Electrochemical device and electronic device having the same

Abstract

The present application proposes an electrochemical device, comprising a shell, an electrode assembly, a first pole ear, a first seal and a first layer. The electrode assembly is arranged in the shell. The first pole ear is electrically connected to the electrode assembly and extends out of the shell from the shell, and the first pole ear includes a first part arranged in the shell. The first seal is arranged on the first pole ear, and at least a part of the first seal is bonded to the shell. The first layer is arranged on at least a part of the surface of the first part, and the thermal conductivity of the first layer is less than or equal to 0.5w / (m·k). The electrochemical device provided in the present application has high safety when overcharged. The present application also provides an electronic device.

Description

Technical Field

[0001] The present application relates to an electrochemical device and an electronic device having the electrochemical device. Background Art

[0002] When an electrochemical device (such as a battery) is overcharged, a large amount of heat is generated due to long-term charging, causing the temperature of the electrochemical device to rise, thereby posing a safety hazard. Summary of the invention

[0003] In view of this, the present application provides an electrochemical device capable of improving safety during overcharging.

[0004] In addition, the present application also provides an electronic device including the electrochemical device.

[0005] The present application provides an electrochemical device, comprising a housing, an electrode assembly, a first pole ear, a first seal, and a first layer. The electrode assembly is disposed in the housing. The first pole ear is electrically connected to the electrode assembly and extends out of the housing from the housing, and the first pole ear comprises a first portion disposed in the housing. The first seal is disposed on the first pole ear, and at least a portion of the first seal is bonded to the housing. The first layer is disposed on at least a portion of the surface of the first portion, and the thermal conductivity of the first layer is less than or equal to 0.5 w / (m·k).

[0006] The present application sets the first layer on at least a portion of the surface of the first part of the first electrode ear. When the electrochemical device is overcharged, the heat generated by the electrode assembly can be directed along the direction of the first electrode ear toward the first seal. The first layer can reduce the heat conduction from the first electrode ear between the isolation membrane and the first seal to the inside of the electrochemical device, so that the heat generated by the electrode assembly can be directed and concentratedly conducted to the first seal, promoting the melting of the first seal when the temperature of the electrochemical device is low, enhancing the internal heat dissipation of the electrochemical device, and thus improving the safety of the electrochemical device when overcharged.

[0007] At the same time, the first layer has a lower thermal conductivity, so that the first layer has a better thermal insulation effect. When the first layer is arranged on at least a portion of the surface of the first part of the first electrode ear, the first layer can minimize the heat conduction from the first electrode ear to the inside of the electrochemical device.

[0008] In some possible implementations, the first layer wraps the first electrode tab.

[0009] In some possible implementations, the first layer includes a first adhesive tape, the first adhesive tape includes a first base layer and a first adhesive layer stacked together, the first adhesive layer is connected to the first part, and the first base layer includes at least one of glass fiber or polyimide.

[0010] The first substrate layer is connected to the first portion of the first electrode tab via the first adhesive layer. Since the first adhesive layer has a strong bonding ability, the first substrate layer can be prevented from falling off the first portion due to temperature increase.

[0011] In some possible implementations, the first layer includes a thermal insulation material, and the thermal insulation material includes at least one of polypropylene, mullite fiber, basalt fiber, or high silica fiber.

[0012] The material of the thermal insulation material has high thermal insulation performance, so that the first layer has a better thermal insulation effect. When the first layer is arranged on at least a portion of the surface of the first part of the first electrode ear, the first layer can minimize the heat conduction from the first electrode ear to the inside of the electrochemical device, so that the heat on the first electrode ear is directed and concentrated to the first seal, which promotes the melting of the first seal when the temperature of the electrochemical device is low, thereby improving the safety of the electrochemical device when overcharged.

[0013] In some possible implementations, the first sealing component includes a second portion disposed in the housing, and the first layer is further disposed on at least a portion of the surface of the second portion.

[0014] The first layer is arranged on the second part of the first sealing member, which can improve the effectiveness of the first sealing member melting when heated, that is, when the first sealing member is not melted, the heat dissipation of the first sealing member is reduced, so that the first sealing member melts at a lower temperature.

[0015] In some possible implementations, the electrochemical device further includes a second layer, the first electrode tab further includes a third portion disposed outside the shell, and the second layer is disposed on at least a portion of a surface of the third portion.

[0016] The second layer can reduce the heat dissipation from the third part of the first electrode ear to the outside, and further make the heat on the first electrode ear directed and concentrated to the first seal, promote the melting of the first seal when the temperature of the electrochemical device is low, thereby improving the safety of the electrochemical device when overcharged.

[0017] In some possible implementations, the electrode assembly includes a first pole piece, the first pole piece includes a first current collector, the first portion includes a first connecting portion connected to the first current collector, and the first layer is also disposed on at least a portion of a surface of the first connecting portion.

[0018] The first layer is arranged on at least a portion of the surface of the first connecting portion to prevent the heat generated by the first electrode from being conducted to the interior of the electrochemical device through the first connecting portion, thereby further reducing the heat generated by the first electrode from being conducted to the interior of the electrochemical device, so that the heat generated by the first electrode can be directed and concentratedly conducted to the first sealant, thereby promoting the melting of the first sealant when the temperature of the electrochemical device is low, enhancing the internal heat dissipation of the electrochemical device, and thus improving the safety of the electrochemical device when overcharged.

[0019] In some possible implementations, the electrode assembly includes a first pole piece, the first pole piece includes a first current collector, the electrochemical device also includes a second pole ear, the second pole ear is respectively connected to the first current collector and the first pole ear, the first layer is also arranged on a portion of the surface of the second pole ear, and the electrochemical device also includes a third layer, and the third layer is arranged on at least a portion of the surface of the second pole ear.

[0020] The electrochemical device has a multi-electrode ear structure, and the first layer and the third layer are both arranged on a portion of the surface of the second electrode ear, which can reduce the heat on the second electrode ear from being conducted to the inside of the electrochemical device, so that the heat generated by the first electrode can be directed and concentratedly conducted to the first seal, promoting the melting of the first seal when the temperature of the electrochemical device is low, enhancing the internal heat dissipation of the electrochemical device, and thus improving the safety of the electrochemical device when overcharged.

[0021] In some possible implementations, the second electrode tab includes a plurality of sub-electrode tabs. The multi-electrode tab structure can improve the ability of the electrochemical device to carry a large current.

[0022] The present application also provides an electronic device, comprising the above electrochemical device.

[0023] Since the electrochemical device has higher safety when overcharged, the present application can improve the safety of the electronic device when overcharged. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of the structure of an electrochemical device provided in one embodiment of the present application.

[0025] Figure 2 for Figure 1 The schematic diagram of the structure of the electrochemical device shown is shown with the shell removed.

[0026] Figure 3 for Figure 2 A cross-sectional view of the electrochemical device along II-II' after the shell is removed.

[0027] Figure 4 for Figure 1 A cross-sectional view of the electrochemical device along line II'.

[0028] Figure 5 for Figure 1 A cross-sectional view of the electrochemical device along line II'.

[0029] Figure 6 A schematic structural diagram of a first pole piece provided in one embodiment of the present application.

[0030] Figure 7 for Figure 6 A cross-sectional view of the first pole ear along 0-0'.

[0031] Figure 8 for Figure 6 A cross-sectional view of the first pole ear along 0-0'.

[0032] Fig. 9 A diagram showing the module composition of an electronic device provided in one embodiment of the present application.

[0033] Main component symbols

[0034] Electrochemical device 100

[0035] Housing 10

[0036] Electrode assembly 20

[0037] The first pole piece 201

[0038] First Fluid 2011

[0039] First active material layer 2012

[0040] Welding 2013

[0041] Isolation film 202

[0042] The second pole piece 203

[0043] Second Collector 2031

[0044] Second active material layer 2032

[0045] First tab 30

[0046] Part 1 301

[0047] First connection part 3011

[0048] Part 302

[0049] First seal 40

[0050] Part 2 401

[0051] Part 4402

[0052] First floor 50

[0053] First substrate layer 501

[0054] First adhesive layer 502

[0055] Thermal insulation material 503

[0056] Second floor 60

[0057] Second pole ear 70

[0058] Zijier 71

[0059] Third floor 80

[0060] Electronic device 200

[0061] The following specific implementation methods will further illustrate the present application in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0062] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0063] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0064] In order to further explain the technical means and effects adopted by the present application to achieve the intended purpose, the present application is described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0065] See also Figure 1 and Figure 2 An embodiment of the present application provides an electrochemical device 100, comprising a housing 10, an electrode assembly 20, a first pole tab 30, a first seal 40 and a first layer 50. The housing 10 is used to accommodate the electrode assembly 20. The first pole tab 30 is electrically connected to the electrode assembly 20 and extends from the housing 10, and the first pole tab 30 includes a first portion 301 disposed in the housing 10. The first seal 40 is disposed on the first pole tab 30, and at least a portion of the first seal 40 is bonded to the housing 10. The first layer 50 is disposed on at least a portion of the surface of the first portion 301, and the thermal conductivity of the first layer 50 is less than or equal to 0.5w / (m·k).

[0066] The first layer 50 is disposed on at least a portion of the surface of the first portion 301 of the first electrode tab 30. When the electrochemical device 100 is overcharged, the heat generated by the electrode assembly 20 can be directed along the first electrode tab 30 toward the first seal 40. The first layer 50 can reduce the heat conduction from the first electrode tab 30 between the separator and the first seal 40 to the inside of the electrochemical device 100, so that the heat generated by the electrode assembly 20 can be directed and concentratedly conducted to the first seal 40, promoting the melting of the first seal 40 when the temperature of the electrochemical device 100 is low, enhancing the internal heat dissipation of the electrochemical device 100, and thus improving the safety of the electrochemical device 100 when overcharged. At the same time, the first layer 50 is a heat-insulating layer, which has a low thermal conductivity, so that the first layer 50 has a good heat-insulating effect. When the first layer 50 is disposed on at least a portion of the surface of the first portion 301 of the first electrode tab 30, the first layer 50 can minimize the heat conduction from the first electrode tab to the inside of the electrochemical device.

[0067] In some embodiments, the housing 10 may be encapsulated by a packaging film (such as an aluminum-plastic film). That is, the electrochemical device 100 may be a soft-pack battery cell. In some embodiments, the first seal 40 may be a tab glue for electrically insulating the first tab 30 from the housing 10. In some embodiments, the material of the first seal 40 includes at least one of polypropylene or polyimide.

[0068] Furthermore, the first layer 50 wraps the first electrode tab 30 , and the first layer 50 surrounds the first electrode tab 30 along an extending direction perpendicular to the first electrode tab 30 .

[0069] See also Figure 3 The first electrode tab 30 includes a first portion 301 disposed in the housing 10 and a third portion 302 disposed outside the housing 10, and the first sealing member 40 includes a second portion 401 disposed in the housing 10 and a fourth portion 402 disposed outside the housing 10. Figure 4 , the first layer 50 is also disposed on at least a portion of the surface of the second portion 401. It can be understood that Figure 3 The dashed line in the figure represents the boundary between the inside and outside of the housing 10. The outer side of the top seal edge of the housing 10 ( Figure 3 The upper side in the figure is the outside of the housing 10, and the inner side of the top sealing edge of the housing 10 ( Figure 3 The lower side in the figure is the interior of the shell 10.

[0070] See also Figures 1 to 3 , the electrochemical device 100 further includes a second layer 60. Figure 3 , the second layer 60 is disposed on at least a portion of the surface of the third portion 302. Figure 4 and Figure 5The second layer 60 may also cover a portion of the surface of the first sealing member 40. In some embodiments, the thermal conductivity of the second layer 60 is less than or equal to 0.5 w / (m·k).

[0071] See also Figure 4 and Figure 5 The electrode assembly 20 includes a plurality of first pole pieces 201, a plurality of separators (not shown) and a plurality of second pole pieces 203, wherein the separators are disposed between the first pole pieces 201 and the second pole pieces 203, the first pole piece 201 includes a first current collector 2011, and the first pole piece 30 is connected to the first current collector 2011. In some embodiments, the first pole piece 201 is a positive pole piece (the first pole piece 30 is a positive pole piece), and the second pole piece 203 is a negative pole piece. In other embodiments, the first pole piece 201 may also be a negative pole piece (the first pole piece 30 is a negative pole piece), and the second pole piece 203 is a positive pole piece, which is not limited in the present application.

[0072] like Figure 4 As shown, the electrochemical device 100 further includes a second pole tab 70, which is connected to the first current collector 2011 and is also connected to the first pole tab 30. Each first pole sheet 201 is connected to a sub-pole tab 71, and a plurality of sub-pole tabs 71 are electrically connected to the second pole tab 70, thereby converging the current of the plurality of first pole sheets 201 to the second pole tab 70. The electrochemical device 100 further includes a third layer 80, which is disposed on at least a portion of the surface of the second pole tab 70. The thermal conductivity of the third layer 80 is less than or equal to 0.5 w / (m·k). Figure 4 In another embodiment, the first layer 50 may also be disposed on a portion of the surface of the second electrode tab 71, the first layer 50 is disposed on a single side of the first portion 301, and the other side is partially attached to the second electrode tab 80. Figure 5 As shown, the first layer 50 may be disposed on both sides of the first portion 301 .

[0073] See also Figure 6 The first electrode sheet 201 includes a first current collector 2011 and a first active material layer 2012 disposed on the first current collector 2011. The first portion 301 of the first electrode tab 30 includes a first connecting portion 3011 connected to the first current collector 2011 (i.e., the portion where the first electrode tab 30 overlaps with the first current collector 2011 in the thickness direction of the first electrode tab). Figure 6 FIG. 2 shows the first connection portion 3011 and the first current collector 2011 being connected by welding. The area of ​​the weld mark 2013 left by the welding is slightly larger than the area of ​​the first connection portion 3011 to ensure a firm connection. It can be understood that the connection method between the first electrode tab 30 and the first current collector 2011 includes but is not limited to welding. The first electrode tab 30 can also be integrally formed with the first current collector 2011. Figure 6As shown, the first layer 50 is also disposed on at least a portion of the surface of the first connecting portion 3011. It can be understood that when the first electrode tab 30 is connected to the first current collector 2011 by welding, the first layer 50 covers the weld mark 2013, which can further improve the heat insulation effect on the one hand, and reduce the risk of the weld mark piercing the diaphragm and causing a short circuit in the electrochemical device 100 on the other hand.

[0074] See also Figure 7 , the first layer 50 includes a first adhesive tape, and the first adhesive tape includes a first substrate layer 501 and a first adhesive layer 502 that are stacked. The first adhesive layer 502 is connected to the first part 301 and the second part 401. In some embodiments, the first substrate layer 501 includes at least one of glass fiber or polyimide. In some embodiments, the first adhesive layer 502 includes at least one of polytetrafluoroethylene, silicone adhesive or rubber.

[0075] See also Figure 8 In other embodiments, the first layer 50 includes a thermal insulation material 503. In some embodiments, the thermal insulation material includes at least one of polyimide, polypropylene, alumina, ceramic fiber, mullite fiber, basalt fiber, or high silica fiber.

[0076] In some embodiments, the second layer 60 includes a first substrate layer 501 and a first adhesive layer 502 which are stacked, the first substrate layer 501 includes at least one of glass fiber or polyimide, and the first adhesive layer 502 includes at least one of polytetrafluoroethylene, silicone adhesive or rubber. In other embodiments, the second layer 60 includes a heat insulating material, and the heat insulating material includes at least one of polyimide, polypropylene, alumina, ceramic fiber, mullite fiber, basalt fiber or high silica fiber.

[0077] In some embodiments, the third layer 80 includes a first substrate layer 501 and a first adhesive layer 502 which are stacked, the first substrate layer 501 includes at least one of glass fiber or polyimide, and the first adhesive layer 502 includes at least one of polytetrafluoroethylene, silicone adhesive or rubber. In other embodiments, the third layer 80 includes a heat insulating material, and the heat insulating material includes at least one of polyimide, polypropylene, alumina, ceramic fiber, mullite fiber, basalt fiber or high silica fiber.

[0078] In some embodiments, the electrochemical device 100 of the present application includes all devices capable of electrochemical reactions. Specifically, the electrochemical device 100 includes all types of primary batteries, secondary batteries, fuel cells, solar cells, and capacitors (e.g., supercapacitors). Optionally, the electrochemical device 100 can be a lithium secondary battery, including a lithium metal secondary battery, a lithium ion secondary battery, a lithium polymer secondary battery, and a lithium ion polymer secondary battery.

[0079] See also Fig. 9 Some embodiments of the present application further provide an electronic device 200 , which includes the electrochemical device 100 .

[0080] In some embodiments, the electrochemical device 100 of the present application is applicable to electronic devices 200 in various fields. In one embodiment, the electronic device 200 of the present application can be, but is not limited to, a laptop computer, a pen-type computer, a mobile computer, an electronic book player, a portable phone, a portable fax machine, a portable copier, a portable printer, a head-mounted stereo headset, a video recorder, an LCD TV, a portable cleaner, a portable CD player, a mini-disc, a transceiver, an electronic notepad, a calculator, a memory card, a portable recorder, a radio, a backup power supply, a motor, a car, a motorcycle, a power-assisted bicycle, a bicycle, a lighting fixture, a toy, a game console, a clock, an electric tool, a flashlight, a camera, a large household battery, and a lithium-ion capacitor.

[0081] The present application is further described below through examples and comparative examples. Among them, the present application is described by taking the electrochemical device as a soft-pack battery cell as an example and combining the specific preparation process and testing method. Those skilled in the art should understand that the preparation method described in the present application is only an example, and any other suitable preparation method is within the scope of the present application.

[0082] Example 1

[0083] The battery is provided with a first layer, which is arranged on the surface of the first part, the surface of the second part and the surface of the first connecting part. The first layer is Teflon tape, and the thermal conductivity is about 0.25W / (m·K). The first layer includes a first base material layer and a first adhesive layer which are stacked. The material of the first base material layer is glass fiber, and the material of the first adhesive layer includes polytetrafluoroethylene.

[0084] Example 2

[0085] The difference from Example 1 is that the first layer is polyimide adhesive tape, the thermal conductivity is about 0.30 W / (m·K), the material of the first substrate layer is polyimide, and the material of the first adhesive layer is silica gel.

[0086] Comparative Example 1

[0087] The difference between Comparative Example 1 and Example 1 is that the battery is not provided with the first layer.

[0088] The batteries in Examples 1-2 and Comparative Example 1 were respectively subjected to charging tests, specifically: the batteries were charged at a current of 15 A and a voltage of 5 V, and the temperature of the batteries during charging, the current flowing through the batteries, and the voltage across the batteries were measured.

[0089] When the battery in Example 1 is charged for 23.4 minutes, the first sealant melts and the battery temperature rises to 85° C. Since the heat dissipation capacity of the battery is improved, the battery does not experience thermal runaway in the end.

[0090] When the battery in Example 2 is charged for 23.5 minutes, the first sealant melts and the battery temperature rises to 87.5° C. Since the heat dissipation capacity of the battery is improved, the battery does not suffer from thermal runaway in the end.

[0091] When the battery in comparative example 1 is charged for 23.7 minutes, the first sealant will melt open, and the temperature of the battery is as high as 90° C. Since the battery in comparative example 1 is not provided with the first layer, the battery will experience thermal runaway due to excessive temperature.

[0092] It can be seen from this that the surface of the first part of the battery in Example 1-2 is provided with a first layer, and the thermal conductivity meets certain conditions. When the battery is overcharged and the temperature rises, due to the heat insulation effect of the first layer, the heat generated inside the battery (i.e., the heat generated by the first pole piece) can be directed along the first pole ear to the position of the first seal, reducing heat loss during conduction, melting the first seal, and enhancing the heat dissipation inside the battery, thereby improving the overcharge capacity of the battery and improving the safety of the battery when overcharged.

[0093] In the present application, the first layer 50 is disposed on at least a portion of the surface of the first portion 301 of the first electrode tab 30. When the electrochemical device 100 is overcharged, the heat generated by the first electrode piece 201 can be directed along the direction of the first electrode tab 30 toward the first seal 40. The first layer 50 can reduce the heat conduction from the first electrode tab 30 between the isolation membrane 202 and the first seal 40 to the inside of the electrochemical device 100, so that the heat generated by the first electrode piece 201 can be directed and concentratedly conducted to the first seal 40, thereby promoting the melting of the first seal 40 when the temperature of the electrochemical device 100 is low, enhancing the internal heat dissipation of the electrochemical device 100, and thus improving the safety of the electrochemical device 100 when overcharged.

[0094] In addition, the present application also arranges the second layer 60 on at least a portion of the surface of the third portion 302 of the first electrode ear 30, thereby reducing the heat generated by the first electrode piece 201 that is conducted to the outside by the third portion 302, so that the heat generated by the first electrode piece 201 is further directed and concentratedly conducted to the first seal 40, further promoting the melting of the first seal 40 when the temperature of the electrochemical device 100 is low, thereby further improving the safety of the electrochemical device 100 when overcharged.

[0095] The above descriptions are some specific implementations of the present application, but they are not limited to these implementations in actual application. For ordinary technicians in this field, other variations and changes made according to the technical concept of the present application should all fall within the protection scope of the present application.

Claims

1. An electrochemical device, characterized in that: include: A shell having a top seal edge; An electrode assembly is disposed in the housing; A first electrode tab, electrically connected to the electrode assembly and extending from the shell at the top seal edge, the first electrode tab comprising a first portion disposed in the shell; A first sealing member is disposed on the first electrode tab, and at least a portion of the first sealing member is bonded to the housing; as well as The first layer is arranged on at least a part of the surface of the first part and is located inside the top seal edge, and the thermal conductivity of the first layer is less than or equal to 0.5w / (m·k).

2. The electrochemical device according to claim 1, characterized in that The first layer wraps the first electrode tab.

3. The electrochemical device according to claim 1, characterized in that The first layer includes a first adhesive tape, which includes a first base material layer and a first adhesive layer that are stacked, the first adhesive layer is connected to the first part, and the first base material layer includes at least one of glass fiber and polyimide.

4. The electrochemical device according to claim 1, characterized in that The first layer includes a thermal insulation material, and the thermal insulation material includes at least one of polypropylene, mullite fiber, basalt fiber or high silica fiber.

5. The electrochemical device according to claim 1, characterized in that The first sealing member includes a second portion disposed in the housing, and the first layer is further disposed on at least a portion of a surface of the second portion.

6. The electrochemical device according to claim 1, wherein: The electrochemical device further includes a second layer, the first electrode tab further includes a third portion disposed outside the shell, and the second layer is disposed on at least a portion of a surface of the third portion.

7. The electrochemical device according to claim 1, characterized in that The electrode assembly includes a first pole piece, the first pole piece includes a first current collector, the first portion includes a first connecting portion connected to the first current collector, and the first layer is also disposed on at least a portion of a surface of the first connecting portion.

8. The electrochemical device according to claim 1, wherein The electrode assembly includes a first electrode sheet, the first electrode sheet includes a first current collector, the electrochemical device also includes a second electrode ear, the second electrode ear is connected to the first current collector and the second electrode ear is also connected to the first electrode ear, the first layer is also arranged on a partial surface of the second electrode ear, and the electrochemical device also includes a third layer, and the third layer is arranged on at least a partial surface of the second electrode ear.

9. The electrochemical device according to claim 8, characterized in that The second electrode tab includes a plurality of sub-electrode tabs.

10. An electronic device, characterized in that: Comprising the electrochemical device according to any one of claims 1 to 9.

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