Battery cell, electrochemical device, and electric equipment

Abstract

The utility model discloses a kind of electric core, electrochemical device and electric equipment, wherein, electric core includes the alternately laminated multiple positive pole piece, multiple diaphragm and multiple negative pole piece, diaphragm is located between adjacent positive pole piece and negative pole piece;Each positive pole piece includes first current collector, first current collector includes first support body layer and first conductor layer, first conductor layer has first conductive part, and the first conductive part of multiple positive pole piece is wound and superimposed to form electrical connection;Each negative pole piece includes second current collector, second current collector includes second support body layer and second conductor layer, second conductor layer has second conductive part, and the second conductive part of multiple negative pole piece is wound and superimposed to form electrical connection.The first conductive part, second conductive part of the application are wound and superimposed to expand conduction area, avoid the problem that electron needs to flow along conductor layer transversely to welding point in traditional structure, shorten electron transmission path, effectively reduce electric core internal resistance, and then improve charging efficiency and rate performance.

Description

Technical Field

[0001] This utility model relates to the field of electrochemical device technology, and in particular to a battery cell, an electrochemical device, and an electrical device. Background Technology

[0002] In electrochemical devices such as lithium-ion batteries, the current collector, as the carrier of active materials and the core channel for electron transport, plays a crucial role throughout the entire device manufacturing process and lifecycle, significantly impacting cell performance. Existing composite current collectors typically employ a three-layer structure consisting of conductive layers on both sides and a polymer insulating layer in the middle. By using a low-density polymer thin film substrate to reduce the overall density of the current collector, combined with the conductive layers on the surface to ensure electron transport capability, this effectively improves the gravimetric energy density of lithium-ion batteries while mitigating the fragility of traditional metal current collectors.

[0003] However, this structure has the following drawbacks: the intermediate polymer layer is an insulating material, which physically isolates the conductive layers on both sides of the composite current collector, allowing only partial connectivity through the solder joints with the tabs (or busbars). Limited by the welding process and the internal space of the cell, the connection area of ​​the solder joints is extremely small. Electrons generated in the conductive layer on the side away from the tabs cannot directly pass through the insulating layer to the tabs; they are forced to traverse laterally along the conductive layer to the solder joint area before converging at the tabs. This transmission process significantly increases the electron travel distance, leading to a significant increase in the battery's internal resistance, which in turn causes problems such as low charging efficiency and poor rate performance, severely impacting the battery's ease of use and overall performance. Utility Model Content

[0004] The main purpose of this utility model is to propose a battery cell, an electrochemical device, and an electrical device, which aims to solve the technical problems of existing battery cells such as long electron transmission distance, high internal resistance, low charging efficiency, and poor rate performance.

[0005] To achieve the above objectives, this utility model proposes a battery cell comprising a plurality of positive electrode plates, a plurality of separators, and a plurality of negative electrode plates arranged in alternating layers, wherein the separators are located between adjacent positive electrode plates and negative electrode plates;

[0006] Each of the positive electrode plates includes a first current collector, the first current collector includes a first support layer and a first conductor layer disposed on both sides of the first support layer, the first conductor layer has a first conductive portion, and the first conductive portions of the plurality of positive electrode plates are wound and stacked to form an electrical connection;

[0007] Each of the negative electrode sheets includes a second current collector, which includes a second support layer and a second conductor layer disposed on both sides of the second support layer. The second conductor layer has a second conductive portion, and the second conductive portions of the plurality of negative electrode sheets are wound and stacked to form an electrical connection.

[0008] In some embodiments, the first conductive portion includes a first connecting segment and a first bending segment, the first connecting segment being connected to the first conductor layer, the first bending segment being connected to the first connecting segment, and the first bending segment bending away from the first conductor layer and making contact with the first connecting segment.

[0009] The second conductive portion includes a second connecting segment and a second bending segment. The second connecting segment is connected to the second conductor layer, and the second bending segment is connected to the second connecting segment. The second bending segment bends away from the second conductor layer and makes contact with the second connecting segment for electrical connection.

[0010] In some embodiments, the first bending segment includes a first sub-bending segment, a second sub-bending segment, and a third sub-bending segment connected in sequence. The first sub-bending segment is connected to the end of the first connecting segment away from the first conductive layer. The third sub-bending segment is connected to the end of the second sub-bending segment away from the first sub-bending segment. The third sub-bending segment bends and makes contact with the first connecting segment.

[0011] The second bending segment includes a fourth sub-bending segment, a fifth sub-bending segment, and a sixth sub-bending segment connected in sequence. The fourth sub-bending segment is connected to the end of the first connecting segment away from the first conductive layer. The sixth sub-bending segment is connected to the end of the fifth sub-bending segment away from the fourth sub-bending segment, and the sixth sub-bending segment bends and makes contact with the second connecting segment.

[0012] In some embodiments, the battery cell further includes a first insulating protective layer, which is sleeved over the first conductive portion.

[0013] In some embodiments, the battery cell further includes a second insulating protective layer, which is sleeved over the second conductive portion.

[0014] In some embodiments, the positive electrode, the separator, and the negative electrode are stacked to form a stacked structure, and the stacked structure has a first side;

[0015] The first conductive portions of the plurality of positive electrode plates protrude from the stacked structure along the first lateral direction, and the second conductive portions of the plurality of negative electrode plates protrude from the stacked structure along the first lateral direction.

[0016] In some embodiments, the stacked structure further has a second side disposed opposite to the first side;

[0017] The battery cell also includes a first tab and a second tab, the first tab being connected to the first conductor layer and the second tab being connected to the second conductor layer, with the first tab and the second tab located on the second side.

[0018] In some embodiments, the length of the first conductive portion is greater than or equal to 5 mm and less than or equal to 50 mm, and the width of the first conductive portion is greater than or equal to 1 mm and less than or equal to 100 mm; and / or,

[0019] The length of the second conductive part is greater than or equal to 5 mm and less than or equal to 50 mm, and the width of the second conductive part is greater than or equal to 1 mm and less than or equal to 100 mm.

[0020] This invention also provides an electrochemical device, including a battery cell.

[0021] This utility model also provides an electrical device, including an electrochemical device.

[0022] The positive electrode of the battery cell provided in this application has a first current collector supported by a first support layer. The first conductor layers on both sides serve as the substrate supporting the first active material layer, and through the reserved first conductive parts without active material coating, the first conductive parts of multiple positive electrode sheets can be wound and stacked to form a large-area, tightly contacted electrical connection area, realizing direct conduction between the first conductor layers on both sides of each positive electrode sheet. Similarly, the second current collector of the negative electrode sheet is supported by a second support layer, and the second conductor layers on both sides form a stable electrical connection through the reserved second conductive parts, ensuring the conduction of the second conductor layers on both sides of each negative electrode sheet. The battery cell provided in this application expands the conduction area by winding and stacking the first and second conductive parts, avoiding the problem in traditional structures where electrons need to flow laterally along the conductor layer to the solder joint, shortening the electron transport path, effectively reducing the internal resistance of the battery cell, and thus improving charging efficiency and rate performance. Attached Figure Description

[0023] Figure 1 This is a cross-sectional schematic diagram of an embodiment of the battery cell of this utility model;

[0024] Figure 2 This is a cross-sectional schematic diagram of another embodiment of the battery cell of this utility model;

[0025] Figure 3 This is a cross-sectional schematic diagram of an embodiment of the positive electrode sheet of this utility model;

[0026] Figure 4 This is a cross-sectional schematic diagram of an embodiment of the negative electrode sheet of this utility model.

[0027] Explanation of icon numbers:

[0028]

[0029]

[0030] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0031] The solutions in the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this utility model.

[0032] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0033] It should also be noted that when a component is described as "fixed to" or "set on" another component, it can be directly on the other component or there may be an intervening component present. When a component is described as "connected to" another component, it can be directly connected to the other component or there may be an intervening component present.

[0034] Furthermore, the use of terms such as "first" and "second" in this utility model is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this utility model.

[0035] Please refer to Figures 1 to 4 This application provides a battery cell 100, which includes a plurality of positive electrode plates 10, a plurality of separators 20 and a plurality of negative electrode plates 30 arranged in alternating layers, wherein the separators 20 are located between adjacent positive electrode plates 10 and negative electrode plates 30.

[0036] Each positive electrode 10 includes a first current collector 11. The first current collector 11 includes a first support layer and a first conductor layer disposed on both sides of the first support layer. The first conductor layer has a first conductive portion 113. The first conductive portions 113 of the plurality of positive electrode 10 are wound and stacked to form an electrical connection.

[0037] Each negative electrode 30 includes a second current collector 21. The second current collector 21 includes a second support layer and a second conductor layer disposed on both sides of the second support layer. The second conductor layer has a second conductive portion 213. The second conductive portions 213 of the multiple negative electrode 30 are wound and stacked to form an electrical connection.

[0038] The first support layer of the first current collector 11 provides structural support, ensuring the morphological stability and fracture resistance of the positive electrode 10. The first conductor layers on both sides are responsible for collecting electrons generated by the positive electrode active material and transmitting them to the electrical connection area. The first conductive part 113 achieves electrical connection of multiple positive electrode 10 through winding and stacking, ensuring efficient electron collection and conduction.

[0039] Similarly, the second support layer of the second current collector 21 also plays a structural support role, improving the mechanical properties of the negative electrode 30. The second conductor layers on both sides are responsible for collecting electrons generated by the negative electrode active material and transmitting them to the electrical connection area. The second conductive part 213 realizes the electrical connection of multiple negative electrode 30 through winding and stacking, ensuring stable electron transmission.

[0040] In this embodiment, the surfaces of the first conductor layers on both sides of the first current collector 11 of the positive electrode 10 and the second conductor layers on both sides of the second current collector 21 of the negative electrode 30 are coated with active material layers adapted to their respective electrode functions (i.e., the first active material layer of the positive electrode 10 and the second active material layer of the negative electrode 30). As the core area of ​​the electrochemical reaction of the cell 100, the active material layer is responsible for realizing the insertion and extraction of lithium ions and the transfer of electrons during charging and discharging. At the same time, in order to ensure the realization of the electrical connection function, the first conductive part 113 reserved on the first conductor layer and the second conductive part 213 reserved on the second conductor layer are not coated with active material layers, so that the first conductive part 113 and the second conductive part 213 maintain the conductivity characteristics of the conductor layer. This ensures that the first conductive parts 113 of multiple positive electrodes 10 can form a stable electrical connection by winding and stacking, and the second conductive parts 213 of multiple negative electrodes 30 can form a stable electrical connection by winding and stacking. This does not affect the electrochemical reaction efficiency of the active material layer, and also achieves efficient conduction of the conductor layer.

[0041] The separator 20 is located between adjacent positive electrode 10 and negative electrode 30. It is used to physically isolate the positive and negative active materials and prevent short circuits inside the cell 100. At the same time, its porous structure can adsorb electrolyte and provide a channel for the migration of lithium ions between the positive and negative electrodes, ensuring the smooth progress of the electrochemical reaction in the cell 100.

[0042] The battery cell 100 provided in this application embodiment uses a reserved first conductive portion 113 to allow the first conductive portions 113 of multiple positive electrode plates 10 to form a large-area, tightly contacted electrical connection region through winding and stacking. This enables direct conduction of the first conductor layers on both sides of each positive electrode plate 10, avoiding the forced lateral flow of electrons due to the insulation of the intermediate support layer. Similarly, the reserved second conductive portion 213 forms a stable electrical connection through winding and stacking, ensuring effective conduction of the second conductor layers on both sides of each negative electrode plate 30. This avoids the problem in traditional structures where electrons need to flow laterally along the conductor layer to the solder joint, shortens the electron transmission path, effectively reduces the internal resistance of the battery cell 100, and thus improves charging efficiency and rate performance.

[0043] Please refer to Figure 1 and Figure 2 In some embodiments, the first conductive portion 113 includes a first connecting segment 1131 and a first bending segment 1132. The first connecting segment 1131 is connected to the first conductor layer, the first bending segment 1132 is connected to the first connecting segment 1131, and the first bending segment 1132 bends away from the first conductor layer and makes contact with the first connecting segment 1131.

[0044] The second conductive part 213 includes a second connecting section 2131 and a second bending section 2132. The second connecting section 2131 is connected to the second conductor layer, and the second bending section 2132 is connected to the second connecting section 2131. The second bending section 2132 bends away from the second conductor layer and makes contact with the second connecting section 2131.

[0045] The first connecting segment 1131 collects electrons transmitted by the first conductor layer through direct connection with the first conductor layer, and provides a stable connection substrate for the first bending segment 1132, ensuring that the first bending segment 1132 can accurately form contact with itself after bending. At the same time, when multiple positive electrode plates 10 are wound and stacked, it serves as the basic contact unit for electrical connection, forming superimposed contact with the first bending segment 1132 or the first connecting segment 1131 of the adjacent positive electrode plate 10.

[0046] The first bending section 1132 increases the contact area and conduction path of the first conductive part 113 through the bending design. It forms a double-layer contact conduction with its own first connecting section 1131, improving the conduction reliability of the first conductive part 113 of a single positive electrode 10. It also expands the contact range with the first conductive parts 113 of other positive electrode 10 during winding and stacking, avoiding conduction interruption caused by failure of a single contact point.

[0047] Similarly, the second connecting segment 2131 and the second bending segment 2132 of the second conductive part 213 are consistent with the corresponding structure of the first conductive part 113 in terms of connection method with the second conductor layer, bending conduction logic and function of winding and stacking to form an electrical connection network. They will not be described in detail here. This design can simultaneously ensure the conduction efficiency and connection stability of the conductive parts of the positive and negative electrode sheets 30.

[0048] This embodiment uses a double-layer contact conduction design for the bending section and the connecting section. Each conductive part forms a dual conduction path. Even if a small gap occurs in one contact, electron transmission can still be guaranteed in the other. At the same time, when multiple conductive parts are wound and stacked, a multi-level contact network is formed, which increases the contact area, reduces the contact resistance, and further reduces electron transmission loss.

[0049] In addition, the design of the bending section allows the conductive part to adapt to the stacking pressure through its own deformation during the winding and stacking process, avoiding the problem of local warping or breakage caused by uneven stacking pressure in traditional rigid planar conductive parts. At the same time, the bending structure can disperse the stress during the winding process, improve the overall mechanical deformation resistance of the conductive part, and ensure the stability of the electrical connection structure during the assembly and long-term cycling of the battery cell 100.

[0050] In some embodiments, the first bending segment 1132 includes a first sub-bending segment 1133, a second sub-bending segment 1134, and a third sub-bending segment 1135 connected in sequence. The first sub-bending segment 1133 is connected to the end of the first connecting segment 1131 away from the first conductive layer. The third sub-bending segment 1135 is connected to the end of the second sub-bending segment 1134 away from the first sub-bending segment 1133. The third sub-bending segment 1135 bends and makes contact with the first connecting segment 1131.

[0051] The second bending segment 2132 includes a fourth sub-bending segment 2133, a fifth sub-bending segment 2134, and a sixth sub-bending segment 2135 connected in sequence. The fourth sub-bending segment 2133 is connected to the end of the first connecting segment 1131 away from the first conductive layer. The sixth sub-bending segment 2135 is connected to the end of the fifth sub-bending segment 2134 away from the fourth sub-bending segment 2133. The sixth sub-bending segment 2135 bends and makes contact with the second connecting segment 2131.

[0052] The first sub-bending segment 1133 provides a stable starting point for the bending structure through direct connection with the first connecting segment 1131, avoiding structural damage caused by subsequent multi-level bending directly acting on the first connecting segment 1131. At the same time, it initially adjusts the extension direction, laying the foundation for the transition of the second sub-bending segment 1134.

[0053] The second sub-bending segment 1134 follows the first sub-bending segment 1133 and further adjusts the bending angle and extension length to disperse the stress generated by the previous bending stage, making the overall bending process smoother. At the same time, through precise directional control, it ensures that the third sub-bending segment 1135 can contact the first connecting segment 1131 at the optimal angle, avoiding insufficient contact area due to angle deviation.

[0054] The third sub-bending segment 1135, through precise bending after multi-stage transitions, forms a large-area close contact with the first connecting segment 1131, constructing a core conduction path. Its contact area is further expanded compared to the double-stage bending, and the multi-stage adjustment makes the contact position more stable. Even with slight deformation, it can still maintain effective contact and ensure electronic transmission efficiency.

[0055] This embodiment uses a multi-stage transition to further expand the contact area between the contact end and the connecting segment compared to a double-stage bend, and the contact angle is more optimized. Compared to a single-stage bend, this design can further expand the contact area with the first connecting segment 1131, reduce contact resistance, and ensure electron transmission efficiency. Moreover, when multiple positive electrode sheets 10 are wound and stacked, this multi-stage bend structure can more flexibly adapt to the shape of the conductive parts of adjacent positive electrode sheets 10, increase the number of contact points, and form effective contact even if there is a slight alignment deviation. This not only improves the reliability of electrical connection, but also reduces the dependence on assembly precision, laying the foundation for optimizing the overall electrochemical performance and production yield of the cell 100.

[0056] Similarly, in the second bending segment 2132, the fourth sub-bending segment 2133, the fifth sub-bending segment 2134, and the sixth sub-bending segment 2135 correspond to the first sub-bending segment 1133, the second sub-bending segment 1134, and the third sub-bending segment 1135 in terms of their cooperation with the second connecting segment 2131, their role in improving structural stability, and their optimization effect on contact area and electrical connection reliability. They will not be elaborated here. Together, they provide a guarantee for the efficient conduction and stable connection of the conductive parts of the positive and negative electrode plates 30.

[0057] In some embodiments, the battery cell 100 further includes a first insulating protective layer 40, which is sleeved over the first conductive portion 113.

[0058] In this embodiment, the first insulating protective layer 40, on the one hand, blocks the current path between the first conductive part 113 and non-target components such as the outer shell of the battery cell 100 by being sleeved on the outside of the first conductive part 113, thus avoiding internal short circuit problems caused by accidental contact of the conductive part; on the other hand, its wrapping structure can provide physical support for the first conductive part 113 during the winding and stacking process of battery cell 100 assembly, as well as during the volume change of the active material layer of battery cell 100 over a long period of time, reducing the impact of external stress on the electrical connection structure of the first conductive part 113, preventing the first conductive part 113 from bending, deforming, or loosening of contacts, and ensuring the stability of the electrical connection.

[0059] In the stacked structure of the battery cell 100, the first insulating protective layer 40 can be connected to the uppermost and lowermost positive electrode plates 10 in the stacked structure of the battery cell 100. It is directly sleeved on the first conductive part 113 of each positive electrode plate 10 of the battery cell 100 in a sleeve-like manner. The sleeve shape is adapted to the segmented bending contour of the first conductive part 113, completely wrapping the first conductive part 113 and reserving contact and conduction space, without affecting the electrical connection. Moreover, the connection range covers the entire area of ​​the first conductive part 113, and the boundary does not exceed the junction of the first conductive part 113 and the first conductor layer, avoiding the covering of the active material layer. No additional fixation is required. Stable connection is achieved by relying on the material properties, which strengthens the insulation protection of the first conductive part 113.

[0060] In some embodiments, the battery cell 100 further includes a second insulating protective layer 50, which is sleeved over the second conductive portion 213.

[0061] In this embodiment, the second insulating protective layer 50, on the one hand, blocks the current path between the second conductive part 213 and non-target components such as the outer shell of the battery cell 100 by being sleeved on the outside of the second conductive part 213, thus avoiding internal short circuit problems caused by accidental contact of the conductive part; on the other hand, its wrapping structure can provide physical support for the second conductive part 213 during the winding and stacking process of battery cell 100 assembly, as well as during the volume change of the active material layer of battery cell 100 over a long period of time, reducing the impact of external stress on the electrical connection structure of the second conductive part 213, preventing the second conductive part 213 from bending, deforming, or loosening of contacts, and ensuring the stability of the electrical connection.

[0062] In the stacked structure of the battery cell 100, the second insulating protective layer 50 can be connected to the uppermost and lowermost negative electrode sheets 30 of the stacked structure of the battery cell 100. It is directly sleeved on the second conductive part 213 of each negative electrode sheet 30 of the battery cell 100 in a sleeve-like manner. The sleeve shape is adapted to the segmented bending contour of the second conductive part 213, completely wrapping the second conductive part 213 and reserving contact and conduction space, without affecting the electrical connection. Moreover, the connection range covers the entire area of ​​the second conductive part 213, and the boundary does not exceed the junction of the second conductive part 213 and the second conductor layer, avoiding the covering of the active material layer. No additional fixation is required. Stable connection is achieved by material properties, which strengthens the insulation protection of the edge second conductive part 213.

[0063] In some embodiments, the positive electrode 10, the separator 20, and the negative electrode 30 are stacked to form a stacked structure, and the stacked structure has a first side;

[0064] The first conductive portion 113 of the plurality of positive electrode plates 10 protrudes from the stacked structure along the first side direction, and the second conductive portion 213 of the plurality of negative electrode plates 30 protrudes from the stacked structure along the first side direction.

[0065] The first conductive part 113 protrudes from the stacked structure along the first side, thus separating it from the dense space inside the stacked structure and forming a wider electrical connection operation area on the outside. This facilitates the implementation of the winding and stacking process. At the same time, the concentrated protrusion layout can reduce the positional deviation of the conductive parts of each positive electrode 10 and improve the alignment accuracy of the electrical connection. In addition, the protrusion structure can also prevent the conductive part from accidentally contacting the separator 20 and negative electrode 30 inside the stacked structure, reducing the risk of short circuit and improving the safety of use.

[0066] The second conductive part 213 functions in conjunction with the first conductive part 113. After protruding from the first side of the stacked structure, it forms a concentrated negative electrode conductive connection area on the first side of the stacked structure, which facilitates the winding and stacking operation of multiple negative electrode sheets 30 conductive parts. At the same time, through the protrusion in an independent area on the same side as the first conductive part 113, the orderly separation of the positive and negative electrode conductive connection areas is achieved, ensuring the independent conduction of the positive and negative electrode circuits and avoiding mutual interference.

[0067] In this embodiment, the first conductive part 113 and the second conductive part 213 protrude from the stacked structure along the first side, so that the electrical connection operation is transferred from the narrow space inside the stacked structure to the open area outside, which greatly reduces the operation difficulty of the winding and stacking process and facilitates the precise operation of automated equipment. At the same time, the concentrated protrusion layout reduces the positional deviation of the first conductive part 113 and the second conductive part 213, eliminating the need to adjust the position of each individual conductive part, shortening the electrical connection process time, and improving the production efficiency of the battery cell 100.

[0068] In some embodiments, the stacked structure further has a second side disposed opposite to the first side;

[0069] The battery cell 100 also includes a first tab 60 and a second tab 70. The first tab 60 is connected to the first conductor layer, and the second tab 70 is connected to the second conductor layer. The first tab 60 and the second tab 70 are located on the second side.

[0070] The design of the second side provides an installation area for the first tab 60 and the second tab 70. By being set relative to the first side, it establishes a spatial separation between the internal conductive connection area and the external discharge area of ​​the cell 100, providing a structural reference for the stable connection between the tab and the corresponding conductor layer. At the same time, the symmetrical layout of the stacked structure on both sides can balance the overall structural stress of the cell 100, avoid uneven local stress caused by the concentrated placement of components, and improve the structural stability of the cell 100.

[0071] One end of the first tab 60 is directly connected to the first conductor layer of the positive electrode 10, which can collect the electron flow after all the positive electrodes 10 are turned on by the first conductive part 113. The other end extends to the outside of the stacked structure, serving as a connection terminal between the positive electrode and the external circuit, ensuring that the positive electrode current is stably led out to the external load or introduced from the external power source. Its layout on the second side can be far away from the conductive part connection area on the first side, avoiding spatial interference or electrical interference with the conductive part.

[0072] One end of the second tab 70 is directly connected to the second conductor layer of the negative electrode 30, collecting the electron flow after all the negative electrodes 30 are turned on by the second conductive part 213. The other end extends to the outside of the stacked structure, serving as a connection terminal between the negative electrode and the external circuit, ensuring the stable transmission of the negative electrode current. The design of being located on the second side makes the positive and negative tabs form a concentrated wiring area on the outside, which facilitates the connection between the battery cell 100 and external devices. At the same time, it is separated from the conductive part on the first side to avoid the current transmission path crossing.

[0073] In this embodiment, the first conductive part 113 and the second conductive part 213 are arranged on the first side, and the first electrode 60 and the second electrode 70 are arranged on the opposite side of the second side. This separates the conductive connection structure inside the battery cell 100 from the electrode output structure outside, avoiding accidental contact due to space congestion on the same side. At the same time, the positive and negative electrodes are located on the second side and are set independently. The positive and negative electrodes can be further prevented from short-circuiting through reasonable spacing design. This strengthens the circuit safety of the battery cell 100 from the perspective of spatial layout and reduces the risk of electrical failure.

[0074] In some embodiments, the length of the first conductive portion 113 is greater than or equal to 5 mm and less than or equal to 50 mm, and the width of the first conductive portion 113 is greater than or equal to 1 mm and less than or equal to 100 mm; and / or,

[0075] The length of the second conductive part 213 is greater than or equal to 5 mm and less than or equal to 50 mm, and the width of the second conductive part 213 is greater than or equal to 1 mm and less than or equal to 100 mm.

[0076] The dimensions of the first conductive part 113 are limited to a length of 5mm-50mm and a width of 1mm-100mm. This size range allows the first conductive part 113 to ensure effective overlapping contact during winding and stacking with sufficient length, ensuring a stable electron transmission path, while controlling its own space ratio through the upper limit of length, avoiding affecting the effective area of ​​the active material layer of the positive electrode sheet 10. At the same time, the width design of 1mm to 100mm can adapt to positive electrode circuits with different current requirements. Small width (such as 1mm-20mm) is suitable for low current scenarios, while large width (such as 20mm to 100mm) can improve current carrying capacity, avoid local overheating problems under high current, and ensure the safe conduction of the positive electrode circuit.

[0077] Similarly, the dimensions of the second conductive part 213 are limited to: a length of 5mm-50mm and a width of 1mm-100mm. This size range ensures that the second conductive part 213 achieves stable contact of multiple negative electrode sheets 30 through sufficient length, and can also control its own space ratio through the upper limit of length to avoid occupying too much space of negative electrode sheets 30; at the same time, the width of 1mm-100mm can be flexibly adjusted according to the current requirements of the negative electrode circuit, ensuring efficient transmission of negative electrode electrons while preventing abnormal current density caused by improper width.

[0078] This application also provides an electrochemical device, including the battery cell 100 as described above. This electrochemical device can be a lithium secondary battery, including a lithium metal secondary battery, a lithium-ion secondary battery, a lithium polymer secondary battery, or a lithium-ion polymer secondary battery. By integrating the battery cell 100 and using a suitable casing, electrolyte, etc., this electrochemical device constructs a complete power conversion and supply system. This electrochemical device can possess all the technical features and corresponding beneficial effects of the aforementioned battery cell 100, which will not be elaborated further here.

[0079] This application also provides an electrical device, including the electrochemical device described above. Specifically, the electrical device can be a new energy vehicle, a battery storage device, a computer, a mobile phone, or other electrical equipment. This electrical device can possess all the technical features and corresponding beneficial effects of the aforementioned electrochemical device, which will not be elaborated further here.

[0080] The above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make other variations or modifications based on the above description. It is impossible to exhaustively list all possible implementations here. All obvious variations or modifications derived from the technical solutions of this utility model are still within the protection scope of this utility model.

Claims

1. An electric cell, characterized by, It includes multiple positive electrode plates, multiple separators and multiple negative electrode plates arranged in alternating layers, wherein the separators are located between adjacent positive electrode plates and negative electrode plates; Each of the positive electrode plates includes a first current collector, the first current collector includes a first support layer and a first conductor layer disposed on both sides of the first support layer, the first conductor layer has a first conductive portion, and the first conductive portions of the plurality of positive electrode plates are wound and stacked to form an electrical connection; Each of the negative electrode sheets includes a second current collector, which includes a second support layer and a second conductor layer disposed on both sides of the second support layer. The second conductor layer has a second conductive portion, and the second conductive portions of the plurality of negative electrode sheets are wound and stacked to form an electrical connection.

2. The electric cell of claim 1, wherein, The first conductive portion includes a first connecting segment and a first bending segment. The first connecting segment is connected to the first conductor layer, and the first bending segment is connected to the first connecting segment. The first bending segment bends away from the first conductor layer and makes contact with the first connecting segment. The second conductive portion includes a second connecting segment and a second bending segment. The second connecting segment is connected to the second conductor layer, and the second bending segment is connected to the second connecting segment. The second bending segment bends away from the second conductor layer and makes contact with the second connecting segment for electrical connection.

3. The electric cell of claim 2, wherein, The first bending segment includes a first sub-bending segment, a second sub-bending segment, and a third sub-bending segment connected in sequence. The first sub-bending segment is connected to the end of the first connecting segment away from the first conductive layer. The third sub-bending segment is connected to the end of the second sub-bending segment away from the first sub-bending segment. The third sub-bending segment bends and makes contact with the first connecting segment. The second bending segment includes a fourth sub-bending segment, a fifth sub-bending segment, and a sixth sub-bending segment connected in sequence. The fourth sub-bending segment is connected to the end of the first connecting segment away from the first conductive layer. The sixth sub-bending segment is connected to the end of the fifth sub-bending segment away from the fourth sub-bending segment, and the sixth sub-bending segment bends and makes contact with the second connecting segment.

4. The electric cell of claim 1, wherein, The battery cell also includes a first insulating protective layer, which is sleeved over the first conductive part.

5. The electric cell of claim 1, wherein, The battery cell also includes a second insulating protective layer, which is sleeved over the second conductive part.

6. The electric cell of any one of claims 1 to 5, wherein, The positive electrode, separator, and negative electrode are stacked to form a stacked structure, and the stacked structure has a first side. The first conductive portions of the plurality of positive electrode plates protrude from the stacked structure along the first lateral direction, and the second conductive portions of the plurality of negative electrode plates protrude from the stacked structure along the first lateral direction.

7. The electric cell of claim 6, wherein, The stacked structure also has a second side disposed opposite to the first side; The battery cell also includes a first tab and a second tab, the first tab being connected to the first conductor layer and the second tab being connected to the second conductor layer, with the first tab and the second tab located on the second side.

8. The electric cell of claim 1, wherein, The length of the first conductive portion is greater than or equal to 5 mm and less than or equal to 50 mm, and the width of the first conductive portion is greater than or equal to 1 mm and less than or equal to 100 mm; and / or, The length of the second conductive part is greater than or equal to 5 mm and less than or equal to 50 mm, and the width of the second conductive part is greater than or equal to 1 mm and less than or equal to 100 mm.

9. An electrochemical device, characterized by, Includes the battery cell as described in any one of claims 1 to 8.

10. An electric device, characterized by Includes the electrochemical device as described in claim 9.

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