Electrochemical apparatus and power consumption apparatus

Abstract

This application relates to the field of electrochemistry technology and discloses an electrochemical device and a power consumption device. The electrochemical device includes a case assembly and an electrode assembly housed in the case assembly. The case assembly includes a case and a lid. The case includes a bottom wall and side walls. One end of each side wall is connected to the bottom wall, and the other end extends away from the bottom wall. The bottom wall and the side walls together define a housing chamber. The lid is attached to one end of the side wall that extends away from the bottom wall to cover the housing chamber. The direction from the bottom wall towards the lid is defined as the first direction. The electrode assembly includes a first electrode sheet, a second electrode sheet, and a separator. The first electrode sheet includes a first electrode sheet unit, and the second electrode sheet includes a second electrode sheet unit. The first electrode sheet unit and the second electrode sheet unit are stacked along the second direction and are both provided perpendicular to the second direction. A separator is provided between the adjacent first electrode sheet unit and second electrode sheet unit. The second direction is perpendicular to the first direction. With this electrochemical device, it is possible to improve the current situation where deformation and cracks are likely to occur in the current electrochemical device.

Description

Cross-reference to Related Applications

[0001] This application claims priority based on a Chinese patent application with application number 202210684872.9 and titled "Electrochemical Device and Power Consumption Device", which was filed with the China National Intellectual Property Administration on June 13, 2022. All of its content is incorporated herein by reference.

Technical Field

[0002] This application relates to the field of electrochemical technology, and particularly to electrochemical devices and power consumption devices.

Background Art

[0003] An electrochemical device is a device that converts external energy into electrical energy and stores it internally, and supplies power to an external power consumption device (such as a portable power consumption device, an electric vehicle, an electric tool, an electric bicycle, etc.) as needed.

[0004] Generally, an electrochemical device includes a case assembly, an electrode assembly, and a tab or pole structure for leading out the polarity of the electrode assembly from the case assembly. Here, the case assembly includes a case and a lid. A housing chamber is provided at one end of the case, and the lid is attached to the open end of the housing chamber to cover the housing chamber. The electrode assembly is housed in the housing chamber and includes a first electrode sheet, a second electrode sheet, and a separator that are stacked and installed. The first electrode sheet and the second electrode sheet have opposite polarities, and a separator for separating them is provided therebetween.

[0005] In an electrochemical apparatus where the electrode assembly has a laminated structure, the lamination direction of the first electrode sheet and the second electrode sheet coincides with the direction in which the case faces the lid. In this electrochemical apparatus, the electrode assembly expands significantly along the lamination direction during charging. At the same time, the case and lid are not a single integrated structure but are usually sealed by welding. In this case, since the case and lid are thin and the welding area between them is small, the welded area tends to become a weak region when the pressure inside the case increases. Therefore, the strength of the case assembly in the lamination direction is low, and the expansion deformation of the electrode assembly makes the case assembly prone to deformation and cracking in the lamination direction, further causing phenomena such as electrolyte leakage, resulting in poor installability of the electrochemical apparatus. [Overview of the project] [Problems that the invention aims to solve]

[0006] The present invention aims to provide an electrochemical apparatus and a power consumption device in order to improve the current situation in which cracks are prone to occur in the case assemblies of electrochemical apparatuses. [Means for solving the problem]

[0007] To solve the technical problem, this application employs the following technical means.

[0008] An electrochemical apparatus comprising a case assembly and an electrode assembly. The case assembly comprises a case and a lid. The case comprises a bottom wall and a side wall. One end of the side wall is connected to the bottom wall, and the other end extends away from the bottom wall, and the bottom wall together with the side wall defines a housing chamber. The lid is attached to the end of the side wall away from the bottom wall and covers the housing chamber. The direction in which the bottom wall faces the lid is defined as the first direction. The electrode assembly is housed in the housing chamber and comprises a first electrode sheet, a second electrode sheet, and a separator. The first electrode sheet comprises a first electrode sheet unit, and the second electrode sheet comprises a second electrode sheet unit. The first electrode sheet unit and the second electrode sheet unit are stacked along a second direction and are both provided perpendicular to the second direction, and the separator is provided between adjacent first electrode sheet units and second electrode sheet units. Here, the second direction is perpendicular to the first direction.

[0009] In the electrochemical apparatus according to the embodiment of the present invention, the stacking direction of each first electrode sheet unit and each second electrode sheet unit is perpendicular to the first direction of the case. Therefore, during the charging process of the electrochemical apparatus, the electrode assembly expands mainly along the second direction, and the degree of expansion in the first direction is extremely small, so the case is also less likely to expand and deform in the first direction.

[0010] In summary, the electrochemical apparatus according to the embodiment of the present invention can improve upon the current situation where electrochemical apparatuses are prone to deformation and cracking. The electrode sheets in the electrochemical apparatus are stacked in a second direction, the degree of cell expansion in the first direction is small, and the cell expansion force is mainly supported by the side walls of the battery case. The side walls of the battery case are usually integrally molded, and even if the side walls are welded, the side walls at the welded points partially overlap, resulting in high welding strength. Therefore, the strength of the side walls in the second direction is increased, and the cell expansion in the second direction is suppressed by the side walls of the battery case, making deformation difficult. As a result, the degree of expansion of the entire electrochemical apparatus is small, and consequently, no expansion occurs. Therefore, this electrochemical apparatus does not require a spare space between the electrode assembly and the case along the above direction, and thus the energy density of this electrochemical apparatus can be increased. In other words, the electrochemical apparatus according to the embodiment of the present invention can improve upon the current situation where the electrochemical apparatus is prone to expansion and deformation in the first direction while increasing the energy density.

[0011] In some embodiments, the sidewalls are integrally molded, and the tensile strength of the sidewall material is 1000 MPa or more. This is to ensure that the sidewalls have sufficient strength to resist deformation of the electrode assembly.

[0012] In some embodiments, the side walls are welded, and the weld strength of the welded area may be 1000 MPa or more. Since welded areas are prone to deformation and fracture, setting the tensile strength of the welded area to 1000 MPa or more ensures that the side walls do not deform when subjected to the expansion of the electrode assembly.

[0013] In some embodiments, the first electrode sheet is an anode sheet. The first electrode sheet comprises a first current collector and a first active material layer provided on the surface of the first current collector. The material of the first active material layer contains silicon, and the percentage of the mass of the silicon element relative to the total mass of the first active material layer is 10% or more. Silicon-based anode active materials have the advantages of high gram capacity and low potential compared to carbon-based anode active materials, and such an installation is advantageous for increasing the energy density of electrochemical devices. However, during the cell cycle process, the expansion rate of silicon-based anode active materials is large, and after lithium is completely absorbed, the volume of silicon expands by about 300%, but the strength of the packaging bags for conventional soft-pack batteries is insufficient to withstand the expansion of silicon anode cells, so silicon anode cells are usually packaged in hard gel such as steel cases. However, conventional stacked batteries with steel cases are stacked along the thickness direction of the case, but due to the expansion of the high-silicon material, deformation can easily cause the welds between the upper and lower cases to break. In actual processes, it is necessary to reserve an expansion space of approximately 10% in the thickness direction in advance to prevent expansion of silicon anode stacked batteries, which significantly affects the battery energy density. The stacked configuration described in this application is particularly suitable for silicon anode stacked cells, eliminating the need for this reserve expansion space, thereby increasing energy density and suppressing battery expansion.

[0014] In some embodiments, preferably, the percentage of the mass of the silicon element relative to the total mass of the first active material layer is 30% or more and 80% or less. Because silicon-based negative electrode active materials have the characteristics of high gram capacity and high expansion, the silicon element in the first active material layer Percentage of massIf the silicon content is less than 30%, its role in increasing the energy density of the electrochemical apparatus is limited. If the silicon content in the first active material layer exceeds 80%, the energy density of the electrochemical apparatus can be maximized, but the degree of anode sheet expansion becomes very large. Although the expansion force of the anode sheet is suppressed by the high-rigidity sidewalls, this expansion force is converted into pressing force between the electrode sheets of the electrode assembly. This applies periodic pressing force to each electrode sheet during the repeated charge-discharge cycles of the electrochemical apparatus, which can cause defects such as active material shedding and lithium deposition, and may affect the cycle life of the electrochemical apparatus to some extent.

[0015] In some embodiments, the first active material layer comprises at least one of silicon, silicon oxide, silicon carbide, silicon nanowires, and silicon nanoparticles.

[0016] In some embodiments, the electrochemical apparatus further comprises a first conductive member. The first electrode sheet comprises a first current collector and a first active material layer. The first current collector comprises a first region and a second region. The first region is provided perpendicular to the second direction. The second region is electrically connected to the first region. The first active material layer is provided on the surface of the first region, and the first region together with the first active material layer constitutes the first electrode sheet unit. Each of the first electrode sheet units is provided at intervals along the second direction, and the second region is electrically connected to the first conductive member.

[0017] In some embodiments, the case has a first sidewall unit and a second sidewall unit positioned opposite each other along a third direction, with each of the second region and the first conductive member located between the first region and the first sidewall unit, and the third direction being perpendicular to the first and second directions, respectively. The second region comprises a first portion and a second portion. The first portion has one end connected to the first region and the other end extending close to the first sidewall unit. The second portion is connected to one end of the first portion away from the first region and is bent relative to the first portion. The second portion is connected to the first conductive member.

[0018] In some embodiments, the electrode assembly comprises three or more first electrode sheets. The second portions are bent relative to the first portions, and the bending direction of each second portion is the same. Along a first predetermined direction, between any two adjacent second portions, at least a portion of the downstream second portion is laminated onto the surface of the upstream second portion, and there is no common laminated area between any three adjacent second portions; that is, each second portion is arranged in a sequential manner. Here, the first predetermined direction is the direction from one end of the second portion closer to the first portion to the other end away from the first portion.

[0019] In other embodiments, the second parts may be stacked sequentially along the third direction, but such an installation configuration requires a large space to be reserved in advance between the first region and the first side wall unit. In contrast, the configuration in this embodiment, in which the second parts are stacked sequentially, can solve the above-mentioned problem.

[0020] In some embodiments, a first insulating tape is further provided. The electrode assembly has a first surface and a second surface facing each other along the second direction. The first insulating tape is fixed at one end to the first surface and at the other end to the second surface, and the first insulating tape is under tension.

[0021] In this way, by sandwiching the electrode assembly between its two ends, the first insulating tape can reduce the risk of slack deformation between the first electrode sheet unit, the second electrode sheet unit and the separator.

[0022] In some embodiments, a second insulating tape is further provided. The second insulating tape is fixed to the electrode assembly and the case respectively so as to fix the electrode assembly to the case.

[0023] In some embodiments, the electrochemical device includes two or more of the electrode assemblies, and each of the electrode assemblies is arranged along the second direction.

[0024] The installation form in which a plurality of electrode assemblies are stacked can avoid the thickness of a single electrode assembly being too thick, thereby making the stacking process of each electrode assembly easier and reducing the error rate during the stacking of the electrode assemblies.

[0025] In some embodiments, a pole attached to the case is further provided. The pole is insulated from the case, and the pole is electrically connected to the second electrode sheet unit.

[0026] In this way, the pole is configured as one of the conductive terminals in this electrochemical device, thereby realizing the extraction of the polarity of the second electrode sheet.

[0027] In some embodiments, a pressure relief portion is provided in the case. The pressure relief portion is for communicating the accommodation chamber with the outside air of the case when the temperature of the electrochemical device is higher than a preset threshold value.

[0028] Considering that the temperature of the electrochemical device is too high, the gas generation in the case will cause the air pressure to rise, which may lead to the explosion of the electrochemical device and pose a high safety risk. When the temperature of the electrochemical device is higher than a preset threshold value, the pressure relief part can communicate the accommodation chamber with the outside air of the case and further discharge the gas in the accommodation chamber to the outside, thereby eliminating the above risks.

[0029] In some embodiments, a liquid injection hole is provided in the bottom wall or the lid. Thereby, when injecting the electrolytic solution into the accommodation chamber, the electrolytic solution can penetrate into the gap between the first electrode sheet unit, the separator, and the second electrode sheet unit from the beginning, thereby increasing the penetration rate of the electrode assembly, and further shortening the manufacturing cycle of the electrochemical device to a certain extent.

[0030] In some embodiments, the liquid injection hole is provided in the lid, and the distance between the liquid injection hole and the geometric center of the lid is less than 5 mm. Alternatively, the liquid injection hole is provided in the bottom wall, and the distance between the liquid injection hole and the geometric center of the bottom wall is less than 5 mm. Thereby, the penetration rate of the electrolytic solution into the electrode assembly can be increased.

[0031] In some embodiments, when viewed along the first direction, the edge of the bottom wall does not exceed the end of the side wall close to the bottom wall, and when viewed along the first direction, the edge of the lid does not exceed the end of the side wall close to the lid. In this way, under the condition that the case provides an accommodation chamber with sufficient volume, the volume of the entire electrochemical device or the volume occupied when the electrochemical device is incorporated into the power consumption device can be made as small as possible.

[0032] In some embodiments, the aspect ratios of both the first and second electrode sheets are 3 to 20. All other things being equal, the impedance of the electrode sheet is greatly affected by its length. If the aspect ratio of the electrode sheet is too large, i.e., the length of the electrode sheet is too long relative to its width, the impedance of a single electrode sheet increases due to the large aspect ratio, and the internal resistance of the battery also increases, preventing the full realization of the low impedance advantage of a multi-tab stacked battery. If the aspect ratio of the electrode sheet is too small, i.e., the length of the electrode sheet is too short relative to its width, the space occupied by the tabs at the ends in the longitudinal direction becomes large relative to the overall length, which is unfavorable for fully realizing the effect of improving volume utilization efficiency by this technology.

[0033] To solve the technical problems, this application employs the following further technical means.

[0034] The power consumption device comprises the electrochemical apparatus described above. Since this power consumption device comprises the electrochemical apparatus described in the above embodiment, it can improve upon the current situation where electrochemical apparatuses tend to expand and deform in the first direction. [Brief explanation of the drawing]

[0035] To more clearly explain the technical proposal in the embodiments of this application, the necessary drawings for the embodiments are briefly described below. Note that the drawings described below represent only some embodiments of this application, and those skilled in the art can obtain other drawings based on the structures shown in these drawings without requiring any creative effort.

[0036] [Figure 1] Figure 1 is a schematic perspective view of an electrochemical apparatus according to one embodiment of the present invention. [Figure 2] Figure 2 is a schematic exploded view of the electrochemical apparatus shown in Figure 1. [Figure 3] Figure 3 is a schematic cross-sectional view of the electrode assembly in Figure 2 along line AA. [Figure 4] Figure 4 is a front view of the first electrode sheet in Figure 2. [Figure 5] Figure 5 is a bottom view of Figure 4. [Figure 6] Figure 6 is a front view of the second electrode sheet in Figure 2. [Figure 7] Figure 7 is a plan view of Figure 6. [Figure 8] Figure 8 is a schematic diagram of a power consumption device according to one embodiment of the present invention. [Explanation of Symbols]

[0037] 1. Electrochemical apparatus, 100: Case assembly, 110: Case, 120: Lid, 130: Pressure relief section, 111: Bottom wall, 112: Side wall, 1121: First side wall unit, 1122: Second side wall unit, 1123: Third side wall unit, 1124: Fourth side wall unit, 101: Containment chamber, 102: Liquid injection port, 200: Electrode assembly, 210: First electrode sheet, 220: Second electrode sheet, 230: Separator, 240: First insulating tape, 250: Second insulating tape, 211: First electrode sheet unit, 212: First current collector, 213: First active material layer, 2121: First region, 2122: Second region, 2123: First part, 2124: Second part, 221: Second electrode sheet unit, 222: Second current collector, 223: Second active material layer, 2221: Third region, 2222: Fourth region, 2223: Third part, 2224: Fourth part, 201: First surface, 202: Second surface, 300: First conductive member, 400: Second conductive member, 500: Paul, Z: 1st direction, X: second direction, Y: Third direction, M: first predetermined direction; N: Second predetermined direction, 1b: Electrochemical apparatus 、 2 :Power consuming device. [Modes for carrying out the invention]

[0038] The present application will be described in more detail below, with reference to the drawings and specific embodiments, in order to facilitate understanding of the present application. Where a component is described as being "fixed" or "fixed to" another component, that component may be directly located on the other component, or one or more intermediate components may be present between the two components. Where a component is described as being "connected" to another component, that component may be directly connected to the other component, or one or more intermediate components may be present between the two components. The terms “vertical,” “horizontal,” “left,” “right,” “inside,” “outside,” and similar expressions used herein are for illustrative purposes only.

[0039] Unless otherwise specified, the meanings of all technical and scientific terms used herein are the same as those generally understood by those skilled in the art. The terms used herein are for illustrative purposes only to describe specific embodiments and are not intended to limit the application. The terms “and / or” as used herein include any and all combinations of one or more of the related enumerated items.

[0040] Furthermore, the technical features of the different embodiments of the present application described below can be combined with each other, as long as they do not contradict each other.

[0041] In this specification, “attach” as described above includes fixing or restricting a part or device to a specific position or location by welding, screwing, engaging, bonding, etc. The part or device may remain stationary in the specific position or location, or it may move within a limited range. The part or device may be removable or not after being fixed or restricted to the specific position or location. This is not limited to embodiments of the present application.

[0042] Referring to Figures 1 to 3, Figures 1 to 3 show a schematic perspective view, a schematic exploded view, and a schematic cross-sectional view of the electrode assembly along line AA in Figure 2, respectively, of an electrochemical apparatus 1 according to one embodiment of the present invention. This electrochemical apparatus 1 comprises a case assembly 100 and an electrode assembly 200. Here, the case assembly 100 comprises a case 110 and a lid 120. The case 110 comprises a bottom wall 111 and a side wall 112. One end of the side wall 112 is connected to the bottom wall 111, and the other end extends away from the bottom wall 111, both defining a containment chamber 101. The lid 120 is attached to the end of the side wall 112 that is away from the bottom wall 111 and covers the containment chamber 101. The direction in which the bottom wall 111 moves toward the lid 120 is the first direction Z. The electrode assembly 200 is housed in the housing chamber 101 and comprises a first electrode sheet 210, a second electrode sheet 220, and a separator 230. The first electrode sheet 210 comprises a first electrode sheet unit 211, and the second electrode sheet 220 comprises a second electrode sheet unit 221. The first electrode sheet unit 211 and the second electrode sheet unit 221 are stacked along the second direction X shown in the figure, and both are provided perpendicular to this second direction X. A separator 230 is provided between adjacent first electrode sheet units 211 and second electrode sheet units 221.

[0043] In this specification, "first direction" refers to the direction in which the case 110 faces the lid 120, i.e., the package direction of both. In this embodiment, this first direction is the thickness direction of the electrochemical apparatus 1. In this specification, "second direction" refers to the direction perpendicular to the first direction Z. In this embodiment, this second direction X is the width direction of the electrochemical apparatus 1. In other embodiments of this application, it will be understood that the second direction X may be the length direction of the electrochemical apparatus 1. Also, for the sake of explanation and understanding, the direction perpendicular to the first direction Z and the second direction X will be defined as the third direction Y below. Next, the case assembly 100 and the electrode assembly 200 will be described in detail in order, using the case where the electrochemical apparatus 1 is a hard-shell lithium-ion battery as an example, but it should be understood that in other embodiments of this application, the electrochemical apparatus 1 may be a soft-pack battery or other form of battery such as a sodium-ion battery.

[0044] Referring to Figures 1 and 2, the case assembly 100 is a container and mounting base for other elements in the electrochemical apparatus 1. This case assembly 100 comprises a case 110 and a lid 120. Here, the case 110 is a box-shaped structure including a bottom wall 111 and side walls 112. The bottom wall 111 is a flat, plate-like structure. The side walls 112 are substantially annular structures forming a closed cross-section, with one end connected to the bottom wall 111 and the other end extending away from the bottom wall 111. Together with the side walls 112, the bottom wall 111 defines the containment chamber 101 for housing the electrode assembly 200 and electrolyte, etc. Selectively, the side walls 112 form a substantially rectangular or rounded rectangular shape when viewed along the first direction Z. The side wall 112 comprises a first side wall unit 1121 and a second side wall unit 1122, which are installed opposite each other along the third direction Y, and a third side wall unit 1123 and a fourth side wall unit 1124, which are installed opposite each other along the second direction X. The lid 120 is similarly a flat plate structure and is installed opposite the bottom wall 111 along the first direction Z. The lid 120 is attached to one end of the side wall 112 away from the bottom wall 111 and covers the containment chamber 101.

[0045] In this embodiment, the bottom wall 111 and the integrally molded side wall 112 may be molded separately. The bottom wall 111 is fixed to the side wall 112 by welding, such as laser welding, and covers one end of the side wall 112 facing the bottom wall 111. The lid 120 is fixed to the integrally molded side wall 112 by welding, such as laser welding, and covers one end of the side wall 112 facing the lid 120. Preferably, the first direction Z When viewed along these lines, the edge of the bottom wall 111 does not extend beyond the end of the side wall 112 closest to the bottom wall 111, and the edge of the lid 120 does not extend beyond the end of the side wall 112 closest to the lid 120, so that the overall volume of the electrochemical apparatus 1, or the volume occupied when the electrochemical apparatus 1 is incorporated into a power consumption device, can be made as small as possible, provided that the case assembly 100 provides a sufficiently large storage chamber 101. Of course, in other embodiments of the present invention, only the edge of the bottom wall 111 or the lid 120 may be set so as not to extend beyond the edge of the side wall 112. It should also be noted that in other embodiments, the bottom wall 111 and the side wall 112 may be integrally molded by conventional methods such as integral stamping.

[0046] Considering the possibility of excessively high temperatures in the electrochemical apparatus 1 or other side reactions, the pressure inside the case assembly 100 may rise due to gas generation, potentially causing the electrochemical apparatus 1 to explode, posing a high safety risk. In this embodiment, to mitigate such risks, a pressure relief section 130 is installed in the case assembly 100 of the electrochemical apparatus 1. The pressure relief section 130 eliminates the above-mentioned risk by connecting the containment chamber 101 to the outside air of the case assembly 100 and further discharging the gas inside the containment chamber 101 to the outside when the pressure inside the electrochemical apparatus 1 is higher than a preset threshold. Here, the "pre-set threshold" described in this specification is the internal pressure value of the electrochemical apparatus 1 when the pressure relief section 130 is switched to a state in which the containment chamber 101 is properly connected to the outside air of the case assembly 100. This preset threshold is higher than the normal internal pressure inside the electrochemical apparatus 1, and lower than the internal pressure value before the electrochemical apparatus 1 explodes if there is no pressure relief section. In practice, there are various structures for the pressure relief section 130. For example, in some embodiments, the pressure relief section 130 is a region with lower strength than other parts of the case assembly 100. Specifically, the pressure relief section 130 may be a region with less thickness than other parts. When the air pressure inside the housing chamber 101 rises above the preset threshold, the pressure relief section 130 is first breached to release the pressure. For example, in another embodiment, the pressure relief section 130 is a minute valve element. Specifically, the case assembly 100 is provided with a through-hole for pressure relief, and the pressure relief section 130 is provided in this hole. When the air pressure inside the housing chamber 101 is below the preset threshold, the pressure relief section 130 covers this hole. On the other hand, when the air pressure inside the housing chamber 101 is above the preset threshold, the pressure relief section 130 opens this hole to release the pressure.

[0047] The electrode assembly 200 described above will be explained with reference to Figure 3, and in combination with Figures 1 and 2. This electrode assembly 200 is a core element of the electrochemical apparatus 1, and the electrochemical apparatus 1 is charged and discharged by the electrode assembly 200. Specifically, the electrode assembly 200 comprises a first electrode sheet 210, a second electrode sheet 220, and a separator 230. The first electrode sheet 210, the second electrode sheet 220, and the separator 230 are stacked in order along the second direction X shown in the figure. The polarities of the first electrode sheet 210 and the second electrode sheet 220 are opposite, and the separator 230 is provided between adjacent first electrode sheets 210 and second electrode sheets 220. In this embodiment, the electrode assembly 200 comprises a plurality of first electrode sheets 210, a plurality of second electrode sheets 220, and a plurality of separators 230, wherein each first electrode sheet 210 and each second electrode sheet 220 are arranged alternately along a second direction X, and separators 230 are provided between adjacent first electrode sheets 210 and second electrode sheets 220. Here, "a plurality" as used in the specification of this application means two or more.

[0048] Specifically, referring to Figures 4 to 7, Figures 4 to 7 show the front view and bottom view of the first electrode sheet 210, and the front view and top view of the second electrode sheet 220, respectively. Referring to the other drawings, the first electrode sheet 210 comprises a first electrode sheet unit 211, which is the main body of the first electrode sheet 210. The second electrode sheet 220 comprises a second electrode sheet unit 221, which is the main body of the second electrode sheet 220. The polarity of the first electrode sheet unit 211 and the second electrode sheet unit 221 are opposite. The first electrode sheet unit 211 of each first electrode sheet 210 and the second electrode sheet unit 221 of each second electrode sheet 220 are stacked along the second direction X, and a separator 230 is provided between adjacent first electrode sheet units 211 and second electrode sheet units 221 for separation.

[0049] Next, the structures of the first electrode sheet 210 and the second electrode sheet 220 will be described in order, using the case where the first electrode sheet 210 is the anode sheet and the second electrode sheet 220 is the cathode sheet as an example. Specifically, referring to Figures 4 and 5, the first electrode sheet 210 comprises a first current collector 212 and a first active material layer 213. The first current collector 212 is a sheet-like structure including a first region 2121 and a second region 2122. The first region 2121 is rectangular in shape overall and is provided perpendicular to the second direction X. The second region 2122 is elongated and is electrically connected to the first region 2121. In this embodiment, the second region 2122 is integrally molded with the first region 2121 and extends outward from the edge of the first region 2121. Of course, in other embodiments of the present application, the second region 2122 may be molded separately from the first region 2121 and electrically connected to the first region 2121 by welding or bonding. The first current collector 212 is a substrate supporting the first active material layer 213 and is also a carrier for electron transfer by the first electrode sheet 210. In some embodiments, the first current collector 212 is copper foil. Of course, in other embodiments of the present application, the first current collector 212 may be other suitable foil material such as nickel foil. The first active material layer 213 is provided on the surface of the first region 2121 and together with the first region 2121 constitutes the first electrode sheet unit 211. In this embodiment, the first active material layer 213 is a silicon-based negative electrode active material. For example, the first active material includes one or more of silicon, silicon oxides, silicon carbide, silicon nanowires, and silicon nanoparticles. Of course, in other embodiments of the present application, the first active material may include other types of silicon-based materials, as long as it is ensured that it contains silicon. Silicon-based anode active materials have the advantages of high gram capacity and low potential compared to carbon-based anode active materials. Therefore, this installation helps to increase the energy density of the electrochemical apparatus 1. Preferably, the percentage of the mass of silicon in the first active material layer 213 relative to the total mass of the first active material layer 213 is 10% or more. More preferably, the percentage of the mass of silicon in the first active material layer 213 relative to the total mass of the first active material layer 213 is 30% or more and 80% or less.Because the silicon-based negative electrode material expands rapidly when the electrochemical apparatus 1 is charged, the above setting aims to ensure that the electrochemical apparatus 1 has a high energy density and to prevent the electrode assembly 200 from expanding excessively during charging. In this electrode assembly 200, each first electrode sheet unit 211 is spaced apart along the second direction X, and each second region 2122 extends outside the separator 230 and is electrically connected, thereby electrically connecting each first electrode sheet 210 to each other.

[0050] Specifically, referring to Figures 6 and 7, the second electrode sheet 220 comprises a second current collector 222 and a second active material layer 223. The second current collector 222 is a sheet-like structure including a third region 2221 and a fourth region 2222. The third region 2221 is rectangular in shape overall and is provided perpendicular to the second direction X. The fourth region 2222 is elongated and is electrically connected to the third region 2221. In this embodiment, the fourth region 2222 is integrally molded with the third region 2221 and extends outward from the edge of the third region 2221. Of course, in other embodiments of the present application, the fourth region 2222 may be molded separately from the third region 2221 and electrically connected to the third region 2221 by welding or bonding. The second current collector 222 is a substrate that supports the second active material layer 223 and is also a carrier for electron transfer by the second electrode sheet 220. In some embodiments, the second current collector 222 is aluminum foil. Of course, in other embodiments of the present application, the second current collector 222 may be other suitable foil material such as nickel foil. The second active material layer 223 is a carrier for intercalation or deintercalation of lithium ions. This second active material layer 223 is provided on the surface of the third region 2221 and together with the third region 2221 constitutes the second electrode sheet unit 221. In this electrode assembly 200, each second electrode sheet unit 221 is spaced apart along the second direction X and alternates with each first electrode sheet unit 211, and each fourth region 2222 extends outside the separator 230 and is electrically connected, thereby electrically connecting each second electrode sheet 220 to each other. In this embodiment, the second active material layer 223 is a positive electrode active material containing a lithium-based compound.

[0051] The separator 230 is provided between adjacent first electrode sheet units 211 and second electrode sheet units 221 and primarily serves to separate the first electrode sheet 210 and the second electrode sheet 220 and conduct ions, but is not limited to its material. In some embodiments, the separator 230 includes a porous substrate. In some embodiments, the separator 230 further includes a functional coating layer disposed on the porous substrate, the functional coating layer may include at least one of a binder or inorganic particles. In some embodiments, the porous substrate is a polymer film, multilayer polymer film, or nonwoven fabric made from one or more polymers selected from the group consisting of polyethylene, polypropylene, polyethylene terephthalate, polybutylene terephthalate, polyphthaloyldiamine, polyester, polyacetal, polyamide, polycarbonate, polyimide, polyetheretherketone, polyaryletherketone, polyetherimide, polyamideimide, polybenzimidazole, polyethersulfone, polyphenylene ether, cycloolefin copolymer, polyphenylene sulfide, and polyethylene naphthalene. Such polymers have high thermal stability and facilitate surface treatment, making coating easy. Furthermore, such polymers have good toughness and are easily bendable.In some embodiments, the binder includes at least one of the following: vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-trichloroethylene copolymer, polyacrylic acid ester, polyacrylic acid, polyacrylate, polyacrylonitrile, polyvinylpyrrolidone, polyvinyl acetate, ethylene-vinyl acetate copolymer, polyimide, polyoxyethylene, cellulose acetate, cellulose butyrate acetate, cellulose propionate acetate, cyanoethyl branched starch, cyanoethyl polyvinyl alcohol, cyanoethylcellulose, cyanoethylsucrose, amylopectin, sodium carboxymethylcellulose, lithium carboxymethylcellulose, acrylonitrile-styrene-butadiene copolymer, polyvinyl alcohol, polyvinyl ether, polytetrafluoroethylene, polyhexafluoropropylene, styrene-butadiene copolymer, and polyvinylidene fluoride. These polymers provide strong adhesive properties that bond inorganic particles together and bond and integrate the separator 230 with the first electrode sheet 210 / second electrode sheet 220, thereby increasing the hardness of the electrode assembly 200. In other embodiments, the binder may contain other polymers. In some embodiments, the inorganic particles include at least one of silica, alumina, titanium oxide, zinc oxide, magnesium oxide, hafnium dioxide, tin oxide, zirconium oxide, yttrium oxide, silicon carbide, boehmite, magnesium hydroxide, aluminum hydroxide, calcium titanate, barium titanate, lithium phosphate, lithium titanium phosphate, and lithium lanthanum titanate. All of these inorganic particles have high thermal stability and can improve the high-temperature resistance of the electrochemical apparatus 1.

[0052] In some embodiments, the electrochemical apparatus 1 further includes a first insulating tape 240 to ensure that the first electrode sheet unit 211, the second electrode sheet unit 221, and the separator 230 can be maintained in a relatively stable stacked state without collapsing before being mounted to the case assembly 100. Specifically, referring to Figure 2, the electrode assembly 200 has a first surface 201 and a second surface 202 facing each other along a second direction X. The first insulating tape 240 is under tension, with one end fixed to the first surface 201 and the other end extending along the second direction X to the second surface 202 and fixed to the second surface 202. In this way, the first insulating tape 240 can reduce the risk of slack deformation between the first electrode sheet unit 211 and the second electrode sheet 220 and the separator 230 by sandwiching the electrode assembly 200 between its ends. Selectively, two first insulating tapes 240 are connected to the electrode assembly 200. The two first insulating tapes 240 are positioned opposite each other along the first direction Z. One of the first insulating tapes 240 is located between the electrode assembly 200 and the bottom wall 111, and the other first insulating tape 240 is located between the electrode assembly 200 and the lid 120.

[0053] In some embodiments, the electrochemical apparatus 1 further includes a second insulating tape 250 for securing the electrode assembly 200 to the inner wall of the case assembly 100. This second insulating tape 250 is fixed to the electrode assembly 200 and the case assembly 100, respectively, so as to secure the electrode assembly 200 to the case assembly 100. Specifically, continuing to refer to Figure 2, the second insulating tape 250 is elongated and positioned between the electrode assembly 200 and the side wall 112. One end of the second insulating tape 250 is fixed to the first surface 201, and the other end extends along the second direction X to the second surface 202 and is fixed to the second surface 202. The second insulating tape 250 is a double-sided tape, with one side adhesively fixed to the electrode assembly 200 and the other side adhesively fixed to the side wall 112, thereby securing the electrode assembly 200 and the case assembly 100. The second insulating tape 250 is intended to secure the electrode assembly 200 to the case assembly 100. Therefore, in other embodiments of the present application, the second insulating tape 250 may be other types of insulating tape, such as hot-melt adhesive or single-sided adhesive tape, but is not particularly limited in the present application. At the same time, in other embodiments, the second insulating tape may be positioned only between any surface of the electrode assembly and any surface of the case assembly, as long as it can perform its function of securing the electrode assembly to the case assembly.

[0054] In this embodiment, the case assembly 100 is conductive, and the electrochemical apparatus 1 further comprises a first conductive member 300. Each of the second regions 2122 is electrically connected by this first conductive member 300, and this first conductive member 300 is electrically connected to the case assembly 100. Thus, the case assembly 100 is configured as a conductive terminal in the electrochemical apparatus 1. Specifically, referring to Figures 3 and 2, the second region 2122 is located between the first region 2121 and the first side wall unit 1121, has a folded shape, and comprises a first portion 2123 and a second portion 2124. One end of the first portion 2123 is connected to the first region 2121, and the other end extends close to the first side wall unit 1121. The second portion 2124 is connected to one end of the first portion 2123 away from the first region 2121 and is bent relative to the first portion 2123, with the bending direction of each second portion being the same. The first conductive member 300 is in the form of a sheet or elongated shape and is provided between the electrode assembly 200 and the first sidewall unit 1121. The second portion 2124 is electrically connected to the first conductive member 300. In this embodiment, each of the second regions 2122 is provided in a sequentially overlapping manner. Specifically, the electrode assembly 200 comprises three or more first electrode sheets 210. Along the first predetermined direction M shown in Figure 3, between any two adjacent second portions 2124, at least a portion of the downstream second portion 2124 is laminated on the surface of the upstream second portion 2124. Between any three adjacent second portions, the region in which the intermediate second portion 2124 covers the upstream second portion 2124 is not covered by the downstream second portion 2124. In other words, there is no common layered region between the three adjacent second portions 2124. Here, the first predetermined direction M is the direction from one end of the second portion 2124 closer to the first portion 2123 to the other end further away from the first portion 2123. In this embodiment, the first predetermined direction M is parallel to the second direction X. Of course, in other embodiments of the present application, this first predetermined direction M may form a constant angle with respect to the second direction X.In other embodiments of the present invention, the second portions 2124 may be stacked sequentially along the third direction Y, but in such an installation configuration, it is necessary to reserve a large space between the first region 2121 and the first side wall unit 1121 in advance. In contrast, the configuration in the present invention, in which the second portions 2124 are stacked sequentially, can solve the above-mentioned problem.

[0055] Furthermore, the electrochemical apparatus 1 includes a second conductive member 400 and a pole 500. Each of the fourth regions 2222 is electrically connected by the second conductive member 400, which is connected to the pole 500. One end of the pole 500 is located in the housing chamber 101 and is connected to the second conductive member 400, i.e., electrically connected to the fourth region 2222, while the other end protrudes from the case assembly 100. Thus, the pole 500 is configured as the other conductive terminal of the electrochemical apparatus 1. Continuing to refer to Figures 3 and 2, the fourth region 2222 is located between the third region 2221 and the second side wall unit 1122, has a folded shape, and comprises a third portion 2223 and a fourth portion 2224. One end of the third portion 2223 is connected to the third region 2221, and the other end extends close to the second side wall unit 1122. The fourth portion 2224 is connected to one end of the third portion 2223 away from the third region 2221 and is bent relative to the third portion 2223, with each fourth portion 2224 having the same bending direction. The second conductive member 400 is in sheet form and is provided between the electrode assembly 200 and the second side wall unit 1122. By laminating the fourth portion 2224 onto the surface of the first conductive member 300, each fourth region 2222 is electrically connected by this first conductive member 300. In this embodiment, each fourth region 2222 is provided overlapping in sequence. Specifically, along the second predetermined direction N shown in Figure 3, between any two adjacent fourth portions 2224, at least a portion of the downstream fourth portion 2224 is laminated onto the surface of the upstream fourth portion 2224. Between any three adjacent fourth portions 2224, the region in which the intermediate fourth portion 2224 covers the upstream second portion is not covered by the downstream second portion. In other words, there is no common stacked region between the three adjacent fourth portions 2224. Here, the second predetermined direction N is the direction from one end of the fourth portion 2224 closer to the third portion 2223 to the other end away from the third portion 2223. In this embodiment, the second predetermined direction N is the same as the first predetermined direction M.Of course, in other embodiments of the present application, the second predetermined direction N may be opposite to the first predetermined direction M, or the second direction described above. X It may form a certain angle with respect to it.

[0056] In this embodiment, the second region 2122 and the fourth region 2222 are understood to be located on one side of the first region 2121, but the present application is not limited thereto. In other embodiments of the present application, the second region 2122 and the fourth region 2222 may be located on the same side of the first region 2121, and accordingly, the widths of the second region 2122 and the fourth region 2222 are both less than half the width of the first region 2121.

[0057] In some embodiments, a liquid injection hole 102 communicating with a containment chamber 101 is provided on the outer surface of the case assembly 100, and this liquid injection hole 102 is for supplying electrolyte to the containment chamber. Correspondingly, the electrochemical apparatus 1 further comprises a liquid injection plug (not shown) which is attached to and covers the liquid injection hole. Selectively, the liquid injection hole 102 is provided on the lid 120. This allows the electrolyte to penetrate from the beginning into the gap between the first electrode sheet unit 211, the separator 230 and the second electrode sheet unit 221 when the electrolyte is injected into the containment chamber 101, thereby increasing the penetration rate of the electrode assembly 200 and further shortening the manufacturing cycle of the electrochemical apparatus 1 to some extent. Furthermore, selectively, the liquid injection hole 102 is provided close to the geometric center of the lid 120. For example, the distance between them is less than 5 mm. Of course, in other embodiments of the present application, the liquid injection hole 102 may be provided on the bottom wall 111. This configuration also increases the penetration rate of the electrode assembly 200. Correspondingly, the liquid injection hole 102 may be located close to the geometric center of the bottom wall 111. For example, the distance between them may be less than 5 mm.

[0058] It should be noted that the above description uses the example that the electrochemical apparatus 1 comprises one electrode assembly 200, but the present invention is not limited to this. For example, in other embodiments of the present invention, the electrochemical apparatus 1 may comprise two or more electrode assemblies 200, each electrode assembly 200 being arranged along the second direction X, each electrode assembly 200 being connected to the same first conductive member 300, and each electrode assembly 200 being connected to the same second conductive member 400. The electrical connection method between each electrode assembly 200 may be series connection, parallel connection, or mixed connection. Furthermore, by stacking multiple electrode assemblies 200, it is possible to avoid the thickness of a single electrode assembly 200 being too thick, thereby making the stacking process of each electrode assembly 200 easier and reducing the error rate during stacking of the electrode assemblies 200.

[0059] In electrochemical apparatuses currently on the market, where the electrode assembly has a laminated structure, the lamination direction of the first electrode sheet and the second electrode sheet (i.e., the second direction X) coincides with the package direction of the case and lid in the case assembly (i.e., the first direction Z). In this electrochemical apparatus, the electrode assembly expands significantly along the lamination direction during charging. At the same time, because the strength of the case assembly in the package direction is low, the expansion deformation of the electrode assembly easily deforms the case assembly in the lamination direction, causing cracks and leading to phenomena such as electrolyte leakage, resulting in poor installability of the electrochemical apparatus.

[0060] The electrochemical apparatus 1 according to the embodiment of the present invention comprises a case assembly 100 and an electrode assembly 200. The electrode assembly 200 comprises a first electrode sheet 210, a second electrode sheet 220, and a separator 230. The first electrode sheet 210 comprises a first electrode sheet unit 211, and the second electrode sheet 220 comprises a second electrode sheet unit 221. The first electrode sheet unit 211 and each second electrode sheet unit 221 are in the first direction ZThe electrodes are stacked along a second direction X perpendicular to the first electrode sheet unit Z, and a separator 230 is provided between adjacent first electrode sheet units 211 and second electrode sheet units 221. Therefore, during the charging process of the electrochemical apparatus, the electrode assembly 200 expands mainly along the second direction X, and the amount of expansion in the first direction Z is extremely small, so the case assembly 100 is less likely to deform or crack due to the expansion of the electrode assembly 200.

[0061] In summary, the electrochemical apparatus 1 according to the embodiment of the present invention can improve upon the current situation in electrochemical apparatuses where the case assembly 100 is prone to deformation and cracking. Furthermore, because the electrochemical apparatus 1 exhibits little or no expansion in the first direction Z, it does not require a spare space between the electrode assembly 200 and the case assembly 100 along the above direction within the case assembly 100, thus increasing the energy density of the electrochemical apparatus. In other words, the electrochemical apparatus 1 according to the embodiment of the present invention ensures that energy density is substantially not lost, while also improving the first direction Z This can improve the current situation where it is prone to expansion and deformation.

[0062] Next, using the case where a negative electrode active material with a silicon element mass ratio of 60% (hereinafter referred to as a high-silicon negative electrode active material) is used in the first active material layer 213 of this electrochemical apparatus 1, we will provide a supplementary explanation of the difference in energy density between the electrochemical apparatus 1 according to the embodiment of this application and conventional electrochemical apparatuses in related technologies. In the example below, the length of the case assembly 100 of each electrochemical apparatus is 82.5 mm, the width is 72.5 mm, and the thickness is 50 mm, and the total gap on both sides between the case assembly 100 and the first electrode sheet unit 211 is calculated to be 2.5 mm.

[0063] First, we define an electrochemical apparatus that uses a conventional graphite-based anode active material and in which each element in the electrode assembly is stacked along the first direction Z as the first electrochemical apparatus. In the first electrochemical apparatus, the case space is almost completely filled in the Z direction. We define an electrochemical apparatus that uses a high-silicon-based anode active material and in which each element in the electrode assembly is stacked along the first direction Z as the second electrochemical apparatus. Due to the expansion characteristics of the high-silicon-based anode stacked cell, this second electrochemical apparatus requires that approximately 10% of the thickness space along the first direction Z be pre-reserved inside the case assembly to prevent deformation and cracking of the case due to its expansion. We define an electrochemical apparatus that uses a high-silicon-based anode active material and in which each element in the electrode assembly is stacked along the second direction X as the third electrochemical apparatus.

[0064] Regarding the first and second electrochemical apparatuses, the high-silicon system has advantages such as high gram capacity and low potential. Therefore, even though the second electrochemical apparatus has pre-reserved expansion space, its energy density is higher than that of the first electrochemical apparatus, and the ratio of their energy densities is S1, which is approximately 1.3.

[0065] The electrode assemblies in the second electrochemical apparatus are stacked along the first direction Z, and it is necessary to reserve 10% space in the first direction Z beforehand. Therefore, the effective dimensions of the electrode assemblies in the second electrochemical apparatus are 80 mm in length, 70 mm in width, and 45 mm in thickness, and the volume of this second electrochemical apparatus is Vb.

[0066] The electrode assemblies in the third electrochemical apparatus are stacked along the width direction of the electrochemical apparatus; that is, the second direction X is the width direction of the electrochemical apparatus, and the effective dimensions of the electrode assemblies in this third electrochemical apparatus are 80 mm in length, 47.5 mm in width, and 72.5 mm in thickness, and the volume of this third electrochemical apparatus is Vc. Therefore, the ratio of the energy densities of the third electrochemical apparatus to that of the second electrochemical apparatus is S2 = Vc / Vb = 1.09325.

[0067] From the above data, it can be seen that the electrochemical apparatus 1 according to the embodiment of the present invention has an energy density that is approximately (S1*S2-1)*100% = 42.12% higher than conventional electrochemical apparatuses currently on the market. In other words, the electrochemical apparatus according to the embodiment of the present invention has an energy density that is approximately 40% higher than conventional electrochemical apparatuses.

[0068] Based on the same idea, the present invention further provides a power consumption device. Referring to Figure 8, Figure 8 is a schematic diagram of a power consumption device 2 according to one embodiment of the present invention. This power consumption device 2 comprises an electrochemical device (1, 1b) according to any of the above embodiments and a load structure to which power is supplied by this electrochemical device. In this embodiment, this power consumption device 2 includes a mobile phone. In other embodiments of the present invention, the power consumption device may be other power-driven devices such as a tablet, wristwatch, earphones, personal computer, drone, electric vehicle, electric bicycle, power tool, or cleaning robot.

[0069] Since this power consumption device 2 includes the electrochemical device 1 in the above embodiment, the electrochemical device in the current power consumption device 2 is in the first direction Z This can improve the current situation where it is prone to expansion and deformation.

[0070] The above embodiments are for illustrative purposes only and are not intended to limit the present application. Based on the concept of the present application, the technical features in the above embodiments or different embodiments can be combined, the steps can be implemented in any order, and there are many other variations in different aspects of the present application as described above, but these will not be described in detail for the sake of simplicity. The present application has been described in detail with reference to the embodiments described above, but those skilled in the art can modify the technical concepts described in each of the embodiments described above or replace some of the technical features with equivalent ones. These modifications or substitutions will not cause the essence of the corresponding technical concepts to deviate from the scope of the technical concepts in each embodiment of the present application.

Claims

1. An electrochemical apparatus comprising a case assembly and an electrode assembly, The case assembly comprises a case and a lid, the case comprises a bottom wall and a side wall, the side wall having one end connected to the bottom wall and the other end extending away from the bottom wall, the bottom wall together with the side wall defining a storage chamber, the lid being attached to the end of the side wall away from the bottom wall and covering the storage chamber, the direction in which the bottom wall faces the lid being the first direction, The electrode assembly is housed in the housing chamber and comprises a first electrode sheet, a second electrode sheet, and a separator, wherein the first electrode sheet comprises a first electrode sheet unit, the second electrode sheet comprises a second electrode sheet unit, the first electrode sheet unit and the second electrode sheet unit are stacked along a second direction and are both provided perpendicular to the second direction, and the separator is provided between adjacent first electrode sheet units and second electrode sheet units. The second direction is perpendicular to the first direction, The first conductive member further comprises a first electrode sheet comprising a first current collector and a first active material layer, the first current collector comprising a first region and a second region, the first region being provided perpendicular to the second direction, the second region being electrically connected to the first region, the first active material layer being provided on the surface of the first region, the first region together with the first active material layer constituting the first electrode sheet unit, each first electrode sheet unit being provided at intervals along the second direction, and the second region being electrically connected to the first conductive member. The case has a first side wall unit and a second side wall unit installed opposite to each other along a third direction, the second region and the first conductive member are both located between the first region and the first side wall unit, and the third direction is perpendicular to the first direction and the second direction, respectively. The second region comprises a first portion and a second portion, the first portion having one end connected to the first region and the other end extending in close proximity to the first sidewall unit, the second portion being connected to one end of the first portion away from the first region and being bent relative to the first portion, and the second portion being connected to the first conductive member. An electrochemical apparatus characterized by the following features.

2. The first electrode sheet is an anode sheet, The first electrode sheet comprises a first current collector and a first active material layer provided on the surface of the first current collector, wherein the material of the first active material layer contains silicon, and the percentage of the mass of the silicon element relative to the total mass of the first active material layer is 10% or more. The electrochemical apparatus according to claim 1, characterized in that

3. The percentage of the mass of the silicon element relative to the total mass of the first active material layer is 30% or more and 80% or less. The electrochemical apparatus according to claim 2, characterized in that

4. The first active material layer comprises at least one of silicon, silicon oxide, silicon carbide, silicon nanowire, and silicon nanoparticles. The electrochemical apparatus according to claim 2, characterized in that

5. The electrode assembly comprises three or more first electrode sheets, the second portion being bent relative to the first portion, and the bending direction of each second portion is the same. Along a first predetermined direction, between any two adjacent second portions, at least a portion of the downstream second portion is laminated on the surface of the upstream second portion, and there is no common laminated region between any three adjacent second portions. The first predetermined direction is the direction from one end of the second portion that is close to the first portion to the other end that is away from the first portion. The electrochemical apparatus according to claim 1, characterized in that

6. Further comprising a first insulating tape, The electrode assembly has a first surface and a second surface facing each other along the second direction, and the first insulating tape has one end fixed to the first surface and the other end fixed to the second surface. The electrochemical apparatus according to claim 1, characterized in that

7. Further equipped with a second insulating tape, The second insulating tape is fixed to the electrode assembly and the case, respectively, so as to fix the electrode assembly to the case. The electrochemical apparatus according to claim 1, characterized in that

8. When viewed along the first direction, the edge of the bottom wall does not extend beyond the end of the side wall closest to the bottom wall. When viewed along the first direction, the edge of the lid does not extend beyond the end of the side wall closest to the lid. The electrochemical apparatus according to claim 7, characterized in that

9. The electrochemical apparatus comprises two or more electrode assemblies, each electrode assembly being arranged along the second direction. The electrochemical apparatus according to claim 1, characterized in that

10. The case further comprises a pole attached to the case, the pole being insulated from the case, and the pole being electrically connected to the second electrode sheet unit. The electrochemical apparatus according to claim 1, characterized in that

11. The lid is provided with a liquid injection hole, and the distance between the liquid injection hole and the geometric center of the lid is less than 5 mm, or the bottom wall is provided with a liquid injection hole, and the distance between the liquid injection hole and the geometric center of the bottom wall is less than 5 mm. The electrochemical apparatus according to claim 1, characterized in that

12. The aspect ratios of both the first electrode sheet and the second electrode sheet are 3 to 20. The electrochemical apparatus according to claim 1, characterized in that

13. The side wall is integrally molded, and the tensile strength of the side wall material is 1000 MPa or more. The electrochemical apparatus according to claim 1, characterized in that

14. The aforementioned side wall is welded, and the weld strength at the welded joint is 1000 MPa or more. The electrochemical apparatus according to claim 1, characterized in that

15. A power consumption device, A power consumption device characterized by comprising an electrochemical apparatus as described in any one of claims 1 to 14.

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