Battery cell and electric device

Abstract

The battery monomer comprises an electrode assembly and a temperature detection piece, the electrode assembly comprises a first pole piece, the first pole piece comprises a first current collector, the first current collector comprises a first coating part, the first coating part is provided with a first area and a second area, and the first area of the first coating part is provided with a first active coating; the temperature detection part is used for temperature sampling and arranged in the second area of the first coating part. Therefore, according to the battery monomer, the space for accommodating the heat-sensitive material layer is formed in the second area of the first pole piece, so that the heat-sensitive material layer can be prevented from protruding out of the first pole piece, the influence on the appearance of the electrode assembly is further avoided, and the temperature detection piece can be arranged at any position of the first pole piece; therefore, the temperature of different positions in the electrode assembly can be monitored, and the electrode assembly has flexible variability.

Description

Technical Field

[0001] This utility model relates to the field of batteries, specifically to a battery cell and an electrical device incorporating the battery cell. Background Technology

[0002] With the widespread application of lithium-ion batteries, their safety performance has become paramount. Among the many factors affecting lithium-ion battery safety, temperature is a primary one. Currently, temperature monitoring is necessary during battery use to prevent overheating and related safety risks. While the external temperature of the battery is relatively easy to monitor, the significant temperature difference between the internal and external components makes it inaccurate to determine the internal temperature solely by monitoring the external temperature.

[0003] Therefore, how to accurately monitor the internal temperature of a battery is a technical problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0004] In view of this, the purpose of this utility model is to provide a battery cell that can solve the problem of inaccurate temperature monitoring inside the battery.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] A single battery cell, comprising:

[0007] An electrode assembly includes a first electrode sheet, the first electrode sheet includes a first current collector, the first current collector includes a first coating portion, the first coating portion has a first region and a second region, and the first region of the first coating portion is provided with a first active coating.

[0008] A temperature sensing element includes a first insulating layer and a thermistor material layer for temperature sampling. The first insulating layer is disposed in the second region of the first coated portion; the thermistor material layer is disposed in the first insulating layer.

[0009] Optionally, in the above-mentioned battery cell, the temperature detection element further includes a second insulating layer, which is provided on the side of the thermosensitive material layer opposite to the first insulating layer; the second insulating layer covers the thermosensitive material layer.

[0010] Optionally, in the aforementioned battery cell, a portion of the second insulating layer covers the first active coating located on both sides of the second region.

[0011] Optionally, in the above-mentioned battery cell, a plurality of temperature detection elements are provided in the same second region of the first coating portion, and the plurality of temperature detection elements are spaced apart along the axial direction of the electrode assembly;

[0012] And / or, the first coating portion includes a plurality of second regions, the second regions and the temperature sensing elements are in a one-to-one correspondence; the plurality of temperature sensing elements are arranged at intervals along a first direction of the electrode assembly, the first direction being perpendicular to the axial direction.

[0013] Optionally, in the above-mentioned battery cell, the electrode assembly further includes: a second electrode with a polarity opposite to that of the first electrode;

[0014] In the electrode assembly, a third insulating layer is provided on the surface of the second electrode facing the second region.

[0015] Optionally, in the aforementioned battery cell, the first insulating layer covers the second region.

[0016] And / or, in the second direction, the width of the second region is a, 0.5cm≤a≤2cm, and the second direction is the winding direction of the electrode assembly;

[0017] And / or, in the second direction, the width of the second insulating layer is b, 0.7cm≤b≤2.2cm;

[0018] And / or, in the second direction, the overlap width between one end of the second insulating layer and the first active coating is c, and the overlap width between the other end of the second insulating layer and the first active coating is d, where 0.1mm≤c≤0.2mm and 0.1mm≤d≤0.2mm;

[0019] And / or, in the second direction, the width of the third insulating layer is e, 0.9cm≤e≤2.4cm.

[0020] Optionally, the above-mentioned battery cell also includes:

[0021] The outer casing has a first through hole;

[0022] The electrode assembly is housed within the housing; the temperature sensing element further includes a temperature sampling wire, one end of which is electrically connected to the thermistor material layer, and the other end of which extends out of the electrode assembly and passes through the first through hole.

[0023] Optionally, the above-mentioned battery cell also includes:

[0024] A cluster plate is disposed inside the outer casing, and the cluster plate is provided with a second through hole; the temperature sampling wires pass through the second through hole one by one.

[0025] Optionally, in the above-mentioned battery cells,

[0026] The first coating portion has a plurality of first regions and at least one second region on both sides along its thickness direction. The plurality of first regions are spaced apart along the winding direction of the electrode assembly, and a second region is provided between two adjacent first regions. The temperature detection element is provided in one of the two corresponding second regions in the thickness direction of the coating portion.

[0027] An electrical device includes the aforementioned battery cell.

[0028] As can be seen from the above technical solution, by forming a space for accommodating the thermosensitive material layer in the second region of the first electrode, this utility model can prevent the thermosensitive material layer from protruding from the first electrode, thereby avoiding any impact on the shape of the electrode assembly. Furthermore, since the temperature detection element can be set at any position on the first electrode, it is possible to monitor the temperature at different positions inside the electrode assembly, thus exhibiting flexibility. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 A partial structural schematic diagram of the first side of the first electrode provided in an embodiment of this utility model;

[0031] Figure 2 A schematic diagram of the structure of the first electrode with a first insulating layer provided in an embodiment of this utility model;

[0032] Figure 3 A schematic diagram of the structure of the first electrode plate provided in this embodiment of the present invention, which includes a first insulating layer and a temperature sensing element. Figure 1 ;

[0033] Figure 4 A schematic diagram of the structure of the first electrode plate provided in this embodiment of the present invention, which includes a first insulating layer and a temperature sensing element. Figure 2 ;

[0034] Figure 5 A schematic diagram of the structure of the first electrode plate provided in this embodiment of the utility model, showing the first insulating layer, temperature detection element, and second insulating layer;

[0035] Figure 6 A partial schematic diagram of the second side of the first electrode provided in an embodiment of the present utility model;

[0036] Figure 7This is a schematic diagram of the structure of the second electrode plate, which is directly opposite the second region of the first electrode plate, provided in an embodiment of the present invention.

[0037] Figure 8a for Figure 5 AA section view in the middle;

[0038] Figure 8b for Figure 8a A magnified view of a portion of the image;

[0039] Figure 9 A schematic diagram of the battery structure provided in an embodiment of this utility model;

[0040] Figure 10 This is a schematic diagram of the structure of the bundled plate provided in an embodiment of the present utility model.

[0041] in:

[0042] 11. First electrode; 12. Second electrode; 111. First active coating; 112. Second region; 13. Tab;

[0043] 2. Temperature sensing element; 21. Thermistor layer; 22. Temperature sampling wire; 3. First insulation layer;

[0044] 4. Second insulating layer; 5. Third insulating layer; 6. Outer shell; 61. First through hole;

[0045] 7. Bundling plate; 71. Second through hole. Detailed Implementation

[0046] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0047] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "front," "rear," "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, or the orientation or positional relationship commonly used when the utility model product is in use. These terms are used only for the convenience of describing this utility model 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 utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0048] like Figures 1 to 10 As shown, this utility model embodiment provides a battery cell that can solve the problem of inaccurate temperature monitoring inside the battery.

[0049] First, the battery cell includes an electrode assembly and a temperature sensing element 2. The electrode assembly includes a first electrode 11, which includes a first current collector. The first current collector includes a first coating portion, which has a first region and a second region 112. The first region of the first coating portion is provided with a first active coating 111, while the second region 112 is an empty foil region without the first active coating 111. The temperature sensing element 2 includes a thermistor layer 21 and a first insulating layer 3. The first insulating layer 3 is disposed in the second region 112 of the coating portion, and the thermistor layer 21 is disposed in the first insulating layer 3. For details regarding the coating length and width directions of the first electrode 11, please refer to [link to details]. Figure 1 .

[0050] Understandably, the first coating portion has a first side and a second side along its thickness direction. The first side and / or the second side is composed of a first region and a second region 112. That is, on the same side in the thickness direction of the first coating portion, the first side / second side is composed of a first region and a second region 112, or the first side / second side is composed of a plurality of first regions and a second region 112 located between two adjacent first regions.

[0051] Specifically, in this embodiment, the first coating portion has multiple first regions and at least one second region 112 on both sides along its thickness direction. When the first electrode 11 is wound to form an electrode assembly, the multiple first regions are spaced apart along the winding direction of the electrode assembly, and there is a second region 112 between two adjacent first regions. At this time, the direction in which the electrode assembly unfolds along its winding direction is parallel to the coating length direction of the first electrode 11, and the axial direction of the electrode assembly is parallel to the coating width direction of the first electrode 11. In the thickness direction of the first coating portion, a temperature detection element 2 is provided on one of the two corresponding second regions 112. As designed above, coating is convenient, that is, the active material is coated onto the first region by intermittent coating on both sides of the thickness direction of the first current collector, thereby forming a first active coating 111 in the first region of the first current collector.

[0052] In this embodiment, since the first electrode 11 does not have a first active coating 111 in the second region 112, that is, the first electrode 11 forms a recessed space in the second region 112. Thus, by accommodating the first insulating layer 3 and the thermosensitive material layer 21 in the recessed space, the temperature sensing element 2 can be prevented from protruding from the first electrode 11, thereby avoiding the occurrence of irregular shape of the electrode assembly when the first electrode 11 is wound to form the electrode assembly, so as to ensure the normal use of the electrode assembly.

[0053] In addition, in this embodiment, the first insulating layer 3 can completely cover the second region 112 (see Figure 1 and Figure 2 As shown), the second region 112 can also be partially covered, as long as the thermistor layer 21 can be completely covered by the first insulating layer 3. This design allows the thermistor layer 21 to be as close as possible to the first current collector, thereby enabling more accurate acquisition of the actual temperature of the first electrode 11. On the other hand, the first insulating layer 3 blocks the thermistor layer 21 and the first current collector, preventing current from flowing from the first current collector to the thermistor layer 21 when the electrode assembly is working.

[0054] In addition, the first current collector also includes a tab 13 connected to the first coating portion. The tab 13 can be a full tab, that is, the dimension of the tab 13 along the coating length direction of the first electrode 11 is equal to the dimension of the first current collector along the coating length direction (see details). Figure 1 The tab 13 can also be a die-cut tab (not shown in the figure). The specific structural form of the tab 13 of the first electrode 11 can be designed by those skilled in the art according to actual needs.

[0055] It should be noted that the temperature range of the thermistor layer 21 is -200℃ to 350℃, which meets the temperature range for use in lithium batteries, but is not limited to this. Those skilled in the art can design the specific temperature range of the thermistor layer 21 according to actual needs.

[0056] Furthermore, in order to ensure a stable connection between the first insulating layer 3 and the first current collector, the first insulating layer 3 is required to be tightly disposed in the second region 112 of the first current collector, so that the first insulating layer 3 can be firmly held in the first current collector and is not easy to fall off.

[0057] It should be noted that, in order to achieve a tight connection between the first insulating layer 3 and the first current collector, the first insulating layer 3 can be made of an electrically insulating and high-temperature resistant material, such as a ceramic material. This allows the first insulating layer 3 to be deposited on the first current collector by thermal spraying, physical vapor deposition, or chemical vapor deposition. Alternatively, a high-temperature resistant and insulating adhesive tape can be used as the first insulating layer 3, allowing it to be deposited on the first current collector by adhesive bonding. Furthermore, to achieve a tight connection between the first insulating layer 3 and the first current collector, the second region 112 of the first current collector can be surface-treated to increase its roughness.

[0058] Furthermore, in order to ensure a stable connection between the thermal material layer 21 and the first insulating layer 3, the thermal material layer 21 must be tightly disposed on the first insulating layer 3. In this way, the thermal material layer 21 can be firmly held in the first insulating layer 3 and is not easy to fall off.

[0059] It should be noted that, in order to achieve a tight connection between the thermistor material layer 21 and the first insulating layer 3, the thermistor material layer 21 can be made of a thermistor material. The thermistor material layer 21 can be deposited on the first insulating layer 3 through electroplating, thermal spraying, physical vapor deposition, or chemical vapor deposition. The specific material of the thermistor material layer 21 can be determined according to specific process requirements. The thermistor material layer 21 can be a resistance temperature detector (RTD) layer or a thermocouple layer. The RTD layer can be a Pt100 platinum RTD layer or a Pt1000 platinum RTD layer; and / or the thermocouple layer can be a nickel-chromium-nickel-silicon thermocouple layer, a copper-copper-nickel thermocouple layer, or an iron-copper-nickel thermocouple layer.

[0060] Furthermore, in order to ensure that the thermistor layer 21 does not protrude from the first electrode 11 while ensuring the temperature measurement capability of the thermistor layer 21, the thickness of the thermistor layer 21 is greater than or equal to 0.02 mm and less than or equal to 0.08 mm; while in order to ensure that the first insulating layer 3 and the thermistor layer 21 do not protrude from the first electrode 11 while ensuring that the first insulating layer 3 is not easily punctured, the thickness of the first insulating layer 3 is greater than or equal to 10 μm and less than or equal to 30 μm.

[0061] Specifically, the thickness of the heat-sensitive material layer 21 can be 0.02mm, 0.03mm, 0.04mm, 0.05mm, 0.06mm, 0.07mm, or 0.08mm; the thickness of the first insulating layer 3 can be 10um, 13um, 15um, 18um, 21um, 23um, 25um, 28um, or 30um.

[0062] It should be noted that, in order to ensure the temperature measurement capability of the thermistor layer 21 while reducing the impact of the thermistor layer 21 on the energy density of the electrode assembly, the width of the thermistor layer 21 is greater than or equal to 1 mm and less than or equal to 4 mm. The length direction of the thermistor layer 21 is parallel to the coating width direction of the first electrode 11, and the length of the thermistor layer 21 is less than or equal to the coating width of the first electrode 11, so that the thermistor layer 21 is completely contained within the second region 112. Specifically, the width of the thermistor layer 21 can be 1 mm, 1.5 mm, 2 mm, 3 mm, or 4 mm.

[0063] Furthermore, to ensure sufficient space is reserved for the heat-sensitive material layer 21 to sample temperature while minimizing the impact on the energy density of the electrode assembly, the width of the second region 112 in the second direction is 'a', where 0.5cm ≤ a ≤ 2cm. Specifically, the width of the second region 112 can be 0.5cm, 0.6cm, 0.7cm, 0.8cm, 1.2cm, 1.4cm, 1.7cm, 1.9cm, or 2cm. It should be noted that when the first electrode 11 is not involved in the electrode assembly fabrication, the second direction refers to the coating length direction of the first electrode 11; when the first electrode 11 is fabricated into an electrode assembly, the second direction refers to the winding direction of the electrode assembly.

[0064] It should be noted that, in order to facilitate the coating of active material onto the first current collector, the second region 112 can be designed to be axially aligned with the first coating portion, with the dimensions of the second region 112 being the same as the dimensions of the first coating portion.

[0065] In some optional embodiments, the temperature sensing element 2 further includes a second insulating layer 4, which is provided on the side of the thermosensitive material layer 21 opposite to the first insulating layer 3; the second insulating layer 4 covers the thermosensitive material layer 21.

[0066] In this embodiment, since the second insulating layer 4 completely covers the thermosensitive material layer 21, the second insulating layer 4 can isolate the thermosensitive material layer 21 and the isolation film in the electrode assembly, thus preventing the thermosensitive material layer 21 from puncturing the isolation film.

[0067] It should be noted that when the second insulating layer 4 covers the heat-sensitive material layer 21, the second insulating layer 4 can also completely cover the second region 112.

[0068] Furthermore, the second insulating layer 4 is a high-temperature resistant adhesive paper, the second insulating layer 4 covers the thermosensitive material layer 21, and a portion of the second insulating layer 4 covers the first active coating 111 located on at least one side of the second region 112, so that the thermosensitive material layer 21 and the first insulating layer 3, as well as the first insulating layer 3 and the first current collector, can be tightly connected through the second insulating layer 4.

[0069] Understandably, when there is only one second region 112 and one first region (i.e., the second region 112 is disposed at the edge of the first current collector), a portion of the second insulating layer 4 covers the first active coating 111 located on one side of the second region 112; when the second region 112 is located between two adjacent first regions, a portion of the second insulating layer 4 may cover only the first active coating 111 located on one side of the second region 112, or it may cover the first active coating 111 located on both sides of the second region 112.

[0070] It should be noted that, in order to minimize the impact of the second insulating layer 4 on the shape of the electrode assembly, the thickness of the second insulating layer 4 is greater than or equal to 10 μm and less than or equal to 30 μm. Specifically, the thickness of the second insulating layer 4 is 10 μm, 11 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 23 μm, 25 μm, 28 μm, or 30 μm.

[0071] It should also be noted that, in order to reduce the impact of the second insulating layer 4 on the energy density while ensuring that it can cover the heat-sensitive material layer 21, the width of the second insulating layer 4 in the second direction is b, 0.7cm≤b≤2.2cm. Specifically, the value of b can be 0.7cm or 0.8cm or 0.9cm or 1.1cm or 1.3cm or 1.5cm or 1.7cm or 1.9cm or 2.2cm.

[0072] It should be noted that, in order to ensure that the second insulating layer 4 covers the second region 112 in the second direction while also partially covering the first active coating 111, the width of the second insulating layer 4 in the second direction can be designed to be greater than the width a of the second region 112, that is, a is in the range of 0.5cm to 2cm, and b is in the range of 0.7cm to 2.2cm, requiring b to be greater than a.

[0073] Furthermore, in order to ensure the connection between the second insulating layer 4 and the first active coating 111 while minimizing the impact on energy density, see [reference needed]. Figure 5 , Figure 8a and Figure 8b In the second direction, the overlap width between one end of the second insulating layer 4 and the first active coating 111 is c, and the overlap width between the other end of the second insulating layer 4 and the first active coating 111 is d, where 0.1mm≤c≤0.2mm and 0.1mm≤d≤0.2mm; the second direction is the winding direction of the electrode assembly.

[0074] Specifically, the values ​​of c and d can be equal or unequal, depending on the design. The value of c can be 0.1mm, 0.12mm, 0.14mm, 0.16mm, 0.18mm, or 0.2mm; the value of d can be 0.1mm, 0.12mm, 0.13mm, 0.15mm, 0.17mm, 0.19mm, or 0.2mm.

[0075] In some optional embodiments, since the second region 112 can be adjusted according to the temperature detection element 2 at different positions inside the battery cell, thereby enabling temperature monitoring at different positions inside the battery, in order to design multiple temperature sampling points in the same second region 112 of the electrode assembly and thus make the temperature measurement more accurate, multiple thermistor material layers 21 are provided in the same second region 112 of the first coating part, and the multiple thermistor material layers 21 are spaced apart along the axial direction of the electrode assembly.

[0076] For example, see details Figure 4 Three thermistor material layers 21 are provided in the same second region 112 of the first coating part, namely a first thermistor material layer, a second thermistor material layer and a third thermistor material layer. In the axial direction of the electrode assembly, the second thermistor material layer extends to the middle of the second region 112. The distance between the first thermistor material layer and the side of the first coating part near the tab 13 is greater than or equal to 0.2 cm and less than or equal to 0.5 cm, wherein the value can be 0.2 cm, 0.3 cm, 0.4 cm or 0.5 cm. The distance between the second thermistor material layer and the side of the first coating part away from the tab 13 is greater than or equal to 0.2 cm and less than or equal to 0.5 cm, wherein the value can be 0.2 cm, 0.25 cm, 0.35 cm or 0.45 cm or 0.5 cm.

[0077] In some optional embodiments, since the second region 112 can be adjusted according to the different positions of the temperature detection element 2 inside the battery cell, thereby enabling temperature monitoring at different positions inside the battery, in order to set multiple temperature sampling points along the first direction of the electrode assembly and thus make the temperature measurement more accurate, the first coating part includes multiple second regions 112, and the second regions 112 and the temperature detection element 2 are in a one-to-one correspondence; the multiple temperature detection elements 2 are arranged at intervals along the first direction of the electrode assembly, which effectively solves the problem of uneven temperature distribution and large temperature differences between regions, thus ensuring accurate temperature monitoring.

[0078] Understandably, the first direction is based on the electrode assembly. When the electrode assembly is cylindrical, the first direction is perpendicular to the axial direction, i.e., the first direction is radial. In other words, multiple second regions 112 are provided along the radial direction of the electrode assembly. When the electrode assembly is flat and cylindrical, the first direction is perpendicular to the axial direction, i.e., the first direction is the thickness direction or length direction of the electrode assembly. In other words, multiple second regions 112 are provided along the thickness direction of the electrode assembly, or multiple second regions 112 are provided along the length direction of the electrode assembly.

[0079] It should be noted that when the electrode assembly is cylindrical, in order to set multiple temperature sampling points around the electrode assembly, multiple second regions 112 can be arranged around the electrode assembly, and each second region 112 is equipped with a temperature detection element 2.

[0080] It should also be noted that when the electrode assembly is cylindrical, while multiple thermistor material layers 21 are provided in the same second region 112, temperature detection elements 2 can also be provided in multiple second regions 112 arranged radially along the electrode assembly, and temperature detection elements 2 can also be provided in multiple second regions 112 evenly distributed circumferentially along the electrode assembly. The specific arrangement of temperature sampling points inside the electrode assembly depends on the design.

[0081] In some alternative embodiments, to promptly transmit the temperature sensed by the thermistor layer 21 to a data processor or data display for timely acquisition by the operator, the temperature sensing element 2 also includes a temperature sampling wire 22. One end of the temperature sampling wire 22 is electrically connected to the thermistor layer 21, and the other end of the temperature sampling wire 22 extends out to an electrode assembly and is electrically connected to an external device.

[0082] Specifically, the battery cell includes a housing 6, an electrode assembly with a temperature detection element 2 is disposed inside the housing 6, a first through hole 61 is provided on the housing 6, and the temperature sampling wire 22 of the temperature detection element 2 passes through the first through hole 61 and is electrically connected to an external device; preferably, the housing 6 includes a cover plate, and the first through hole 61 is disposed on the cover plate.

[0083] Furthermore, to better organize the temperature sampling leads 22, see [link / reference]. Figure 9 and Figure 10 A cluster plate 7 is provided inside the outer casing 6. The cluster plate 7 is provided with a second through hole 71. The number of second through holes 71 is the same as the number of temperature sampling wires 22. This allows the temperature sampling wires 22 to pass through the second through holes 71 one by one. Of course, only one second through hole 71 can be provided, so that all temperature sampling wires 22 can pass through the same second through hole 71. The specific design depends on the design requirements.

[0084] It should be noted that, in order to better organize the temperature sampling wires 22, a wire arrangement groove can be set on the side of the cluster plate 7 away from the electrode assembly. In this way, multiple temperature sampling wires 22 at different positions can pass through their respective second through holes 71 and be arranged according to the trajectory of the wire arrangement groove. Finally, all the temperature sampling wires 22 pass through the first through hole 61 on the cover plate from the same position.

[0085] It should also be noted that, in order to further consolidate the temperature sampling wires 22, a clustering plate 7 can be provided on the outside of the housing 6. In addition, it should be noted that the clustering plate 7 can be rectangular or circular, but is not limited to these shapes. The specific shape of the clustering plate 7 can be designed by those skilled in the art according to actual needs.

[0086] In some optional embodiments, when the first current collector is made of copper foil, i.e., the first electrode 11 is the negative electrode and the second electrode 12 is the positive electrode, considering the principle of lithium ion insertion and extraction: during charging, lithium ions are extracted from the positive electrode and inserted into the negative electrode through the electrolyte; during discharging, lithium ions are extracted from the negative electrode and return to the positive electrode through the electrolyte. That is to say, when the first electrode 11 is the negative electrode and the second region 112 of the first electrode 11 does not have the first active coating 111, the lithium ions extracted from the second region 112 of the second electrode 12 cannot be inserted into the first electrode 11, which will cause lithium plating at the corresponding position of the second region 112 of the second electrode 12.

[0087] Therefore, to avoid lithium plating at the position corresponding to the second region 112 in the second electrode 12, see... Figure 7 In the electrode assembly, a third insulating layer 5 is provided on the surface of the second electrode 12 facing the second region 112; by providing the third insulating layer 5 on the second electrode 12, lithium ions are prevented from being extracted from the position of the second electrode 12 facing the second region 112, thereby avoiding the lithium plating problem.

[0088] It should be noted that since lithium ions are extracted from the positive electrode, when the first electrode 11 is the positive electrode and the second electrode 12 is the negative electrode, it is not necessary to provide a third insulating layer 5 on the surface of the second electrode 12 facing the second region 112. That is, there is no lithium plating problem when the second electrode 12 is the negative electrode.

[0089] It should also be noted that the third insulating layer 5 is made of an electrically insulating and high-temperature resistant material, such as a ceramic material, so that the first insulating layer 3 can be deposited on the second electrode 12 by thermal spraying, physical vapor deposition or chemical vapor deposition; of course, high-temperature resistant and insulating adhesive paper can also be used as the third insulating layer 5, so that the third insulating layer 5 can be deposited on the second electrode 12 by adhesive.

[0090] Furthermore, to ensure coverage of the second region 112 while minimizing the impact on energy density, see [link to relevant documentation]. Figure 7 In the second direction, the width of the third insulating layer 5 is e, where 0.9cm ≤ e ≤ 2.4cm. In the axial direction of the electrode assembly, the length of the third insulating layer 5 is the same as the length of the second region 112. When the first electrode 11 is not involved in the electrode assembly fabrication, the second direction is the coating length direction of the first electrode 11; when the first electrode 11 is fabricated into an electrode assembly, the second direction is the winding direction of the electrode assembly. Specifically, the value of e can be 0.9cm, 1.2cm, 1.4cm, 1.6cm, 1.8cm, 2.1cm, or 2.3cm.

[0091] It should be noted that the dimensions of the second region 112, the first insulating layer 3, the second insulating layer 4, the third insulating layer 5, and the thermosensitive material layer 21 are all interrelated and can be designed within their selectable ranges. That is, the first insulating layer 3 completely covers the second region 112, and / or, in the second direction, the width of the second region 112 is a, 0.5cm ≤ a ≤ 2cm; and / or, in the second direction, the width of the second insulating layer 4 is b, 0.7cm ≤ b ≤ 2.2cm; and / or, in the second direction, the overlap width between one end of the second insulating layer 4 and the first active coating 111 is c, and the overlap width between the other end of the second insulating layer 4 and the first active coating 111 is d, 0.1mm ≤ c ≤ 0.2mm, 0.1mm ≤ d ≤ 0.2mm; and / or, in the second direction, the width of the third insulating layer 5 is e, 0.9cm ≤ e ≤ 2.4cm.

[0092] The manufacturing steps of a single battery cell in this embodiment are as follows:

[0093] Manufacturing the first electrode 11: The first current collector is made of aluminum foil; an active material is coated onto both sides of the thickness direction of the first current collector using an intermittent coating method, so that a first active coating 111 is formed in the first region of the first current collector, and a second region 112 is formed on the first current collector; a first insulating layer 3 is then placed in the second region 112 of the first current collector, a thermistor layer 21 is placed in the first insulating layer 3, and a second insulating layer 4 is placed over the thermistor layer 21, while a portion of the second insulating layer 4 overlaps with the first active coating 111 placed near the thermistor layer 21; and one end of the temperature sampling wire 22 is electrically connected to the thermistor layer 21, and the other end of the temperature sampling wire 22 extends out of the second region 112;

[0094] Then, the second current collector of the second electrode 12 is made of copper foil; the second electrode 12, the diaphragm and the manufactured first electrode 11 are wound into a cylindrical electrode assembly; the electrode assembly is then placed inside the housing 6, and the temperature sampling wire 22 is allowed to pass through the second through hole 71 of the bundle plate 7 and the first through hole 61 on the cover plate. Then, the cover plate and the housing are connected as one unit.

[0095] Another step in manufacturing a single battery cell in this embodiment is as follows:

[0096] Manufacturing the first electrode 11: The first current collector is made of copper foil; an active material is coated onto both sides of the thickness direction of the first current collector using an intermittent coating method, so that a first active coating 111 is formed in the first region of the first current collector, and a second region 112 is formed on the first current collector; a first insulating layer 3 is then placed in the second region 112 of the first current collector, a thermistor layer 21 is placed in the first insulating layer 3, and a second insulating layer 4 is placed over the thermistor layer 21, while a portion of the second insulating layer 4 overlaps with the first active coating 111 placed near the thermistor layer 21; and one end of the temperature sampling wire 22 is electrically connected to the thermistor layer 21, and the other end of the temperature sampling wire 22 extends out of the second region 112;

[0097] Then, the second current collector of the second electrode 12 is made of aluminum foil, and a third insulating layer 5 is provided on the surface of the second electrode 12 corresponding to the second region 112.

[0098] Next, the second electrode 12, the diaphragm, and the manufactured first electrode 11 are wound into a cylindrical electrode assembly; then the electrode assembly is placed inside the housing 6, and the temperature sampling wire 22 is allowed to pass through the second through hole 71 of the bundle plate 7 and the first through hole 61 of the cover plate. Then the cover plate and the housing are connected as one unit.

[0099] This utility model provides an electrical device, including the aforementioned battery cell.

[0100] There are no particular limitations on the electrical devices used in this invention, which may include, but are not limited to: laptops, pen-based computers, mobile computers, e-book players, portable telephones, portable fax machines, portable copiers, portable printers, stereo headphones, video recorders, LCD TVs, portable cleaners, portable CD players, mini CDs, transceivers, electronic notebooks, calculators, memory cards, portable recorders, radios, backup power supplies, motors, automobiles, motorcycles, electric bicycles, bicycles, lighting fixtures, toys, game consoles, clocks, power tools, flashlights, cameras, large household batteries, and lithium-ion capacitors, etc.

[0101] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0102] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0103] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A battery cell, characterized by, The electrode assembly comprises a first pole piece (11) comprising a first current collector, the first current collector comprising a first coating portion, the first coating portion having a first region and a second region (112), the first region of the first coating portion being provided with a first active coating (111); The temperature detection member (2) comprises a first insulating layer (3) and a layer of thermosensitive material (21) for temperature sampling, the first insulating layer (3) being arranged at the second region (112) of the first coating portion; the layer of thermosensitive material (21) being arranged at the side of the first insulating layer (3) away from the first insulating layer (3). The temperature detection member (2) further comprises a second insulating layer (4), the second insulating layer (4) being arranged at the side of the layer of thermosensitive material (21) away from the first insulating layer (3); the second insulating layer (4) covering the layer of thermosensitive material (21).

2. The battery cell of claim 1, wherein, Part of the second insulating layer (4) covers the first active coating (111) located on at least one side of the second region (112).

3. The battery cell of claim 2, wherein, A plurality of layers of thermosensitive material (21) are arranged at the same second region (112) of the first coating portion, and the plurality of layers of thermosensitive material (21) are arranged at intervals along the axial direction of the electrode assembly.

4. The battery cell according to any one of claims 1 to 3, characterized in that, And / or, the first coating portion comprises a plurality of second regions (112), the second regions (112) and the temperature detection members (2) are in one-to-one correspondence; a plurality of temperature detection members (2) are arranged at intervals along a first direction of the electrode assembly, the first direction being perpendicular to the axial direction. The electrode assembly further comprises a second pole piece (12) opposite in polarity to the first pole piece (11); 5. The battery cell of claim 3, wherein, In the electrode assembly, a third insulating layer (5) is arranged at the surface of the second pole piece (12) opposite the second region (112). The first insulating layer (3) covers the second region (112), 6. The battery cell of claim 5, wherein, And / or, in a second direction, the width of the second region (112) is a, 0.5cm≤a≤2cm, the second direction being the winding direction of the electrode assembly; And / or, in the second direction, the width of the second insulating layer (4) is b, 0.7cm≤b≤2.2cm; And / or, in the second direction, the overlapping width of one end of the second insulating layer (4) and the first active coating (111) is c, the overlapping width of the other end of the second insulating layer (4) and the first active coating (111) is d, 0.1mm≤c≤0.2mm, 0.1mm≤d≤0.2mm; And / or, in the second direction, the width of the third insulating layer (5) is e, 0.9cm≤e≤2.4cm. Further comprising:

7. The battery cell of claim 2, wherein, A housing (6) provided with a first through hole (61); ​ The electrode assembly is accommodated in the shell (6); the temperature detection member (2) further comprises a temperature sampling lead wire (22), one end of the temperature sampling lead wire (22) is electrically connected with the thermosensitive material layer (21), and the other end of the temperature sampling lead wire (22) extends out of the electrode assembly and passes through the first through hole (61).

8. The battery cell of claim 7, wherein, Further comprising: A bundling plate (7) is arranged in the shell (6), and the bundling plate (7) is provided with a second through hole (71); The temperature sampling lead wire (22) penetrates the second through hole (71) one by one.

9. The battery cell according to claim 1, wherein The first coating part has a plurality of first regions and at least one second region (112) on both sides along the thickness direction thereof, the plurality of first regions are arranged at intervals along the winding direction of the electrode assembly, and the second region (112) is arranged between two adjacently arranged first regions; one of the two correspondingly arranged second regions (112) in the thickness direction of the first coating part is provided with the temperature detection member (2).

10. An electrical device, characterized by The battery cell according to any one of claims 1 to 9.

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