pasted on the first side 113, and the other four second adhesive tapes 13 are pasted on the second side 114. The first adhesive tape 12 is pasted on the first side 113 and is located between the two second adhesive tapes 13 on the first side 113.

[0087] Specifically, based on the above embodiment, one first adhesive tape 12 and six second adhesive tapes 13 are affixed to the bare cell 11. On the first edge 11a, two second adhesive tapes 13 and one first adhesive tape 12 are affixed, with the first adhesive tape 12 positioned between the two second adhesive tapes 13. On the second edge 11b, four second adhesive tapes 13 are affixed, and the four second adhesive tapes 13 are evenly spaced. Of course, in other embodiments, the number of second adhesive tapes 13 on the second edge 11b can be greater than four, meaning that the total number of second adhesive tapes 13 on the bare cell 11 is greater than six.

[0088] Further, such as Figure 8 As shown, the first adhesive tape 12 itself is axisymmetric about the first symmetry axis M, and the four second adhesive tapes 13 at the second edge 11 b are axisymmetric about the first symmetry axis M.

[0089] The adhesive tape on the bare cell 11 is set in the above manner, so that the cell 10 can be mainly used in the scenario of liquid injection at the top (second edge 11b). Because the energy storage device 100 is top-injected, the exhaust channel in the energy storage device 100 is also at the top. If there is too much adhesive on the top, it will affect the exhaust during the injection process and the infiltration of the electrolyte. Therefore, the adhesive tape at the second edge 11b needs to be optimized. In this way, the exhaust capacity of the energy storage device 100 during the injection process can be guaranteed, and the amount of second adhesive tape 13 at the second edge 11b can be adjusted according to the expansion force.

[0090] By setting one side of the bare cell 11 as a combination of the first adhesive tape 12 and the second adhesive tape 13 and the other side as the second adhesive tape 13, a larger exhaust space can be provided on the side where only the second adhesive tape 13 is provided. In the application scenario of top liquid injection, safe exhaust is not affected, and uniform expansion force is ensured on both sides of the bare cell 11.

[0091] In one embodiment, please refer to Figure 7 Along the first direction Y of the bare cell 11, the width L3 of the first adhesive tape 12 is 100 mm to 400 mm. Specifically, ensuring that the width of the first adhesive tape 12 is within this range ensures that the first adhesive tape 12 can suppress edge expansion of the bare cell 11 and effectively restrain the bare cell 11. Optionally, the width L3 of the first adhesive tape 12 is 100 mm, 150 mm, 200 mm, 250 mm, 300 mm, 350 mm, or 400 mm.

[0092] In one embodiment, please refer to Figure 7Along the first direction Y of the bare cell 11, the width L4 of the second adhesive tape 13 is 25mm to 50mm. Specifically, ensuring that the width of the second adhesive tape 13 is within this range ensures that the second adhesive tape 13 effectively restrains the corners of the bare cell 11, thereby preventing lithium deposition at the corners. Optionally, the width L4 of the second adhesive tape 13 is 25mm, 30mm, 35mm, 40mm, 45mm, or 50mm.

[0093] In one embodiment, along the first direction Y of the bare cell 11, there is a gap between the first adhesive tape 12 and the second adhesive tape 13, and the width L5 of the gap is 2mm to 6mm. Specifically, the gap between the first adhesive tape 12 and the second adhesive tape 13 can be used to allow the electrolyte to penetrate, making it easier for the equipment to position the adhesive tape during adhesive application. At the same time, the width of the first adhesive tape 12 and the second adhesive tape 13 can be controlled to prevent the first adhesive tape 12 and the second adhesive tape 13 from overlapping too closely or being too far apart, thereby reducing the restraining effect. Optionally, the width L5 of the gap can be 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, or 6mm.

[0094] In the description of the embodiments of the present invention, it should be noted that the orientation or positional relationship of terms such as "center", "up", "down", "left", "right", "vertical", "horizontal", "inside" and "outside" is based on the orientation or positional relationship of the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0095] The above disclosure is only a preferred embodiment of the present invention, and certainly cannot be used to limit the scope of the claims of the present invention. Ordinary technicians in this field can understand that all or part of the processes of the above embodiment and equivalent changes made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. A battery cell (10), characterized in that: The invention comprises a bare battery cell (11), a first adhesive tape (12) and a second adhesive tape (13), wherein the first adhesive tape (12) and the second adhesive tape (13) are both pasted on the bare battery cell (11); there are at least two second adhesive tapes (13), and along a first direction (Y) of the bare battery cell (11), the two second adhesive tapes (13) are respectively arranged on two opposite sides of the first adhesive tape (12); along a second direction (Z) of the bare battery cell (11), the length of the first adhesive tape (12) is greater than the length of the second adhesive tape (13), and the first direction (Y) and the second direction (Z) intersect.

2. The battery cell (10) according to claim 1, characterized in that Along a first direction (Y) of the bare battery cell (11), the first adhesive tape (12) includes a first adhesive section (12d) and two second adhesive sections (12e), the first adhesive section (12d) is located between the two second adhesive sections (12e), and along a third direction (X) of the bare battery cell (11), the thickness of the first adhesive section (12d) is greater than the thickness of the second adhesive section (12e).

3. The battery cell (10) according to claim 2, characterized in that The first adhesive tape (12) satisfies the relationship: 0.2≤A1 / A≤0.5, wherein, along the first direction (Y) of the bare battery cell (11), A1 is the width of the first adhesive section (12d), and A is the width of the first adhesive tape (12).

4. The battery cell (10) according to claim 1, characterized in that The thickness of the first adhesive tape (12) is greater than the thickness of the second adhesive tape (13).

5. The battery cell (10) according to claim 1, characterized in that Along the third direction of the first adhesive tape (12), a through hole (123) is provided on the first adhesive tape (12).

6. The battery cell (10) according to claim 5, characterized in that The battery cell (10) comprises a first large surface (111), a second large surface (112) and a first side surface (113); the first large surface (111) and the second large surface (112) are opposite to each other; the two opposite sides of the first side surface (113) are respectively connected to the first large surface (111) and the second large surface (112); the first adhesive tape (12) is pasted on the first large surface (111), the first side surface (113) and the second large surface (112); and the orthographic projection of the through hole (123) on the battery cell (10) is located on the first side surface (113).

7. The battery cell (10) according to claim 5, characterized in that The number of the through holes (123) is multiple, and along the third direction (X) of the bare battery core (11), the center distance L1 between two adjacent through holes (123) is 20 mm to 30 mm, and / or the diameter D of the through hole (123) is 6 mm to 10 mm.

8. The battery cell (10) according to claim 6, characterized in that On the first large surface (111) or the second large surface (112), along the second direction (Z) of the bare battery cell (11), the length L21 of the first adhesive tape (12) is 25 mm to 70 mm, and the length L22 of the second adhesive tape is 25 mm to 40 mm.

9. The battery cell (10) according to claim 1, characterized in that The two second adhesive tapes (13) and the first adhesive tape (12) are pasted on the same side edge of the bare battery cell (11), and along the first direction (Y) of the bare battery cell (11), the width of the first adhesive tape (12) is greater than the width of the second adhesive tape (13).

10. The battery cell (10) according to claim 9, characterized in that: Along the second direction (Z) of the bare battery cell (11), the bare battery cell (11) includes a first side surface (113) and a second side surface (114) facing each other, and the number of the second adhesive tapes (13) is greater than or equal to four, two of which are pasted on the first side surface (113), and the other two are pasted on the second side surface (114), and the two second adhesive tapes (13) located on the outermost side of the first side surface (113) and the two second adhesive tapes (13) located on the outermost side of the second side surface (114) are rotationally symmetrically arranged.

11. The battery cell (10) according to claim 10, characterized in that: The number of the first adhesive tapes (12) is greater than or equal to two, one of the first adhesive tapes (12) is pasted on the first side surface (113) and is located between the two second adhesive tapes (13) on the first side surface (113), and the other first adhesive tape (12) is pasted on the second side surface (114) and is located between the two second adhesive tapes (13) on the second side surface (114), and the first adhesive tape (12) located on the first side surface (113) and the first adhesive tape (12) located on the second side surface (114) are arranged axially symmetrically.

12. The battery cell (10) according to claim 10, characterized in that: The number of the second adhesive tapes (13) is greater than or equal to six, wherein two of the second adhesive tapes (13) are pasted on the first side surface (113), and the other four of the second adhesive tapes (13) are pasted on the second side surface (114), and the first adhesive tape (12) is pasted on the first side surface (113) and is located between the two second adhesive tapes (13) on the first side surface (113).

13. The battery cell (10) according to claim 1, characterized in that Along the first direction (Y) of the bare battery core (11), the width L3 of the first adhesive tape (12) is 100 mm to 400 mm, and / or the width L4 of the second adhesive tape (13) is 25 mm to 50 mm.

14. The battery cell (10) according to claim 1, characterized in that Along the first direction (Y) of the bare battery core (11), there is a gap between the first adhesive tape (12) and the second adhesive tape (13), and the width L5 of the gap is 2 mm to 6 mm.

15. An energy storage device (100), characterized in that The invention comprises a housing and a battery core (10) according to any one of claims 1 to 14, wherein the battery core (10) is accommodated in the housing.

16. An electrical device, characterized in that: The energy storage device (100) according to claim 15 is included, and the energy storage device (100) supplies power to the electrical equipment.

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