Battery monomer, battery device and electric device

Abstract

The utility model provides a battery monomer, a battery device and a power utilization device. The battery monomer comprises a shell, an electrode assembly, electrolyte and a positive pole, the shell comprises a first wall, a second wall and a side wall, the first wall and the second wall are oppositely arranged on the two sides of the side wall and define a containing cavity with the side wall, the first wall is made of iron, chromium or nickel, the electrode assembly is arranged in the containing cavity, the electrolyte is contained in the containing cavity, and the positive pole is arranged in the shell. The electrolyte infiltrates at least part of the electrode assembly, the positive pole is arranged on the first wall, the positive pole is electrically connected with the electrode assembly, the shell is provided with a liquid injection hole, the liquid injection hole penetrates through the shell, the liquid injection hole is formed in the first wall, the minimum distance between the liquid injection hole and the positive pole is not smaller than 20 mm, and / or the liquid injection hole is formed in the second wall or the side wall. According to the battery monomer, the battery device and the power utilization device, the risk of internal corrosion of the battery monomer due to potential problems can be reduced, the reliability of the battery monomer is improved, and the service life of the battery monomer is prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a battery monomer, a battery device and a power utilization device. BACKGROUND

[0002] Energy saving and emission reduction is the key to the sustainable development of the automobile industry. Electric vehicles have become an important part of the sustainable development of the automobile industry due to their energy saving and environmental protection advantages. For electric vehicles, battery technology is an important factor for their development.

[0003] The production of batteries involves electrolyte injection and other operations. During the injection process, liquid injection problems may occur, causing electrolyte to flow between the pole and the shell, and resulting in shell corrosion due to potential problems after the pole is turned on, affecting the service life of the battery. Therefore, how to reduce the internal corrosion risk of the battery monomer has become a problem to be solved. UTILITY MODEL CONTENT

[0004] The present application provides a battery monomer, a battery device and a power utilization device, which can reduce the risk of internal corrosion of the battery monomer due to potential problems, improve the reliability and service life of the battery monomer.

[0005] In a first aspect, the present application provides a battery monomer, comprising a shell, an electrode assembly, an electrolyte and a positive pole, the shell comprising a first wall, a second wall and a side wall, the first wall and the second wall being oppositely arranged on both sides of the side wall and enclosing the side wall to form a containing cavity, the material of the first wall comprising iron, chromium or nickel, the electrode assembly being arranged in the containing cavity, the electrolyte being contained in the containing cavity, the electrolyte infiltrating at least part of the electrode assembly, the positive pole being arranged on the first wall, the positive pole and the electrode assembly being electrically connected, the shell being provided with an injection hole, the injection hole penetrating through the shell, the injection hole being arranged on the first wall, the minimum distance between the injection hole and the positive pole being not less than 20mm, and / or the injection hole being arranged on the second wall or the side wall.

[0006] In the present application, by arranging the injection hole away from the positive pole, the positive pole can be located outside the injection range of the injection hole, thereby reducing the risk of electrolyte flowing between the positive pole and the first wall when electrolyte injection occurs during the injection process, and preventing chemical corrosion of the shell due to potential problems when the positive pole is turned on, thereby improving the reliability and service life of the battery monomer.

[0007] In some embodiments, the material of the first wall is steel, which has high strength and can meet the strength requirements of the shell, is easy to process and has low cost.

[0008] In the embodiments of the present application, since the main components of the steel material are iron, chromium and nickel, when the material of the first wall is steel and the liquid injection hole is arranged on the first wall, by making the minimum distance between the liquid injection hole and the positive pole column not less than 20 mm, the problem of chemical corrosion of the shell caused by the potential problem can be prevented while meeting the strength requirement of the shell, and the reliability and service life of the battery monomer are improved.

[0009] In some embodiments, the material of the first wall is stainless steel or carbon steel.

[0010] In some embodiments, the material of at least one of the second wall and the side wall includes iron, chromium or nickel, i.e., the material of at least one of the second wall and the side wall can be the same as the material of the first wall, so as to simplify the structure of the shell and reduce the manufacturing cost of the shell.

[0011] In some embodiments, the material of at least one of the second wall and the side wall is steel.

[0012] In some embodiments, the electrolyte includes a fluorine-containing lithium salt, which can improve the electrochemical stability of the electrolyte system, improve the conductivity of the electrolyte, and improve the performance of the battery monomer.

[0013] In some embodiments, the fluorine-containing lithium salt includes at least one of lithium tetrafluoroborate, lithium hexafluoroarsenate, lithium hexafluorophosphate, lithium difluoro(oxalato)borate, lithium bisfluorosulfonylimide and lithium bis-trifluoromethylsulfonylimide.

[0014] In some embodiments, the battery monomer further includes a negative pole column, the negative pole column is arranged on the first wall, the positive pole column and the negative pole column are arranged at intervals along the first direction, the liquid injection hole is arranged on the first wall and is arranged between the positive pole column and the negative pole column along the first direction, or the liquid injection hole is arranged on the side of the negative pole column away from the positive pole column along the first direction.

[0015] In the embodiments of the present application, when the positive pole column and the negative pole column are both arranged on the first wall, the liquid injection hole can be arranged on the first wall and located on the side away from the positive pole column, which can more conveniently increase the distance between the liquid injection hole and the positive pole column on the basis of limited size of the battery monomer, thereby further reducing the risk of electrolyte flowing into the space between the positive pole column and the first wall when the liquid injection hole sprays liquid, and improving the reliability of the battery monomer.

[0016] In some embodiments, the minimum distance between the liquid injection hole and the positive pole column is greater than or equal to the minimum distance between the liquid injection hole and the negative pole column, which can increase the distance between the liquid injection hole and the positive pole column and further reduce the risk of electrolyte flowing into the space between the positive pole column and the first wall when the liquid injection hole sprays liquid.

[0017] In some embodiments, the battery monomer further includes a negative pole column, the negative pole column is arranged on the first wall, and the liquid injection hole is arranged on one of the side wall and the second wall.

[0018] In the embodiments of the present application, when the positive pole column and the negative pole column are both arranged on the first wall, the liquid injection hole can be arranged on one of the side wall and the second wall, and the electrolyte sprayed from the liquid injection hole will not flow to the first wall, thereby significantly reducing the risk of internal corrosion of the shell caused by potential problems.

[0019] In some embodiments, the side wall comprises a first side wall and a second side wall arranged in intersection, the area of the first side wall is smaller than the area of the second side wall, and the liquid injection hole is arranged on one of the first side wall and the second side wall.

[0020] In some embodiments, the battery monomer further comprises a negative pole column, and the negative pole column and the liquid injection hole are both arranged on the second wall, that is, when the positive pole column and the negative pole column are arranged on different wall parts respectively, the liquid injection hole can be arranged on the side of the negative pole column, so as to shorten the electrolyte injection path while reducing the risk of internal corrosion of the battery monomer, so that the electrolyte can enter the inside of the battery monomer more quickly, improve the infiltration efficiency of the electrolyte and the production efficiency, and improve the overall performance of the battery monomer.

[0021] In some embodiments, the battery monomer further comprises a first insulating plastic, and the first insulating plastic is assembled between the shell and the negative pole column. The liquid injection hole and the negative pole column are arranged on different wall parts of the shell, or the liquid injection hole and the negative pole column are arranged on the same wall part of the shell, and the minimum distance between the liquid injection hole and the outer edge of the first insulating plastic is greater than or equal to 8 mm, thereby effectively reducing the risk of burning the first insulating plastic when welding the sealing nail at the liquid injection hole in the subsequent process, and improving the reliability of the battery monomer.

[0022] In some embodiments, the battery monomer further comprises a pressure relief mechanism, and the liquid injection hole and the pressure relief mechanism are arranged on different wall parts of the shell, or the liquid injection hole and the pressure relief mechanism are arranged on the same wall part of the shell, and the minimum distance between the liquid injection hole and the outer edge of the pressure relief mechanism is greater than or equal to 8 mm, thereby effectively reducing the risk of burning the pressure relief mechanism when welding the sealing nail at the liquid injection hole in the subsequent process, and improving the reliability of the battery monomer.

[0023] In some embodiments, the battery monomer further comprises a second insulating plastic, and the second insulating plastic is assembled between the shell and the positive pole column. The insulation resistance of the second insulating plastic under a voltage of 500 V is greater than 200 MΩ.

[0024] In some embodiments, the second insulating plastic comprises one of polypropylene, polyphenylene sulfide, and tetrafluoroethylene.

[0025] In a second aspect, the embodiments of the present application provide a battery device comprising a plurality of battery monomers of the first aspect.

[0026] In a third aspect, the embodiments of the present application provide a power consumption device comprising the battery device of the second aspect.

[0027] The above description is only a summary of the technical solutions of the present application. In order to enable one skilled in the art to better understand the technical means of the present application and implement the same according to the contents of the description, and in order to enable the above and other purposes, characteristics and advantages of the present application to be more apparent and easy to understand, the following specific embodiments of the present application are described. BRIEF DESCRIPTION OF DRAWINGS

[0028] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a description of the preferred embodiments and are not meant to limit the present application. Furthermore, the same reference numerals are used throughout the several views that follow. In the drawings:

[0029] Figure 1 is a structural schematic diagram of a vehicle provided by some embodiments of the present application;

[0030] Figure 2 is an exploded schematic diagram of a battery device provided by some embodiments of the present application;

[0031] Figure 3 is a structural schematic diagram of a battery cell provided by some embodiments of the present application;

[0032] Figure 4 is an exploded schematic diagram of a battery cell provided by some embodiments of the present application;

[0033] Figure 5 is a structural schematic diagram of a battery cell provided by some other embodiments of the present application;

[0034] Figure 6 is a structural schematic diagram of a battery cell provided by yet some other embodiments of the present application;

[0035] Figure 7 is a structural schematic diagram of a battery cell provided by yet some other embodiments of the present application;

[0036] Figure 8 is a top view of a battery cell provided by some embodiments of the present application.

[0037] Reference signs in the detailed description of the embodiments are as follows:

[0038] 100 battery device, 200 controller, 300 motor;

[0039] 10 battery cell, 20 case body;

[0040] 1 housing, 11 first wall, 12 second wall, 13 side wall, 131 first side wall, 132 second side wall, 2 electrode assembly, 21 positive electrode tab, 22 negative electrode tab, 3 positive electrode post, 4 liquid injection hole, 5 negative electrode post, 6 sealing pin, 7 first insulating plastic, 8 second insulating plastic, 9 pressure relief mechanism;

[0041] X first direction, Y third direction, Z second direction. DETAILED DESCRIPTION

[0042] The embodiments of the technical solutions of the present application will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present application, and therefore only serve as examples, and cannot limit the protection scope of the present application.

[0043] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in the embodiments of the present application should be understood as the usual meaning understood by the skilled person in the field to which the embodiments of the present application belong.

[0044] In the description of the embodiments of the present application, the orientations or positional relationships indicated by the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the purpose of facilitating the description of the embodiments of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the embodiments of the present application.

[0045] In addition, the technical terms "first", "second" and the like are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0046] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connecting", "connecting", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0047] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, a first feature is "on" or "under" a second feature can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature can be "above", "over" and "on" the second feature, which can be that the first feature is directly above or obliquely above the second feature, or only indicates that the first feature is higher in horizontal height than the second feature. The first feature can be "below", "under" and "under" the second feature, which can be that the first feature is directly below or obliquely below the second feature, or only indicates that the first feature is lower in horizontal height than the second feature.

[0048] At present, from the development of market situation, the application of power battery is more and more extensive. Power battery is not only applied to energy storage power supply system of hydropower, thermal power, wind power and solar power station, but also widely used in electric bicycles, electric motorcycles, electric vehicles and other electric vehicles, military equipment, aerospace and other fields. With the continuous expansion of the application field of power battery, the market demand is also increasing.

[0049] The battery monomer includes a shell and a liquid injection hole arranged on the shell. The battery monomer includes an outer shell and an electrode assembly arranged in the outer shell to isolate the inner environment of the outer shell from the external environment. The battery monomer further includes a pole installed on the outer shell, and the pole is electrically connected to the electrode assembly through a adapter piece. In order to improve the energy density, the electrode assembly of the battery monomer is high and closely attached to the end cover assembly. Therefore, the end of the liquid injection hole opposite to the inner side of the battery monomer is blocked by many components, such as the adapter piece and the pole piece, which causes the electrolyte flow to be blocked and the liquid injection efficiency to be low during the liquid injection of the battery monomer. At the same time, the electrolyte is prone to be sprayed during the liquid injection, so that the electrolyte flows into the space between the pole and the outer shell.

[0050] In a lithium battery, the positive electrode is at a relatively high potential. Since the main components of steel are iron (Fe), chromium (Cr) and nickel (Ni), the iron atoms, chromium atoms and nickel atoms tend to lose electrons and be oxidized at high potential. In the scenario where the insulation state of the lithium battery positive electrode and the outer shell is damaged, the positive electrode pole and the outer shell form an electron path, and an ion path is formed inside the lithium battery. The potential of the outer shell is pulled up by the positive electrode, and the oxidation reaction of iron, chromium and nickel in the outer shell is more likely to occur. The Fe, Cr and Ni in the shell lose electrons, and the electrons participate in the lithium intercalation reaction through the external circuit. In the electrolyte solution containing fluoride ions and other anion groups, the generated ferrous ions can combine with fluoride ions and other anions to undergo chemical reactions, causing different degrees of corrosion to the outer shell and affecting the service life of the battery.

[0051] Based on the above considerations, in order to reduce the risk of corrosion of the battery shell, the battery monomer provided by the embodiments of the present application adjusts the position of the liquid injection hole, so that the positive pole is located outside the liquid injection range of the liquid injection hole, thereby reducing the risk of electrolyte flowing between the positive pole and the shell when the liquid is injected. The following will be described in detail in combination with the accompanying Figures 1 to 8 The battery monomer, the battery device and the power utilization device in the embodiments of the present application will be described in detail.

[0052] The technical solutions described in the embodiments of the present application are applicable to the battery device 100 and the power utilization device using the battery device 100.

[0053] The power utilization device can be a vehicle, a mobile phone, a portable device, a notebook computer, a ship, a spacecraft, an electric toy and an electric tool, etc. The vehicle can be a fuel automobile, a gas automobile or a new energy automobile, and the new energy automobile can be a pure electric automobile, a hybrid electric automobile or a range extended automobile, etc. The spacecraft includes an airplane, a rocket, a space shuttle and a spacecraft, etc. The electric toy includes a fixed or mobile electric toy, for example, a game machine, an electric automobile toy, an electric ship toy and an electric airplane toy, etc. The electric tool includes a metal cutting electric tool, a grinding electric tool, an assembling electric tool and a railway electric tool, for example, an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact electric drill, a concrete vibrator and an electric planer, etc. The embodiments of the present application do not specially limit the above power utilization devices.

[0054] It should be understood that the technical solutions described in the embodiments of the present application are applicable to all battery devices 100 and power utilization devices using the battery device 100, but for the sake of brevity of description, the following embodiments are described taking an electric vehicle as an example.

[0055] Please refer to Figure 1 , Figure 1 The structural schematic diagram of the vehicle provided by some embodiments of the present application is shown.

[0056] The vehicle is internally provided with the battery device 100, which can be arranged at the bottom, the head or the tail of the vehicle. The battery device 100 can be used for power supply of the vehicle, for example, the battery device 100 can be used as the operating power supply of the vehicle. The vehicle can further include a controller 200 and a motor 300, and the controller 200 is used to control the battery device 100 to supply power to the motor 300, for example, to meet the working power demand of the vehicle during starting, navigation and driving.

[0057] Please refer to Figure 2 , Figure 2 The explosion schematic diagram of the battery device 100 provided by some embodiments of the present application is shown.

[0058] The battery device 100 mentioned in the embodiments of the present application can include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly can include a plurality of battery cells 10 connected in series, in parallel or in a mixed connection through a busbar component. The battery cell assembly can be a battery module formed by arranging and fixing a plurality of battery cells 10 into an independent module.

[0059] In some embodiments, the battery device 100 can be a battery pack including a box 20 and one or more battery cell assemblies accommodated in the box 20 for packaging one or more battery cells 10 to avoid the influence of liquid or other foreign matters on the charging or discharging of the battery cells 10.

[0060] In the embodiments of the present application, the battery cell 10 can be a secondary battery, which refers to a battery cell 10 that can be activated by charging after discharging to continue to be used.

[0061] Please refer to Figure 3 and Figure 4 , Figure 3 the structural schematic diagram of the battery cell 10 provided in some embodiments of the present application, Figure 4 the exploded schematic diagram of the battery cell 10 provided in some embodiments of the present application.

[0062] The embodiments of the present application provide a battery cell 10 including an outer shell 1, an electrode assembly 2, an electrolyte, a positive electrode post 3 and a liquid injection hole 4.

[0063] The outer shell 1 includes a first wall 11, a second wall 12 and a side wall 13, one of the first wall 11 and the second wall 12 is a top wall and the other is a bottom wall, the first wall 11 and the second wall 12 are oppositely arranged on both sides of the side wall 13 along a second direction Z and form an accommodation cavity together with the side wall 13, and the second direction Z can be the height direction of the battery cell 10.

[0064] The accommodation cavity can be used to accommodate the electrode assembly 2, the electrolyte and other components, and isolate the accommodation cavity of the outer shell 1 from the external environment. The outer shell 1 can be various shapes and sizes, such as a cuboid, a cylinder, a hexagonal prism, etc. Specifically, the shape of the outer shell 1 can be determined according to the specific shape and size of the electrode assembly 2.

[0065] The electrode assembly 2 is arranged in the accommodation cavity, and the electrode assembly 2 includes a positive electrode, a negative electrode, and a separator arranged between the negative electrode and the positive electrode. During the charging and discharging of the battery monomer 10, active ions are embedded and extracted between the positive electrode and the negative electrode. The separator arranged between the positive electrode and the negative electrode can prevent the short circuit of the positive electrode and the negative electrode, and can also allow the active ions to pass through. The positive electrode includes a positive electrode current collector and a positive electrode active material layer, the positive electrode active material layer is coated on the surface of the positive electrode current collector and serves as the main body of the positive electrode, and the current collector without the positive electrode active material layer serves as the positive electrode tab 21.

[0066] The positive electrode column 3 is arranged on the first wall 11, the material of the first wall 11 includes iron, chromium or nickel, the positive electrode column 3 is used for electrically connecting with the positive electrode tab 21 of the electrode assembly 2, the positive electrode column 3 can be directly connected with the positive electrode tab 21, or the positive electrode column 3 can be correspondingly arranged with a connecting member, or also referred to as a current collecting member, the connecting member is located between the shell 1 and the electrode assembly 2, and is used for electrically connecting the positive electrode column 3 and the positive electrode tab 21.

[0067] The liquid injection hole 4 is arranged through the shell 1, the liquid injection hole 4 is used for injecting electrolyte into the accommodation cavity, the electrolyte is accommodated in the accommodation cavity and is immersed in at least part of the electrode assembly 2, and the electrolyte plays a role of conducting ions between the positive electrode and the negative electrode.

[0068] In order to reduce the corrosion risk of the first wall 11, the liquid injection hole 4 in the embodiment of the application is arranged on the first wall 11, the minimum distance between the liquid injection hole 4 and the positive electrode column 3 is not less than 20 mm, and / or the liquid injection hole 4 is arranged on the second wall 12 or the side wall 13.

[0069] The battery monomer 10 in the embodiment of the application can make the positive electrode column 3 located outside the liquid injection range of the liquid injection hole 4 by making the minimum distance between the liquid injection hole 4 and the positive electrode column 3 not less than 20 mm when the liquid injection hole 4 is arranged on the first wall 11, so as to reduce the risk of electrolyte flowing between the positive electrode column 3 and the first wall 11 when the electrolyte is sprayed during the liquid injection process, and to prevent the chemical corrosion of the shell 1 caused by the potential problem when the positive electrode column 3 is in conduction, thereby improving the reliability and service life of the battery monomer 10.

[0070] It should be noted that, considering that the maximum liquid injection radius of the liquid injection hole 4 reaches a region 20 mm from the center of the liquid injection hole 4 in the current liquid injection process, the minimum distance between the liquid injection hole 4 and the positive pole 3 is not less than 20 mm in the embodiment of the present application, so that the positive pole 3 is located outside the liquid injection radius of the liquid injection hole 4. However, according to other liquid injection processes of the battery, for example, when the liquid injection radius of the liquid injection hole 4 is greater than 20 mm, the minimum distance between the liquid injection hole 4 and the positive pole 3 is appropriately increased to reduce the risk of electrolyte flowing into the positive pole 3 and the first wall 11 when the electrolyte is injected, that is, the minimum distance between the liquid injection hole 4 and the positive pole 3 can be adjusted according to the actual manufacturing requirements of the battery monomer 10, which can meet the requirement that the positive pole 3 is located outside the liquid injection range of the liquid injection hole 4.

[0071] In addition, since the liquid injection range of the liquid injection hole 4 is only on a certain wall of the shell when the liquid injection hole 4 is arranged on the wall, when the liquid injection hole 4 and the positive pole 3 are arranged on the same wall, that is, when the liquid injection hole 4 is on the first wall 11, the minimum distance between the liquid injection hole 4 and the positive pole 3 needs to be greater than 20 mm. However, when the liquid injection hole 4 and the positive pole 3 are arranged on different walls, for example, the liquid injection hole 4 is arranged on the side wall 13 or the second wall 12, the arrangement position of the liquid injection hole 4 is not limited by the liquid injection range, and the liquid injection hole 4 can be arranged at any position on the side wall 13 or the second wall 12 of the battery monomer 10 as long as the liquid injection requirement of the battery monomer 10 is met.

[0072] In some optional embodiments, the material of the first wall 11 is steel. Steel has greater strength and can meet the strength requirement of the shell. In addition, steel is easy to process and has low cost.

[0073] Since the main components of steel are iron, chromium and nickel, when the material of the first wall 11 is steel and the liquid injection hole 4 is arranged on the first wall 11, the minimum distance between the liquid injection hole 4 and the positive pole 3 is not less than 20 mm, which can prevent the shell 1 from being chemically corroded due to the potential problem while meeting the strength requirement of the shell 1, thereby improving the reliability and service life of the battery monomer 10.

[0074] Further, the material of the first wall 11 is stainless steel or carbon steel. If the first wall 11 is made of stainless steel, the structural strength is large and can generally meet the requirement of tensile strength under the above high temperature condition. In addition, the first wall 11 made of stainless steel is not easy to rust, and compared with other materials, the service life of the first wall 11 can be improved. If the first wall 11 is made of carbon steel, the structural strength is large and can generally meet the requirement of tensile strength under the above high temperature condition.

[0075] Similarly to the first wall 11, in some optional embodiments, the material of at least one of the second wall 12 and the side wall 13 includes iron, chromium or nickel.

[0076] The material of the second wall 12 and at least one of the side walls 13 can be the same as that of the first wall 11 by including iron, chromium or nickel in the material of the second wall 12 and at least one of the side walls 13, so as to simplify the structure of the shell 1 and reduce the manufacturing cost of the shell 1.

[0077] In some optional embodiments, the material of the second wall 12 and at least one of the side walls 13 is steel, i.e., the shell can be a steel shell. Steel has a large strength and can meet the strength requirement of the shell, and is easy to process and has a low cost. Alternatively, the material of the second wall 12 and at least one of the side walls 13 is stainless steel or carbon steel, which can be adjusted according to the requirements of the first wall 11 and the battery cell.

[0078] In some optional embodiments, the electrolyte includes a lithium salt containing fluorine. By including the lithium salt containing fluorine in the electrolyte, the electrochemical stability of the electrolyte system can be improved, the conductivity of the electrolyte can be improved, and the performance of the battery cell can be improved.

[0079] Since the lithium salt containing fluorine contains fluorine ions, by arranging the liquid injection hole 4 away from the positive pole 3, the flow of the electrolyte between the positive pole 3 and the first wall 11 can be reduced, so as to reduce the risk of electrochemical corrosion of the shell 1 due to potential problems in the scenario where the insulation state between the positive pole 3 of the lithium battery and the first wall 11 is destroyed, and improve the reliability and service life of the battery cell 10.

[0080] Alternatively, the lithium salt containing fluorine includes at least one of lithium tetrafluoroborate, lithium hexafluoroarsenate, lithium hexafluorophosphate, lithium difluoro oxalate borate, lithium bisfluorosulfonylimide and lithium bis-trifluoromethylsulfonylimide. These kinds of lithium salts have good solubility, can form a local high-concentration electrolyte in the negative active layer, and improve the stability and ion conductivity of the SEI film.

[0081] It can be understood that, for the liquid injection hole 4, since the influence of the electrolyte spray on the negative pole 5 is smaller than that on the positive pole 3, the opening position of the liquid injection hole 4 on the shell 1 can be designed according to the arrangement positions of the positive pole 3 and the negative pole 5.

[0082] Please refer to Figure 3 and Figure 4 In some optional embodiments, the battery cell 10 further includes a negative pole 5 arranged in one of the first wall 11 and the second wall 12.

[0083] The negative electrode includes a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode current collector and serves as the negative electrode main body. The current collector without the negative electrode active material layer serves as the negative electrode tab 22. The negative electrode post 5 is arranged on the shell 1 and is used to electrically connect the negative electrode of the electrode assembly 2. The negative electrode post 5 can be directly connected to the electrode assembly 2, or the negative electrode post 5 can be provided with a connecting member, which is also referred to as a current collecting member, and is arranged between the shell 1 and the electrode assembly 2 to electrically connect the negative electrode post 5 and the negative electrode tab 22.

[0084] The negative electrode post 5 is arranged on one of the first wall 11 and the second wall 12. That is, the positive electrode post 3 and the negative electrode post 5 can be arranged on the same wall, or the positive electrode post 3 and the negative electrode post 5 can be arranged on different walls. The specific arrangement mode can be adjusted according to the model and use environment of the battery.

[0085] Please refer to Figure 3 and Figure 4 In some optional embodiments, the negative electrode post 5 is arranged on the first wall 11, and the positive electrode post 3 and the negative electrode post 5 are arranged at intervals along the first direction X. The liquid injection hole 4 is arranged on the first wall 11 and is arranged between the negative electrode post 5 and the positive electrode post 3 along the first direction X, or the liquid injection hole 4 is arranged on the side of the negative electrode post 5 away from the positive electrode post 3 along the first direction X.

[0086] When the liquid injection hole 4 is arranged on the first wall 11, compared with arranging the liquid injection hole 4 on the side of the positive electrode post 3 away from the negative electrode post 5, the battery monomer 10 in the embodiment of the application can more conveniently increase the distance between the liquid injection hole 4 and the positive electrode post 3 on the basis of limited size of the battery monomer 10, thereby further reducing the risk of electrolyte flowing into the space between the positive electrode post 3 and the first wall 11 when the liquid injection hole 4 sprays liquid, and improving the reliability of the battery monomer 10.

[0087] Optionally, the first direction X is the length direction of the battery monomer 10, so as to more reasonably utilize the space and realize the arrangement of the positive electrode post 3, the negative electrode post 5 and the liquid injection hole 4.

[0088] In some optional embodiments, the minimum distance between the liquid injection hole 4 and the positive electrode post 3 is greater than or equal to the minimum distance between the liquid injection hole 4 and the negative electrode post 5.

[0089] When the liquid injection hole 4 is arranged between the negative electrode post 5 and the positive electrode post 3 along the first direction X, the minimum distance between the liquid injection hole 4 and the positive electrode post 3 can be greater than or equal to the minimum distance between the liquid injection hole 4 and the negative electrode post 5, that is, the liquid injection hole 4 is arranged away from the positive electrode post 3, thereby further reducing the risk of electrolyte flowing into the space between the positive electrode post 3 and the first wall 11 when the liquid injection hole 4 sprays liquid, and improving the reliability of the battery monomer 10.

[0090] Please refer to Figures 5 to 7 , Figure 5 Fig. 1 shows a structural schematic diagram of a battery cell 10 provided by some embodiments of the present application, Figure 6 Fig. 2 shows a structural schematic diagram of a battery cell 10 provided by some other embodiments of the present application, Figure 7 Fig. 3 shows a structural schematic diagram of a battery cell 10 provided by yet some other embodiments of the present application.

[0091] As another optional implementation, the negative pole 5 is arranged on the first wall 11, and the liquid injection hole 4 is arranged on one of the side wall 13 and the second wall 12.

[0092] When the positive pole 3 and the negative pole 5 are both arranged on the first wall 11, the liquid injection hole 4 can also be arranged on one of the side wall 13 and the second wall 12, so that the position of the liquid injection hole 4 can be reasonably arranged under the condition that the size of the battery cell 10 is limited, the risk of the electrolyte sprayed by the liquid injection hole 4 flowing to the space between the positive pole 3 and the first wall 11 is reduced, and the reliability of the battery production process is improved.

[0093] When the liquid injection hole 4 is arranged on the side wall 13, in some optional embodiments, the side wall 13 includes a first side wall 131 and a second side wall 132 arranged intersectingly, the area of the first side wall 131 is smaller than the area of the second side wall 132, and the liquid injection hole 4 is arranged on one of the first side wall 131 and the second side wall 132.

[0094] Taking the battery cell 10 as a rectangular battery cell 10 as an example, the first side wall 131 is arranged oppositely along the first direction X, and the second side wall 132 is arranged oppositely along the third direction Y, which is the width direction of the battery cell 10. When the liquid injection hole 4 is arranged on the side wall 13, the liquid injection hole 4 can be arranged on the first side wall 131 or the second side wall 132, and the specific position can be adjusted according to the actual structure of the battery cell 10.

[0095] Optionally, when the liquid injection hole 4 is arranged on the side wall 13, the vertical distance between the liquid injection hole 4 and the first wall 11 along the second direction Z is smaller than the vertical distance between the liquid injection hole 4 and the second wall 12 along the second direction Z. By arranging the liquid injection hole 4 close to the positive pole 3 and the negative pole 5, the distance between the liquid injection hole 4 and the positive pole 3 and the negative pole 5 can be shortened, so that the path of the electrolyte injection can be shortened, and the electrolyte can enter the inside of the battery cell 10 more quickly. Moreover, the overall structure of the battery cell 10 can be more compact and reasonable, and such design can help to reduce the invalid space inside the battery cell 10 and improve the energy density and overall performance of the battery cell 10.

[0096] As yet another optional implementation, the negative pole 5 and the liquid injection hole 4 are both arranged on the second wall 12.

[0097] When the positive pole 3 is arranged on the first wall 11 and the negative pole 5 is arranged on the second wall 12, the liquid injection hole 4 can also be arranged on the second wall 12 (not shown in the figure). By arranging the liquid injection hole 4 on the second wall 12, since the liquid injection hole 4 and the positive pole 3 are arranged on the second wall 12 and the first wall 11 respectively, the risk of the electrolyte flowing into the positive pole 3 when the liquid injection hole 4 sprays liquid can be largely solved. Moreover, by arranging the liquid injection hole 4 and the negative pole 5 on the second wall 12, the liquid injection hole 4 can be arranged close to the negative pole 5, the path of the electrolyte injection is shortened, the electrolyte can enter the inside of the battery monomer 10 more quickly, the electrolyte immersion efficiency and the production efficiency are improved, and the overall performance of the battery monomer 10 is improved.

[0098] It can be understood that for the liquid injection hole 4, it can be arranged on the same wall part as the negative pole 5, or it can be arranged on different wall parts as the negative pole 5. When the liquid injection hole 4 and the negative pole 5 are arranged on the same wall part, although the distance between the center of the liquid injection hole 4 and the center of the negative pole 5 is not limited by the spraying range of the liquid injection hole 4, the distance between the center of the liquid injection hole 4 and the center of the negative pole 5 still cannot be too small.

[0099] Please refer to Figure 3 , Figure 4 and Figure 8 , Figure 8 show the top view of the battery monomer 10 provided by some embodiments of the application.

[0100] In some optional embodiments, the battery monomer 10 further comprises a first insulating plastic 7, the first insulating plastic 7 is arranged between the shell 1 and the negative pole 5, the liquid injection hole 4 and the negative pole 5 are arranged on the same wall part, and the minimum distance D1 between the liquid injection hole 4 and the outer edge of the first insulating plastic 7 is greater than or equal to 8mm.

[0101] The first insulating plastic 7 refers to the plastic structure arranged between the negative pole 5 and the shell 1, which functions to reduce the risk of electrolyte leakage inside the battery monomer 10, and can fix the negative pole 5 at a suitable position, effectively isolate the current inside the battery from the external environment, and improve the reliability of the battery monomer 10.

[0102] Optionally, the area of the first insulating plastic 7 is greater than the area of the negative pole 5 to completely cover and protect the pole, the first insulating plastic 7 has various shapes, and the outer edge of the first insulating plastic 7 can be circular, square, oval or other special-shaped structures.

[0103] The injection hole 4 and the negative pole 5 are arranged on the same wall, which means that the injection hole 4 and the negative pole 5 are arranged on the first wall 11 or the second wall 12. By making the minimum distance D1 between the outer edge of the first insulating plastic 7 of the injection hole 4 and the negative pole 5 greater than or equal to 8 mm, the risk of burning the first insulating plastic 7 when welding the sealing nail 6 on the injection hole 4 can be effectively reduced, and the reliability of the battery cell 10 can be improved.

[0104] In some optional embodiments, the battery cell 10 further comprises a pressure relief mechanism 9, the injection hole 4 and the pressure relief mechanism 9 are arranged on different walls, or the injection hole 4 and the pressure relief mechanism 9 are arranged on the same wall, and the minimum distance D2 between the outer edges of the injection hole 4 and the pressure relief mechanism 9 is greater than or equal to 8 mm.

[0105] The pressure relief mechanism 9 is used to actuate to release the internal pressure or temperature when the internal pressure or temperature of the battery cell 10 reaches a predetermined threshold. As an example, when the internal pressure or temperature of the battery cell 10 reaches the predetermined threshold, the pressure relief mechanism 9 performs an action or a weak structure provided in the pressure relief mechanism 9 is broken, thereby forming an opening or a passage for the internal pressure or temperature to be released. The threshold value is designed differently according to different design requirements. The threshold value can depend on the material of one or more of the positive plate, the negative plate, the electrolyte, and the separator in the battery cell 10.

[0106] The "actuation" mentioned in the present application means that the pressure relief mechanism 9 generates an action or is activated to a certain state, so that the internal pressure and temperature of the battery cell 10 can be released. The action generated by the pressure relief mechanism 9 can include but is not limited to: the movement of a component in the pressure relief mechanism 9 to form an exhaust passage, the breaking, crushing, tearing or opening of at least a part of the pressure relief mechanism 9, etc. When the pressure relief mechanism 9 is actuated, the high-temperature and high-pressure substances in the interior of the battery cell 10 will be discharged outward from the actuated part as exhaust. In this way, the pressure relief and temperature relief of the battery cell 10 can be achieved under controllable pressure or temperature, thereby avoiding potential more serious accidents.

[0107] As an example, the pressure relief mechanism 9 can be integrally formed with the shell, or the pressure relief mechanism 9 can be arranged separately from the shell and connected.

[0108] When the injection hole 4 and the pressure relief mechanism 9 are arranged on the same wall, the minimum distance D2 between the outer edges of the injection hole 4 and the pressure relief mechanism 9 is greater than or equal to 8 mm, which can effectively reduce the risk of burning the pressure relief mechanism 9 when welding the sealing nail 6 on the injection hole 4, and improve the reliability of the battery cell 10.

[0109] In some alternative embodiments, the battery cell 10 further comprises a second insulating plastic 8, the second insulating plastic 8 is arranged between the shell 1 and the positive pole 3, and the insulation resistance of the second insulating plastic 8 under 500V voltage is greater than 200MΩ.

[0110] By making the insulation resistance of the second insulating plastic 8 under 500V voltage greater than 200MΩ, that is, the second insulating plastic 8 can be insulated under high voltage, thereby further reducing the risk of electrolyte flowing between the positive pole 3 and the first wall 11, improving the reliability and service life of the battery cell 10.

[0111] In some alternative embodiments, the second insulating plastic 8 comprises one of polypropylene PP, polyphenylene sulfide PPS, and tetrafluoroethylene PFA, so as to improve the high-voltage insulation performance of the second insulating plastic 8, and improve the heat conduction performance of the second insulating plastic 8, thereby timely releasing the heat of the battery cell 10.

[0112] Please refer to Figures 1 to 8 Take the battery cell 10 in an embodiment of the present application as an example to illustrate the specific structure of the battery cell 10 in the embodiment of the present application.

[0113] The battery cell 10 in the embodiment of the present application comprises a shell 1, an electrode assembly 2, a positive pole 3, a negative pole 5, and a pressure relief mechanism 9. The shell 1 comprises a first wall 11, a second wall 12, and a side wall 13. The first wall 11 and the second wall 12 are oppositely arranged along a second direction Z and are enclosed with the side wall 13 to form an accommodating cavity. The shell 1 is arranged as a steel shell. The electrode assembly 2 is arranged in the accommodating cavity. The positive pole 3 and the negative pole 5 are arranged on the first wall 11 along a first direction X. The positive pole 3 and the negative pole 5 are insulatedly arranged on the shell 1 by the second insulating plastic 8 and the first insulating plastic 7 respectively and are electrically connected with the electrode assembly 2.

[0114] The shell 1 is provided with a liquid injection hole 4, the liquid injection hole 4 penetrates the shell 1, the liquid injection hole 4 is arranged on the first wall 11 and between the positive pole 3 and the negative pole 5 along the first direction X, the minimum distance between the liquid injection hole 4 and the positive pole 3 is not less than 20mm, and the minimum distance between the liquid injection hole 4 and the first insulating plastic 7 on the negative pole 5 is not less than 8mm, so as to prevent the electrolyte from flowing between the positive pole 3 and the first wall 11 when the liquid injection hole 4 sprays liquid, and reduce the risk of burning the first insulating plastic 7 when the liquid injection hole 4 is welded with a sealing nail 6 subsequently, thereby improving the reliability and service life of the battery cell 10.

[0115] The battery device and the electric device in the embodiment of the present application also have the beneficial effects of the battery cell 10 in the above-mentioned embodiments, and the present application will not be repeated here.

[0116] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can still be modified, or some or all of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should be covered in the scope of the claims and the description of the present application. In particular, as long as there is no structural conflict, all the embodiments and optional embodiments of the present application can be combined with each other to form new technical solutions, and all the technical features and optional technical features of the present application can be combined with each other to form new technical solutions. The present application is not limited to the specific embodiments disclosed in the present application, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized by, The battery cell comprises: a housing comprising a first wall, a second wall and a side wall, the first wall and the second wall oppositely arranged on two sides of the side wall and enclosing the side wall to form a containing cavity, the material of the first wall comprising iron, chromium or nickel; an electrode assembly arranged in the containing cavity; an electrolyte contained in the containing cavity, the electrolyte infiltrating at least part of the electrode assembly; a positive pole arranged on the first wall, the positive pole being electrically connected with the electrode assembly; the housing is provided with a liquid injection hole, the liquid injection hole penetrating through the housing; the liquid injection hole is arranged on the first wall, the minimum distance between the liquid injection hole and the positive pole being not less than 20 mm; and / or, the liquid injection hole is arranged on the second wall or the side wall.

2. The battery cell of claim 1, wherein, The material of the first wall is steel.

3. The battery cell of claim 2, wherein, The material of the first wall is stainless steel or carbon steel.

4. The battery cell of claim 1, wherein, The material of at least one of the second wall and the side wall comprises iron, chromium or nickel.

5. The battery cell of claim 4, wherein, The material of at least one of the second wall and the side wall is steel.

6. The battery cell of claim 1, wherein, The electrolyte comprises a fluorine-containing lithium salt.

7. The battery cell of claim 6, wherein, The fluorine-containing lithium salt comprises at least one of lithium tetrafluoroborate, lithium hexafluoroarsenate, lithium hexafluorophosphate, lithium difluoro oxalate borate, lithium bisfluorosulfonylimide and lithium bis-trifluoromethylsulfonylimide.

8. The battery cell of any one of claims 1 to 7, wherein, The battery cell further comprises a negative pole, the negative pole being arranged on the first wall, the positive pole and the negative pole being arranged apart along a first direction; the liquid injection hole is arranged on the first wall, the liquid injection hole being arranged between the negative pole and the positive pole along the first direction, or the liquid injection hole is arranged on a side of the negative pole away from the positive pole along the first direction.

9. The battery cell of claim 8, wherein, The minimum distance between the liquid injection hole and the positive pole is greater than or equal to the minimum distance between the liquid injection hole and the negative pole.

10. The battery cell of any one of claims 1 to 7, wherein, The battery cell further comprises a negative pole, the negative pole being arranged on the first wall, the liquid injection hole being arranged on one of the side wall and the second wall.

11. The battery cell of claim 10, wherein, The side wall comprises a first side wall and a second side wall intersectingly arranged, the area of the first side wall being smaller than the area of the second side wall, the liquid injection hole being arranged on one of the first side wall and the second side wall.

12. The battery cell of any one of claims 1 to 7, wherein, The battery cell further comprises a negative pole, the negative pole and the liquid injection hole being arranged on the second wall.

13. The battery cell of any one of claims 1 to 7, wherein, The battery cell further comprises a negative pole and a first insulating plastic, the first insulating plastic being assembled between the housing and the negative pole; the liquid injection hole and the negative pole are arranged on different wall portions of the housing, or the liquid injection hole and the negative pole are arranged on the same wall portion of the housing, the minimum distance between the liquid injection hole and the outer edge of the first insulating plastic being not less than 8 mm.

14. The battery cell of any one of claims 1 to 7, wherein, The battery cell further comprises a pressure relief mechanism; the liquid injection hole and the pressure relief mechanism are arranged on different wall portions of the housing, or the liquid injection hole and the pressure relief mechanism are arranged on the same wall portion of the housing, the minimum distance between the liquid injection hole and the outer edge of the pressure relief mechanism being not less than 8 mm.

15. The battery cell of any one of claims 1 to 7, wherein, The battery cell further comprises a second insulating plastic, the second insulating plastic being assembled between the housing and the positive pole, the insulation resistance of the second insulating plastic under 500 V voltage being greater than 200 MΩ.

16. The battery cell of claim 15, wherein, The second insulating plastic includes one of polypropylene, polyphenylene sulfide, tetrafluoroethylene.

17. A battery device characterized by comprising: A plurality of battery cells according to any one of claims 1 to 16 are included.

18. An electrical device, comprising: A battery device as claimed in claim 17 is included.

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