Battery device and electric appliance

Abstract

The application relates to the technical field of new energy, and discloses a battery device and an electric equipment, the battery device comprising: a battery pack; a heat exchange plate; a fixed plate, the fixed plate comprising a first fixed plate and a second fixed plate, and being arranged on two second sides respectively; a metal fastening belt is fixedly connected with the first fixed plate and the second fixed plate respectively, and the metal fastening belt is arranged opposite to the first end face at least partially along a second direction; the width of the metal fastening belt is A mm; a soft package battery comprises a shell and a battery core arranged in the shell, the battery core comprises a plurality of pole pieces arranged in a first direction in a laminated mode, and the shell comprises at least a first metal layer; along a direction perpendicular to the first end face, the thickness of the first metal layer is D mm; the distance between the outermost pole piece of the battery core along the first direction and the inner wall of the shell adjacent to the pole piece is H mm, and the following condition is met: 0.02 <= A * D * H <= 4.425. The battery device provided by the application guarantees the heat exchange efficiency of the battery pack and avoids damage of the battery core caused by shell deformation.

Description

[0001] This application is a divisional application of the invention entitled "Battery Device and Electrical Equipment", the original application was filed on February 4, 2026, and the application number is 2026101569934. Technical Field

[0002] This invention relates to the field of new energy technology, specifically to a battery device and electrical equipment. Background Technology

[0003] Compared to traditional metal-cased batteries, pouch batteries have a softer outer shell material with better plasticity, making them easier to adapt to spaces of different shapes, thereby improving space utilization.

[0004] However, the casing of pouch batteries is relatively soft and lacks sufficient rigid support. The casing is prone to deformation. When multiple pouch batteries are stacked to form a battery pack, the pouch batteries need to be fastened. When the fasteners are placed between the pouch batteries and the base plate, they will hinder the close contact between the two, resulting in poor heat exchange efficiency between the pouch batteries and the base plate, which will affect the overall safety of the battery. Summary of the Invention

[0005] In view of this, the present invention provides a battery device and electrical equipment to solve the problem of poor heat exchange efficiency between the pouch battery and the base plate.

[0006] In a first aspect, the present invention provides a battery device, comprising: The battery pack is composed of multiple pouch cells stacked along a first direction; A heat exchange plate is disposed on one side of the battery pack along the second direction, and the battery pack includes a first end face disposed opposite to the heat exchange plate; A fixing plate is disposed on the outer periphery of the battery pack; the battery pack includes two second side surfaces opposite each other along a first direction, and the fixing plate includes a first fixing plate and a second fixing plate, which are respectively disposed on the two second side surfaces; The metal fastening band is fixedly connected to the first fixing plate and the second fixing plate respectively, and the metal fastening band is at least partially opposite to the first end face along the second direction. The metal fastening band is disposed between the heat exchange plate and the first end face. The width of the metal fastening band is A mm; The pouch battery includes a casing and a cell disposed within the casing. The cell includes a plurality of electrode sheets stacked along a first direction. The casing includes at least a first metal layer. The thickness of the first metal layer is D mm. The distance between the outermost electrode sheet of the cell along the first direction and the inner wall of the casing on the adjacent side is H mm. It satisfies: 0.02≤A×D×H≤4.425; Among them, the first direction, the second direction, and the third direction are perpendicular to each other.

[0007] Beneficial effects: By constraining the bottom of the battery pack with metal fastening bands and forming a hollow area, efficient heat exchange between the bottom of the battery pack and the heat exchange plate is ensured. At the same time, by controlling the width of the metal fastening bands, the thickness of the metal layer of the battery shell, and the distance between the electrode and the shell, the structural strength and heat exchange efficiency of the battery pack are ensured, while avoiding the risk of short circuits inside the battery.

[0008] When the formula value of A×D×H is too small, the metal fastening band will exert greater squeezing force on the soft-pack battery, increasing the risk of cell material falling out and posing a short circuit risk. When the formula value of A×D×H is too large, although it can reduce the squeezing risk and improve structural stability, it will lead to a decrease in the heat dissipation efficiency of the battery pack bottom to the cell, affecting the battery pack's safety and charge / discharge rate.

[0009] Secondly, the present invention also provides an electrical appliance, comprising: The electrical equipment body and the battery device as described above, wherein the electrical equipment body and the battery device are electrically connected.

[0010] Since electrical equipment includes battery devices and has the same effect as battery devices, it will not be elaborated on here. Attached Figure Description

[0011] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0012] Figure 1 This is a three-dimensional schematic diagram of the battery device of the present invention; Figure 2 This is an exploded view of the battery device of the present invention; Figure 3 This is a bottom view of the battery device of the present invention after the heat exchange plate has been removed. Figure 4 for Figure 3 A magnified view of section AA in the middle; Figure 5 This is a schematic diagram of the battery pack and metal fastening band of the present invention; Figure 6 This is an exploded view of the battery pack and metal fastening band of the present invention; Figure 7 for Figure 5 A bottom view; Figure 8 This is an exploded view of the soft-pack battery of the present invention; Figure 9This is a side view of the soft-pack battery of the present invention; Figure 10 for Figure 9 A schematic diagram of the BB section; Figure 11 for Figure 10 Partial detail display image; Figure 12 This is a partially enlarged view of the metal fastening band of the present invention.

[0013] Explanation of reference numerals in the attached figures: 1. Battery pack; 11. Soft-pack battery; 111. Casing; 1112. First metal layer; 112. Cell; 1121. Electrode; 101. First end face; 102. Second side face; 2. Fixing plate; 21. First fixing plate; 22. Second fixing plate; 3. Heat exchange plate; 4. Metal fastening band; 41. Second metal layer; 42. Second insulating layer; 5. Isolation plate; 6. Heat spreader plate. Detailed Implementation

[0014] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0015] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0016] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0017] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0018] Soft-pack batteries typically use aluminum-plastic composite film as the outer shell material. Compared with traditional metal-cased batteries, the outer shell material of soft-pack batteries is more flexible and has better plasticity, making it easier to adapt to spaces of different shapes, thereby improving space utilization.

[0019] However, the casing of pouch batteries is relatively soft and lacks sufficient rigid support, making it prone to deformation. When multiple pouch batteries are stacked to form a battery pack, they need to be fastened. When fasteners are placed between the pouch batteries and the base plate, they can hinder the close contact between the two, resulting in obstructed heat conduction paths and poor heat exchange efficiency between the pouch batteries and the base plate. This can affect the heat dissipation performance of the battery pack and may cause local overheating under long-term operation, affecting the overall safety of the battery.

[0020] Research has found that because the bottom surface of a pouch battery pack corresponds to the small surface of the pouch battery, the heat exchange area for a single pouch battery is limited. Furthermore, to ensure reliable fixation of the battery pack, certain technologies result in an excessive distance between the heat exchange plate and the bottom surface of the pouch battery, affecting the heat exchange efficiency between the pouch battery and the heat exchange plate. By creating a hollowed-out area on the end face where the battery pack exchanges heat with the base plate, and using metal fastening straps to fix the opposite sides of the battery pack, a reliable heat exchange area between the heat exchange plate and the pouch battery can be ensured, improving heat dissipation efficiency. Simultaneously, this increases the structural strength of the battery pack and suppresses its expansion. However, because the contact area between the metal fastening straps and the bottom surface of the pouch battery is small, and the metal fastening straps are typically made of a hard material, stress concentration occurs on the bottom surface of some pouch batteries, squeezing the pouch battery casing. This poses a safety risk of cell shedding, affecting battery energy density and increasing the risk of short circuits.

[0021] To alleviate the above problems, the battery device proposed in this invention constrains the bottom of the battery pack with metal fastening bands to form a hollow area, ensuring efficient heat exchange between the bottom of the battery pack and the heat exchange plate. At the same time, by controlling the width of the metal fastening bands, the thickness of the metal layer of the battery shell, and the distance between the electrode and the shell, the structural strength and heat exchange efficiency of the battery pack are ensured, while further reducing the compressive stress of the metal fastening bands on the soft-pack battery, avoiding cell damage caused by shell deformation, and avoiding the risk of short circuit inside the battery.

[0022] To facilitate understanding of the technical solution of this application, several technical terms that may be involved in this application will first be explained: Battery Pack 1: Multiple battery cells with similar capacity and internal resistance are connected in series or in parallel to form a battery pack.

[0023] Casing 111: The casing of a pouch battery is a multi-layered structure consisting of an outer insulating layer, a metal layer, and an inner insulating layer. The outer insulating layer can be made of one or more materials such as polycaprolactam (nylon 6), PET (polyethylene terephthalate), or polybutylene succinate. The metal layer can be made of one or more metals or alloys such as aluminum, aluminum alloy, copper, or nickel. The inner insulating layer can be made of one or more materials such as polypropylene film (PP) or cast polypropylene film (CPP).

[0024] Cell 112: A battery cell is the component in a battery where electrochemical reactions occur; it is the smallest unit in a battery capable of performing electrochemical reactions such as charging and discharging. A battery cell is the basic unit of a battery and typically includes a positive electrode, a negative electrode, and a separator. Lithium-ion battery cells primarily function by the movement of lithium ions between the positive and negative electrodes. In cylindrical cells, a three-layer thin-film structure is wound into a cylindrical electrode assembly, while in cuboid cells, the thin-film structure is wound or stacked into an electrode assembly with a roughly cuboid shape.

[0025] Extreme Film 1121: Including positive and negative electrodes, let's first talk about the positive electrode: The positive electrode is one of the core components in a battery that carries the positive electrode active material. During charging, metal ions (such as lithium ions) are released from the crystal lattice of the positive electrode active material (oxidation reaction), migrate through the electrolyte, and intercalate into the negative electrode. During discharging, metal ions (such as lithium ions in a lithium battery) are released from the negative electrode and intercalated into the crystal lattice of the positive electrode active material (reduction reaction), thus realizing the storage and release of lithium ions.

[0026] A positive electrode generally includes a positive current collector and a positive active material layer. The positive active material layer is coated on at least one surface of the positive current collector and includes: a positive active material, a conductive agent, and a binder. The positive active material includes, but is not limited to, at least one of the following: lithium phosphates, lithium transition metal oxides and their respective modified compounds, or other conventional materials that can be used as positive electrode active materials in batteries. These positive active materials can be used alone or in combination. Lithium phosphates include, but are not limited to, at least one of lithium iron phosphate (e.g., LiFePO4 (also abbreviated as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (e.g., LiMnPO4), lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites. Lithium transition metal oxides include, but are not limited to, lithium cobalt oxide (e.g., LiCoO2), lithium nickel oxide (e.g., LiNiO2), lithium manganese oxide (e.g., LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (e.g., LiNi). 1 / 3 Co 1 / 3Mn 1 / 3 O2 (also known as NCM333), LiNi 0.5 Co 0.2 Mn 0.3O2 (Also known as NCM523), LiNi 0.5 Co 0.25 Mn 0.25O2 (Also known as NCM211), LiNi 0.6 Co 0.2 Mn 0.2O2 (Also known as NCM622), LiNi 0.8 Co 0.1 Mn 0.1O2 (Also known as NCM811)), lithium nickel cobalt aluminum oxide (such as LiNi) 0.85 Co 0.15 Al 0.05O2 At least one of the following: ) and its modified compounds.

[0027] The positive electrode conductive agent includes, but is not limited to, one or more combinations of graphite, superconducting carbon, carbon black (such as acetylene black, Ketjen black, Super P, etc.), carbon nanotubes, graphene and carbon nanofibers.

[0028] The positive electrode binder includes, but is not limited to, one or more combinations of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), PVDF-tetrafluoroethylene-propylene terpolymer, PVDF-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, fluorinated acrylate resin, styrene-butadiene rubber, polyacrylic acid, sodium polyacrylate, polyacrylamide, polyvinyl alcohol, sodium alginate, polymethacrylic acid, carboxymethyl chitosan, etc.

[0029] Secondly, regarding the negative electrode: During battery charging, active ions (such as Li) from the positive electrode are embedded in the negative electrode, while electrons from the positive electrode are transferred to the negative electrode through an external circuit to maintain charge balance. During discharge, active ions (such as Li) previously embedded in the negative electrode can be released, while electrons from the negative electrode are transferred to the positive electrode through an external circuit to maintain charge balance, thus achieving energy storage and release.

[0030] The negative electrode sheet includes a negative electrode current collector and a negative electrode active layer disposed on at least one surface of the negative electrode current collector. The negative electrode current collector is a conductive metal foil, which can be made of stainless steel, copper, aluminum, nickel, carbon electrodes, or titanium with a silver-plated surface. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloy, copper, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.). The negative electrode active layer includes a negative electrode active material, a conductive agent, and a binder.

[0031] The negative electrode active material can be carbon-based materials such as graphite, porous carbon, hard carbon, soft carbon, and mesophase carbon microspheres, or silicon-based materials such as elemental silicon, silicon oxides, silicon-carbon composites, and silicon-nitrogen composites. The conductive agent can be conductive carbon black, carbon nanotubes, etc., and the binder can be styrene-butadiene rubber, polyacrylic acid, etc.

[0032] Fixing plate 2: A fixing plate is disposed on at least one surface of the pouch battery pack to constrain the pouch battery. Since the pouch battery casing is a thin-film structure with relatively low strength, the fixing plate is needed to constrain the pouch battery during charging and discharging to prevent excessive expansion. In addition, the fixing plate also protects the pouch battery from direct external impacts and pressure on its relatively weak casing, thus reinforcing the safety of the battery pack.

[0033] The fixing plate 2 can be made of copper, iron, aluminum, steel, stainless steel, aluminum alloy, plastic, etc., or other metal materials or composite materials of metal and non-metal; it can be made of engineering plastics, fiberglass or carbon fiber; it can be made of aluminum alloy sheet by extrusion and / or machine tool processing. The common structure is a flat plate structure with a certain thickness, usually 2mm to 25mm, so as to meet the strength requirements of the battery device. When the thickness is too small, it cannot meet the structural strength, and when the thickness is too large, it affects the energy density of the battery device.

[0034] Metal fastening band 4: Used to secure pouch battery packs to surfaces without mounting plates. The metal fastening straps do not completely cover the surface; they are also used when a portion of the pouch battery casing needs to be exposed for subsequent heat exchange structures. The metal fastening straps are fixed to the mounting plate using methods including, but not limited to, welding, riveting, and screwing.

[0035] Typically, a strip of metal is used, and the material can be copper, iron, aluminum, steel, stainless steel, aluminum alloy, etc. It is preferred that the same material be used as the fixing plate.

[0036] To prevent short circuits caused by overlapping between the metal fastening strap and the pouch battery casing, an insulating protective layer can be provided at least on the end of the metal fastening strap facing the pouch battery casing. This can be achieved by using insulating components, insulating films, or insulating spraying processes to create the insulating protective layer.

[0037] Examples of insulating film compositions include: polyester film (PET, Polyethylene Terephthalate), polyimide (PI), polypropylene (PP), or polyethylene (PE).

[0038] Examples of insulating coating components: (1) modified epoxy resin; (2) polyacrylate; (3) polyethylene phthalate (PET); (4) insulating coatings also include main materials such as oil-based insulating resin or water-based insulating resin. Main materials of insulating resin include epoxy resin, acrylic resin, polyurethane resin, hydroxyl acrylic resin and other multifunctional resins. Various additives may also be included in insulating materials, such as photoinitiators, reactive diluents, flame retardants, wetting agents, leveling agents, defoamers, etc.; (5) polyimide coating or insulating coating formed by polymers such as polyimide (PI) and epoxy resin; (6) styrene-butadiene rubber emulsion.

[0039] Isolation plate 5: It is made of insulating material to achieve insulation between the soft-pack battery casing and the mounting plate.

[0040] The insulating material can be plastic, rubber, or other insulating materials. Plastics can be polyethylene terephthalate (PET), polypropylene (PP), polycarbonate (PC), or polyvinyl chloride (PVC). Rubber can be fluororubber, nitrile rubber, or isobutyl rubber.

[0041] Heat spreader 6: Soft-pack batteries are usually arranged by stacking them on their large sides. However, the large sides are often the surfaces where the battery heat is concentrated. Therefore, a heat spreader is set between the batteries to balance the heat of the batteries and prevent the batteries from getting too hot in some areas, which would affect the charging and discharging performance of the batteries.

[0042] The heat spreader can be made of materials with high thermal conductivity, such as aluminum, aluminum alloy, copper, stainless steel, and titanium.

[0043] The following is combined with Figures 1 to 12 The following describes embodiments of the present invention.

[0044] According to an embodiment of the present invention, in one aspect, a battery device is provided, comprising: Battery pack 1 is formed by stacking multiple pouch cells 11 along a first direction; The heat exchange plate 3 is disposed on one side of the battery pack 1 along the second direction, and the battery pack 1 includes a first end face 101 disposed opposite to the heat exchange plate 3. A fixing plate 2 is disposed on the outer periphery of the battery pack 1; the battery pack 1 includes two second side surfaces 102 opposite to each other along a first direction; the fixing plate 2 includes a first fixing plate 21 and a second fixing plate 22, the first fixing plate 21 and the second fixing plate 22 are respectively disposed on the two second side surfaces 102; Metal fastening band 4 is fixedly connected to the first fixing plate 21 and the second fixing plate 22 respectively, and the metal fastening band 4 is at least partially opposite to the first end face 101 along the second direction. The metal fastening band 4 is disposed between the heat exchange plate 3 and the first end face 101. The width of the metal fastening band 4 is A mm; The soft-pack battery 11 includes a housing 111 and a cell 112 disposed within the housing 111. The cell 112 includes a plurality of electrode sheets 1121 stacked along a first direction. The housing 111 includes at least a first metal layer 1112. The thickness of the first metal layer 1112 is D mm. The distance between the outermost electrode sheet 1121 of the cell 112 along the first direction and the inner wall of the housing 111 on the adjacent side is H mm. It satisfies: 0.02≤A×D×H≤4.425; Among them, the first direction, the second direction, and the third direction are perpendicular to each other.

[0045] In this embodiment, the battery pack 1 is formed by stacking multiple pouch batteries 11 along a first direction. A pouch battery 11 refers to a battery that uses a soft outer shell as its encapsulation material. For example, the shell 111 of the pouch battery 11 has a three-layer structure consisting of an inner insulating layer, an intermediate metal layer, and an outer insulating layer, preferably made of aluminum-plastic film. For example, the inner insulating layer can be one or more materials such as polypropylene film (PP) or cast polypropylene film (CPP); the intermediate metal layer can be one or more metals or alloys such as aluminum, aluminum alloy, copper, or nickel; and the outer insulating layer can be one or more materials such as polycaprolactam (nylon 6), PET (polyethylene terephthalate), or polybutylene succinate. In this embodiment, the first metal layer 1112 is the intermediate metal layer, typically aluminum foil, which has good thermal and electrical conductivity.

[0046] The soft-pack battery 11 has a cell 112 inside its casing 111. The cell 112 includes a plurality of electrode sheets 1121 stacked along a first direction. A separator is provided between the electrode sheets 1121 to achieve electrical isolation. The cell 112 is connected to an external circuit through tabs.

[0047] In this embodiment, the pouch battery 11 is constructed in a cuboid shape. The battery pack 1 is formed by stacking multiple pouch batteries 11 along a first direction, wherein the first direction can be consistent with the thickness direction of the pouch battery 11, thereby effectively improving the energy density of the battery pack during stacking.

[0048] The heat exchange plate 3 is attached to the first end face 101 of the battery pack, and the heat exchange plate 3 is disposed on one side of the battery pack 1 along the second direction. The second direction can be the height direction of the battery pack 1 and corresponds to the width direction of the soft pack battery 11. That is, the heat exchange plate 3 is attached to the long and thick surface formed by the long side and the thick side of the soft pack battery 11, which is used to concentrate heat dissipation of the battery pack 1 and reduce the temperature difference between adjacent soft pack batteries caused by uneven heating.

[0049] To achieve stable stacking of multiple pouch batteries 11 in the first direction, the battery pack 1 includes two second side surfaces 102 opposite to each other along the first direction. A first fixing plate 21 and a second fixing plate 22 are respectively disposed on the two second side surfaces 102 and clamp the battery pack 1. Then, the first fixing plate 21 and the second fixing plate 22 are clamped and connected by metal fastening straps 4 to achieve the stability of the overall structure.

[0050] However, the metal fastening band 4 is at least partially positioned opposite the first end face 101 along the second direction, meaning that the metal fastening band 4 overlaps with the long and thick side of the pouch battery 11. When the width of the metal fastening band 4 is relatively wide, it will to some extent obstruct the contact area between the heat exchange plate 3 and the pouch battery 11, affecting the heat dissipation efficiency. When the width of the metal fastening band 4 is relatively narrow, although it can reduce the obstruction of the heat exchange plate 3, since the material of the metal fastening band 4 is usually relatively hard, it is easy for the metal fastening band 4 to squeeze the casing 111 of the pouch battery 11, resulting in local stress concentration, which may in turn squeeze the battery cell 112 inside the casing 111, causing a safety risk of the battery cell 112 falling out.

[0051] To alleviate the above problems, this embodiment controls the relationship between the width A of the metal fastening band 4, the thickness D of the first metal layer 1112, and the distance H between the outermost electrode 1121 of the cell 112 along the first direction and the inner wall of the adjacent shell 111, thereby ensuring the structural strength and heat exchange efficiency of the battery pack while avoiding the risk of short circuit inside the battery.

[0052] The bottom of the battery pack 1 is constrained by the metal fastening band 4, while forming a hollow area to ensure efficient heat exchange between the bottom of the battery pack and the heat exchange plate. At the same time, by controlling the width Amm of the metal fastening band 4, the thickness Dmm of the first metal layer of the battery shell, and the distance Hmm between the outermost electrode 1121 of the cell 112 along the first direction and the inner wall of the shell 111 on the adjacent side, the structural strength and heat exchange efficiency of the battery pack are ensured, while avoiding the risk of short circuit inside the battery.

[0053] The width A of the metal fastening band 4 is the dimension along the third direction.

[0054] It should be noted that if the battery device is equipped with multiple metal fastening bands 4, then Amm refers to the sum of the widths of the multiple metal fastening bands 4.

[0055] The distance between the outermost electrode 1121 of the battery cell 112 along the first direction and the inner wall of the adjacent casing 111 is H mm, wherein, combined with Figure 11 As shown, since the electrode 1121 includes a current collector and an active material layer coated on at least one surface of the current collector, in this embodiment, the outermost electrode 1121 of the cell 112 along the first direction refers to the electrode 1121 closest to the housing 111 along the first direction, specifically the surface of the active material layer of the electrode 1121 closest to the housing 111 along the first direction. Furthermore, since the housing 111 includes an outer insulating layer, a metal layer, and an inner insulating layer, in this embodiment, the inner wall of the housing 111 on the adjacent side refers to the surface of the inner insulating layer on the side closest to the cell 112 along the first direction.

[0056] When the width A of the metal fastening band 4 is small, it can reduce the obstruction of the contact area between the heat exchange plate 3 and the battery pack, thus improving heat dissipation efficiency. However, if the width A of the metal fastening band 4 is too small, it is more likely that the metal fastening band 4 will squeeze the casing 111 of the pouch battery 11, leading to local stress concentration, which in turn can squeeze the cell 112 and cause the electrode to fall off, posing a safety risk. Moreover, if the width A of the metal fastening band 4 is too small, it will result in insufficient constraint on the battery pack, affecting the overall structural stability. On the other hand, if the width A of the metal fastening band 4 is too large, although it can reduce the risk of squeezing the casing 111 of the pouch battery 11 and improve the constraint, it will significantly obstruct the contact area between the heat exchange plate 3 and the pouch battery 11, reducing heat dissipation efficiency. Therefore, it is necessary to control the width A of the metal fastening band 4 within a reasonable range to balance the contradiction between heat dissipation efficiency and squeezing risk.

[0057] Along the direction perpendicular to the first end face 101, if the thickness D of the first metal layer 1112 is too small, the compressive strength of the pouch battery casing 111 will easily decrease, making it more prone to deformation under the clamping action of the metal fastening band 4, thus exacerbating the risk of compression on the cell 112. Conversely, if the thickness D of the first metal layer 1112 is too large, it will increase the overall thickness of the pouch battery 11, reduce the energy density of the battery pack 1, and increase material costs. In addition, an excessively thick first metal layer 1112 may also lead to a decrease in the flexibility of the casing 111, making it prone to cracks in the bending encapsulation area and affecting sealing reliability. Therefore, it is necessary to comprehensively consider compressive strength, lightweighting, and manufacturing process compatibility to control the thickness D of the first metal layer 1112 within a reasonable range.

[0058] When the distance H between the outermost electrode 1121 of the cell 112 along the first direction and the inner wall of the adjacent casing 111 is too small, the electrode is prone to directly contacting the inner wall of the casing 111 due to volume expansion during charge and discharge cycles. This increases the risk of stress transfer between the electrode and the casing when squeezed by the metal fastening band 4, potentially leading to material loss or internal short circuits. Conversely, when the distance H between the outermost electrode 1121 of the cell 112 along the first direction and the inner wall of the adjacent casing 111 is too large, although it reduces the risk of short circuits caused by compression, it compresses the effective space of the cell, affecting the improvement of battery capacity and energy density. It also increases the internal cavity of the casing, potentially causing localized shaking of the cell during charge and discharge, affecting the stability of the battery's internal structure. Therefore, while ensuring sufficient allowance for electrode volume expansion, it is necessary to maximize the use of the internal space of the casing, improve energy density, and suppress cell shaking, keeping the distance H within a reasonable range.

[0059] In summary, the parameters of the metal fastening band width A, the first metal layer thickness D, and the distance H between the electrode and the inner wall of the casing need to be optimized in a coordinated manner. When the formula value of A×D×H is too small, it is easy to cause the metal fastening band 4 to exert a large squeezing force on the soft-pack battery 11, which increases the risk of the cell 112 falling off and poses a short circuit risk. When the formula value of A×D×H is too large, although it can reduce the squeezing risk and improve the structural stability, it will lead to a decrease in the heat dissipation efficiency of the bottom of the battery pack 1 to the cell, affecting the safety of the battery pack 1 and the charging and discharging rate.

[0060] In this embodiment, the width Amm of the metal fastening band 4 is in the range of 10mm≤Amm≤60mm.

[0061] In this embodiment, the thickness Dmm of the first metal layer 1112 is in the range of 0.03mm≤Dmm≤0.08mm.

[0062] In this embodiment, the distance Hmm between the outermost electrode 1121 of the battery cell 112 along the first direction and the inner wall of the adjacent housing 111 is in the range of 0.05mm≤Hmm≤1mm.

[0063] As a further preferred option, the value range of the formula A×D×H is 0.02≤A×D×H≤4.425.

[0064] It should be noted that the measurement methods for Amm, Dmm, and Hmm are as follows: Use measuring instruments such as a micrometer or calipers to measure parameters such as length, width, distance, and thickness. For example, the width Amm of the fastening band can be measured using a micrometer or calipers. The thickness Dmm of the first metal layer 1112 can be measured by taking a 2.5cm × 2.5cm sample from the large side of the battery casing, scraping off the portion other than the first metal layer, and then measuring the thickness of the first metal layer 1112 with a micrometer. The distance Hmm between the outermost electrode 1121 of the cell 112 along the first direction and the inner wall of the adjacent casing 111 can be measured by X-ray imaging, showing the distance between them on the photograph.

[0065] For example, in this embodiment, the value of A×D×H can be 0.02 or 0.03 or 0.06 or 0.12 or 0.24 or 0.48 or 0.96 or 1.92 or 3.84 or 4.425, or it can be any range formed by any two of the above values.

[0066] In this embodiment, the battery pack 1 can specifically be a pouch battery module. The preparation method of the pouch battery module is as follows: (1) Preparation of the positive electrode: The positive electrode active material, conductive agent acetylene black, and binder PVDF are mixed, and solvent NMP is added. The mixture is stirred under vacuum until the system is homogeneous to obtain a positive electrode slurry. The positive electrode slurry is uniformly coated on both surfaces of the positive electrode current collector aluminum foil, air-dried at room temperature, and then transferred to an oven for further drying. Finally, it is cold-pressed and slit to obtain the positive electrode sheet. Specifically, the mass ratio of positive electrode active material: conductive agent: binder satisfies (92~98):(4~1):(4~1).

[0067] (2) Preparation of negative electrode: The negative electrode active material, conductive agent acetylene black, thickener CMC, and binder SBR are mixed, and deionized water is added as a solvent. The mixture is stirred under vacuum until the system is homogeneous to obtain a negative electrode slurry. The negative electrode slurry is uniformly coated on both surfaces of the negative electrode current collector copper foil, air-dried at room temperature, and then transferred to an oven for further drying. After cold pressing and slitting, the negative electrode sheet is obtained. The ratio of negative electrode active material: conductive agent: thickener: binder satisfies (90~96):(4~2):(2~1):(4~1).

[0068] (3) Preparation of electrolyte: Ethylene carbonate (EC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC) were mixed in a volume ratio of 1:1:1 to obtain an organic solvent. Then, fully dried lithium salt LiPF6 was dissolved in the mixed organic solvent to prepare an electrolyte with a concentration of 1 mol / L.

[0069] (4) Preparation of the diaphragm: Polyethylene film is selected as the diaphragm.

[0070] (5) Preparation of pouch cells: The positive electrode, separator, and negative electrode are stacked in sequence to form a bare battery cell. This bare cell is then placed in a pouch battery casing made of aluminum-plastic film. The first inner insulating layer of the aluminum-plastic film casing is made of cast polypropylene film (CPP), the second metal layer is made of aluminum, and the third outer insulating layer is made of polycaprolactam (nylon 6). The battery is dried, injected with electrolyte, and then encapsulated, allowed to stand, formed, and volume-adjusted to obtain the pouch battery.

[0071] The positive electrode active material can be selected from one or more lithium-containing positive electrode active materials, including lithium iron phosphate, ternary materials containing nickel, cobalt, and manganese, and lithium manganese iron phosphate; the negative electrode active material can be selected from one or more negative electrode active main materials, such as artificial graphite, natural graphite, silicon carbide, silicon oxide, and lithium titanate.

[0072] (6) Assembly of soft-pack battery modules: Multiple pouch batteries are connected in series or in parallel and then installed into a pouch battery module housing consisting of a fixing plate 2 and a metal fastening band 4. An isolation plate 5 is provided between the first fixing plate 21 and the second fixing plate 22 and the pouch battery 11 to form a pouch battery module.

[0073] Referring to Table 1 below, through several embodiments and comparative tests, the provided battery device was tested for capacity retention rate of the pouch battery module and temperature rise rate of the pouch battery module to verify its qualification.

[0074] Table 1

[0075] Regarding Table 1 above, the explanation is as follows: Performance 1: Soft-pack battery module capacity retention rate test (used to measure the module's material loss), the method is as follows: Following the battery fabrication method described above, corresponding pouch cells were prepared for each embodiment and comparative example. Twelve pouch cells were connected in series to form a pouch cell module, with all other test conditions remaining consistent. The pouch cell module was placed at room temperature (20°C) until thermal equilibrium was reached. The pouch cell module was then charged at a constant current of 0.33C to the upper limit voltage at room temperature, and then charged at a constant voltage of 0.33C until the current dropped to 0.05C. After standing for 30 minutes, the pouch cell module was discharged at a constant current of 0.33C to the lower limit voltage. This process was repeated three times to obtain the third discharge capacity Q1, which was taken as the fixed capacity.

[0076] The pouch battery module was mounted on a vibration table according to GB / T2423.43. The testing process was conducted according to GB / T2423.56. Random and fixed-frequency vibration loads were applied in each direction, and the loading sequence should preferably be random z-axis, fixed-frequency z-axis, random y-axis, fixed-frequency y-axis, random x-axis, fixed-frequency x-axis (the line connecting the front and rear of the pouch battery module is the x-axis direction, and the other horizontal direction perpendicular to the x-axis is the y-axis direction). The vibration frequency, power spectral density (PSD), vibration time, etc., are shown in the table below.

[0077]

[0078] After vibration, the pouch battery module is charged at room temperature with a constant current of 0.33C to the upper limit voltage, and then charged with a constant voltage of 0.33C until the current drops to 0.05C. After standing for 30 minutes, the pouch battery module is discharged with a constant current of 0.33C to the lower limit voltage. This constitutes one cycle. After n cycles, the discharge capacity Qn of the pouch battery module in the nth cycle is recorded. The formula for calculating the capacity retention rate of the pouch battery module is "Pouch battery module capacity retention rate = Qn / Q1 × 100%". The number of cycles n when the capacity retention rate first falls below 80% is recorded as the number of cycles for the pouch battery module. If n is less than 1200, it is unqualified; if n is greater than or equal to 1200 and less than 1400, it is qualified; and if n is greater than or equal to 1400, it is good.

[0079] When the positive electrode active material of the pouch battery is nickel-cobalt-manganese ternary, the upper limit voltage of the pouch battery module is 4.25V×12=51V, and the lower limit voltage is 2.5V×12=30V; when the positive electrode active material of the pouch battery is lithium iron phosphate, the upper limit voltage of the pouch battery module is 3.6V×12=43.2V, and the lower limit voltage is 2.5V×12=30V.

[0080] In this test, the active material for the positive electrode of the pouch battery was selected from a nickel-cobalt-manganese ternary LiNi alloy. 0.6 Co 0.2 Mn 0.2 Taking O2 as an example, the mass ratio of positive electrode active material: conductive agent: binder meets 96:2:2; the negative electrode active material is selected from artificial graphite, and the ratio of negative electrode active material: conductive agent: thickener: binder meets 95:2:1:2.

[0081] Performance 2, Temperature rise rate test of soft-pack battery module, the method is as follows: Following the battery fabrication method described above, for each embodiment and comparative example, corresponding pouch cells were prepared. Twelve pouch cells were connected in series to form a pouch cell module. At the bottom of the pouch cell module, a heat exchange plate was connected via thermally conductive adhesive. The heat exchange plate was a stamped and brazed cold plate, and the heat exchange medium circulating through the stamped and brazed cold plate was an ethylene glycol aqueous solution. All other test conditions remained consistent. In the pouch cell module, temperature sensors were respectively installed between the sides of the pouch cells 11 and the separator 5. The sensors were positioned at the center point of the corresponding side of the pouch cell 11. The temperatures collected from both sides were averaged to obtain the real-time temperature of the pouch cell module.

[0082] After discharging the pouch battery module to the lower limit voltage at a constant current of 0.33℃, let it stand for 60 minutes. After standing, measure the temperature of the pouch battery module at this time and record it as t1. Then charge the pouch battery module at 1C to the upper limit voltage, record the time as T, and measure the temperature of the pouch battery module at this time as t2. Calculate the temperature rise rate of the pouch battery module using the formula: Temperature rise rate = (t2 - t1) / T. If the temperature rise rate is greater than or equal to 0.9℃ / min, it is unqualified; if the temperature rise rate is less than 0.9℃ / min, it is qualified.

[0083] When the positive electrode active material of the pouch battery is nickel-cobalt-manganese ternary, the upper limit voltage of the pouch battery module is 4.25V×12=51V, and the lower limit voltage is 2.5V×12=30V; when the positive electrode active material of the pouch battery is lithium iron phosphate, the upper limit voltage of the pouch battery module is 3.6V×12=43.2V, and the lower limit voltage is 2.5V×12=30V.

[0084] In this test, the active material for the positive electrode of the pouch battery was selected from a nickel-cobalt-manganese ternary LiNi alloy. 0.6 Co 0.2 Mn 0.2 Taking O2 as an example, the mass ratio of positive electrode active material: conductive agent: binder meets 96:2:2; the negative electrode active material is selected from artificial graphite, and the ratio of negative electrode active material: conductive agent: thickener: binder meets 95:2:1:2.

[0085] Regarding the test results, referring to Table 1 above, the explanation is as follows: As can be seen from Examples 1-16, when the value of the formula A×D×H meets the range of 0.02≤A×D×H≤4.425, the capacity retention rate test of the soft-pack battery module shows that the test results are all good or qualified, and no unqualified results are found; the temperature rise rate test of the soft-pack battery module shows that the temperature rise rate is less than 0.9℃ / min, and the conclusion is qualified; the performance requirements are met.

[0086] In Comparative Examples 1 and 2, the value of the formula A×D×H exceeded the upper limit. The temperature rise rate test of the soft-pack battery module showed a rate greater than or equal to 0.9℃ / min, which was considered unqualified and failed to meet performance requirements. In Comparative Example 3, the value of the formula A×D×H was below the lower limit. The battery capacity retention rate test also showed an unqualified result, failing to meet performance requirements.

[0087] In some embodiments, the length direction of the battery pack 1 is parallel to the width direction of the metal fastening band 4, and the width direction of the metal fastening band 4 is parallel to a third direction.

[0088] Since the battery pack 1 deforms significantly along its length, by aligning the width of the metal fastening band 4 with the length of the battery pack 1, the expansion and deformation of the battery pack in the length direction can be effectively suppressed, preventing the battery pack 1 from detaching from the fixing plate 2 and improving structural stability.

[0089] In some embodiments, the length direction of the pouch battery 11 is parallel to the width direction of the metal fastening band 4.

[0090] By making the length direction of the pouch battery 11 parallel to the width direction of the metal fastening band 4, the metal fastening band 4 can be fixed to each pouch battery 11 simultaneously, applying a uniform constraint force to the pouch battery 11 and ensuring the compactness and connection strength of the overall structure.

[0091] In some embodiments, the width Amm of the metal fastening band 4 is in the range of 10mm≤Amm≤55mm.

[0092] When the width A of the metal fastening band 4 is small, it can reduce the obstruction of the contact area between the heat exchange plate 3 and the battery pack, thus improving heat dissipation efficiency. However, if the width A of the metal fastening band 4 is too small, it is more likely that the metal fastening band 4 will squeeze the casing 111 of the pouch battery 11, leading to local stress concentration, which in turn can squeeze the cell 112 and cause the electrode to fall off, posing a safety risk. In addition, if the width A of the metal fastening band 4 is too small, it will result in insufficient constraint on the battery pack, affecting the overall structural stability. On the other hand, when the width A of the metal fastening band 4 is too large, although it can reduce the risk of squeezing the casing 111 of the pouch battery 11 and improve the constraint, it will significantly obstruct the contact area between the heat exchange plate 3 and the pouch battery 11, reducing heat dissipation efficiency.

[0093] Meanwhile, since the length direction of the pouch battery 11 is parallel to the width direction of the metal fastening band 4, the width A of the metal fastening band 4 does not need to be too wide to cover all the pouch batteries 11. This can reduce the obstruction of the heat dissipation area while ensuring the constraint effect, resulting in better heat dissipation.

[0094] For example, in this embodiment, the value of Amm can be 10mm or 12mm or 15mm or 20mm or 25mm or 30mm or 40mm or 50mm or 55mm, or it can be a range formed by any two of the above values.

[0095] In some embodiments, at least two metal fastening bands 4 are provided at intervals along the length of the battery pack 1.

[0096] By having at least two metal fastening bands 4 spaced apart along the length of the battery pack 1, the constraint force can be distributed more evenly, resulting in a better constraint effect. This effectively suppresses uneven expansion of the battery pack at different locations and avoids structural failure caused by local stress concentration. At the same time, the multi-point distribution of the metal fastening bands 4 can improve the overall stiffness and enhance the resistance to vibration and impact.

[0097] In some embodiments, combined with Figure 7 As shown, the interval between adjacent metal fastening bands 4 is C mm, which satisfies: 80 mm ≤ C mm ≤ 250 mm.

[0098] If the spacing C between adjacent metal fastening bands 4 is too small, although it can further improve the uniformity of constraint, it will increase the assembly complexity and cost, and cause the contact area of ​​the heat exchange plate 3 to be over-divided, affecting the heat dissipation effect; if the spacing C is too large, it will be difficult to effectively suppress the local deformation of the battery pack 1 along the length direction, reducing the structural stability.

[0099] For example, in this embodiment, the value of Cmm can be 85mm or 90mm or 95mm or 100mm or 110mm or 120mm or 130mm or 140mm or 170mm or 190mm or 200mm or 220mm or 230mm or 250mm, or it can be any range formed by any two of the above values.

[0100] In some embodiments, the metal fastening band 4 is offset from the centerline of the pouch battery 11 along its length.

[0101] Since the expansion is most pronounced at the middle of the length of the pouch battery 11, when the metal fastening band 4 is set at the center line of the length of the pouch battery 11, the metal fastening band 4 will cause excessive restraint on the pouch battery 11, resulting in stress concentration in the area, which can easily cause shell deformation or cell damage, and is not conducive to long-term reliability.

[0102] Therefore, by avoiding the centerline of the pouch battery 11 along its length and offsetting it to both sides, the constraint pressure in the high-stress area in the middle can be effectively relieved, and the risk of local deformation of the casing and damage to the battery cell can be reduced.

[0103] In some embodiments, combined with Figure 7 As shown, the distance between the metal fastening band 4 and the center line of the soft-pack battery 11 in the length direction is Emm, which satisfies: 30mm≤Emm≤125mm.

[0104] When the distance E between the metal fastening band 4 and the center line of the soft-pack battery 11 in the length direction is too small, the metal fastening band 4 is still close to the expansion core area and cannot effectively disperse the stress; while when the distance E is too large, the metal fastening band 4 is too far away from the center of force, reducing the constraint effect and making it difficult to effectively suppress expansion deformation.

[0105] For example, in this embodiment, the value of Emm can be 30mm or 40mm or 50mm or 60mm or 70mm or 80mm or 90mm or 100mm or 125mm, or it can be a range formed by any two of the above values.

[0106] In some embodiments, the value of Amm ranges from 10mm to Amm to 60mm. And / or, the value range of Dmm is: 0.03mm≤Dmm≤0.08mm; And / or, the value range of Hmm is: 0.05mm≤Hmm≤1mm.

[0107] When the width A of the metal fastening band 4 is small, it can reduce the obstruction of the contact area between the heat exchange plate 3 and the battery pack, thus improving heat dissipation efficiency. However, if the width A of the metal fastening band 4 is too small, it is more likely that the metal fastening band 4 will squeeze the casing 111 of the pouch battery 11, leading to local stress concentration, which in turn can squeeze the cell 112 and cause the electrode to fall off, posing a safety risk. Moreover, if the width A of the metal fastening band 4 is too small, it will result in insufficient constraint on the battery pack, affecting the overall structural stability. On the other hand, if the width A of the metal fastening band 4 is too large, although it can reduce the risk of squeezing the casing 111 of the pouch battery 11 and improve the constraint, it will significantly obstruct the contact area between the heat exchange plate 3 and the pouch battery 11, reducing heat dissipation efficiency. Therefore, it is necessary to control the width A of the metal fastening band 4 within a reasonable range to balance the contradiction between heat dissipation efficiency and squeezing risk.

[0108] Along the direction perpendicular to the first end face 101, if the thickness D of the first metal layer 1112 is too small, the compressive strength of the pouch battery casing 111 will easily decrease, making it more prone to deformation under the clamping action of the metal fastening band 4, thus exacerbating the risk of compression on the cell 112. Conversely, if the thickness D of the first metal layer 1112 is too large, it will increase the overall thickness of the pouch battery 11, reduce the energy density of the battery pack 1, and increase material costs. In addition, an excessively thick first metal layer 1112 may also lead to a decrease in the flexibility of the casing 111, making it prone to cracks in the bending encapsulation area and affecting sealing reliability. Therefore, it is necessary to comprehensively consider compressive strength, lightweighting, and manufacturing process compatibility to control the thickness D of the first metal layer 1112 within a reasonable range.

[0109] When the distance H between the outermost electrode 1121 of the cell 112 along the first direction and the inner wall of the adjacent casing 111 is too small, the electrode is prone to directly contacting the inner wall of the casing 111 due to volume expansion during charge and discharge cycles. This increases the risk of stress transfer between the electrode and the casing when squeezed by the metal fastening band 4, potentially leading to material loss or internal short circuits. Conversely, when the distance H between the outermost electrode 1121 of the cell 112 along the first direction and the inner wall of the adjacent casing 111 is too large, although it reduces the risk of short circuits caused by compression, it compresses the effective space of the cell, affecting the improvement of battery capacity and energy density. It also increases the internal cavity of the casing, potentially causing localized shaking of the cell during charge and discharge, affecting the stability of the battery's internal structure. Therefore, while ensuring sufficient allowance for electrode volume expansion, it is necessary to maximize the use of the internal space of the casing, improve energy density, and suppress cell shaking, keeping the distance H within a reasonable range.

[0110] For example, in this embodiment, the value of Amm can be 10mm or 12mm or 15mm or 20mm or 25mm or 30mm or 40mm or 50mm or 55mm or 60mm, or it can be a range formed by any two of the above values.

[0111] For example, in this embodiment, the value of Dmm can be 0.03mm, 0.04mm, 0.05mm, 0.06mm, 0.07mm, or 0.08mm, or it can be a range formed by any two of the above values.

[0112] For example, in this embodiment, the value of Hmm can be 0.05mm or 0.1mm or 0.2mm or 0.3mm or 0.4mm or 0.5mm or 0.6mm or 0.7mm or 0.8mm or 0.9mm or 1mm, or it can be a range formed by any two of the above values.

[0113] In some embodiments, combined with Figure 12 As shown, the metal fastening band 4 includes a second metal layer 41 and a second insulating layer 42 located outside the second metal layer 41, with the second insulating layer 42 at least partially located between the second metal layer 41 and the housing 111.

[0114] By providing a second insulating layer 42 outside the second metal layer 41, direct metal contact between the metal fastening band and the casing can be effectively avoided, reducing the risk of short circuits and improving the insulation reliability of the battery pack.

[0115] In addition, since the metal fastening band 4 will rub against the housing 111 under vibration conditions, the second insulating layer 42 can also play a wear-resistant protection role, preventing the metal layer from scratching the housing surface, thereby avoiding sealing failure caused by damage to the housing.

[0116] Additionally, the second insulating layer 42 can also buffer stress concentration between the metal fastening band and the housing to a certain extent, reducing the risk of damage to the cell structure caused by local compression.

[0117] In some embodiments, combined with Figure 4 As shown, along the direction perpendicular to the first end face 101, the shortest distance from the metal fastening band 4 to the housing 111 is Fmm, which satisfies: 0mm≤Fmm≤5mm.

[0118] Along the direction perpendicular to the first end face 101, when the closest distance F between the metal fastening band 4 and the housing 111 is too small, the metal fastening band and the housing are prone to direct contact due to assembly deviation or vibration, which increases the risk of squeezing the battery cell 112, and then squeezing the battery cell 112, causing the electrode to fall off, which poses a safety hazard; while when the distance F is too large, the constraint effect of the metal fastening band on the housing is weakened, which may cause the battery cell to shift or vibrate more under dynamic conditions, affecting the structural stability.

[0119] For example, in this embodiment, the value of Fmm can be 0mm or 0.1mm or 0.5mm or 0.8mm or 0.9mm or 1mm or 1.2mm or 1.8mm or 2.4mm or 3.6mm or 4.7mm or 5mm, or it can be a range formed by any two of the above values.

[0120] In some embodiments, a buffer is provided between the metal fastening band 4 and the housing 111 along a direction perpendicular to the first end face 101; the dimension of the buffer along the length of the battery pack 1 is greater than the width of the metal fastening band 4.

[0121] Along the direction perpendicular to the first end face 101, a buffer is provided between the metal fastening band 4 and the housing 111, which can effectively absorb the relative vibration stress between the two and further reduce the mechanical impact on the battery cell.

[0122] The buffer is at least disposed between the metal fastening band 4 and the housing 111. The buffer can be disposed by inserting it between the two, wrapping it around the outer periphery of the metal fastening band 4, or spraying it on the surface of the metal fastening band 4, including but not limited to film, pad, thermal conductive adhesive, thermal pad, coating, etc.

[0123] In this embodiment, the buffer can specifically be thermally conductive adhesive. This adhesive not only effectively fills the gap between the metal fastening band 4 and the housing 111, improving structural stability, but also acts as a buffer and shock absorber under vibration conditions, reducing the impact of stress concentration on the battery cell. Simultaneously, the excellent thermal conductivity of the adhesive helps dissipate heat within the battery pack 1, improving overall heat dissipation efficiency and further ensuring the thermal safety performance of the battery during high-load operation.

[0124] The buffer component is larger than the width of the metal fastening band 4 along the length of the battery pack 1 to ensure that the buffer component can fully cover the contact area between the metal fastening band and the shell during assembly, thereby enhancing the buffer effect and avoiding stress concentration or uneven heat conduction due to partial uncovering.

[0125] In some embodiments, the thermal conductivity of the buffer is greater than or equal to 0.2 W / m·K.

[0126] By limiting the thermal conductivity of the buffer components, sufficient thermal conductivity is ensured, effectively transferring the heat generated inside the battery pack while achieving mechanical buffering, thus avoiding localized overheating.

[0127] In some embodiments, the pouch battery 11 includes a first long side facing the first end face 101 and a second long side perpendicular to the first end face 101, wherein the area of ​​the first long side is smaller than the area of ​​the second long side.

[0128] The first long side is the long-thick side formed by the long side and the thick side of the pouch battery 11, and the second long side is the long-wide side formed by the long side and the wide side of the pouch battery 11. The area of ​​the long-wide side is larger than that of the long-thick side. By aligning the first long side with the first end face 101 of the battery pack 1, the overall size of the battery pack in the width direction can be effectively reduced, thus improving space utilization.

[0129] In some embodiments, combined with Figure 7 As shown, the width of the first long side along the first direction is Gmm, which satisfies: 6mm≤Gmm≤30mm.

[0130] The width G of the first long side along the first direction is the thickness of the pouch battery 11. By limiting the upper limit of G, the thickness of the pouch battery 11 is prevented from being too small, which would reduce the space utilization rate; at the same time, the thickness of the pouch battery 11 is prevented from being too large, which would reduce the heat exchange efficiency.

[0131] For example, in this embodiment, the value of Gmm can be 6mm or 8mm or 10mm or 12mm or 14mm or 16mm or 18mm or 20mm or 22mm or 30mm, or it can be a range formed by any two of the above values.

[0132] In some embodiments, the surface with the largest area in the pouch battery 11 is the battery surface, and the first fixing plate 21 and the second fixing plate 22 are both provided corresponding to the battery surface.

[0133] In this embodiment, the soft-pack battery 11 is stacked by bonding the large surfaces together.

[0134] By aligning the first fixing plate 21 and the second fixing plate 22 with the large surface of the battery, the overall clamping force of the fixing plates on the battery pack 1 can be effectively improved, battery expansion can be suppressed, and the structural reliability of the battery pack 1 under complex working conditions such as vibration and impact can be enhanced.

[0135] In some embodiments, the metal fastening band 4 extends from the first end face 101 to the outer side of the first fixing plate 21 and the second fixing plate 22, respectively.

[0136] The metal fastening band 4 extends to the outside of the first fixing plate 21 and the second fixing plate 22, thereby facilitating the connection and fixation of the metal fastening band 4 to the first fixing plate 21 and the second fixing plate 22, ensuring that the overall constraint force of the metal fastening band 4 on the battery pack is evenly transmitted, and effectively suppressing structural loosening caused by battery expansion.

[0137] The metal fastening band 4 can be connected to the fixing plate 2 by welding, screwing, riveting or snap fastening, etc. The connection structure is stable and reliable and facilitates automated assembly.

[0138] In some embodiments, combined with Figure 4 As shown, along the second direction, the metal fastening band 4 extends to the first fixing plate 21 or the second fixing plate 22 by a dimension of J mm, satisfying: 10 mm ≤ J mm ≤ 40 mm.

[0139] If the dimension J of the metal fastening band 4 extending to the first fixing plate 21 or the second fixing plate 22 is too small along the second direction, it may cause the metal fastening band to be not firmly connected to the fixing plate, affecting the transmission of constraint force; while if the dimension J of the metal fastening band 4 extending to the first fixing plate 21 or the second fixing plate 22 is too large, it will increase structural redundancy and affect the space utilization rate.

[0140] For example, in this embodiment, the value of Jmm can be 10mm or 13mm or 16mm or 19mm or 22mm or 25mm or 28mm or 31mm or 34mm or 37mm or 40mm, or it can be a range formed by any two of the above values.

[0141] In some embodiments, the end of the metal fastening band 4 is below the centerline of the fixing plate 2 along the second direction.

[0142] Since the pouch battery 11 undergoes volume changes during charge and discharge cycles, especially the large surface volume of the pouch battery 11 changes significantly, by making the end of the metal fastening band 4 lower than the center line of the fixing plate 2 along the second direction, the fixing position of the metal fastening band 4 can avoid the severely expanded central area of ​​the large surface of the pouch battery 11, thereby preventing the battery from being squeezed and falling off.

[0143] In some embodiments, the distance from the end of the metal fastening band 4 to the center line of the fixing plate 2 along the second direction is Kmm, satisfying: 15mm≤Kmm≤65mm.

[0144] By limiting the lower limit of the distance K from the end of the metal fastening band 4 to the center line of the fixing plate 2 along the second direction, the direct compression of the metal fastening band on the center area of ​​the large surface of the battery can be effectively avoided, preventing the electrode material from falling off due to local stress concentration. At the same time, by limiting the upper limit of the distance K from the end of the metal fastening band 4 to the center line of the fixing plate 2 along the second direction, it is ensured that the metal fastening band can still provide stable constraint force when the battery expands, avoiding connection failure.

[0145] For example, in this embodiment, the value of Kmm can be 15mm or 20mm or 25mm or 30mm or 35mm or 40mm or 45mm or 50mm or 55mm or 60mm or 65mm, or it can be a range formed by any two of the above values.

[0146] In some embodiments, the metal fastening band 4 is riveted to the first fixing plate 21 and / or the second fixing plate 22.

[0147] The metal fastening band 4 is connected to the first fixing plate 21 and / or the second fixing plate 22 by riveting. The riveting process can achieve a high-strength and high-reliability connection, which is suitable for mass production scenarios and does not require additional anti-loosening structures.

[0148] In some embodiments, combined with Figure 2 As shown, an isolation plate 5 is provided between the first fixing plate 21 and / or the second fixing plate 22 and the soft-pack battery 11.

[0149] By setting an isolation plate 5 between the first fixing plate 21 and / or the second fixing plate 22 and the soft-pack battery 11, the stress generated during the riveting process of the metal fastening band 4 and the fixing plate 2 can be prevented from being directly transmitted to the soft-pack battery 11, thus avoiding damage to the battery body; at the same time, the isolation plate 5 can also play a role in insulation and buffering.

[0150] In some embodiments, along the second direction, the ends of the metal fastening band 4 at opposite ends on the first fixing plate 21 and the second fixing plate 22 are flush.

[0151] By aligning the ends of the metal fastening band 4 with the opposite ends on the first fixing plate 21 and the second fixing plate 22, balanced force on both sides is ensured, preventing structural deformation or loosening of connections due to uneven loading. This improves the overall structural stability and reliability, effectively maintaining the consistency of the tension of the metal fastening band 4 when the volume changes caused by the charging and discharging cycle of the pouch battery, reducing the risk of local stress concentration, and thus extending the service life of the battery module.

[0152] In some embodiments, the heat exchange plate 3 is provided with a heat exchange channel for passing a heat exchange medium.

[0153] The heat exchange channel is used to circulate the cooling medium, enabling efficient thermal management of the pouch battery 11.

[0154] The heat exchange plate 3 has heat exchange channels inside, including multiple heat exchange channels, which are arranged at intervals along the first direction and extend along the third direction.

[0155] It should be noted that in this embodiment, the heat exchange plate 3 is also called the cold plate, which is used to dissipate heat from the battery cells to regulate the temperature of the battery cells. Materials / Composition: (1) The cold plate can be constructed as a liquid cooling plate or a phase change cooling plate and is thermally connected to the battery. (2) A refrigerant can be stored in the cold plate. The cooling of the battery cells is achieved through the phase change of the refrigerant. The refrigerant can be a gas (pure water, ethylene glycol aqueous solution, silicone oil, etc.), a solid, or a liquid. A liquid with a high specific heat capacity, such as water, can also be set in the liquid refrigerant as a coolant to achieve liquid cooling of the battery cells. (3) The air-cooled plate is set at the bottom of the box, that is, connected to the bottom of the side wall to form a closed box structure. The air-cooled plate can be fixed to the side wall of the box by means of nuts, etc. In order to form an airflow cavity inside the box, the bottom plate is set inside the barrel-shaped structure. Since the bottom of the battery is flat, the bottom plate also needs to be set parallel to the air-cooling plate. A gap is left between the air-cooling plate and the bottom plate so that the bottom plate, side wall and air-cooling plate together form an airflow cavity; (4) The liquid-cooling plate has a liquid-cooling channel. Specifically, the shape of the liquid-cooling channel is various, such as "U", "U" or "S". Optionally, the liquid-cooling plate also includes an inlet and an outlet. The inlet and outlet are connected to the current collector for the inlet and outlet of the heat exchange medium. The liquid-cooling plate can be made of a material with a certain hardness and strength (such as stainless steel). In this way, the liquid-cooling plate is not easily deformed when the battery cell is squeezed and collided, which can enable the battery cell to have higher structural strength and improve safety performance. The material of the liquid-cooling plate can be various, including but not limited to: copper, iron, aluminum, stainless steel, aluminum alloy, etc. The material of the liquid-cooling plate can also be nylon, plastic, etc.

[0156] In some embodiments, the heat exchange channel extends parallel to a third direction.

[0157] In some embodiments, combined with Figure 6 As shown, a heat exchange plate 6 is provided between adjacent soft-pack batteries 11, and the heat exchange plate 6 is at least partially in contact with the buffer.

[0158] By setting a heat spreader 6 between adjacent soft-pack batteries 11, the temperature distribution between batteries can be effectively balanced, local overheating can be reduced, and the thermal stability of the battery module can be improved. At the same time, the heat spreader 6 is at least partially in contact with the buffer. In this embodiment, the buffer is specifically thermally conductive adhesive. The heat spreader 6 and the thermally conductive adhesive are closely attached to each other, which can effectively transfer the heat generated when the battery is working.

[0159] In some embodiments, the following condition is satisfied: 0.525≤A×D×H≤2.585.

[0160] For example, in this embodiment, the value of A×D×H can be 0.525 or 0.7 or 0.95 or 1.2 or 1.45 or 1.7 or 1.95 or 2.2 or 2.45 or 2.585, or it can be any range formed by any two of the above values.

[0161] According to an embodiment of the present invention, in another aspect, an electrical appliance is also provided, comprising: The electrical equipment body and the battery device as described above, wherein the electrical equipment body and the battery device are electrically connected.

[0162] In this embodiment, the electrical equipment can specifically be electronic devices, electric vehicles, or energy storage systems. Among them, electronic devices include smartphones, tablets, or laptops; electric vehicles include pure electric vehicles, hybrid electric vehicles, or electric motorcycles, etc.; and energy storage systems are used for grid energy storage or home energy management.

[0163] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and all such modifications and variations fall within the scope defined by the present invention.

Claims

1. A battery device, characterized in that, include: The battery pack (1) is formed by stacking multiple pouch cells (11) along a first direction; A heat exchange plate (3) is disposed on one side of the battery pack (1) along a second direction. The battery pack (1) includes a first end face (101) disposed opposite to the heat exchange plate (3). A fixing plate (2) is disposed on the outer periphery of the battery pack (1); the battery pack (1) includes two second side surfaces (102) opposite each other along the first direction, and the fixing plate (2) includes a first fixing plate (21) and a second fixing plate (22), the first fixing plate (21) and the second fixing plate (22) are respectively disposed on the two second side surfaces (102); Metal fastening band (4) is fixedly connected to the first fixing plate (21) and the second fixing plate (22) respectively, and the metal fastening band (4) is at least partially opposite to the first end face (101) along the second direction, and the metal fastening band (4) is disposed between the heat exchange plate (3) and the first end face (101); The soft-pack battery (11) includes a first long side surface opposite to the first end face (101) and a second long side surface perpendicular to the first end face (101), wherein the area of ​​the first long side surface is smaller than the area of ​​the second long side surface. The heat exchange plate (3) is made of aluminum alloy; the metal fastening band (4) is made of stainless steel. The width of the metal fastening band (4) is A mm; The pouch battery (11) includes a housing (111) and a cell (112) disposed within the housing (111). The cell (112) includes a plurality of electrode sheets (1121) stacked along the first direction. The housing (111) includes at least a first metal layer (1112). The thickness of the first metal layer (1112) is D mm. The distance between the outermost electrode sheet (1121) of the cell (112) along the first direction and the inner wall of the housing (111) on the adjacent side is H mm. It satisfies: 0.02≤A×D×H≤4.425; Among them, the first direction, the second direction, and the third direction are perpendicular to each other.

2. The battery device according to claim 1, characterized in that, The length direction of the pouch battery (11) is parallel to the width direction of the metal fastening band (4).

3. The battery device according to claim 2, characterized in that, The length direction of the battery pack (1) is parallel to the width direction of the metal fastening band (4), the width direction of the metal fastening band (4) is parallel to the third direction, and the width Amm of the metal fastening band (4) is in the range of 10mm≤Amm≤55mm.

4. The battery device according to claim 1, characterized in that, The metal fastening band (4) includes a second metal layer (41) and a second insulating layer (42) located outside the second metal layer (41), the second insulating layer (42) being at least partially located between the second metal layer (41) and the housing (111).

5. The battery device according to claim 1, characterized in that, The housing (111) consists of a three-layer structure consisting of an inner insulating layer, an intermediate metal layer, and an outer insulating layer.

6. The battery device according to any one of claims 1 to 5, characterized in that, Along the direction perpendicular to the first end face (101), the closest distance from the metal fastening band (4) to the housing (111) is Fmm, which satisfies: 0mm≤Fmm≤5mm.

7. The battery device according to any one of claims 1 to 5, characterized in that, Along a direction perpendicular to the first end face (101), a buffer is provided between the metal fastening band (4) and the housing (111); the dimension of the buffer along the length direction of the battery pack (1) is greater than the width of the metal fastening band (4).

8. The battery device according to claim 7, characterized in that, The thermal conductivity of the buffer component is greater than or equal to 0.2 W / m·K.

9. The battery device according to claim 1, characterized in that, The width of the first long side along the first direction is Gmm, which satisfies: 6mm≤Gmm≤30mm.

10. The battery device according to any one of claims 1 to 5, characterized in that, The material of the fixing plate (2) includes copper, iron, aluminum, steel, stainless steel, aluminum alloy, engineering plastic, fiberglass, carbon fiber or plastic, or a composite material of metal and non-metal.

11. The battery device according to any one of claims 1 to 5, characterized in that, The thickness of the fixing plate (2) is 2mm to 25mm.

12. The battery device according to any one of claims 1 to 5, characterized in that, The largest surface area in the soft-pack battery (11) is the battery surface, and the first fixing plate (21) and the second fixing plate (22) are both set corresponding to the battery surface.

13. The battery device according to claim 12, characterized in that, The metal fastening band (4) extends from the first end face (101) to the outside of the first fixing plate (21) and the second fixing plate (22), respectively.

14. The battery device according to claim 13, characterized in that, Along the second direction, the metal fastening band (4) extends to the first fixing plate (21) or the second fixing plate (22) by a dimension of J mm, satisfying: 10 mm ≤ J mm ≤ 40 mm.

15. The battery device according to claim 13, characterized in that, The metal fastening band (4) is riveted to the first fixing plate (21) and / or the second fixing plate (22).

16. The battery device according to claim 15, characterized in that, An isolation plate (5) is provided between the first fixing plate (21) and / or the second fixing plate (22) and the soft-pack battery (11).

17. The battery device according to claim 7, characterized in that, A heat spreader (6) is provided between adjacent soft-pack batteries (11), and the heat spreader (6) is at least partially in contact with the buffer.

18. The battery device according to claim 17, characterized in that, The material of the heat spreader (6) includes aluminum, aluminum alloy, copper, stainless steel or titanium.

19. The battery device according to any one of claims 1 to 5, characterized in that, It satisfies: 0.525≤A×D×H≤2.

585.

20. An electrical appliance, characterized in that, include: The electrical device body and the battery device as described in any one of claims 1 to 19, wherein the electrical device body is electrically connected to the battery device.

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