Electrochemical device and electronic equipment
Patent Information
- Application Number
- CN202522538664.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-28
- Publication Date
- 2026-10-27
- Estimated Expiration
- 2035-11-28
AI Technical Summary
但现有的补锂电极的锂离子流动至负极极片的传输路径较长，补锂效率较低
由于本申请的第一锂部设置于补锂集流体垂直于厚度方向的边缘，则第一锂部中的锂在转化成锂离子后，能够更快抵达多个导电部的边缘，并进入到各个导电部的负极活性物质层，增加各个导电部的含锂量，上述方案减少了锂离子的传输路径，提高了补锂效率。
Smart Images
Figure CN224908063U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of electrochemical energy storage, specifically to electrochemical devices and electronic equipment. Background Technology
[0002] Lithium-ion battery cells replenish lithium to the negative electrode through a lithium-ion replenishment electrode. During this process, the lithium metal on the existing replenishment electrode is electrolyzed into lithium ions and transported to the negative electrode, increasing its lithium content. However, the lithium ion transport path from the existing replenishment electrode to the negative electrode is relatively long, resulting in low replenishment efficiency. Utility Model Content
[0003] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes an electrochemical device with higher lithium replenishment efficiency.
[0004] This application also proposes an electronic device having the above-mentioned electrochemical device.
[0005] A negative electrode assembly includes multiple conductive parts arranged along the thickness direction, and each conductive part includes a negative electrode current collector and a negative electrode active material layer stacked along the thickness direction; A lithium electrode sheet is stacked on at least one of the conductive portions; A lithium replenishing tab is connected to the lithium replenishing electrode sheet; A first diaphragm is disposed between the lithium-filling electrode and the conductive portion; The lithium replenishing electrode includes a lithium replenishing current collector and a first lithium portion, the first lithium portion being stacked on one side of the lithium replenishing current collector in the thickness direction; the negative electrode assembly is electrically connected to the lithium replenishing electrode tab so that the first lithium portion can replenish lithium to the negative electrode active material layer; the first lithium portion is disposed on the edge of the lithium replenishing current collector perpendicular to the thickness direction.
[0006] The electrochemical device according to the embodiments of this application has at least the following beneficial effects: Since the first lithium section of this application is located at the edge of the lithium replenishment current collector perpendicular to the thickness direction, the lithium in the first lithium section, after being converted into lithium ions, can reach the edges of multiple conductive sections more quickly and enter the negative electrode active material layer of each conductive section, increasing the lithium content of each conductive section. The above solution reduces the lithium ion transport path and improves the lithium replenishment efficiency.
[0007] According to some embodiments of this application, the negative electrode assembly includes a negative electrode sheet and a negative electrode tab, the negative electrode tab being connected to the negative electrode current collector; the electrochemical device further includes a positive electrode sheet and a positive electrode tab, the positive electrode tab being connected to the positive electrode sheet; the negative electrode sheet and the positive electrode sheet together form a winding structure around an axis parallel to the length direction; the winding structure includes a straight region and a bent region arranged along the width direction, and the negative electrode sheet includes a plurality of conductive portions located in the straight region.
[0008] According to some embodiments of this application, the first lithium portion is disposed at the edge of the lithium replenishment current collector in the length direction.
[0009] According to some embodiments of this application, the lithium-filling electrode is located on one side of all the conductive portions in the thickness direction.
[0010] According to some embodiments of this application, the negative electrode assembly includes a plurality of negative electrode plates and a plurality of negative electrode tabs, each negative electrode plate includes a conductive portion, and each negative electrode current collector is connected to at least one negative electrode tab. The electrochemical device further includes a plurality of positive electrode plates, a plurality of positive electrode tabs, and a plurality of third membranes, and each positive electrode plate is connected to at least one positive electrode tab. Along the thickness direction, the negative electrode plates and positive electrode plates are staggered and stacked, and the third membranes are provided between adjacent negative electrode plates and positive electrode plates.
[0011] According to some embodiments of this application, the first lithium portion is disposed at the edge of the lithium replenishment current collector in the length and width directions.
[0012] According to some embodiments of this application, the lithium supplement electrode is located on one side of all the negative electrode electrodes in the thickness direction.
[0013] According to some embodiments of this application, the lithium-filling electrode is located on the side of the third separator closer to the negative electrode.
[0014] According to some embodiments of this application, the lithium replenishing electrode further includes a second lithium portion, which is stacked on the side of the lithium replenishing current collector on which the first lithium portion is located in the thickness direction; the negative electrode assembly can be electrically connected to the lithium replenishing electrode tab so that the second lithium portion can replenish lithium to the negative electrode active material; the second lithium portion is further away from the edge of the lithium replenishing current collector perpendicular to the thickness direction relative to the first lithium portion. The dimension of the second lithium portion in the thickness direction is smaller than the dimension of the first lithium portion in the thickness direction.
[0015] An electronic device according to a second aspect embodiment of this application, The electronic device according to the embodiments of this application has at least the following beneficial effects: Since the first lithium part of this application is disposed at the edge of the lithium replenishment current collector perpendicular to the thickness direction, the lithium in the first lithium part can reach the edge of multiple conductive parts more quickly after being converted into lithium ions, and enter the negative electrode active material layer of each conductive part, thereby increasing the lithium content of each conductive part. The above solution reduces the lithium ion transport path, improves the lithium replenishment efficiency, and is conducive to improving the service life of the electronic device.
[0016] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description
[0017] The present application will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 This is a schematic diagram of some embodiments of the first aspect of this application; Figure 2 for Figure 1 A cross-sectional view shown at point AA; Figure 3 for Figure 2 A magnified view shown at point D; Figure 4 This is a cross-sectional schematic diagram of some embodiments of the second aspect of this application; Figure 5 This is a schematic diagram of some embodiments of the third aspect of this application; Figure 6 for Figure 5 A cross-sectional view shown at point BB; Figure 7 This is a schematic diagram of some embodiments of the fourth aspect of this application; Figure 8 This is a schematic diagram of the structure of the lithium electrode sheet connected to the lithium electrode tab in some embodiments of the fifth aspect of this application; Figure 9 for Figure 8 A cross-sectional view shown at point CC; Figure 10 This is a schematic diagram of the structure of the lithium electrode sheet in some embodiments of the sixth aspect of this application.
[0018] Figure label: Electrochemical device 10; Negative electrode assembly 100, conductive part 110, negative electrode current collector 111, negative electrode active material layer 112, negative electrode sheet 120, negative electrode tab 130; Lithium-replenishing electrode 200, lithium-replenishing current collector 210, first lithium section 220, second lithium section 230; Lithium-ion electrode 300; First diaphragm 400; Positive electrode plate 500, second straight section 510; Positive electrode tab 600; Winding structure 700, straight section 710, bending section 720; Second diaphragm 800; Third diaphragm 900. Detailed Implementation
[0019] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. The embodiments of this application may omit unnecessary detailed descriptions. For example, detailed descriptions of well-known matters and repeated descriptions of actually identical structures may be omitted. This is to avoid making the following description unnecessarily lengthy and to facilitate understanding by those skilled in the art.
[0020] In this application, the technical features described in an open-ended manner include both closed technical solutions consisting of the listed features and open technical solutions that include the listed features.
[0021] As used herein, the terms “approximately,” “generally,” “substantially,” and “about” are used to describe and indicate small variations. When used in conjunction with an event or situation, the terms may refer to examples in which the event or situation occurred precisely and examples in which the event or situation occurred very approximately. For example, when used in conjunction with numerical values, the terms may refer to a range of variation less than or equal to ±10% of the numerical value, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%. For example, if the difference between two values is less than or equal to ±10% of the average of the values (e.g., less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%), then the two values can be considered "substantially" the same.
[0022] Furthermore, for ease of description, "first," "second," "third," etc., can be used in this article to distinguish different components of a figure or a series of figures. "First," "second," "third," etc., are not intended to describe the corresponding components.
[0023] Additionally, quantities, ratios, and other numerical values are sometimes presented in range format in this document. It should be understood that such range format is for convenience and brevity and should be interpreted flexibly to include not only the numerical values explicitly specified as range limits, but also all individual numerical values or subranges covered within the range, as if each numerical value and subrange were explicitly specified.
[0024] In the detailed description and claims, a list of items connected by the terms "one of," "among," "a kind of," or other similar terms may mean any of the listed items. For example, if items A and B are listed, then the phrase "one of A and B" means only A or only B. In another example, if items A, B, and C are listed, then the phrase "one of A, B, and C" means only A; only B; or only C. Item A may contain a single element or multiple elements. Item B may contain a single element or multiple elements. Item C may contain a single element or multiple elements. In the detailed description and claims, a list of items connected by the term "at least one of" may mean any combination of the listed items. For example, if items A and B are listed, then the phrase "at least one of A and B" means only A; only B; or A and B. In another instance, if items A, B, and C are listed, then the phrase "at least one of A, B, and C" means only A; or only B; only C; A and B (excluding C); A and C (excluding B); B and C (excluding A); or all of A, B, and C.
[0025] In the following description, all figures disclosed in this application are approximate values, regardless of whether the terms "about" or "approximately" are used in conjunction. They may vary by 1%, 2%, 5%, or sometimes 10% to 20%. Whenever a range of values with a lower limit (RL) and an upper limit (RU) is disclosed, any values falling within that range are specifically disclosed. Specifically, the following values within this range are specifically disclosed: R = RL + k * (RU - RL), where k is a variable ranging from 1% to 100% with a 1% increment, i.e., k is 1%, 2%, 3%, 4%, 5%, ..., 50%, 51%, 52%, ..., 95%, 96%, 97%, 98%, 99%, or 100%. Furthermore, any range of values defined by the two R values as defined above are also specifically disclosed.
[0026] Throughout this specification, references to "implementation," "partial implementation," "one implementation," "another implementation," "specific method," or "partial method" mean that at least one implementation or embodiment in this application includes the specific features, structures, materials, or characteristics described in that implementation or embodiment.
[0027] In this application, numerical ranges are involved. Unless otherwise specified, the numerical ranges mentioned above are considered continuous and include the minimum and maximum values of the range, as well as every value between the minimum and maximum values. Any lower limit can be combined with any upper limit to form a range not explicitly stated; and any lower limit can be combined with other lower limits to form a range not explicitly stated, just as any upper limit can be combined with any other upper limit to form a range not explicitly stated. Furthermore, each individually disclosed point or single value can itself serve as a lower or upper limit and be combined with any other point or single value or with other lower or upper limits to form a range not explicitly stated.
[0028] Please refer to Figures 1 to 10 As shown, this application proposes an electrochemical device 10 having a length direction, a width direction and a thickness direction, including a negative electrode component 100, a lithium replenishing electrode 200, a lithium replenishing tab 300 and a first separator 400.
[0029] Please refer to Figure 1 , Figure 2 , Figure 3 , Figure 8 , Figure 9 As shown, the negative electrode assembly 100 of this application includes a plurality of conductive portions 110, which are arranged along the thickness direction. Each conductive portion 110 includes a negative electrode current collector 111 and a negative electrode active material layer 112 stacked along the thickness direction. A lithium replenishing electrode 200 is stacked on at least one conductive portion 110. A lithium replenishing tab 300 is connected to the lithium replenishing electrode 200. A first separator 400 is disposed between the lithium replenishing electrode 200 and the conductive portions 110. The lithium replenishing electrode 200 includes a lithium replenishing current collector 210 and a first lithium portion 220, which is stacked on one side of the lithium replenishing current collector 210 in the thickness direction. The negative electrode assembly 100 can be electrically connected to the lithium replenishing tab 300 so that the first lithium portion 220 can replenish lithium to the negative electrode active material layer 112. The first lithium portion 220 is disposed at the edge of the lithium replenishing current collector 210 perpendicular to the thickness direction.
[0030] In the above scheme, the negative electrode active material layer 112 stacked along the thickness direction in the conductive part 110 is used to store electrical energy, and the electrical energy in the negative electrode active material layer 112 can be transmitted through the negative electrode current collector 111. The multiple conductive parts 110 arranged along the thickness direction enable the negative electrode active material layer 112 and the negative electrode current collector 111 to be stacked along the thickness direction, thereby making the electrical energy stored in the negative electrode active material layer 112 stacked in the thickness direction, thereby improving the overall electrical energy of the electrochemical device 10.
[0031] The first lithium section 220 of this application is used to store lithium. The first separator 400 disposed between the lithium replenishing electrode 200 and the conductive section 110 can isolate the lithium replenishing electrode 200 and the conductive section 110, avoiding short circuits caused by direct contact between the lithium replenishing electrode 200 and the conductive section 110. When the negative electrode assembly 100 is electrically connected to the lithium replenishing tab 300, the lithium in the first lithium section 220 can be converted into lithium ions and migrate towards the negative electrode active material layer 112 of the negative electrode assembly 100, increasing the lithium content of the negative electrode assembly 100. Since the first lithium section 220 of this application is disposed at the edge of the lithium replenishing current collector 210 perpendicular to the thickness direction, the lithium in the first lithium section 220, after being converted into lithium ions, can reach the edges of the multiple conductive sections 110 more quickly and enter the negative electrode active material layer 112 of each conductive section 110, increasing the lithium content of each conductive section 110. The above scheme reduces the lithium ion transport path and improves the lithium replenishment efficiency.
[0032] Those skilled in the art can further improve the structure of the lithium-filled electrode 200.
[0033] For example, please refer to Figure 8 , Figure 9 As shown, in some embodiments, the lithium replenishing electrode 200 further includes a second lithium portion 230, which is stacked on the side of the lithium replenishing current collector 210 where the first lithium portion 220 is located in the thickness direction. The negative electrode assembly 100 can be electrically connected to the lithium replenishing tab 300 so that the second lithium portion 230 can replenish lithium to the negative electrode active material. The second lithium portion 230 is further away from the edge of the lithium replenishing current collector 210 perpendicular to the thickness direction than the first lithium portion 220. The dimension of the second lithium portion 230 in the thickness direction is smaller than the dimension of the first lithium portion 220 in the thickness direction.
[0034] Through the above scheme, the second lithium section 230 can further utilize the space away from the edge on the lithium replenishing current collector 210 to increase the lithium content of the lithium replenishing electrode 200, providing more lithium to the negative electrode assembly 100 and improving the cycle performance of lithium ions. Furthermore, since the second lithium section 230 is smaller in the thickness direction than the first lithium section 220, the lithium replenishing electrode 200 mainly transmits lithium through the first lithium section 220 during lithium replenishment, ensuring that the lithium ions provided by the lithium replenishing electrode 200 can reach the edges of the multiple conductive sections 110 more quickly, resulting in higher lithium replenishment efficiency.
[0035] Without departing from the inventive concept of this application, those skilled in the art can adjust the shapes of the second lithium portion 230 and the first lithium portion 220. For example, please refer to... Figure 2 , Figure 3 , Figure 8 , Figure 9 As shown, where Figure 8 It shows Figure 2In some embodiments, the structure of the lithium-filled electrode 200 includes a first lithium portion 220 disposed on two edges along the length direction of the lithium-filled current collector 210, and a second lithium portion 230 disposed in the center along the length direction of the lithium-filled current collector 210.
[0036] In some embodiments, the lithium replenishing tab 300 and the lithium replenishing current collector 210 are integrally connected. Through the above solution, the lithium replenishing tab 300 and the lithium replenishing current collector 210 can become an integral structure, resulting in stronger mechanical stability.
[0037] In some embodiments, the electrochemical device 10 includes a plurality of lithium replenishing tabs 300, all of which are connected to the lithium replenishing current collector 210. Each of the plurality of lithium replenishing tabs 300 can be connected to the negative electrode tab 130. When the plurality of lithium replenishing tabs 300 are simultaneously connected to the negative electrode tab 130, the lithium replenishing electrode 200 can transmit current through the plurality of lithium replenishing tabs 300, resulting in a more uniform potential and current distribution on the lithium replenishing electrode 200. This facilitates higher lithium migration efficiency at various points in the first lithium portion 220 and improves the lithium replenishment efficiency for the portion of the negative electrode 120 far from the negative electrode connection portion.
[0038] This application does not limit the material of the lithium replenishing current collector 210. In some embodiments, the lithium replenishing current collector 210 is made of copper foil or stainless steel foil. In some embodiments, the lithium replenishing current collector 210 is a composite current collector. In some embodiments, the lithium replenishing current collector 210 is made of a mixture of polymer materials and conductive fillers, wherein the polymer materials include polyethylene, polypropylene, polytetrafluoroethylene, polyacrylamide, polyamide, polymethyl methacrylate, polyacrylonitrile, polyethylene oxide, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, and polyvinylpyrrolidone, etc., and the conductive fillers include non-metallic fillers such as carbon black, graphite, carbon fiber, and carbon nanotubes, as well as metallic fillers such as copper and aluminum, and metal oxide fillers such as copper oxide and zinc oxide, or purchased polymeric PTC.
[0039] In some embodiments, the electrochemical device 10 includes a positive electrode 500, a negative electrode 120, an electrolyte, and a separator, with the separator located between the positive electrode 500 and the negative electrode 120.
[0040] It should be noted that the electrochemical device 10 provided in this application includes any device in which an electrochemical reaction occurs to convert chemical energy into electrical energy and vice versa. Specific, non-limiting examples include all types of primary batteries, secondary batteries, fuel cells, solar cells, or capacitors. In particular, the electrochemical device 10 is a lithium secondary battery, including lithium metal secondary batteries, lithium-ion secondary batteries, lithium polymer secondary batteries, or lithium-ion polymer secondary batteries.
[0041] Those skilled in the art can adjust the structure of the negative electrode assembly 100 according to the type of electrochemical device 10.
[0042] For example, please refer to Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 8 , Figure 9 As shown, where Figure 8 It shows Figure 2 In some embodiments, the structure of the lithium electrode 200 includes a negative electrode assembly 100 comprising a negative electrode 120 and a negative electrode tab 130 connected to a negative current collector 111. The electrochemical device 10 also includes a positive electrode 500 and a positive electrode tab 600 connected to the positive electrode 500. The negative electrode 120 and the positive electrode 500 together form a winding structure 700 around an axis parallel to the length direction. The winding structure 700 includes a straight region 710 and a bent region 720 arranged along the width direction. The negative electrode 120 includes a plurality of conductive portions 110 located in the straight region 710.
[0043] In the above embodiments, the negative electrode 120 and the positive electrode 500 belonging to the negative electrode component 100 can be directly formed into a winding structure 700 that can be assembled into a shell through a winding action, which is beneficial to use existing winding machines for automated production and has higher production efficiency.
[0044] Without departing from the inventive concept of this application, those skilled in the art can further adjust the shape of the first lithium portion 220.
[0045] As a preferred option, please refer to Figure 2 , Figure 3 , Figure 8 As shown, in some embodiments, the first lithium portion 220 is disposed at the edge of the lithium current collector 210 in the length direction. Through this scheme, since the positive electrode 500 and the negative electrode 120 are wound around an axis parallel to the length direction to form a winding structure 700, the lithium in the first lithium portion 220, after being converted into lithium ions, can more easily migrate from the edge of the flat region 710 in the length direction to the negative electrode active material layer 112 of the different conductive portions 110, thereby resulting in higher lithium ion migration efficiency.
[0046] Those skilled in the art can further adjust the position of the lithium-filled electrode 200 in the thickness direction. As a preferred embodiment, please refer to... Figure 2 , Figure 3As shown, in some embodiments, the lithium-supplementing electrode 200 is located on one side of all conductive portions 110 in the thickness direction. With this arrangement, the lithium-supplementing electrode 200 is located on one side of all conductive portions 110 in the thickness direction, and the first separator 400 is disposed between the closest negative electrode 120 and the lithium-supplementing electrode 200. When foreign matter on one side of the thickness direction compresses the electrochemical device 10, the lithium-supplementing electrode 200 can reduce the compression of the winding structure 700 by the foreign matter, thus protecting the winding structure 700.
[0047] Please refer to Figure 3 As shown, in some embodiments, the electrochemical device 10 further includes a second separator 800 disposed between the positive electrode 500 and the negative electrode 120 to separate them. The positive electrode 500 also includes a plurality of second straight portions 510 located in the straight region 710. In the thickness direction, the lithium-filled electrode 200 is located on the side of the second separator 800 near the conductive portion 110. With the above solution, the lithium-filled electrode 200 is separated from the negative electrode 120 by the first separator 400, and also separated from the positive electrode 500 by the second separator 800 disposed between the positive electrode 500 and the negative electrode 120, thereby preventing the lithium-filled electrode 200 from being short-circuited to either the negative electrode 120 or the positive electrode 500. Furthermore, since the lithium replenishing electrode 200 is disposed inside the winding structure 700, the rigidity of the lithium replenishing electrode 200 itself can further strengthen the structure of the winding structure 700, thereby improving the stability of the electrochemical device 10.
[0048] The electrochemical device 10 of this application can also be of other types. For example, please refer to... Figure 5 , Figure 6 , Figure 7 , Figure 8 , Figure 9 As shown, where Figure 8 It shows Figure 6 In some embodiments, the structure of the lithium electrode 200 includes a plurality of negative electrode plates 120 and a plurality of negative electrode tabs 130. Each negative electrode plate 120 includes a conductive part 110, and each negative electrode current collector 111 is connected to at least one negative electrode tab 130. The electrochemical device 10 also includes a plurality of positive electrode plates 500, a plurality of positive electrode tabs 600, and a plurality of third separators 900. Each positive electrode plate 500 is connected to at least one positive electrode tab 600. Along the thickness direction, the negative electrode plates 120 and the positive electrode plates 500 are staggered and stacked, and a third separator 900 is provided between adjacent negative electrode plates 120 and positive electrode plates 500.
[0049] Through the above scheme, multiple conductive parts 110 and multiple positive electrode plates 500 are stacked alternately along the thickness direction and separated by a third diaphragm 900, so that the electrochemical device 10 has a higher energy density.
[0050] Without departing from the inventive concept of this application, those skilled in the art can further adjust the shape of the first lithium portion 220. As a preferred embodiment, please refer to... Figure 10 As shown, the first lithium portion 220 is disposed at the edge of the lithium current collector 210 in both length and width directions. With this arrangement, since the positive electrode 500 and the negative electrode 120 are directly stacked along the thickness direction, the lithium in the first lithium portion 220, after being converted into lithium ions, can more easily migrate from the edge perpendicular to the thickness direction to the negative electrode active material layer 112 of the different conductive portions 110, thereby resulting in higher lithium ion migration efficiency.
[0051] Without departing from the inventive concept of this application, those skilled in the art can further adjust the position of the lithium supplement electrode 200 in the thickness direction.
[0052] Please refer to Figure 6 As shown, in some embodiments, the lithium-supplementing electrode 200 is located on one side of all the negative electrode plates 120 in the thickness direction. With this arrangement, the lithium-supplementing electrode 200 is located on one side of all the negative electrode plates 120 in the thickness direction, and the first separator 400 is disposed between the closest negative electrode plate 120 and the lithium-supplementing electrode 200. When foreign matter on one side of the thickness direction compresses the electrochemical device 10, the lithium-supplementing electrode 200 can reduce the compression of the positive electrode plate 500 and the negative electrode plate 120 by the foreign matter, thus protecting the positive electrode plate 500 and the negative electrode plate 120.
[0053] Please refer to Figure 7 As shown, in some embodiments, the lithium-replenishing electrode 200 is located on the side of the third separator 900 closer to the negative electrode 120. Through this arrangement, the lithium-replenishing electrode 200 is separated from the negative electrode 120 by the first separator 400, and also separated from the positive electrode 500 by the third separator 900 disposed between the positive electrode 500 and the negative electrode 120, thereby preventing the lithium-replenishing electrode 200 from being short-circuited to either the negative electrode 120 or the positive electrode 500. Furthermore, since the lithium-replenishing electrode 200 is disposed between the positive electrode 500 and the negative electrode 120, the rigidity of the lithium-replenishing electrode 200 itself can further reinforce the structure formed by the stacking of multiple positive electrode 500s and multiple negative electrode 120s, improving the stability of the electrochemical device 10.
[0054] In some embodiments, the negative electrode 120 may include a negative electrode current collector 111 and a negative electrode active material layer 112 disposed on at least one side of the negative electrode current collector 111.
[0055] In some embodiments, the negative current collector 111 is a metal foil or a composite current collector. In some embodiments, the metal foil is a copper foil. The composite current collector may include a metal foil substrate and a conductive layer disposed on at least one side of the metal foil substrate. In some embodiments, the negative electrode active material may include at least one of natural graphite particles, synthetic graphite particles, hard carbon, soft carbon, mesophase carbon microspheres (MCMB), Sn, SnO2, SnO, Li4Ti5O12 (LTO), Si materials, silicon-carbon (Si-C) composite materials, silicon-nitrogen (Si-N) composite materials, and silicon-oxygen (Si-O) composite materials. The negative electrode active material of this application is not limited to the above-mentioned materials, but also includes other materials that can be used as negative electrode active materials in batteries.
[0056] In some embodiments, the negative electrode binder may include at least one of polyacrylic acid, polymethacrylic acid, polyacrylate, polymethacrylate, polyacrylamide, styrene-butadiene rubber, acrylic styrene-butadiene rubber, acrylic acid-acrylonitrile-acrylamide copolymer, acrylic acid-acrylonitrile-acrylate copolymer, acrylonitrile-butadiene rubber, nitrile rubber, acrylonitrile-styrene-butadiene copolymer, acryloyl rubber, butyl rubber, fluororubber, polytetrafluoroethylene, polyvinyl alcohol, polyvinyl acetate, polyepoxychloropropane, polyphosphazene, polyacrylonitrile, polystyrene, latex, acrylic resin, phenolic resin, epoxy resin, carboxymethyl cellulose, hydroxypropyl cellulose, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethyl cellulose, carboxymethyl chitosan, polyester, polyamide, polyether, polyimide, polycarboxylic acid ester, polycarboxylic acid, polyurethane, alginate, fluorinated polymer, chlorinated polymer, polyvinylidene fluoride, and poly(vinylidene fluoride)-hexafluoropropylene. The negative electrode binder of this application is not limited to the above-mentioned materials, but also includes other materials that can be used as battery negative electrode binders.
[0057] In some embodiments, the negative electrode conductive agent may include at least one of carbon, carbon black, graphite, expanded graphite, graphene, graphene nanosheets, superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon fibers, carbon nanofibers, graphitized carbon sheets, carbon nanotubes, carbon nanotubes, activated carbon, and mesoporous carbon. The negative electrode conductive agent of this application is not limited to the above-mentioned materials, but also includes other materials that can be used as battery negative electrode conductive agents.
[0058] In some embodiments, the positive electrode 500 may include a positive current collector and a positive active material layer disposed on at least one side of the positive current collector.
[0059] In some embodiments, the positive current collector is a metal foil or a composite current collector. In some embodiments, the metal foil is an aluminum foil. The composite current collector may include a metal foil substrate and a conductive layer disposed on at least one side of the metal foil substrate.
[0060] In some embodiments, the conductive layer may include at least one of carbon, carbon black, graphite, expanded graphite, graphene, graphene nanosheets, carbon fiber, carbon nanofiber, graphitized carbon sheet, carbon tube, carbon nanotube, activated carbon, and mesoporous carbon. In some embodiments, the positive electrode active material layer may include a positive electrode active material, a positive electrode binder, and a positive electrode conductive agent. In some embodiments, the positive electrode active material is selected from the group consisting of LiCoO2, LiNiO2, LiNixMnyO2, Li1+zNixMnyCo1-x-yO2, LiNixCoyAlzO2, LiV2O5, LiTiS2, LiMoS2, LiMnO2, LiCrO2, LiMn2O4, Li2MnO3, LiFeO2, LiFePO4, LiMnPO4, and combinations thereof, wherein each x is independently from 0.2 to 0.9; each y is independently from 0.1 to 0.45; and each z is independently from 0 to 0.2. The positive electrode active material of this application is not limited to the above-mentioned materials, but also includes other materials that can be used as positive electrode active materials. In some embodiments, the positive electrode active material is selected from the group consisting of LiCoO2, LiNiO2, LiNixMnyO2, Li1+zNixMnyCo1-x-yO2, LiNixCoyAlzO2, LiV2O5, LiTiS2, LiMoS2, LiMnO2, LiCrO2, LiMn2O4, LiFeO2, LiFePO4, and combinations thereof, wherein each x is independently 0.4 to 0.6; each y is independently 0.2 to 0.4; and each z is independently 0 to 0.1. In some embodiments, the positive electrode active material is Li1+xNiaMnbCocAl(1-abc)O2; wherein -0.2≤x≤0.2, 0≤a<1, 0≤b<1, 0≤c<1, and a+b+c≤1.
[0061] In some embodiments, the positive electrode active material has the general formula Li1+xNiaMnbCocAl(1-abc)O2, wherein 0.33≤a≤0.92, 0.33≤a≤0.9, 0.33≤a≤0.8, 0.5≤a≤0.92, 0.5≤a≤0.9, 0.5≤a≤0.8, 0.6≤a≤0.92, or 0.6≤a≤0.9. The following conditions apply: 0≤b≤0.5, 0≤b≤0.3, 0.1≤b≤0.5, 0.1≤b≤0.4, 0.1≤b≤0.3, 0.1≤b≤0.2, or 0.2≤b≤0.5; 0≤c≤0.5, 0≤c≤0.3, 0.1≤c≤0.5, 0.1≤c≤0.4, 0.1≤c≤0.3, 0.1≤c≤0.2, or 0.2≤c≤0.5. In some embodiments, the positive electrode active material is doped with a dopant selected from the group consisting of Fe, Ni, Mn, Al, Mg, Zn, Ti, La, Ce, Sn, Zr, Ru, Si, Ge, and combinations thereof. In some embodiments, the dopant is not Fe, Ni, Mn, Mg, Zn, Ti, La, Ce, Ru, Si, or Ge. In some embodiments, the dopant is not Al, Sn, or Zr. In some embodiments, the positive electrode active material may include at least one of LiNi0.33Mn0.33Co0.33O2, LiNiO2, LiNi0.4Mn0.4Co0.2O2, LiNi0.5Mn0.3Co0.2O2, LiNi0.6Mn0.2Co0.2O2, LiNi0.7Mn0.15Co0.15O2, LiNi0.8Mn0.1Co0.1O2, LiNi0.92Mn0.04Co0.04O2, and LiNi0.8Co0.15Al0.05O2.
[0062] In some embodiments, the positive electrode binder includes at least one of polyvinylidene fluoride (PVDF), poly(vinylidene fluoride)-hexafluoropropylene (PVDF-HFP), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, fluorinated acrylate resin, polyacrylic acid, polyacrylonitrile, polyimide, polyurethane, polyvinyl butyral, polyvinylpyrrolidone (PVP), acrylic acid-acrylonitrile-acrylamide copolymer, and acrylic acid-acrylonitrile-acrylate copolymer.
[0063] The positive electrode binder of this application is not limited to the materials mentioned above, but also includes other materials that can be used as battery positive electrode binders. In some embodiments, the positive electrode conductive agent may include at least one of carbon, carbon black, graphite, expanded graphite, graphene, graphene nanosheets, superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon fibers, carbon nanofibers, graphitized carbon sheets, carbon nanotubes, carbon nanotubes, activated carbon, and mesoporous carbon. The positive electrode conductive agent of this application is not limited to the materials mentioned above, but also includes other materials that can be used as battery positive electrode conductive agents.
[0064] This application also proposes an electronic device including an electrochemical device 10 as described in any of the above embodiments. Since the first lithium portion 220 of this application is disposed at the edge of the lithium replenishment current collector 210 perpendicular to the thickness direction, the lithium in the first lithium portion 220, after being converted into lithium ions, can reach the edges of the multiple conductive portions 110 more quickly and enter the negative electrode active material layer 112 of each conductive portion 110, increasing the lithium content of each conductive portion 110. This solution reduces the lithium ion transport path, improves lithium replenishment efficiency, and helps extend the service life of the electronic device.
[0065] It should be understood that the electronic device described in this application is not particularly limited, and can be any electronic device known in the prior art. The purpose of this invention is not particularly limited, and it can be used with any electronic device known in the prior art. According to some embodiments of the invention, the electronic device includes, but is not limited to, mobile phones, smartphones, laptops, tablets, wearable devices, smartwatches, smart bracelets, smart glasses, power banks, televisions, game consoles, game controllers, digital cameras, smart speakers, headphones, keyboards, mice, monitors, drones, audio equipment, home appliances, toys, power tools, automobiles, motorcycles, electric bicycles, bicycles, robots, robot dogs, industrial robots, and android robots.
[0066] Although illustrative embodiments have been demonstrated and described, those skilled in the art should understand that the above embodiments should not be construed as limiting the invention, and that changes, substitutions and modifications can be made to the embodiments without departing from the spirit, principles and scope of the invention.
[0067] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this application. Furthermore, unless otherwise specified, the embodiments and features described in the embodiments of this application can be combined with each other.
Claims
1. An electrochemical device having a length direction, a width direction, and a thickness direction, characterized in that, include: A negative electrode assembly includes multiple conductive parts arranged along the thickness direction, and each conductive part includes a negative electrode current collector and a negative electrode active material layer stacked along the thickness direction; A lithium electrode sheet is stacked on at least one of the conductive portions; A lithium replenishing tab is connected to the lithium replenishing electrode sheet; A first diaphragm is disposed between the lithium-filling electrode and the conductive portion; The lithium replenishing electrode includes a lithium replenishing current collector and a first lithium portion, the first lithium portion being stacked on one side of the lithium replenishing current collector in the thickness direction; the negative electrode assembly is electrically connected to the lithium replenishing electrode tab so that the first lithium portion can replenish lithium to the negative electrode active material layer; the first lithium portion is disposed on the edge of the lithium replenishing current collector perpendicular to the thickness direction.
2. The electrochemical device according to claim 1, characterized in that, The negative electrode assembly includes a negative electrode sheet and a negative electrode tab, the negative electrode tab being connected to the negative electrode current collector. The electrochemical device also includes a positive electrode sheet and a positive electrode tab, the positive electrode tab being connected to the positive electrode sheet. The negative electrode sheet and the positive electrode sheet together form a winding structure around an axis parallel to the length direction. The winding structure includes a straight region and a bent region arranged along the width direction. The negative electrode sheet includes a plurality of conductive portions located in the straight region.
3. The electrochemical device according to claim 2, characterized in that, The first lithium portion is disposed at the edge of the lithium replenishment current collector in the length direction.
4. The electrochemical device according to claim 2, characterized in that, The lithium-filling electrode is located on one side of all the conductive parts in the thickness direction.
5. The electrochemical device according to claim 1, characterized in that, The negative electrode assembly includes multiple negative electrode plates and multiple negative electrode tabs. Each negative electrode plate includes a conductive portion, and each negative electrode current collector is connected to at least one negative electrode tab. The electrochemical device also includes multiple positive electrode plates, multiple positive electrode tabs, and multiple third membranes. Each positive electrode plate is connected to at least one positive electrode tab. Along the thickness direction, the negative electrode plates and positive electrode plates are stacked alternately, and the third membranes are provided between adjacent negative electrode plates and positive electrode plates.
6. The electrochemical device according to claim 5, characterized in that, The first lithium portion is disposed at the edge of the lithium replenishment current collector in the length and width directions.
7. The electrochemical device according to claim 5, characterized in that, The lithium-filling electrode is located on one side of all the negative electrode electrodes in the thickness direction.
8. The electrochemical device according to claim 5, characterized in that, The lithium-filling electrode is located on the side of the third separator closer to the negative electrode.
9. The electrochemical device according to claim 1, characterized in that, The lithium replenishing electrode further includes a second lithium portion, which is stacked on the side of the lithium replenishing current collector where the first lithium portion is located in the thickness direction; the negative electrode assembly can be electrically connected to the lithium replenishing electrode tab so that the second lithium portion can replenish lithium to the negative electrode active material; the second lithium portion is further away from the edge of the lithium replenishing current collector perpendicular to the thickness direction relative to the first lithium portion. The dimension of the second lithium portion in the thickness direction is smaller than the dimension of the first lithium portion in the thickness direction.
10. An electronic device, characterized in that, Includes the electrochemical device as described in any one of claims 1 to 9.