Patent Description:
An electrochemical apparatus is an apparatus that converts external energy into electric energy and that stores the electric energy in the electrochemical apparatus, to supply power to an external device (for example, a portable electronic apparatus) as needed. Generally, an electrochemical apparatus includes a housing, an electrode assembly accommodated in the housing, and tabs. The electrode assembly includes a first electrode plate, a second electrode plate, and a separator, where the first electrode plate and the second electrode plate have opposite polarities, with the separator sandwiched therebetween for separation. One end of one tab is connected to the first electrode plate, and an other end of the tab extends out of the housing; a plurality of conducting strips protrude from an edge of the second electrode plate, where the plurality of conducting strips are stacked; and one end of another tab is welded to the conducting strips stacked, and an other end of the tab extends out of the housing. <CIT> describes relevant electrode tab shape and connections to balance high-rate charge-discharge performance and safety performance of an electrochemical device. <CIT> describes a relevant tab of a battery cell having distinct portions connected in sequence.

During implementation of this application, the inventors of this application found that when the first tab is experiencing vibration and impact, the first tab directly connected to the first electrode plate is prone to damage at a joint between the first tab and the first electrode plate, resulting in failure of the electrochemical apparatus.

This application intends to provide an electrochemical apparatus and an electronic apparatus, to alleviate the problem that the first tab directly connected to the first electrode plate is prone to damage at a joint between the first tab and the first electrode plate.

The following technical solutions are adopted for this application to resolve the technical problem:
An electrochemical apparatus is provided, including a housing, an electrode assembly, a first tab, and a second tab. The electrode assembly is accommodated in the housing and includes a first electrode plate, a second electrode plate, and a separator disposed between the first electrode plate and the second electrode plate, where the first electrode plate, the second electrode plate, and the separator are stacked and then wound. The first electrode plate includes a first current collector. The second electrode plate includes a second current collector and a plurality of conducting strips integrally arranged with the second current collector, where the plurality of conducting strips protrude from the second current collector along a first direction, the plurality of conducting strips are stacked in a thickness direction of the electrode assembly to form a collecting portion, and the first direction is perpendicular to the thickness direction. The first tab directly connected to the first electrode plate and made of a sheet structure extending in a bent shape as a whole, the first tab includes a first portion, a second portion, and a third portion, where the first portion, the second portion, and the third portion are connected in sequence, the first portion is connected to the first current collector, the second portion is located outside the first current collector and disposed in a bent shape, and the third portion extends out of the housing. The second tab is connected to the collecting portion and extends out of the housing.

Since the first tab includes the second portion disposed in a bent way, when the first tab is impacted, the first tab can relieve part of impact force through deformation of the second portion, such that impact force finally reaching a joint between the first tab and the first electrode plate is reduced to some extent. Therefore, the electrochemical apparatus according to some embodiments of this application can alleviate the problem that the first tab directly connected to the first electrode plate is prone to damage at a joint between the first tab and the first electrode plate caused by external impact.

In some embodiments, the electrode assembly has a first surface and a second surface, where the first surface and the second surface are opposite to each other in the thickness direction, and the second portion includes a first connecting section and a second connecting section. One end of the first connecting section is connected to the first portion and an other end of the first connecting section extends toward the first surface. The second connecting section is located on a side of the first connecting section far away from the electrode assembly, one end of the second connecting section is connected to an end of the first connecting section far away from the first portion, and an other end of the second connecting section is connected to the third portion. Therefore, when the first tab is impacted, the second connecting section bends elastically toward the second connecting section, so as to relieve part of impact force.

In some embodiments, the second portion further includes a bending section. The first connecting section and the second connecting section are oppositely disposed in the first direction, one end of the bending section is connected to an end of the first connecting section facing toward the first surface, and an other end of the bending section is connected to an end of the second connecting section facing toward the first surface. In this way, the second portion is a U-shaped structure as a whole.

In some embodiments, a thickness of the electrode assembly in the thickness direction is L<NUM> mm. Viewed from a second direction, a distance from an overlapping part of the first portion and the first current collector in the thickness direction to the first surface is L<NUM> mm, where <NUM> ≤ L<NUM>/L<NUM> ≤ <NUM>. The second direction is perpendicular to the first direction and the thickness direction. Such arrangement can maintain sufficient elasticity of the second portion of the first tab and realize low temperature rise in a charging process of the electrochemical apparatus.

In some embodiments, viewed from a second direction, a distance from an overlapping part of the first portion and the first current collector in the thickness direction to the first surface is L<NUM> mm. Viewed from a second direction, a distance from the second portion to the first surface in the thickness direction is L<NUM> mm, where <NUM> ≤ (L<NUM>-L<NUM>)/L<NUM> ≤ <NUM>. The second direction is perpendicular to the first direction and the thickness direction. Such arrangement allows the electrochemical apparatus to have excellent anti-drop performance and vibration resistance.

In some embodiments, viewed from a second direction, a distance from an end of the third portion close to the second portion to the first surface in the thickness direction is L<NUM> mm, and a distance from an overlapping part of the first portion and the first current collector in the thickness direction to the first surface is L<NUM> mm, where L<NUM>/L<NUM> ≤ <NUM>. The second direction is perpendicular to the first direction and the thickness direction. When the first tab is impacted by an external force, the second connecting section bends toward the electrode assembly. In the thickness direction, under the condition that an end of the second connecting section facing away from the first surface goes significantly beyond an end of the first connecting section facing away from the first surface, the end of the second connecting section facing away from the first surface may be inserted inversely to touch the second electrode plate in the electrode assembly, causing short circuit to the electrochemical apparatus. Such arrangement with L<NUM>/L<NUM> ≤ <NUM> is designed to control the end of the second connecting section facing away from the second surface not to go beyond the end of the first connecting section facing away from the first surface, or to go slightly beyond the end of the first connecting section facing away from the first surface, so as to reduce the risk of short circuit.

In some embodiments, a length of the first portion beyond an edge of the second current collector is L<NUM> mm, where <NUM> ≤ L<NUM> ≤ <NUM>. Such arrangement is designed to form a specified gap between the second portion and the edge of the second current collector, so as to reduce the risk of the second portion coming into contact with the second electrode plate to some extent due to shaking and the risk of short circuit resulting therefrom.

In some embodiments, the housing includes a body portion and a sealing portion connected to the body portion. The body portion is provided with an accommodating chamber, the electrode assembly is accommodated in the accommodating chamber, and the first tab and the second tab pass through the sealing portion to extend out of the housing. A length of the third portion extending in the accommodating chamber in the first direction is L<NUM>, and a length of the second tab extending in the accommodating chamber in the first direction is L<NUM>, where |L<NUM>-L<NUM>| ≤ <NUM>. Such arrangement is designed to enable the electrochemical apparatus to have better anti-drop performance.

In some embodiments, the first tab is welded to the first current collector, and the first tab and the second tab extend out of the housing in the first direction.

In some embodiments, the first electrode plate is an anode electrode plate, and the second electrode plate is a cathode electrode plate. A material of the first tab includes copper, a copper alloy, nickel, or a nickel alloy, and a material of the second tab includes aluminum or an aluminum alloy.

In some embodiments, a cross-section area of the first tab is s<NUM> mm<NUM>, a cross-section area of the second tab is s<NUM> mm<NUM>, and s<NUM> > s<NUM>. Tunneling of electrons in or out the first electrode plate is realized by using the first tab, while tunneling of electrons in or out the second electrode plate is realized by using the plurality of conducting strips and the second tab. Compared with the entirety composed of all the conducting strips and the second tab, the first tab is more difficult to dissipate heat. Such arrangement with s<NUM> > s<NUM> is beneficial to increase a surface area of the first tab, thereby increasing a heat dissipation rate of the first tab, such that the first tab and the second tab dissipate heat in a more uniform manner.

In some embodiments, the housing includes a body portion and a sealing portion connected to the body portion, where the body portion is provided with an accommodating chamber, the electrode assembly is accommodated in the accommodating chamber, and the first tab passes through the sealing portion to extend out of the housing. The housing is provided with a third surface and a fourth surface, where the first surface and the second surface are opposite to each other in the thickness direction. In the thickness direction, the third surface, the first surface, the second surface, and the fourth surface are sequentially arranged, and a distance from the sealing portion to the third surface is greater than a distance from the sealing portion to the fourth surface. Therefore, the body portion includes a first accommodating space located between the sealing portion and the third surface and a second accommodating space located between the sealing portion and the fourth surface; and the entire second portion is located in the first accommodating space.

In some embodiments, the first electrode plate further includes a first active material layer disposed on the first current collector, a first concave portion is disposed on the first active material layer, the first concave portion exposes the first current collector, and the first tab is disposed at the first concave portion and connected to the first current collector.

The following technical solutions are further adopted for this application to resolve the technical problem:
An electronic apparatus is provided including the foregoing electrochemical apparatus. With the electrochemical apparatus provided, the electronic apparatus can also alleviate the problem that a first tab in the electrochemical apparatus thereof is prone to damage at a joint between the first tab and a first electrode plate caused by external impact.

To describe the technical solutions in some embodiments of this application more clearly, the following briefly describes the accompanying drawings required for describing some embodiments. Apparently, the accompanying drawings in the following descriptions show only some embodiments of this application, and persons of ordinary skill in the art may still derive others drawings from structures shown in these accompanying drawings.

For ease of understanding this application, the following further describes this application in detail with reference to the accompanying drawings and specific embodiments. It should be noted that when an element is expressed as being "fastened/fixed" to another element, it may be directly fastened/fixed to the another element or one or more intermediate elements may be present. When an element is expressed as being "connected" to another element, it may be directly connected to the another element or one or more intermediate elements may be present. The terms "vertical", "horizontal", "left", "right", "inside", "outside", and similar expressions used in this specification are merely for description purposes.

Unless otherwise defined, all technical and scientific terms used herein shall have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are merely intended to describe specific embodiments but not to constitute any limitations on this application. The term "and/or" used herein includes any and all combinations of one or more associated items that are listed.

In addition, technical features involved in different embodiments of this application that are described below may be combined as long as they do not conflict with each other.

In this specification, "installing" includes fixing or limiting an element or apparatus to a specific location or place by means of welding, screwing, clamping, bonding, or the like. The element or apparatus may stay still at the specific position or place, or may move within a limited range. After being fixed or limited to the specific position or place, the element or apparatus can be disassembled or cannot be disassembled. This is not limited in the embodiments of this application.

Referring to <FIG>. <FIG> is a schematic diagram of an electrochemical apparatus <NUM> according to an embodiment of this application; <FIG> is a schematic cross-sectional diagram of the electrochemical apparatus <NUM> along line A-A; <FIG> is a schematic cross-sectional diagram of the electrochemical apparatus along line B-B; and <FIG> is a schematic cross-sectional diagram of the electrochemical apparatus along line C-C. The electrochemical apparatus <NUM> includes a housing <NUM>, an electrode assembly <NUM>, a first tab <NUM>, and a second tab <NUM>. The housing <NUM> is an installation support structure of the foregoing structures and also is a protective structure of the electrochemical apparatus <NUM>. The electrode assembly <NUM> is accommodated in the housing <NUM>, and includes a first electrode plate <NUM>, a second electrode plate <NUM>, and a separator <NUM> disposed between the first electrode plate <NUM> and the second electrode plate <NUM>, where the first electrode plate <NUM>, the second electrode plate <NUM>, and the separator <NUM> are stacked and then wound. The first electrode plate <NUM> includes a first current collector <NUM>. The second electrode plate <NUM> includes a second current collector <NUM> and a plurality of conducting strips <NUM> integrally arranged with the second current collector <NUM>. All the conducting strips <NUM> protrude from the second current collector <NUM> along a first direction X shown in the figure, and all the conducting strips <NUM> are stacked in a thickness direction Z of the electrode assembly <NUM> shown in the figure to form a collecting portion <NUM>, where the first direction X is perpendicular to the thickness direction Z. The first tab <NUM> includes a first portion <NUM>, a second portion <NUM>, and a third portion <NUM>, where the first portion <NUM>, the second portion <NUM>, and the third portion <NUM> are connected in sequence, the first portion <NUM> is connected to the first electrode plate <NUM>, the second portion <NUM> is located outside the first electrode plate <NUM> and disposed in a bent shape, and an end of the third portion <NUM> far away from the second portion <NUM> extends out of the housing <NUM>. One end of the second tab <NUM> is connected to the collecting portion <NUM>, and an other end of the second tab <NUM> extends out of the housing <NUM>. "A plurality of" mentioned in this application means more than two. The following describes the housing <NUM>, the electrode assembly <NUM>, the first tab <NUM>, and the second tab <NUM> in sequence.

For the housing <NUM>, specifically referring to <FIG>. The housing <NUM> as a whole appears like a flat box-like structure, and a thickness direction of the housing <NUM> is the same as the thickness direction Z of the electrode assembly <NUM>. The housing <NUM> is provided with a third surface <NUM> and a fourth surface <NUM>, where the third surface <NUM> and a fourth surface <NUM> are opposite to each other in the thickness direction thereof. The housing <NUM> is further provided with a first end portion <NUM> and a second end portion <NUM>, where the first end portion <NUM> and the second end portion <NUM> are opposite to each other each other. The first end portion <NUM> is an end of the housing <NUM> from which the first tab <NUM> and the second tab <NUM> extend, and the second end portion <NUM> is an end of the housing <NUM> far away from the first tab <NUM>; and a direction determined by pointing from one of the first end portion <NUM> and the second end portion <NUM> to the other is consistent with the first direction X. In addition, the housing <NUM> is further provided with an accommodating chamber <NUM> to accommodate the electrode assembly <NUM>, part of the first tab <NUM>, part of the conducting strip <NUM>, and part of the second tab <NUM>.

In this embodiment, the electrochemical apparatus <NUM> is a pouch battery; and the housing <NUM> is made of a flexible sheet material, for example, aluminum-plastic film. Specifically, referring to <FIG>, <FIG>, and with references to other accompanying drawings, the housing <NUM> includes a body portion <NUM> and a sealing portion <NUM> connected to the body portion <NUM>. The body portion <NUM> is provided with the accommodating chamber <NUM>. The electrode assembly <NUM> is accommodated in the accommodating chamber <NUM>. The sealing portion <NUM> extends outward from a surface of the body portion <NUM> and is a region for sealing in a forming process of the housing <NUM>; and the first tab <NUM> and the second tab <NUM> pass through the sealing portion <NUM> to extend out of the housing <NUM>. A distance from a side of the sealing portion <NUM> close to the third surface <NUM> to the third surface <NUM> in the thickness direction Z is D<NUM>, and a distance from a side of the sealing portion <NUM> close to the fourth surface <NUM> to the fourth surface <NUM> in the thickness direction Z is D<NUM>, where D<NUM> > D<NUM>. In this way, the accommodating chamber <NUM> includes a first accommodating space <NUM> and a second accommodating space <NUM>, where the first accommodating space <NUM> is located between the sealing portion <NUM> and the third surface <NUM> in the thickness direction Z, the second accommodating space <NUM> is located between the sealing portion <NUM> and the fourth surface <NUM> in the thickness direction Z, and a size of the first accommodating space <NUM> in the thickness direction Z is greater than a size of the second accommodating space <NUM> in the thickness direction Z. It should be noted that, in other embodiments of this application, the electrochemical apparatus <NUM> may alternatively be a hard shell battery. Correspondingly, the housing <NUM> may be made of a hard material, for example, a polymer material or a metal material.

For the electrode assembly <NUM>, specifically referring to <FIG> and with reference to other accompanying drawings. The electrode assembly <NUM> includes a first electrode plate <NUM>, a second electrode plate <NUM>, and a separator <NUM>, where the first electrode plate <NUM>, the second electrode plate <NUM>, and the separator <NUM> are stacked. The first electrode plate <NUM> and the second electrode plate <NUM> have opposite polarities, and the separator <NUM> is disposed therebetween for separation. The first electrode plate <NUM>, the second electrode plate <NUM>, and the separator <NUM> are jointly wound and integrally present a cylindrical structure with a flat circular end face. The electrode assembly <NUM> is provided with a first surface <NUM> and a second surface <NUM>, where the first surface <NUM> and the second surface <NUM> are opposite to each other in the thickness direction Z, the first surface <NUM> is disposed close to the third surface <NUM>, and the second surface <NUM> is disposed close to the fourth surface <NUM>. A thickness of the electrode assembly <NUM> in the thickness direction Z is L<NUM> mm. Persons skilled in the art may take a CT picture for the electrochemical apparatus <NUM> in the second direction Y; then may obtain a distance from the first surface <NUM> and the second surface <NUM> by using CT equipment, or may measure a distance from the first surface <NUM> and the second surface <NUM>, namely L<NUM>, by using an instrument. It should be noted that a comparison of dimensions related to this application shall be made after a reasonable measurement error has been eliminated.

In this embodiment, the first electrode plate <NUM> is an anode electrode plate, and the second electrode plate <NUM> is a cathode electrode plate. Referring to <FIG> is a schematic diagram of a connection between a first electrode plate <NUM> and a first tab <NUM> both in a flattened state, where the first electrode plate <NUM> includes the first current collector <NUM> and a first active material layer <NUM>. The first current collector <NUM> is a substrate material layer for supporting the first active material layer <NUM>, and also serves as a carrier for electron moving in the first electrode plate <NUM>; and the first active material layer <NUM> is disposed on a surface of the first current collector <NUM>, and serves as a carrier for intercalation and deintercalation of lithium ions. The first active material layer <NUM> is provided with a first concave portion <NUM> to expose the first current collector <NUM>; and the first tab <NUM> is connected to the first current collector <NUM> at the first concave portion <NUM>. Certainly, in other embodiments of this application, the first active material layer <NUM> may alternatively be provided with no first concave portion <NUM>. Correspondingly, the first current collector <NUM> is provided with a naked foil region with no first active material layer <NUM> provided at its end, and the first current collector <NUM> is connected to the first tab <NUM> through the naked foil region.

For material selection for the first current collector <NUM>, in some embodiments, a material of the first current collector <NUM> includes copper, which is specifically a foil made of copper. It should be understood that, in other embodiments, the first current collector <NUM> may alternatively include another suitable conductive material. For example, in some embodiments, the first current collector <NUM> includes a copper alloy, nickel, or a nickel alloy. The first active material layer <NUM> includes an anode active material. For example, in some embodiments, the first active material layer <NUM> includes graphite, a conductive agent, and a binder. These materials are mixed, stirred to uniformity, and applied on a surface of the first current collector <NUM>, such that the first active material layer <NUM> is obtained.

Referring to <FIG> is a schematic diagram of the second electrode plate <NUM> in a flattened state. The second electrode plate <NUM> includes a second current collector <NUM>, a second active material layer <NUM>, and a plurality of conducting strips <NUM> protruding from the second current collector <NUM> in the first direction X. The second current collector <NUM> is a substrate material layer for supporting the second active material layer <NUM>, and also serves as a carrier for electron moving in the second electrode plate <NUM>; and the second active material layer <NUM> is provided on a surface of the second current collector <NUM>, and serves as a carrier for intercalation and deintercalation of lithium ions.

For material selection for the second current collector <NUM>, in some embodiments, a material of the second current collector <NUM> includes aluminum, which is specifically a foil made of aluminum. It should be understood that, in other embodiments, the second current collector <NUM> may alternatively include another suitable conductive material. For example, in some embodiments, the second current collector <NUM> includes aluminum alloy, nickel, or nickel alloy. The second active material layer <NUM> includes a cathode active material. For example, in some embodiments, the second active material layer <NUM> includes lithium iron phosphate particles, a dispersing agent, a binder, and a conductive agent. These materials are mixed, stirred to uniformity, and applied on a surface of the second current collector <NUM>, such that the second active material layer <NUM> is obtained.

The conducting strip <NUM> is of a sheet structure and is connected to the second current collector <NUM>. The conducting strips <NUM> are spaced from each other in a winding direction of the second electrode plate <NUM>, thereby dividing the second electrode plate <NUM> into a plurality of regions staggered in the winding direction. Still referring to <FIG>. The conducting strips <NUM> are connected to an end of the second current collector <NUM> and are sequentially arranged in the thickness direction Z, ends of the conducting strips <NUM> far away from the second electrode plate <NUM> are stacked, and stacked portions of the conducting strips <NUM> constitute the collecting portion <NUM>. In this way, the conducting strips <NUM> connect these regions in parallel, which is beneficial to reduce overall internal resistance of the second electrode plate <NUM> and reduce heat dissipated by the second electrode plate <NUM>.

In some embodiments, the conducting strips <NUM> are integrally formed with the second current collector <NUM>. In other words, the conducting strips <NUM> are formed by extending outward from an edge of the second current collector <NUM>. In a process of preparing the electrochemical apparatus <NUM>, the second active material layer <NUM> is applied on a surface of the second current collector <NUM>; a region of the second current collector <NUM> not applied with the second active material layer <NUM> is cut into a shape shown in <FIG>; and the first electrode plate <NUM>, the separator <NUM>, the second electrode plate <NUM>, and the separator <NUM> are stacked sequentially and wound, ensuring that the conducting strips <NUM> are roughly aligned in the thickness direction; and finally ends of the conducting strips <NUM> far away from the second electrode plate <NUM> are laminated and fixed by welding, such that the electrode assembly <NUM> shown in <FIG> and <FIG> is obtained.

In some embodiments, the entire collecting portion <NUM> is U-shaped, and the collecting portion <NUM> includes a first extension section <NUM>, a second extension section <NUM>, and a third extension section <NUM>, where the first extension section <NUM>, the second extension section <NUM>, and the third extension section <NUM> are connected in sequence. Along an extension path of the collecting portion <NUM>, the first extension section <NUM> is part of the collecting portion <NUM> close to the second electrode plate <NUM>, and the third extension section <NUM> is part of the collecting portion <NUM> far away from the second electrode plate <NUM>. In the first direction X, the first extension section <NUM> and the third extension section <NUM> are opposite to each other, and the first extension section <NUM> is located between the electrode assembly <NUM> and the third extension section <NUM>. The second extension section <NUM> is connected to the first extension section <NUM> and the third extension section <NUM> separately, such that the first extension section <NUM>, the second extension section <NUM>, and the third extension section <NUM> jointly enclose a U-shaped structure. It should be understood that, even if the collecting portion <NUM> in this embodiment extends in a U-shaped manner, in other embodiments of this application, the collecting portion <NUM> may also extend in a straight line, an arc, or in any another shape, which is not specifically limited in this application.

For the first tab <NUM>, still referring to <FIG> and <FIG>, one end of the first tab <NUM> is connected to the electrode assembly <NUM>, and an other end of the first tab <NUM> extends out of the housing <NUM> in the first direction X, such that a conductive terminal of the electrochemical apparatus <NUM> is constituted and configured to be connected to an external electricity load. The first tab <NUM> is of a sheet structure and extends in a bent shape as a whole, and the first tab <NUM> includes a first portion <NUM>, a second portion <NUM>, and a third portion <NUM>, where the first portion <NUM>, the second portion <NUM>, and the third portion <NUM> are connected in sequence. The following describes the first portion <NUM>, the second portion <NUM>, and the third portion <NUM> in sequence with reference to <FIG>.

The first portion <NUM> is connected to the first electrode plate <NUM>, is flatshaped, and extends in the first direction X. The first portion <NUM> is located in the first concave portion <NUM> and is fixed to the first current collector <NUM> by welding. Viewed from the second direction Y, a distance from an overlapping part of the first portion <NUM> and the first current collector <NUM> in the thickness direction Z to the first surface <NUM> is L<NUM> mm. Persons skilled in the art may take a CT picture for the electrochemical apparatus <NUM> in the second direction Y; then may obtain a distance from the part of the first portion <NUM> overlapping on a surface of the first current collector <NUM> to the first surface <NUM> by using CT equipment, or may measure a distance from the part of the first portion <NUM> overlapping on a surface of the first current collector <NUM> to the first surface <NUM>, namely, L<NUM>, by using an instrument. In this embodiment, in the first direction X, an end of the first portion <NUM> connecting to the second portion <NUM> is disposed beyond an edge of the first electrode plate <NUM>, and a length of the first portion <NUM> beyond an edge of the second current collector <NUM> is L<NUM> mm. Persons skilled in the art may take a CT picture for the electrochemical apparatus <NUM> in the second direction Y; then may obtain a distance from an upper end of the first portion <NUM> to an upper edge of the second electrode plate <NUM>, namely, L<NUM> as shown in <FIG>, by using CT equipment or an instrument.

The second portion <NUM> is located outside the first electrode plate <NUM> and is disposed in a bent shape; and an end of the second portion <NUM> is connected to the first portion <NUM>, and an other end of the second portion <NUM> is connected to the third portion <NUM>. In this embodiment, the entire second portion <NUM> is U-shaped, and the second portion <NUM> includes a first connecting section <NUM>, a second connecting section <NUM>, and a bending section <NUM>. One end of the first connecting section <NUM> is connected to the first portion <NUM> and an other end of the first connecting section <NUM> extends toward the first surface <NUM>. An end of the bending section <NUM> is connected to an end of the first connecting section <NUM> facing toward the first surface <NUM>, and the end of the bending section <NUM> bends toward a side of the first connecting section <NUM> far away from the electrode assembly <NUM>. In the first direction X, the second connecting section <NUM> is located on a side of the first connecting section <NUM> far away from the electrode assembly <NUM>, and the second connecting section <NUM> and the first connecting section <NUM> are opposite to each other in the first direction X. One end of the second connecting section <NUM> is connected to an end of the bending section <NUM> far away from the first connecting section <NUM>, and an other end of the second connecting section <NUM> extends leaving away from the first surface <NUM>. In other words, an end of the second connecting section <NUM> far away from the third portion <NUM> is indirectly connected to the first connecting section <NUM> through the bending section <NUM>. In this way, the first connecting section <NUM>, the bending section <NUM>, and the second connecting section <NUM> jointly form a U-shaped structure. Viewed from the second direction Y, a distance from the second portion <NUM> to the first surface <NUM> in the thickness direction Z is L<NUM> mm. Specifically, L<NUM> refers to a minimum distance, viewed from the second direction Y, from the second portion <NUM> to the first surface <NUM> in the thickness direction Z. Persons skilled in the art may take a CT picture for the electrochemical apparatus <NUM> in the second direction Y, and may draw a tangent line P-P on a side of the second portion <NUM> close to the first surface <NUM>, where the tangent line is parallel to the first surface <NUM>; and then may measure a distance from the tangent line P-P to the first surface <NUM>, namely distance L<NUM>, by using an instrument.

It should be understood that in this embodiment, the second portion <NUM> includes the first connecting section <NUM>, the bending section <NUM>, and the second connecting section <NUM>, all of which form a U-shaped structure. However, this application is not limited thereto, provided that the second portion <NUM> is in a bent shape. For example, in some other embodiments of this application, the second connecting section <NUM> of the second portion <NUM> is directly connected to the first connecting section <NUM>, and in this case, the second portion <NUM> is a V-shaped structure. In other words, in some cases, the bending section <NUM> may be omitted. For another example, in some other embodiments of this application, the second portion <NUM> includes two V-shaped structures, where the two V-shaped structures are connected in sequence such that the second portion <NUM> is continuously bent.

The third portion <NUM> is flat shaped on the whole, one end of which is connected to an end of the second portion <NUM> far away from the first portion <NUM>, and an other end of which extends out of the housing <NUM>. A length of the third portion <NUM> extending in the first direction X in the accommodating chamber <NUM> is L<NUM> mm. Persons skilled in the art may take a CT picture for the electrochemical apparatus <NUM> in the second direction Y, and may obtain a distance from an upper corner of the second portion <NUM> to an inner surface of the housing <NUM>, as shown in <FIG>, by using CT equipment, or measure a distance from an upper corner of the second portion <NUM> to an inner surface of the housing <NUM>, namely, distance L<NUM> as shown in <FIG>, by using an instrument. When the first tab <NUM> is impacted, by means of elastic deformation of the second portion <NUM>, at least part of impact force applied on the first tab <NUM> can be relieved such that impact force finally transferred to the first portion <NUM> and affecting a connection region between the first portion <NUM> and the first electrode plate <NUM> is reduced.

In some embodiments, to alleviate transitions among the first portion <NUM>, the second portion <NUM>, and the third portion <NUM> through sharp corners, which leads to stress concentration in a connection region of the three portions in the first tab <NUM>, and affects mechanical performance of the first tab <NUM>, a rounded corner is arranged at an end of the second portion <NUM> close to the first portion <NUM>, and the rounded corner is connected to the first portion <NUM>; and a rounded corner is arranged at an end of the second portion <NUM> close to the third portion <NUM>, and the rounded corner is connected to the third portion <NUM>.

In some embodiments, L<NUM> ≥ <NUM>; such arrangement is designed to form a specified gap between the second portion <NUM> and an edge of the second electrode plate <NUM>, so as to reduce the risk of the second portion <NUM> coming into contact with the second electrode plate <NUM> due to shaking and a risk of short circuit resulting therefrom to some extent. The following describes a relationship between distance L<NUM> and short circuit of electrochemical apparatus <NUM> with reference to experimental data.

Specifically, referring to Table <NUM>. Table <NUM> is a comparison table of short-circuit test for electrochemical apparatuses <NUM> of different examples. The electrochemical apparatuses <NUM> of various examples were the same except for the distance L<NUM>; and the test aims to obtain the relationship based on the test results by controlling the distance L<NUM> of the electrochemical apparatus <NUM>.

A short-circuit test method of electrochemical apparatus includes the following steps:.

In the examples, <NUM> electrochemical apparatuses <NUM> were tested according to the method described above. The number of electrochemical apparatuses <NUM> that had passed the test was recorded, and the number of electrochemical apparatuses passed the test and the total number of tested electrochemical apparatuses were recorded in Table <NUM> in a fractional form. It can be learned from Examples <NUM> to <NUM> that when L<NUM> < <NUM>, the electrochemical apparatus <NUM> has a specified risk of short circuit of the electrode assembly; and when L<NUM> ≥ <NUM>, the preceding deficiencies may be better overcome.

In addition, in this embodiment, L<NUM> ≤ <NUM>. Such arrangement with L<NUM> leads to an increase in an volume of the electrochemical apparatus <NUM>, thus reducing energy density of the electrochemical apparatus <NUM> to some extent; and such arrangement with L<NUM> ≤ <NUM> is designed to ensure that there is a sufficient safe distance between the second portion <NUM> and the second electrode plate <NUM> and that the electrochemical apparatus <NUM> has high energy density. It should be noted that the "second direction" mentioned in this application is perpendicular to the thickness direction Z and the first direction X separately; in other words, the second direction Y, the first direction X, and the thickness direction Z are perpendicular to each other.

It should be noted that change of the distance L<NUM> causes a position where the first tab <NUM> is connected to the first electrode plate <NUM> to change accordingly in the winding direction (that is, the length direction of the first electrode plate <NUM> shown in <FIG>), which further causes the internal resistance of the first electrode plate <NUM> to be different; and correspondingly, heat dissipated by the first electrode plate <NUM> and temperature rise of the entire electrochemical device <NUM> also change.

Referring to Table <NUM>. Table <NUM> is a comparison table of temperature rise test for electrochemical apparatuses <NUM> of various examples. The electrochemical apparatuses <NUM> of various examples were the same except for the parameter distance L<NUM>. This test aims to control change of L<NUM>, so as to control change of L<NUM>/L<NUM>, in other words, control change of a position of the first electrode plate <NUM> with respect to the first electrode plate <NUM> in the winding direction; and determine influence of the parameter L<NUM>/L<NUM> on the temperature rise of the electrochemical device <NUM> according to temperature rise in different examples. The temperature rise test includes the following steps:.

In this application, the electrochemical apparatus <NUM> satisfies <NUM> ≤ L<NUM>/L<NUM> ≤ <NUM>. Specifically, referring to Table <NUM>. It can be learned with reference to Examples <NUM> to <NUM> that when L<NUM>/L<NUM> < <NUM> or L<NUM>/L<NUM> > <NUM>, the temperature rise of the electrochemical apparatus <NUM> is greater than <NUM>; conversely, when <NUM> ≤ L<NUM>/L<NUM> ≤ <NUM>, the temperature rise of the electrochemical apparatus <NUM> is less than <NUM>. When L<NUM>/L<NUM> = <NUM>, in the winding direction of the first electrode plate <NUM> (namely, a length direction of the first electrode plate), the first tab <NUM> is approximately located at a relatively central position of the first electrode plate <NUM>, where internal resistance of the first electrode plate <NUM> is small, and accordingly, the temperature rise of the electrochemical apparatus <NUM> is low. It should be understood that when <NUM> ≤ L<NUM>/L<NUM> ≤ <NUM>, the electrochemical apparatus <NUM> still has a small temperature rise. However, in this case, the second portion <NUM> has a short bending toward the first surface <NUM> with respect to the first portion <NUM>, which is not conducive to providing sufficient elasticity to relieve sufficient impact force when the electrochemical apparatus <NUM> is impacted. However, such arrangement with L<NUM>/L<NUM> ≥ <NUM> is beneficial for the electrochemical apparatus <NUM> to overcome these shortcomings. In conclusion, setting of <NUM> ≤ L<NUM>/L<NUM> ≤ <NUM> can ensure sufficient elasticity of the second portion <NUM> of the first tab <NUM> and realize low temperature rise of the electrochemical apparatus <NUM>.

It should be noted that a distance (L<NUM>-L<NUM>) from a side of the second portion <NUM> close to the first surface <NUM> to the first portion <NUM> in the thickness direction Z affects anti-drop performance and vibration resistance of the electrochemical apparatus <NUM>. Specifically, the distance being too short results in a weak effect of relieving the impact force exerted on the second portion <NUM>; correspondingly, the impact on the first tab <NUM> is still mostly transmitted to the first portion <NUM> and the first electrode plate <NUM>. This may cause damage to the joint between the first tab <NUM> and the first electrode plate <NUM>, or pierce the separator <NUM> to cause a short circuit of the electrode assembly <NUM>. As a result, the electrochemical apparatus <NUM> has poor anti-drop performance. If the distance is too long, when the electrochemical apparatus <NUM> vibrates due to transportation, operation, and other factors, the second portion <NUM> may squeeze the housing <NUM> or even penetrate the housing <NUM>, resulting in electrolyte leakage.

Referring to Table <NUM>. Table <NUM> is a comparison table of vibration test and drop test for electrochemical apparatuses <NUM> of various examples. The electrochemical apparatuses <NUM> of various examples were the same except for the distance L<NUM>. This test aims to control change of L<NUM>, and realize change of (L<NUM>-L<NUM>)/L<NUM>, so as to determine influence of (L<NUM>-L<NUM>)/L<NUM> on the anti-drop performance and vibration resistance of the electrochemical apparatus <NUM> according to vibration test and drop test conditions in different examples.

The drop test includes the following steps:.

The vibration test includes the following steps:.

It can be learned from Examples <NUM> to <NUM> that when (L<NUM>-L<NUM>)/L<NUM> < <NUM>, or (L<NUM>-L<NUM>)/L<NUM> > <NUM>, a pass rate of the drop test does not reach <NUM>/<NUM>, and when <NUM> ≤ (L<NUM>-L<NUM>)/L<NUM> ≤ <NUM>, a pass rate of the drop test is <NUM>/<NUM>, indicating that these electrochemical apparatuses <NUM> have excellent anti-drop performance.

In addition, it can be learned from Examples <NUM> to <NUM> that when (L<NUM>-L<NUM>)/L<NUM> > <NUM>, a pass rate of the electrochemical apparatus <NUM> is low; on the contrary, when (L<NUM>-L<NUM>)/L<NUM> ≤ <NUM>, a pass rate of the drop test of the electrochemical apparatus <NUM> is close to or even can reach <NUM>/<NUM>.

It can be learned from test results of the drop test and the vibration test that when <NUM> ≤ (L<NUM>-L<NUM>)/L<NUM> ≤ <NUM>, the electrochemical apparatuses <NUM> have both excellent anti-drop performance and vibration resistance.

In some embodiments, the electrochemical apparatus <NUM> satisfies L<NUM>/L<NUM> ≤ <NUM>; where viewed in the second direction Y, a distance from an end of the third portion <NUM> close to the second portion <NUM> and on a side facing away from the first surface <NUM> to the first surface <NUM> in the thickness direction Z is L<NUM> mm, and a distance from a side of the first portion <NUM> facing away from the first surface <NUM> to the first surface <NUM> in the thickness direction Z is L<NUM> mm. Persons skilled in the art may take a CT picture for the electrochemical apparatus <NUM> in the second direction Y; then may obtain a distance from the left side of the lower end of the third portion <NUM> to the first surface <NUM>, namely L<NUM> as shown in <FIG>, by using CT equipment or an instrument; and persons skilled in the art may take a CT picture for the electrochemical apparatus <NUM> in the second direction Y, and may measure a distance from the left side of the first portion <NUM> to the first surface <NUM>, namely distance L<NUM> as shown in <FIG>, by using CT equipment or an instrument.

When the first tab <NUM> is subjected to an external force in the first direction X shown in the figure, or has a component force in the first direction X, the second connecting section <NUM> bends toward the electrode assembly <NUM>. Under the condition that, in the thickness direction Z, an end of the second connecting section <NUM> facing away from the first surface <NUM> goes significantly beyond an end of the first connecting section <NUM> facing away from the first surface <NUM>, the end of the second connecting section <NUM> facing away from the first surface <NUM> may be inserted inversely to touch the second electrode plate <NUM> in the electrode assembly <NUM>, causing short circuit to the electrochemical apparatus <NUM>. Such arrangement with L<NUM>/L<NUM> ≤ <NUM> is designed to control the end of the second connecting section <NUM> facing away from the first surface <NUM> not to go beyond the end of the first connecting section <NUM> facing away from the first surface <NUM>, or to go slightly beyond the end of the first connecting section <NUM> facing away from the first surface <NUM>, so as to reduce the risk of short circuit.

In addition, to reduce a risk of short circuit caused by inverse insertion of the second connecting section <NUM>, in some embodiments, the electrochemical apparatus <NUM> further includes insulating glue. Specifically, the insulating glue is disposed on a surface of the second connecting section <NUM> facing toward the electrode assembly <NUM>; and the insulating glue is used to prevent the second connecting section <NUM> from coming into contact with the second electrode plate <NUM> when the second connecting section <NUM> is bending toward the electrode assembly <NUM>, thereby reducing the preceding hidden dangers.

For the second tab <NUM>, specifically referring to <FIG> and other accompanying drawings. One end of the second tab <NUM> is connected to the collecting portion <NUM>, and an other end of the second tab <NUM> passes through the first end portion <NUM> and extends out of the housing <NUM>, to constitute another conductive terminal of the electrochemical apparatus <NUM> for being connected to an external electricity load. In this embodiment, the second tab <NUM> includes a fourth portion <NUM> and a fifth portion <NUM>. The fourth portion <NUM> is stacked on the third extension section <NUM>. The fourth portion <NUM> is disposed in a bent way with respect to the fourth portion <NUM> and extends linearly; and one end of the fifth portion <NUM> is connected to the fourth portion <NUM>, and an other end of the fifth portion <NUM> extends out of the housing <NUM> in the first direction X. A length of the fifth portion <NUM> extending in the accommodating chamber <NUM> in the first direction X is L<NUM>, that is, a length of the second tab <NUM> extending in the accommodating chamber <NUM> in the first direction X. Persons skilled in the art may take a CT picture for the electrochemical apparatus <NUM> in the second direction Y, and may directly obtain a distance from an upper corner of the fourth portion <NUM> to an inner surface of the housing <NUM>, as shown in <FIG>, by using CT equipment, or measure a distance from an upper corner of the fourth portion <NUM> to an inner surface of the housing <NUM>, namely, distance L<NUM> as shown in <FIG>, by using an instrument.

Optionally, a cross-sectional area of the first tab <NUM> perpendicular to an extension path thereof is s<NUM> mm<NUM>, and a cross-sectional area of the second tab <NUM> perpendicular to an extension path thereof is s<NUM> mm<NUM>, where the first tab <NUM> and the second tab <NUM> satisfy s<NUM> > s<NUM>. Tunneling of electrons in or out of the first electrode plate <NUM> is realized by using the first tab <NUM>, while tunneling of electrons in or out of the second electrode plate <NUM> is realized by using the plurality of conducting strips <NUM> and the second tab <NUM>. Compared with the entirety composed of all the conducting strips <NUM> and the second tab <NUM>, the first tab <NUM> is more difficult to dissipate heat. Such arrangement with s<NUM> > s<NUM> is designed to increase a surface area of the first tab <NUM>, thereby increasing a heat dissipation rate of the first tab <NUM>, such that the first tab <NUM> and the second tab <NUM> dissipate heat in a more uniform manner.

In some embodiments, the electrochemical apparatus satisfies |L<NUM>-L<NUM>| ≤ <NUM>. Specifically, when the sealing portion <NUM> is impacted, an impact force is transferred toward the first tab <NUM> and the second tab <NUM>; under the condition that there is a large difference between L<NUM> and L<NUM>, one of the tabs is subjected to concentrated force, in other words, forces on the two tabs are uneven, which reduces anti-drop performance of the electrochemical apparatus <NUM>. The following describes an influence of the difference between the distance L<NUM> and the distance L<NUM> on anti-drop performance of the electrochemical apparatus <NUM> with reference to test data.

Referring to Table <NUM>. Table <NUM> is a comparison table of drop test for electrochemical apparatuses <NUM> of various examples. The electrochemical apparatuses <NUM> of various examples were the same except for a distance from the sealing portion <NUM> to the second portion <NUM> of the first tab <NUM> and/or a distance from the sealing portion <NUM> to the fourth portion <NUM> of the second tab <NUM>, that is, the distance L<NUM> and/or distance L<NUM>. This test aims to control changes of L<NUM> and/or L<NUM>, and control change of |L<NUM>-L<NUM>|, so as to determine influence of |L<NUM>-L<NUM>| on the anti-drop performance the electrochemical apparatus <NUM> according to vibration cases in different examples. For the temperature rise test, referring to the steps S301 to S303, which will not be repeated herein.

With reference to Examples <NUM> to <NUM>, when |L<NUM>-L<NUM>| > <NUM>, a pass rate of the drop test cannot reach <NUM>/<NUM>; correspondingly, when |L<NUM>-L<NUM>| ≤ <NUM>, a pass rate of the drop test can reach <NUM>/<NUM>, indicating that the electrochemical apparatus <NUM> has excellent anti-drop performance. With reference to Examples <NUM>, <NUM>, and <NUM>, the electrochemical apparatuses <NUM> of various examples satisfy |L<NUM>-L<NUM>| = <NUM>, except for L<NUM> (or a specific value of L<NUM>). It can be learned that even though both L<NUM> and L<NUM> change, as long as an absolute value of the difference therebetween is constant, there is no obvious difference in the anti-drop performance of the electrochemical apparatuses <NUM>.

To sum up, the electrochemical apparatus <NUM> according to some embodiments of this application includes a housing <NUM>, an electrode assembly <NUM>, a first tab <NUM>, and a second tab <NUM>. The first tab <NUM> includes: a first portion <NUM> connected to a first electrode plate <NUM>, a second portion <NUM> located outside the first electrode plate <NUM> and disposed in a bent shape, and a third portion <NUM>, at least part of which extends out of the housing <NUM>. Tunneling of electrons in or out of the first electrode plate <NUM> is realized by using the first tab <NUM>, while Tunneling of electrons in or out of the second electrode plate <NUM> is realized by using the plurality of conducting strips <NUM> thereon.

As the first tab <NUM> includes the second portion <NUM> disposed in a bent way, in a case that the first tab <NUM> is impacted, the first tab <NUM> can relieve part of impact force through deformation of the second portion <NUM>, such that impact force finally reaching a joint between the first tab <NUM> and the first electrode plate <NUM> is reduced to some extent. Therefore, the electrochemical apparatus according to some embodiments of this application can alleviate the problem that the first tab <NUM> directly connected to the first electrode plate <NUM> is prone to damage at a joint between the first tab <NUM> and the first electrode plate <NUM> caused by external impact.

In addition, the arrangement of the conducting strips <NUM> and the second tab <NUM> allows the housing <NUM> have a space not filled by the electrode assembly <NUM> in the first end portion <NUM>; and the second portion <NUM> disposed in a bent way in the first tab <NUM> and the conducting strips <NUM> disposed in a bent way can support the housing <NUM> in the thickness direction Z to some extent. This reduces a disadvantage that the first end portion <NUM> of the housing <NUM> is not suitable for an expected installation environment due to excessive deformation and collapse caused by extrusion.

It should be noted that the foregoing embodiments are described by using an example of the first tab <NUM> and the second tab <NUM> both being located on the same end of the electrode assembly <NUM>, that is, both being close to the first end portion <NUM>. However, in other embodiments of this application, the first tab <NUM> and the second tab <NUM> are also located on different ends of the electrode assembly <NUM>.

Based on the same inventive concept, this application further provides an electric apparatus. Referring to <FIG> is a schematic diagram of an electronic apparatus <NUM> according to an embodiment of this application. The electronic apparatus includes the electrochemical apparatus <NUM> according to any one of the foregoing embodiments and a load structure powered by the electrochemical apparatus <NUM>. In this embodiment, the electronic apparatus <NUM> includes a mobile phone. It can be understood that, in other embodiments of this application, the electronic apparatus may alternatively be a tablet computer, a computer, a drone, and other apparatus driven by electricity.

Claim 1:
An electrochemical apparatus (<NUM>), comprising:
a housing (<NUM>);
an electrode assembly (<NUM>) accommodated in the housing (<NUM>) and comprising a first electrode plate (<NUM>), a second electrode plate (<NUM>), and a separator disposed between the first electrode plate (<NUM>) and the second electrode plate (<NUM>); wherein the first electrode plate (<NUM>), the second electrode plate (<NUM>), and the separator (<NUM>) are stacked and then wound; the first electrode plate (<NUM>) comprises a first current collector (<NUM>), the second electrode plate (<NUM>) comprises a second current collector (<NUM>) and a plurality of conducting strips (<NUM>) integrally arranged with the second current collector (<NUM>), the plurality of conducting strips (<NUM>) protrude from the second current collector (<NUM>) along a first direction (X), the plurality of conducting strips (<NUM>) are stacked in a thickness direction of the electrode assembly (<NUM>) to form a collecting portion (<NUM>), and the first direction (X) is perpendicular to the thickness direction (Z);
a first tab (<NUM>) directly connected to the first electrode plate (<NUM>) and made of a sheet structure extending in a bent shape as a whole, the first tab (<NUM>) comprising a first portion (<NUM>), a second portion (<NUM>), and a third portion (<NUM>); wherein the first portion (<NUM>), the second portion (<NUM>), and the third portion (<NUM>) are connected in sequence, the first portion (<NUM>) is connected to the first current collector (<NUM>), the second portion (<NUM>) is located outside the first current collector (<NUM>) and disposed in a bent shape, and the third portion (<NUM>) extends out of the housing (<NUM>); and
a second tab (<NUM>) connected to the collecting portion (<NUM>) and extending out of the housing (<NUM>).