Negative-electrode current collector, battery cell, battery, and electric apparatus

Abstract

A negative-electrode current collector, a battery cell, a battery, and an electric apparatus. The negative-electrode current collector comprises a foam metal matrix, wherein the electrochemical active mass specific surface area of the foam metal matrix ranges between 2.5 cm2 / g and 20 cm2 / g, and the electrochemical active volume specific surface area of the foam metal matrix ranges between 22 cm2 / cm3 and 180 cm2 / cm3. The negative-electrode current collector can slow down the growth of dendrites, reduce the risk of a short circuit occurring in a battery, improve the reliability and cycle life of the battery, and can further allow the battery to be charged at a high rate.

Description

Negative electrode current collector, battery cell, battery and electrical device

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application No. 202410002356.2, filed on January 2, 2024, entitled “Negative electrode current collector, battery cell, battery and electrical device,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application relates to a negative electrode current collector, a battery cell, a battery and an electrical device. Background Art

[0004] Compared to ion-type batteries, metal batteries can have higher energy density. However, unlike the negative electrodes of ion-type batteries, the negative electrodes of metal batteries suffer from uneven deposition, which affects the reliability and electrochemical performance of metal batteries.

[0005] Summary of the Invention

[0006] The present application provides a negative electrode current collector, a battery cell, a battery and an electrical device, which can slow down the growth of dendrites, reduce the risk of internal short circuits in the battery, improve the reliability and cycle life of the battery, and enable the battery to be charged at a high rate.

[0007] In a first aspect, the present application provides a negative electrode current collector, the negative electrode current collector comprising a foam metal matrix, the electrochemically active mass specific surface area of ​​the foam metal matrix being 2.5 cm 2 / g-20cm 2 / g, and an electrochemically active volume-to-surface area of ​​22 cm 2 / cm 3 -180cm 2 / cm 3 .

[0008] Compared with the two-dimensional planar copper foil current collector, the negative electrode current collector of the present application has a larger electrochemically active specific surface area, so that the negative electrode can have a higher electrochemically active area when the battery is charged. It can also reduce the current density on the negative electrode surface and improve the metal deposition morphology, thereby reducing the risk of internal short circuits in the battery, improving the reliability and cycle life of the battery, and allowing the battery to be charged at a high rate.

[0009] At the same time, the electrochemically active specific surface area of ​​the metal foam matrix is ​​not the larger the better. Generally speaking, the larger the electrochemically active specific surface area of ​​the metal foam matrix, the more small pores it contains. Since the deposition of metal is highly selective, it will preferentially deposit in the pores on the negative electrode side close to the separator. In this case, if the electrochemically active specific surface area of ​​the metal foam matrix is ​​too large, the pores on the negative electrode side close to the separator will quickly be blocked by the deposited metal. After the pores on the negative electrode side close to the separator are blocked, it is difficult or even impossible for the ions in the electrolyte to be replenished to the internal position of the negative electrode, thereby reducing the space utilization of the negative electrode. At the same time, it will also cause the electrolyte wettability of the negative electrode to deteriorate, which in turn causes the battery's cycle performance to deteriorate.

[0010] Therefore, the embodiment of the present application adjusts the electrochemical active mass specific surface area of ​​the foam metal matrix of the negative electrode current collector to 2.5 cm 2 / g-20cm 2 / g, and an electrochemically active volume-to-surface area of ​​22 cm 2 / cm 3 -180cm 2 / cm 3 It can reduce the current density on the negative electrode surface and adjust the metal deposition morphology during charging, thereby slowing down the growth of dendrites, reducing the risk of short circuits in the battery, improving the reliability and cycle life of the battery, and allowing the battery to be charged at a high rate.

[0011] In some embodiments, the electrochemically active mass specific surface area of ​​the metal foam matrix is ​​3.2 cm 2 / g-10cm 2 / g, and an electrochemically active volume-to-surface area of ​​29 cm 2 / cm 3 -90cm 2 / cm 3 .

[0012] In some embodiments, the electrochemically active mass specific surface area of ​​the metal foam matrix is ​​3.2 cm 2 / g-5cm 2 / g, and an electrochemically active volume-to-surface area of ​​29 cm 2 / cm 3 -45cm 2 / cm 3 .

[0013] By further adjusting the electrochemically active mass specific surface area and the electrochemically active volume specific surface area of ​​the foam metal matrix within the above range, the battery can have a high coulombic efficiency while having good cycle performance and rate performance.

[0014] In some embodiments, the pore size of the foam metal matrix is ​​0.5 times the average pore size D avg and 1.5 times the average pore diameter D avg The number of pores between the two is 80%-90% of the number of all pores in the foam metal matrix; and / or the pore diameter in the foam metal matrix is ​​less than 0.5 times the average pore diameter D avg The number of pores is 4.5%-12% of the number of all pores in the foam metal matrix; and / or the pore diameter in the foam metal matrix is ​​greater than 1.5 times the average pore diameter D avg The number of the pores is 2% to 12% of the number of all pores in the foam metal matrix.

[0015] By adjusting the pore size distribution of the foam metal matrix within the above range, the foam metal matrix can have a higher electrochemically active specific surface area, thereby reducing the current density on the negative electrode surface, adjusting the metal deposition morphology, and improving the space utilization of the negative electrode, thereby helping to improve the coulombic efficiency, cycle performance and rate performance of the battery; it can also make the foam metal matrix and the negative electrode current collector have good electrolyte wettability, thereby making the battery have a long cycle life.

[0016] In some embodiments, the average pore size D of the foam metal matrix is avg 120μm-290μm.

[0017] By adjusting the average pore size of the foam metal matrix within the above range, on the one hand, the foam metal matrix can have a higher electrochemically active specific surface area, and on the other hand, the metal deposition morphology can be adjusted and the space utilization of the negative electrode can be improved, thereby helping the battery to have high coulombic efficiency, good cycle performance and rate performance.

[0018] In some embodiments, the maximum pore size D of the foam metal matrix max 200μm-500μm.

[0019] In some embodiments, the rib width of the foam metal matrix is ​​5 μm-100 μm.

[0020] By adjusting the rib width of the metal foam matrix within the above range, the battery can have high coulombic efficiency, good cycle performance and rate performance.

[0021] In some embodiments, the pore density of the foam metal matrix is ​​135 PPI-200 PPI.

[0022] In some embodiments, the porosity of the foam metal matrix is ​​65%-91%.

[0023] In some embodiments, the foam metal matrix has an open-pore structure, and an open-pore ratio is greater than or equal to 98%.

[0024] In some embodiments, the thickness of the foam metal matrix is ​​80 μm-1000 μm.

[0025] The thickness of the foam metal matrix is ​​within the above range, which can shorten the ion diffusion path and improve the deposition and stripping activity and space utilization of the negative electrode.

[0026] In some embodiments, the metal elements in the foam metal matrix include one or more of copper, nickel, titanium, aluminum, cobalt, iron, manganese, tin, gold, silver, chromium, zinc, cadmium, lead, platinum, antimony, bismuth, gallium, indium, and palladium.

[0027] In some embodiments, the negative electrode current collector further comprises an alkali metal affinity layer located on the surface of the metal foam matrix. The alkali metal affinity layer can adjust the metal deposition morphology and slow down the growth of dendrites, thereby improving the rate performance and cycle performance of the battery.

[0028] In some embodiments, the alkali metal affinity layer includes one or more of Cu2O and Li3N.

[0029] In some embodiments, the alkali metal affinity layer has a thickness of 50 nm to 5 μm.

[0030] In a second aspect, the present application provides a battery cell comprising the negative electrode current collector according to the first aspect of the present application.

[0031] In some embodiments, the battery cell includes at least one of a negative electrode-free lithium metal battery cell and a negative electrode-free sodium metal battery cell.

[0032] In a third aspect, the present application provides a battery comprising the battery cell according to the second aspect of the present application.

[0033] In a fourth aspect, the present application provides an electrical device comprising the battery according to the third aspect of the present application, wherein the battery is used to provide electrical energy.

[0034] The electric device of the present application includes the battery provided by the present application, and thus has at least the same advantages as the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] To more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on the drawings without inventive effort.

[0036] FIG1 is a schematic diagram of a battery cell provided by some embodiments of the present application.

[0037] FIG2 shows an exploded schematic diagram of a battery cell provided in some embodiments of the present application.

[0038] FIG3 shows a schematic diagram of a battery module provided in some embodiments of the present application.

[0039] FIG4 shows a schematic diagram of a battery pack provided in some embodiments of the present application.

[0040] FIG5 is an exploded schematic diagram of the battery pack shown in FIG4 .

[0041] FIG6 shows a schematic diagram of an electrical device provided in some embodiments of the present application.

[0042] In the accompanying drawings, which are not necessarily drawn to scale, the reference numerals are as follows: 1. battery pack; 2. upper housing; 3. lower housing; 4. battery module; 5. battery cell; 51. housing; 52. electrode assembly; 53. cover plate. DETAILED DESCRIPTION

[0043] Below, with appropriate reference to the accompanying drawings, the embodiments of the negative electrode current collector, battery cell, battery, and electrical device of the present application are described in detail. However, there may be cases where unnecessary detailed descriptions are omitted. For example, there may be cases where detailed descriptions of well-known matters and repeated descriptions of actually the same structure are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate the understanding of those skilled in the art. In addition, the drawings and the following description are provided for those skilled in the art to fully understand the present application and are not intended to limit the subject matter described in the claims.

[0044] " scope " disclosed in the present application is limited in the form of lower limit and upper limit, and given range is limited by selecting a lower limit and an upper limit, and selected lower limit and upper limit define the boundary of special scope.The scope that this mode limits can be to include end value or not include end value, and can be combined arbitrarily, and promptly any lower limit can form a scope with any upper limit combination.For example, if the scope of 60-120 and 80-110 is listed for specific parameter, it is understood that the scope of 60-110 and 80-120 is also expected.In addition, if the minimum range value 1 and 2 listed, and if the maximum range value 3,4 and 5 listed, then the following scope can all be expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5.In the present application, unless otherwise specified, numerical range " ab " represents the abbreviation of any real number combination between a and b, and wherein a and b are all real numbers. For example, a numerical range of "0-5" indicates that all real numbers between "0-5" are listed herein, and "0-5" is simply an abbreviation for these numerical combinations. Furthermore, when a parameter is expressed as an integer ≥ 2, this is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0045] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form new technical solutions, and such technical solutions should be considered to be included in the disclosure of the present application.

[0046] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form new technical solutions, and such technical solutions should be deemed to be included in the disclosure of this application.

[0047] Unless otherwise specified, all steps of the present application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), indicating that step (c) may be added to the method in any order, for example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0048] In this application, the term "about" is used to describe and illustrate small changes. When used in conjunction with a numerical value, the term can refer to a range of less than or equal to ±5% of the numerical value, optionally less than or equal to 1%.

[0049] In this application, the terms "plurality" and "multiple" refer to two or more.

[0050] In the description of the embodiments of the present application, unless otherwise specified, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, a first feature being "above," "above," and "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is at a higher level than the second feature. A first feature being "below," "below," and "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0051] Unless otherwise specified, the terms used in this application have the common meanings that are commonly understood by those skilled in the art.

[0052] Unless otherwise stated, the numerical values ​​of the various parameters mentioned in this application can be measured using various test methods commonly used in the art, for example, they can be measured according to the test methods given in the examples of this application. Unless otherwise stated, the test temperature of each parameter is 25°C.

[0053] The battery mentioned in the embodiments of the present application may be a single physical module including one or more battery cells to provide higher voltage and capacity. For example, the battery mentioned in the present application may include a battery cell, a battery module, or a battery pack.

[0054] A battery cell is the smallest unit of a battery, independently capable of charging and discharging. A battery cell can be cylindrical, rectangular, or have other shapes, though this is not a limitation in the present invention. Figure 1 shows a battery cell 5 with a rectangular structure as an example.

[0055] When there are multiple battery cells, the multiple battery cells are connected in series, in parallel, or in mixed series via a busbar. In some embodiments, the battery may be a battery module; when there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module. In some embodiments, the battery may be a battery pack, which includes a housing and battery cells, with the battery cells or battery modules housed in the housing. In some embodiments, the housing may serve as part of the vehicle's chassis structure. For example, a portion of the housing may form at least a portion of the vehicle's floor, or a portion of the housing may form at least a portion of the vehicle's crossbeam or longitudinal beam.

[0056] In some embodiments, the battery may be an energy storage device, including an energy storage container, an energy storage cabinet, and the like.

[0057] The battery cell includes an electrode assembly, which may be a wound structure or a laminated structure, and the present invention is not limited thereto.

[0058] The battery cell may also include an outer packaging that can be used to encapsulate the electrode assembly. The outer packaging can be a hard shell, such as a hard plastic shell, aluminum shell, steel shell, etc. The outer packaging can also be a soft shell, such as a bag-type soft shell. The soft shell can be made of plastic, such as one or more of polypropylene, polybutylene terephthalate (PBT), and polybutylene succinate (PBS).

[0059] In some embodiments, as shown in Figure 2, the outer packaging may include a housing 51 and a cover plate 53. The housing 51 may include a bottom plate and side plates connected to the bottom plate, which together form a receiving cavity. The housing 51 has an opening communicating with the receiving cavity, and the cover plate 53 is used to cover the opening, thereby sealing the receiving cavity. The electrode assembly 52 is enclosed in the receiving cavity. The number of electrode assemblies 52 contained in the battery cell 5 can be one or more, and can be adjusted according to needs.

[0060] In some embodiments, battery cells can be assembled into a battery module. The number of battery cells contained in a battery module can be multiple, and the specific number can be adjusted according to the application and capacity of the battery module. Figure 3 is a schematic diagram of a battery module 4 as an example. As shown in Figure 3, in the battery module 4, multiple battery cells 5 can be arranged in sequence along the length of the battery module 4. Of course, they can also be arranged in any other manner. The multiple battery cells 5 can further be fixed by fasteners.

[0061] Optionally, the battery module 4 may further include a housing having an accommodation space, and the plurality of battery cells 5 are accommodated in the accommodation space.

[0062] In some embodiments, the battery modules described above may also be assembled into a battery pack, and the number of battery modules contained in the battery pack may be adjusted according to the application and capacity of the battery pack.

[0063] Figures 4 and 5 are schematic diagrams of an exemplary battery pack 1. As shown in Figures 4 and 5, the battery pack 1 may include a housing and multiple battery modules 4 disposed within the housing. The housing comprises an upper housing 2 and a lower housing 3. The upper housing 2 covers the lower housing 3 and forms an enclosed space for accommodating the battery modules 4. The multiple battery modules 4 may be arranged in any manner within the housing.

[0064] The battery cells provided in the embodiments of the present application may be metal battery cells, for example, they may include negative electrode-free lithium metal battery cells, negative electrode-free sodium metal battery cells, etc.

[0065] A negative electrode-free battery cell generally refers to a battery cell constructed without the active negative electrode layer being applied during the manufacturing process. For example, a negative electrode active material layer is not applied to the negative electrode through coating or deposition, or a carbonaceous active material layer is formed. During initial charging, ions on the negative electrode gain electrons and deposit on the surface of the negative electrode current collector, forming metal. During discharge, the metal converts to ions and returns to the positive electrode, enabling cyclic charge and discharge. Compared to other battery cells, the absence of a negative electrode active material layer allows for higher energy density. The cell balance (CB) value of a negative electrode-free battery cell is typically very low. For example, in some embodiments, the CB value of a negative electrode-free battery cell can be less than or equal to 0.1. The CB value is the unit area capacity of the negative electrode divided by the unit area capacity of the positive electrode in the battery cell. Because negative electrode-free battery cells contain no or only a small amount of negative electrode active material, the unit area capacity of the negative electrode is relatively low, resulting in a very low CB value, typically less than or equal to 0.1.

[0066] The present invention provides a negative electrode current collector, which includes a foam metal matrix. The electrochemically active mass specific surface area of ​​the foam metal matrix is ​​2.5 cm 2 / g-20cm 2 / g, and an electrochemically active volume-to-surface area of ​​22 cm 2 / cm 3 -180cm 2 / cm 3 .

[0067] At present, the current collector commonly used in the negative electrode is a two-dimensional planar current collector, such as copper foil, which has a very small electrochemically active mass specific surface area of ​​about 0.3 cm 2 When using a two-dimensional planar current collector for metal batteries, the charge rate of the metal battery is often limited. This is because at high charge current densities, metal deposition problems may arise, such as accelerated dendrite growth, increased side reactions, and more uneven metal deposition. This can lead to increased risk of internal short circuits in the battery and faster capacity decay.

[0068] The electrochemically active mass specific surface area of ​​the foam metal matrix of the negative electrode current collector provided in the embodiment of the present application is greater than or equal to 2.5 cm 2 / g, electrochemically active volume specific surface area greater than or equal to 22cm 2 / cm 3Therefore, compared with the two-dimensional planar copper foil current collector, the negative electrode current collector of the present application has a larger electrochemically active specific surface area. As a result, the negative electrode can have a higher electrochemically active area when the battery is charged. It can also reduce the current density on the negative electrode surface and improve the metal deposition morphology, thereby reducing the risk of internal short circuits in the battery, improving the reliability and cycle life of the battery, and allowing the battery to be charged at a high rate.

[0069] At the same time, the electrochemically active specific surface area of ​​the metal foam matrix is ​​not the larger the better. Generally speaking, the larger the electrochemically active specific surface area of ​​the metal foam matrix, the more small pores it contains. Since the deposition of metal is highly selective, it will preferentially deposit in the pores on the negative electrode side close to the separator. In this case, if the electrochemically active specific surface area of ​​the metal foam matrix is ​​too large, the pores on the negative electrode side close to the separator will quickly be blocked by the deposited metal. After the pores on the negative electrode side close to the separator are blocked, it is difficult or even impossible for the ions in the electrolyte to be replenished to the internal position of the negative electrode, thereby reducing the space utilization of the negative electrode. At the same time, it will also cause the electrolyte wettability of the negative electrode to deteriorate, which in turn causes the battery's cycle performance to deteriorate.

[0070] Therefore, the embodiment of the present application adjusts the electrochemical active mass specific surface area of ​​the foam metal matrix of the negative electrode current collector to 2.5 cm 2 / g-20cm 2 / g, and an electrochemically active volume-to-surface area of ​​22 cm 2 / cm 3 -180cm 2 / cm 3 It can reduce the current density on the negative electrode surface and adjust the metal deposition morphology during charging, thereby slowing down the growth of dendrites, reducing the risk of short circuits in the battery, improving the reliability and cycle life of the battery, and allowing the battery to be charged at a high rate.

[0071] Optionally, the electrochemically active mass specific surface area of ​​the metal foam matrix can be 3.2 cm 2 / g-10cm 2 / g, and the electrochemically active volume specific surface area can be 29cm 2 / cm 3 -90cm 2 / cm 3 .

[0072] In some embodiments, the electrochemically active mass specific surface area of ​​the metal foam matrix can be 3.2 cm 2 / g-5cm 2 / g, and the electrochemically active volume specific surface area can be 29cm 2 / cm 3 -45cm 2 / cm 3 .

[0073] The increased electrochemically active surface area of ​​the metal foam matrix requires more active ions to activate deposition sites on the negative electrode surface during the first charge of the battery, which reduces the battery's initial coulombic efficiency. Therefore, by further adjusting the electrochemically active mass surface area and electrochemically active volume surface area of ​​the metal foam matrix within the aforementioned ranges, the battery can achieve high coulombic efficiency while maintaining good cycle performance and rate capability.

[0074] The electrochemically active mass specific surface area and the electrochemically active volume specific surface area of ​​the foam metal matrix can be tested as follows: the foam metal matrix is ​​cut into small disc samples with a diameter of 20 mm, and a button battery is prepared with a metal lithium sheet as the counter electrode. The electrolyte salt of the button battery electrolyte is LiFSI with a concentration of 1 mol / L, the solvent of the electrolyte is ethylene glycol dimethyl ether (DME), and the probe molecule is ferrocene with a concentration of 50 mmol / L. The isolation membrane of the button battery can be a PE film with a thickness of 12 μm. At 25°C, the assembled button battery is left to stand for 12 hours, and then discharged at a constant voltage of 2.5 V, waiting for the current to drop to 0.0025 mA / cm 2 Cyclic voltammetry scans were performed at 3 mV / s, 2 mV / s, 1 mV / s, and 0.5 mV / s in the 2.5 V to 3.4 V range, with the peak current read at each positive sweep rate. A linear regression was performed using the peak current and the square root of the sweep rate to obtain the slope. The electrochemically active specific surface area of ​​the metal foam matrix was calculated using the Randles-Sevick equation. The test instrument was a SOLARTRON electrochemical workstation from Transtron (UK).

[0075] The electrochemically active specific surface area of ​​the foam metal matrix can be adjusted by adjusting the pore size, pore size distribution, porosity, pore number, rib width, etc. of the foam metal matrix.

[0076] In some embodiments, the foam metal matrix has an open-pore structure, and optionally, the open-pore ratio can be greater than or equal to 98%.

[0077] In some embodiments, the pore size in the foam metal matrix is ​​0.5 times the average pore size D avg and 1.5 times the average pore diameter D avg The number of pores between the electrodes may be 72%-90% of the number of all pores in the foam metal matrix, and optionally 80%-90%.

[0078] In some embodiments, the pore size in the foam metal matrix is ​​less than 0.5 times the average pore size D avg The number of the pores may be 4.5% to 15%, and optionally 4.5% to 12%, of the total number of pores in the foam metal matrix.

[0079] In some embodiments, the pore size in the foam metal matrix is ​​greater than 1.5 times the average pore size D avg The number of the pores may be 2%-15% of the number of all pores in the foam metal matrix, optionally 2%-12%, or 5%-12%.

[0080] By adjusting the pore size distribution of the foam metal matrix within the above range, the foam metal matrix can have a higher electrochemically active specific surface area, thereby reducing the current density on the negative electrode surface, adjusting the metal deposition morphology, and improving the space utilization of the negative electrode, thereby helping to improve the coulombic efficiency, cycle performance and rate performance of the battery; it can also make the foam metal matrix and the negative electrode current collector have good electrolyte wettability, thereby making the battery have a long cycle life.

[0081] In some embodiments, the pore size in the foam metal matrix is ​​0.5 times the average pore size D avg and 1.5 times the average pore diameter D avg The number of pores between the foam metal matrix can be 80%-90% of the number of all surface pores in the foam metal matrix, and the pore diameter in the foam metal matrix is ​​less than 0.5 times the average pore diameter D avg The number of pores can be 4.5% to 12% of the number of all surface pores in the foam metal matrix, and the pore diameter in the foam metal matrix is ​​greater than 1.5 times the average pore diameter D avg The number of pores may be 5% to 12% of the number of all surface pores in the foam metal matrix.

[0082] In some embodiments, the average pore size D of the foam metal matrix is avg It can be 120μm-290μm, optionally 180μm-290μm, 200μm-290μm, 230μm-290μm, 230μm-280μm.

[0083] All other conditions being equal, the smaller the average pore size of the metal foam matrix, the greater the electrochemically active specific surface area of ​​the metal foam matrix. Because metal deposition is highly selective, it preferentially deposits in the pores on the negative electrode side near the separator. In this case, the smaller the average pore size of the metal foam matrix, the more quickly these pores will be clogged by the deposited metal. Once these pores are clogged, it becomes difficult or impossible for ions in the electrolyte to reach the negative electrode's interior, reducing the negative electrode's spatial utilization and impairing its wettability with the electrolyte.

[0084] By adjusting the average pore size of the foam metal matrix within the above range, on the one hand, the foam metal matrix can have a higher electrochemically active specific surface area, and on the other hand, the metal deposition morphology can be adjusted and the space utilization of the negative electrode can be improved, thereby helping the battery to have high coulombic efficiency, good cycle performance and rate performance.

[0085] In some embodiments, the maximum pore size D of the foam metal matrix is max It can be 200μm-500μm, 250μm-480μm, 300μm-480μm, 350μm-480μm, 400μm-480μm, 420μm-480μm.

[0086] The metal foam matrix is ​​a porous material formed by interconnected ribs, and its microstructure may be composed of ribs and pores. In some embodiments, the rib width of the metal foam matrix may be 5 μm-100 μm, optionally 5 μm-50 μm, more preferably 10 μm-50 μm, 15 μm-50 μm, 20 μm-50 μm, or 25 μm-50 μm.

[0087] When the battery is charging, metal can be deposited on the ribs. When the average pore size of the foam metal matrix is ​​the same, a larger rib width can reduce the current density on the negative electrode surface. At low current density, the nucleation diameter of metal deposition increases, and a larger nucleation diameter can slow down dendrite growth and reduce the repeated generation of solid electrolyte interface film (SEI), thereby improving the coulombic efficiency, cycle performance and rate performance of the battery. At the same time, the rib width is not the larger the better. Ribs that are too wide will occupy the volume that can be used for metal deposition, thereby reducing the energy density of the battery. In addition, in the daily operating conditions of the battery, a larger current tends to be used to charge the battery, and a current that is too small is usually difficult to meet user needs.

[0088] Therefore, by adjusting the rib width of the foam metal matrix within the above range, the battery can have high coulombic efficiency, good cycle performance and rate performance.

[0089] The pore size, pore size distribution, and rib width of a metal foam substrate can be measured as follows: 10 random areas on the metal foam substrate are observed using an optical microscope. Photographs are taken at 200x magnification. The pore size and rib width of all surface pores on the metal foam substrate are measured and annotated. Each area must contain at least 20 surface pores in the photograph.

[0090] The pore size refers to the average diameter of the pores, and the average diameter refers to the arithmetic mean of the longest diameter and the shortest diameter of the pores.

[0091] The rib width refers to the width of the ribs between holes.

[0092] The average pore size of all surface pores is obtained as the average pore size D of the foam metal matrix. avg .

[0093] The maximum pore size of all surface pores is taken as the maximum pore size D of the foam metal matrix. max .

[0094] The number of all surface pores is used as the denominator, and the pore diameter is 0.5 times the average pore diameter D avg and 1.5 times the average pore diameter D avg The number of pores between the two is taken as the numerator, and the pore diameter is calculated at 0.5 times the average pore diameter D avg and 1.5 times the average pore diameter D avg The proportion of the number of holes.

[0095] The number of all surface pores is taken as the denominator, and the pore diameter is less than 0.5 times the average pore diameter D avg The number of pores is taken as the numerator, and the pore diameter is calculated to be less than 0.5 times the average pore diameter D avg The proportion of the number of holes.

[0096] The number of all surface pores is taken as the denominator, and the pore diameter is greater than 1.5 times the average pore diameter D avg The number of pores is taken as the numerator, and the pore diameter is calculated to be greater than 1.5 times the average pore diameter D avg The proportion of the number of holes.

[0097] The average value of the obtained rib widths is taken as the rib width of the foam metal matrix.

[0098] In some embodiments, the pore density of the metal foam matrix may be 135 PPI-260 PPI, optionally 135 PPI-200 PPI, 135 PPI-180 PPI, or 150 PPI-180 PPI. PPI, Pores Per Linear Inch, represents the average number of pores per unit inch (ie, 2.54 cm).

[0099] The pore density of the metal foam matrix can be tested with reference to GB / T 20251-2006. For example, an optical microscope with a magnification of 100 times can be used for inspection. During the test, 10 areas can be randomly selected on the metal foam matrix, and the test results are averaged.

[0100] In some embodiments, the porosity of the foam metal matrix may be 65%-91%, optionally 70%-88%, 76%-88%, 80%-88%, or 82%-88%.

[0101] The porosity of a metal foam can be measured using the kerosene displacement method. The porosity of a metal foam is P = (V0 - V) / V0 x 100%. V0 represents the volume (or apparent volume) of the metal foam in its natural state, and V0 = t x s. t represents the thickness of the metal foam in cm; s represents the area of ​​the metal foam in cm. 2 V represents the absolute dense volume of the foam metal matrix and can be measured using the kerosene displacement method.

[0102] In some embodiments, the thickness of the foam metal matrix may be 80 μm-1000 μm, optionally 100 μm-600 μm.

[0103] The thickness of the foam metal matrix can be measured using a micrometer with an accuracy of 0.01 mm, and the average value of 10 points is measured.

[0104] The thickness of the foam metal matrix is ​​within the above range, which can shorten the ion diffusion path and improve the deposition and stripping activity and space utilization of the negative electrode.

[0105] In some embodiments, the metal elements in the foam metal matrix may include one or more of copper, nickel, titanium, aluminum, cobalt, iron, manganese, tin, gold, silver, chromium, zinc, cadmium, lead, platinum, antimony, bismuth, gallium, indium, and palladium, and may optionally include one or more of copper and nickel.

[0106] In some embodiments, the negative electrode current collector may further include an alkali metal affinity layer located on the surface of the metal foam substrate. The alkali metal affinity layer can adjust the metal deposition morphology and slow down dendrite growth, thereby improving the rate capability and cycle performance of the battery.

[0107] Optionally, the alkali metal affinity layer may include one or more of metal oxides, non-metal oxides, metal sulfides, non-metal sulfides, metal nitrides, and non-metal nitrides, and may optionally include one or more of Cu2O and Li3N.

[0108] Optionally, the thickness of the alkali metal affinity layer may be 50 nm-5 μm, optionally 1 μm-3 μm.

[0109] The foam metal matrix can be prepared by electrodeposition.

[0110] In some embodiments, the preparation method of the foam metal matrix includes the following steps: providing a foam polymer material; performing chemical deposition and electroplating in sequence on the foam polymer material as a matrix to deposit a metal material on the foam polymer material, and then performing thermal reduction treatment to remove the foam polymer material to obtain a foam metal matrix.

[0111] Optionally, in some embodiments, the foam polymer material may include any one of polyurethane foam, melamine foam, polyethylene foam material (EPE), polypropylene foam material (EPP), polystyrene foam material (EPS), expandable polyethylene and styrene polymer (EPO), and neoprene foam material (CR foam).

[0112] Optionally, in some embodiments, the porosity of the foamed polymer material may be 65%-95%, optionally 70%-92%, 76%-92%, 80%-92%, 82%-92%.

[0113] Optionally, in some embodiments, the pore density of the foamed polymer material may be 135 PPI-260 PPI, optionally 135 PPI-200 PPI.

[0114] Optionally, in some embodiments, the average pore size D of the foamed polymer material is avg It can be 120μm-400μm, optionally 180μm-400μm, 200μm-400μm, 230μm-400μm, 230μm-400μm.

[0115] Optionally, in some embodiments, the maximum pore size D of the foamed polymer material is max It can be 200μm-600μm, optionally 250μm-600μm, 300μm-600μm, 350μm-600μm, 400μm-600μm, 420μm-600μm.

[0116] Optionally, in some embodiments, the pore size in the foamed polymer material is 0.5 times the average pore size D avg and 1.5 times the average pore diameter D avg The number of pores between the foamed polymer material and the average pore size D can be 72%-90%, and optionally 80%-90% of the total number of pores in the foamed polymer material. avg The number of pores can be 4.5%-15% of the number of all pores in the foamed polymer material, and can be 4.5%-12%. The pore diameter in the foamed polymer material is greater than 1.5 times the average pore diameter D avg The number of cells may be 2% to 15%, optionally 2% to 12%, of the number of all cells in the foamed polymer material.

[0117] Optionally, in some embodiments, the thickness of the foamed polymer material may be 80 μm-1000 μm, optionally 100 μm-600 μm.

[0118] The test method for the foam polymer material can refer to the test method for the foam metal matrix mentioned above.

[0119] The foamed polymer material can be purchased commercially or prepared according to a preparation method known in the art. The foaming agent can be a physical foaming agent and / or a chemical foaming agent.

[0120] Physical blowing agents expand the polymer by changing the physical state of the blowing agent. Physical blowing agents can include one or more of supercritical carbon dioxide, supercritical nitrogen, n-pentane, isopentane, n-butane, isobutane, n-hexane, n-heptane, cyclopentane, and propane.

[0121] Chemical foaming agents, also known as decomposable foaming agents, release gas through chemical changes during the foaming process, causing the polymer to expand. Chemical foaming agents can include one or more of azo compounds, sulfonylhydrazides, and nitroso compounds.

[0122] Optionally, the foamed polymer material may be pre-treated before chemical deposition.

[0123] In some embodiments, pretreatment may include degreasing, roughening, sensitizing, activating, and debonding steps performed sequentially.

[0124] Roughening can open blind holes in the foam polymer material; it can also form many microscopic pits on the surface of the foam polymer material, where metal particles will be deposited during chemical deposition; it can also generate hydrophilic groups on the inner and outer surfaces of the foam polymer material to facilitate subsequent processing.

[0125] The purpose of the sensitization treatment is to form a layer of easily oxidizable substances on the surface of the foamed polymer material. These easily oxidizable substances are oxidized during the activation treatment, and the activator is reduced to catalytic crystal nuclei and remains on the surface of the foamed polymer material.

[0126] Activation involves immersing the sensitized polymer foam in a solution containing a catalytically active precious metal compound. This treatment creates a catalytically active precious metal layer on the surface of the polymer foam, which then acts as a catalyst for the redox reaction in electroless plating. Activation is essentially a reduction reaction of the precious metal. The resulting precious metal particles are typically gel-like and highly surface-active, allowing them to adsorb onto the surface of the polymer foam.

[0127] The purpose of the debonding treatment is to remove the gel layer formed by the activation treatment so that the noble metal atoms are fully exposed, thereby enabling them to produce better catalytic effects in the chemical deposition stage.

[0128] Optionally, the roughening solution may be a sulfuric acid solution containing potassium permanganate.

[0129] Optionally, the sensitizing solution may be a hydrochloric acid solution containing stannous chloride.

[0130] Optionally, the activation solution may be a hydrochloric acid solution containing palladium chloride or an ammonia solution containing silver nitrate.

[0131] Optionally, the degumming solution may be a formaldehyde solution or a hydrochloric acid solution.

[0132] Polymer foam is an insulating material and cannot be directly electroplated with metal. The purpose of chemical deposition is to coat the polymer foam with a thin metal film to make the polymer foam conductive, thereby making the electrodeposited coating structure more uniform and the surface smoother.

[0133] Chemical deposition can adopt a plating solution formula known in the art. Taking chemical deposition of copper as an example, the plating solution can include: copper sulfate, formaldehyde, potassium sodium tartrate, sodium hydroxide, etc.

[0134] In order to further reduce costs, the metal deposited chemically can be different from the metal deposited electrolytically, for example, it can be a cheaper base metal. Taking electrolytic copper as an example, the metal deposited chemically can be nickel, which is cheaper.

[0135] Electrodeposition can adopt a plating solution formula known in the art. Taking copper electrodeposition as an example, the plating solution can include: copper sulfate, sulfuric acid, potassium chloride, polyethylene glycol, etc.

[0136] By adjusting the process parameters of electrodeposition, such as deposition time, voltage, current density and the like, the amount of metal deposited can be adjusted, and thus the surface density of the foam metal matrix can be adjusted.

[0137] The purpose of the thermal reduction treatment is to remove the foamed polymer material.

[0138] Optionally, the thermal reduction gas used in the thermal reduction treatment may be a mixture of hydrogen and argon or a mixture of hydrogen and nitrogen.

[0139] Optionally, the temperature of the thermal reduction treatment may be 650°C-850°C.

[0140] [Positive electrode]

[0141] The battery cell includes a positive electrode plate.

[0142] In some embodiments, the positive electrode sheet includes a positive electrode current collector and a positive electrode film layer disposed on at least one surface of the positive electrode current collector and comprising a positive electrode active material. For example, the positive electrode current collector has two opposing surfaces in its thickness direction, and the positive electrode film layer is disposed on either or both of the two opposing surfaces of the positive electrode current collector.

[0143] In some embodiments, the positive electrode active material includes a material capable of extracting and inserting lithium.

[0144] As an example, the positive electrode active material may include, but is not limited to, one or more of lithium transition metal oxides, metal chalcogenides, lithium-containing phosphates, and their respective modified compounds. Examples of lithium transition metal oxides may include, but are not limited to, one or more of lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium titanium oxide, and their respective modified compounds. Lithium transition metal oxides may include, but are not limited to, layered structures and spinel structures. Examples of lithium-containing phosphates may include, but are not limited to, one or more of lithium iron phosphate, a composite material of lithium iron phosphate and carbon, lithium manganese phosphate, a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, a composite material of lithium iron manganese phosphate and carbon, and their respective modified compounds.

[0145] In some embodiments, in order to further improve the energy density of the battery, the positive electrode active material may include a general formula of Li a Ni b Co c M d O e D f One or more lithium transition metal oxides and modified compounds thereof. 0.8≤a≤1.2, 0.5≤b<1, 0<c<1, 0<d<1, 1≤e≤2, 0≤f≤1, M may include but is not limited to one or more of Ge, Mo, Sn, Mn, Al, Zr, Zn, Cu, Cr, Mg, Fe, V, Ti and B, and D may include but is not limited to one or more of N, F, S and Cl.

[0146] In some embodiments, the positive electrode active material may include both a lithium transition metal oxide and a lithium-containing phosphate, thereby facilitating the production of a battery with both high capacity and high reliability.

[0147] As an example, the positive electrode active material may include but is not limited to LiCoO2, LiNiO2, LiMnO2, LiNi 1 / 2 Mn 1 / 2 O2、LiMn2O4、Li 4 / 3 Ti 5 / 3 O4、LiNi 1 / 2 Mn 1 / 2 O2、LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2(NCM333),LiNi 0.5 Co 0.2 Mn 0.3 O2(NCM523), LiNi 0.6 Co 0.2 Mn 0.2O2(NCM622),LiNi 0.8 Co 0.1 Mn 0.1 O2(NCM811), LiNi 0.80 Co 0.15 Al 0.05 O2, LiFePO4, LiMnPO4, Li 1.13 Ti 0.57 Fe 0.3 One or more of S2.

[0148] The battery cells are accompanied by Li intercalation and deintercalation and consumption during the charge and discharge process. The molar content of Li in the battery cells varies when discharged to different states. The molar content of Li in the list of positive electrode active materials in this application refers to the initial state of the material, that is, the state before the material is added. The molar content of Li will change after the positive electrode active material is applied to the battery cells and the charge and discharge cycles. The molar content of O in the list of positive electrode active materials in this application is only a theoretical state value. Lattice oxygen release will cause the molar content of O to change, and the actual molar content of O will also fluctuate.

[0149] In some embodiments, the positive electrode active material includes a material capable of extracting and inserting sodium. For example, the positive electrode active material may include, but is not limited to, one or more of layered transition metal oxides (including but not limited to P2 type, O3 type, etc.), polyanionic materials (such as phosphates, fluorophosphates, pyrophosphates, sulfates, etc.), and Prussian materials.

[0150] In some embodiments, as examples, the positive electrode active material may include but is not limited to NaFeO2, NaCoO2, NaCrO2, NaMnO2, NaNiO2, Na 0.67 MO2 (M includes at least two of Fe, Co, Cr, Mn, Ni, V, Ti, Mo), NaMO2 (M includes at least two of Fe, Co, Ni, V, Ti, Mo), NaFePO4, NaMnPO4, NaCoPO4, Na4Fe3(PO4)2O7, Na3V2(PO4)2F3, Na3V2(PO4)3, Prussian blue, Prussian white, and one or more of their respective modified compounds.

[0151] The modified compounds of the above-mentioned positive electrode active materials may be used to perform doping modification and / or surface coating modification on the positive electrode active materials.

[0152] In some embodiments, the positive electrode film layer may further optionally include a positive electrode conductive agent. As an example, the positive electrode conductive agent may include, but is not limited to, one or more of superconducting carbon, conductive graphite, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0153] In some embodiments, the positive electrode film layer may further optionally include a positive electrode binder. As an example, the positive electrode binder may include, but is not limited to, polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, polyethylene oxide, fluorinated acrylic resin, styrene-butadiene rubber (SBR), water-soluble unsaturated resin SR-1B, water-based acrylic resin (e.g., polyacrylic acid PAA, polymethacrylic acid PMAA, sodium polyacrylate PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), and one or more of carboxymethyl chitosan (CMCS).

[0154] In some embodiments, the positive electrode current collector may be a metal foil or a composite current collector. As an example of a metal foil, aluminum foil may be used. The composite current collector may include a polymer material base layer and a metal material layer formed on at least one surface of the polymer material base layer. As an example, the metal material may include, but is not limited to, one or more of aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy. As an example, the polymer material base layer may include, but is not limited to, one or more of polypropylene, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), and polyethylene (PE).

[0155] The positive electrode film layer is typically formed by coating a positive electrode slurry onto a positive electrode current collector, drying, and cold pressing. The positive electrode slurry is typically formed by dispersing the positive electrode active material, optional positive electrode conductive agent, optional positive electrode binder, and any other components in a solvent and stirring them uniformly. The solvent may be, but is not limited to, N-methylpyrrolidone (NMP).

[0156] [Electrolytes]

[0157] The battery cells include an electrolyte.

[0158] In some embodiments, the electrolyte is an electrolyte solution including an electrolyte salt and an organic solvent.

[0159] In some embodiments, the electrolyte includes anions, which may include bis(fluorosulfonyl)imide anions (FSI - ), bis(trifluoromethanesulfonyl)imide anion (TFSI - ), dioxalatoborate anion (BOB - ), difluorooxalatoborate anion (DFOB - ), difluorobis(oxaloyl)phosphate anion (DFOP - ), tetrafluorooxalophosphate anion (TFOP -), difluorophosphate anion (PO2F2 - ), hexafluorophosphate anion (PF6 - ), tetrafluoroborate anion (BF4 - ), hexafluoroarsenate anion (AsF6 - ), trifluoromethanesulfonate anion (CF3SO3 - )

[0160] In some embodiments, the electrolyte includes cations, which may include one or more of lithium ions and sodium ions.

[0161] In some embodiments, the concentration of the electrolyte salt may be greater than 0.3 mol / L, and may be greater than 0.7 mol / L. The concentration of the electrolyte salt may further be less than 4 mol / L, and may be less than 2.5 mol / L or less than 1.7 mol / L. When the concentration of the electrolyte salt is within the above range, the electrolyte solution can have suitable ionic conductivity.

[0162] Organic solvent can include but not limited to one or more in esters, ethers, sulfones, nitrile etc.Ester can include but not limited to one or more in carbonate, phosphate, carboxylate, sulfate, sulfonate etc.Carbonate can comprise cyclic carbonate and / or chain carbonate, alternatively, carbonate can comprise cyclic carbonate and chain carbonate simultaneously.Chain carbonate can comprise low-viscosity polar chain carbonate, aliphatic branched-chain carbonate etc.

[0163] As an example, the organic solvent may include, but is not limited to, ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate, ethyl methyl carbonate (EMC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethyl propyl carbonate (EPC), butylene carbonate (BC), fluoroethylene carbonate (FEC), methyl formate (MF), methyl acetate (MA), ethyl acetate (EA), propyl acetate (PA), methyl propionate (MP), ethyl propionate (EP), propyl propionate (PP), methyl butyrate (MB), ethyl butyrate (EB), 1,4-butyrolactone (GBL), sulfolane (SF), dimethyl sulfone (MSM), methyl ethyl sulfone (EMS), diethyl sulfone (ESE), tetraethylene glycol dimethyl ether (TEGDME), ethylene glycol dimethyl ether (DME), 1,3-dioxolane (DOL), trimethyl phosphate, 3-methoxypropionitrile, H(CF2)2OCH3, C4F9O CH3, H(CF2)2OCH2CH3, H(CF2)2OCH2CF3, H(CF2)2CH2O(CF2)2H, CF3CHFCF2OCH3, CF3CHFCF2OCH2CH3, 2-trifluoromethylhexafluoropropyl methyl ether, 2-trifluoromethylhexafluoropropyl ethyl ether, 2-trifluoromethylhexafluoropropyl propyl ether, 3-trifluoromethyloctafluorobutyl methyl ether, 3-trifluoromethyloctafluorobutyl ethyl ether, 3-trifluoromethyloctafluorobutyl propyl ether, 4-trifluoromethyl One or more of trifluoromethyl decafluoropentyl methyl ether, 4-trifluoromethyl decafluoropentyl ethyl ether, 4-trifluoromethyl decafluoropentyl propyl ether, 5-trifluoromethyl dodecafluorohexyl methyl ether, 5-trifluoromethyl dodecafluorohexyl ethyl ether, 5-trifluoromethyl dodecafluorohexyl propyl ether, 6-trifluoromethyl tetradecafluoroheptyl methyl ether, 6-trifluoromethyl tetradecafluoroheptyl ethyl ether, 6-trifluoromethyl tetradecafluoroheptyl propyl ether, 7-trifluoromethyl hexafluorooctyl methyl ether, 7-trifluoromethyl hexafluorooctyl ethyl ether, and 7-trifluoromethyl hexafluorooctyl propyl ether.

[0164] In some embodiments, the electrolyte may optionally include additives. For example, the additives may include negative electrode film-forming additives, positive electrode film-forming additives, or additives that can improve certain battery properties, such as additives that improve battery overcharge performance, additives that improve battery high-temperature performance, and additives that improve battery low-temperature power performance.

[0165] [Isolation film]

[0166] A battery cell may also include a separator, which is located between the positive electrode and the negative electrode and mainly serves to prevent internal short circuits.

[0167] The present application has no particular limitation on the type of isolation membrane, and any known isolation membrane with a porous structure having good chemical stability and mechanical stability can be selected.

[0168] In some embodiments, the material of the isolation membrane may include, but is not limited to, one or more of fiberglass, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The isolation membrane may be a single-layer film or a multi-layer composite film. When the isolation membrane is a multi-layer composite film, the materials of each layer may be the same or different.

[0169] The preparation method of battery cells is well known. In some embodiments, the positive electrode, separator, negative electrode and electrolyte can be assembled to form a battery cell. As an example, the positive electrode, separator, and negative electrode can be formed into an electrode assembly through a winding process and / or a lamination process. The electrode assembly is placed in an outer package, dried, and then injected with the above-mentioned electrolyte. After vacuum packaging, standing, formation and other processes, a battery cell is obtained. Multiple battery cells can also be further connected in series, in parallel, or in a mixed manner to form a battery module. Multiple battery modules can also be connected in series, in parallel, or in a mixed manner to form a battery pack. In some embodiments, multiple battery cells can also directly form a battery pack.

[0170] The present application also provides an electrical device, which includes a battery provided in the present application. The battery can be used as a power source for the electrical device or as an energy storage unit for the electrical device. The electrical device can be, but is not limited to, a mobile device (such as a mobile phone, a tablet computer, a laptop computer, etc.), an electric vehicle (such as a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, an electric bicycle, an electric scooter, an electric golf cart, an electric truck, etc.), an electric train, a ship, a satellite, an energy storage system, etc.

[0171] The electric device can select the type of battery according to its usage requirements, such as a battery cell, a battery module or a battery pack.

[0172] Figure 6 is a schematic diagram of an exemplary electric device. This device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle. To meet the high power and high energy density requirements of this device, a battery pack or battery module may be used.

[0173] As another example, an electric device may be a mobile phone, a tablet computer, a laptop computer, etc. Such an electric device is usually required to be lightweight and thin, and may use a battery cell as a power source.

[0174] Example

[0175] The following examples describe the present disclosure in more detail and are intended to be illustrative only, as various modifications and variations within the scope of the present disclosure will be apparent to those skilled in the art. Unless otherwise indicated, all parts, percentages, and ratios reported in the following examples are by weight, and all reagents used in the examples are commercially available or synthesized according to conventional methods and used directly without further processing, and all instruments used in the examples are commercially available.

[0176] Example 1

[0177] Commercially available polyurethane foam is used as a matrix, and then degreasing, roughening, sensitization, activation, degumming, chemical deposition, electrodeposition and thermal reduction treatments are carried out in sequence to obtain a foam metal matrix.

[0178] The thickness of the polyurethane foam is 120 μm, the pore density is 135 PPI, the porosity is 80%-95%, the average pore diameter is about 290 μm, the maximum pore diameter is about 480 μm, and the pore diameter of the polyurethane foam is 0.5 times the average pore diameter D avg and 1.5 times the average pore diameter D avg The number of pores between the two layers accounts for about 83.3%, and the pore diameter is less than 0.5 times the average pore diameter D avg The number of pores accounts for about 5.7%, and the pore diameter is greater than 1.5 times the average pore diameter D avg The number of holes accounts for about 11.0%.

[0179] (1) Degreasing

[0180] The polyurethane foam was soaked in degreasing liquid at 40°C for 10 minutes, then cleaned with deionized water and squeezed dry.

[0181] The formula of the degreasing liquid is: 30g / L sodium carbonate, 30g / L sodium phosphate, 15g / L sodium lauryl sulfate, and the solvent is water.

[0182] (2) Roughening

[0183] Soak the degreased polyurethane foam in a roughening solution at 35°C for 5 minutes. After soaking, rinse it with deionized water and squeeze it dry.

[0184] The formula of the coarsening solution is: potassium permanganate 13g / L, concentrated sulfuric acid 7mL / L, and the solvent is water.

[0185] (3) Sensitization

[0186] The roughened polyurethane foam was immersed in a roughening liquid at 25° C. for 5 minutes.

[0187] The formula of the sensitizing solution is: 20 g / L of stannous chloride and 40 mL / L of 36% hydrochloric acid, and tin particles are added into the sensitizing solution.

[0188] (4) Activation

[0189] The sensitized polyurethane foam was washed with deionized water and then immersed in an activation solution at 25° C. for 5 minutes.

[0190] The formula of the activation solution is: 3g / L silver nitrate, 5mL / L ammonia water with a mass fraction of 25%, and the solvent is water.

[0191] (5) Degumming

[0192] The activated polyurethane foam was immersed in a hydrochloric acid aqueous solution with a mass fraction of 14% for 2 minutes.

[0193] (6) Chemical deposition

[0194] The debonded polyurethane foam was immersed in a chemical plating solution at 60°C for 5 minutes.

[0195] The formula of the chemical plating solution is: copper sulfate 10g / L, formaldehyde 20mL / L, potassium sodium tartrate 3g / L, EDTA 40g / L, sodium hydroxide 10g / L, and the solvent is water.

[0196] (7) Electrodeposition

[0197] A DC power supply device is used to make an electrolytic cell. The chemically deposited polyurethane foam is cleaned with deionized water and then immersed in the electroplating solution as the cathode. The metal copper sheet is used as the anode for electrochemical plating. The electrochemical copper deposition amount is about 230g / cm 2 .

[0198] The formula of the electroplating solution is: copper sulfate 70g / L, sulfuric acid 25ml / L, potassium chloride 0.6ml / L, polyethylene glycol 0.003g / L, and the solvent is water.

[0199] (8) Thermal reduction

[0200] The polyurethane foam after electrochemical plating was cleaned with deionized water and anhydrous ethanol and placed in a tubular furnace and evacuated to below 100 Pa. Then, a hydrogen-argon mixture with a hydrogen volume ratio of 10% was introduced until the pressure in the furnace tube reached atmospheric pressure. The outlet valve was opened to maintain the pressure in the furnace tube at the same as the atmospheric pressure. The heating rate was set to 5°C / min, the temperature was raised to 700°C, kept warm for 2 hours, and cooled naturally. The foam metal matrix with the polyurethane foam removed, i.e., foam copper, was taken out of the furnace.

[0201] Example 2

[0202] The preparation method of the foam metal substrate is similar to that of Example 1, except that the parameters of the polyurethane foam substrate are different.

[0203] The thickness of the polyurethane foam is 120μm, the pore density is 150PPI, the porosity is 80%-95%, the average pore diameter is about 280μm, the maximum pore diameter is about 480μm, and the pore diameter of the polyurethane foam is 0.5 times the average pore diameter D avg and 1.5 times the average pore diameter D avg The number of pores between the two layers accounts for about 83.9%, and the pore diameter is less than 0.5 times the average pore diameter D avg The number of pores accounts for about 4.7%, and the pore diameter is greater than 1.5 times the average pore diameter D avg The number of holes accounts for about 11.4%.

[0204] Example 3

[0205] The preparation method of the foam metal substrate is similar to that of Example 1, except that the parameters of the polyurethane foam substrate are different.

[0206] The thickness of the polyurethane foam is 120μm, the pore density is 160PPI, the porosity is 80%-95%, the average pore diameter is about 270μm, the maximum pore diameter is about 470μm, and the pore diameter of the polyurethane foam is 0.5 times the average pore diameter D avg and 1.5 times the average pore diameter D avg The number of pores between the two layers accounts for about 81.3%, and the pore diameter is less than 0.5 times the average pore diameter D avg The number of pores accounts for about 10.3%, and the pore diameter is greater than 1.5 times the average pore diameter D avg The number of holes accounts for about 8.4%.

[0207] Example 4

[0208] The preparation method of the foam metal substrate is similar to that of Example 1, except that the parameters of the polyurethane foam substrate are different.

[0209] The thickness of the polyurethane foam is 120μm, the pore density is 170PPI, the porosity is 80%-95%, the average pore diameter is about 260μm, the maximum pore diameter is about 470μm, and the pore diameter of the polyurethane foam is 0.5 times the average pore diameter D avg and 1.5 times the average pore diameter D avg The number of pores between the two layers accounts for about 81.5%, and the pore diameter is less than 0.5 times the average pore diameter D avg The number of pores accounts for about 11.1%, and the pore diameter is greater than 1.5 times the average pore diameter D avg The number of holes accounts for about 7.4%.

[0210] Example 5

[0211] The preparation method of the foam metal substrate is similar to that of Example 1, except that the parameters of the polyurethane foam substrate are different.

[0212] The thickness of polyurethane foam is 120μm, the pore density is 180PPI, the porosity is 80%-95%, the average pore diameter is about 250μm, the maximum pore diameter is about 450μm, and the pore diameter of polyurethane foam is 0.5 times the average pore diameter D avg and 1.5 times the average pore diameter D avg The number of pores between the two layers accounts for about 82.0%, and the pore diameter is less than 0.5 times the average pore diameter D avg The number of pores accounts for about 11.5%, and the pore diameter is greater than 1.5 times the average pore diameter D avg The number of holes accounts for about 6.5%.

[0213] Example 6

[0214] The preparation method of the foam metal substrate is similar to that of Example 1, except that the parameters of the polyurethane foam substrate are different.

[0215] The thickness of the polyurethane foam is 120μm, the pore density is 190PPI, the porosity is 80%-95%, the average pore diameter is about 240μm, the maximum pore diameter is about 430μm, and the pore diameter of the polyurethane foam is 0.5 times the average pore diameter D avg and 1.5 times the average pore diameter D avg The number of pores between the two layers accounts for about 83.5%, and the pore diameter is less than 0.5 times the average pore diameter D avg The number of pores accounts for about 11.9%, and the pore diameter is greater than 1.5 times the average pore diameter D avg The number of holes accounts for about 4.6%.

[0216] Example 7

[0217] The preparation method of the foam metal substrate is similar to that of Example 1, except that the parameters of the polyurethane foam substrate are different.

[0218] The thickness of the polyurethane foam is 120 μm, the pore density is 200 PPI, the porosity is 80%-95%, the average pore diameter is about 230 μm, the maximum pore diameter is about 420 μm, and the pore diameter of the polyurethane foam is 0.5 times the average pore diameter D avg and 1.5 times the average pore diameter D avg The number of pores between the two layers accounts for about 85.8%, and the pore diameter is less than 0.5 times the average pore diameter D avg The number of pores accounts for about 11.9%, and the pore diameter is greater than 1.5 times the average pore diameter D avg The number of holes accounts for about 2.3%.

[0219] Example 8

[0220] The preparation method of the foam metal substrate is similar to that of Example 1, except that the parameters of the polyurethane foam substrate are different.

[0221] The thickness of the polyurethane foam is 120 μm, the pore density is 240 PPI, the porosity is 80%-95%, the average pore diameter is about 160 μm, the maximum pore diameter is about 300 μm, and the pore diameter of the polyurethane foam is 0.5 times the average pore diameter D avg and 1.5 times the average pore diameter D avg The number of pores between the two layers accounts for about 73.2%, and the pore diameter is less than 0.5 times the average pore diameter D avg The number of pores accounts for about 12.3%, and the pore diameter is greater than 1.5 times the average pore diameter D avg The number of holes accounts for about 14.5%.

[0222] Example 9

[0223] The preparation method of the foam metal substrate is similar to that of Example 1, except that the parameters of the polyurethane foam substrate are different.

[0224] The thickness of the polyurethane foam is 120μm, the pore density is 250PPI, the porosity is 80%-95%, the average pore diameter is about 140μm, the maximum pore diameter is about 260μm, and the pore diameter of the polyurethane foam is 0.5 times the average pore diameter D avg and 1.5 times the average pore diameter D avg The number of pores between the two layers accounts for about 72.6%, and the pore diameter is less than 0.5 times the average pore diameter D avg The number of pores accounts for about 13.9%, and the pore diameter is greater than 1.5 times the average pore diameter D avg The number of holes accounts for about 13.5%.

[0225] Example 10

[0226] The preparation method of the foam metal substrate is similar to that of Example 1, except that the parameters of the polyurethane foam substrate are different.

[0227] The thickness of the polyurethane foam is 120μm, the pore density is 260PPI, the porosity is 80%-95%, the average pore diameter is about 120μm, the maximum pore diameter is about 250μm, and the pore diameter of the polyurethane foam is 0.5 times the average pore diameter D avg and 1.5 times the average pore diameter D avg The number of pores between the two layers accounts for about 72.4%, and the pore diameter is less than 0.5 times the average pore diameter D avg The number of pores accounts for about 14.7%, and the pore diameter is greater than 1.5 times the average pore diameter D avg The number of holes accounts for about 12.9%.

[0228] Comparative Example 1

[0229] The preparation method of the foam metal substrate is similar to that of Example 1, except that the parameters of the polyurethane foam substrate are different.

[0230] The thickness of the polyurethane foam is 120μm, the pore density is 120PPI, the porosity is 80%-95%, the average pore diameter is about 300μm, the maximum pore diameter is about 500μm, and the pore diameter of the polyurethane foam is 0.5 times the average pore diameter D avg and 1.5 times the average pore diameter D avg The number of pores between the two layers accounts for about 66.2%, and the pore diameter is less than 0.5 times the average pore diameter D avg The number of pores accounts for about 1.9%, and the pore diameter is greater than 1.5 times the average pore diameter D avg The number of holes accounts for about 31.9%.

[0231] Comparative Example 2

[0232] The preparation method of the foam metal substrate is similar to that of Example 1, except that the parameters of the polyurethane foam substrate are different.

[0233] The thickness of the polyurethane foam is 120μm, the pore density is 270PPI, the porosity is 80%-95%, the average pore diameter is about 100μm, the maximum pore diameter is about 250μm, and the pore diameter of the polyurethane foam is 0.5 times the average pore diameter D avg and 1.5 times the average pore diameter D avg The number of pores between the two layers accounts for about 70.9%, and the pore diameter is less than 0.5 times the average pore diameter D avg The number of pores accounts for about 16.7%, and the pore diameter is greater than 1.5 times the average pore diameter D avg The number of holes accounts for about 12.4%.

[0234] Performance testing of polyurethane foam and foam metal matrix

[0235] (1) Testing of pore size, pore size distribution, and rib width of polyurethane foam and foam metal matrix

[0236] Randomly select 10 areas on the metal foam substrate and observe the sample using an optical microscope. Take photos at 200x magnification and measure and annotate the pore diameters and ridge widths of all surface pores on the metal foam substrate. Each area should contain at least 20 surface pores in the corresponding photo.

[0237] The pore size refers to the average diameter of the pores, and the average diameter refers to the arithmetic mean of the longest diameter and the shortest diameter of the pores.

[0238] The rib width refers to the width of the ribs between holes.

[0239] The average pore size of all surface pores is obtained as the average pore size D of the foam metal matrix. avg .

[0240] The maximum pore size of all surface pores is taken as the maximum pore size D of the foam metal matrix. max .

[0241] The number of all surface pores is used as the denominator, and the pore diameter is 0.5 times the average pore diameter D avg and 1.5 times the average pore diameter D avg The number of pores between the two is taken as the numerator, and the pore diameter is calculated at 0.5 times the average pore diameter D avg and 1.5 times the average pore diameter D avg The proportion of the number of holes.

[0242] The number of all surface pores is taken as the denominator, and the pore diameter is less than 0.5 times the average pore diameter D avg The number of pores is taken as the numerator, and the pore diameter is calculated to be less than 0.5 times the average pore diameter D avg The proportion of the number of holes.

[0243] The number of all surface pores is taken as the denominator, and the pore diameter is greater than 1.5 times the average pore diameter D avg The number of pores is taken as the numerator, and the pore diameter is calculated to be greater than 1.5 times the average pore diameter D avg The proportion of the number of holes.

[0244] The average value of the obtained rib widths is taken as the rib width of the foam metal matrix.

[0245] The test method for polyurethane foam is the same as that for foam metal matrix.

[0246] (2) Pore density test of polyurethane foam and foam metal matrix

[0247] The test was conducted in accordance with GB / T 20251-2006. The average number of surface pores per unit inch (i.e., 2.54 cm) was used as the pore density.

[0248] The pore count of the polyurethane foam and the foam metal substrate was examined using an optical microscope at a magnification of 100. Ten areas were randomly selected on the polyurethane foam and the foam metal substrate, and the test results were averaged.

[0249] (3) Porosity test of polyurethane foam and foam metal matrix

[0250] The porosity was measured using the kerosene displacement method.

[0251] The volume (or apparent volume) of the foam metal matrix in its natural state is V0 = t × s. t represents the thickness of the foam metal matrix in cm; s represents the area of ​​the foam metal matrix in cm 2 . Determination of the thickness of the foam metal matrix: Use a micrometer with an accuracy of 0.01mm to measure the thickness t of the foam metal matrix, and measure 10 points and take the average value. Determination of the area of ​​the foam metal matrix: Place the coordinate paper on a flat transparent glass surface, place a white plane light source under the glass, and then place the foam metal matrix to be measured on the coordinate paper. Read the area of ​​the foam metal matrix projected on the coordinate paper. Measure the sample to be measured twice and take the average value, recorded as s. The difference between the two measurement readings should not exceed 1%.

[0252] The absolute compact volume V of the metal foam matrix is ​​measured as follows.

[0253] Take a calibrated measuring cylinder, clean it and dry it. Place the measuring cylinder, dropper, kerosene and the foam metal matrix sample to be tested in the calibration laboratory 4 hours in advance. The temperature is controlled at 20±5℃, and the temperature change is no more than 1℃ / h. During the test, first place the foam metal matrix in the measuring cylinder, then place the measuring cylinder on the balance and peel it, and then use the dropper to drip kerosene into the measuring cylinder. After the meniscus of the kerosene liquid level line submerges the foam metal matrix, add kerosene drop by drop to accurately adjust the liquid level to a certain mark on the measuring cylinder, and then read the reading V1 (unit mL) of the measuring cylinder and the weight m3 (unit g) displayed on the balance. The absolute dense volume V of the foam metal matrix = (V1×ε)–(m3 / ρ). ε is the correction coefficient of the measuring cylinder; ρ is the density of kerosene, in g / cm 3 .

[0254] The porosity P of the foam metal matrix = (V0-V) / V0×100%.

[0255] The test method for polyurethane foam is the same as that for foam metal matrix.

[0256] (4) Electrochemically active specific surface area test of foam metal matrix

[0257] The prepared metal foam matrix was cut into small discs with a diameter of 20 mm and a button cell was fabricated using a lithium metal sheet as the counter electrode. The electrolyte salt in the button cell's electrolyte solution was LiFSI at a concentration of 1 mol / L, the solvent was ethylene glycol dimethyl ether (DME), and the probe molecule was ferrocene at a concentration of 50 mmol / L. The separator of the button cell was a 12 μm thick PE film.

[0258] At 25°C, the assembled button cell was left to stand for 12 hours, and then discharged at a constant voltage of 2.5V until the current dropped to 0.0025mA / cm 2Cyclic voltammetry scans were performed at 3 mV / s, 2 mV / s, 1 mV / s, and 0.5 mV / s in the 2.5 V to 3.4 V range. The peak current at each positive sweep rate was recorded. A linear regression was performed using the peak current and the square root of the sweep rate to obtain the slope. The electrochemically active surface area of ​​the metal foam matrix was calculated using the Randles-Sevick equation. The test instrument was a SOLARTRON electrochemical workstation from Transtron (UK).

[0259] Next, the foam metal matrix prepared above was directly used as the negative electrode current collector to assemble a battery, and the following performance tests were performed.

[0260] Battery Preparation: Lithium iron phosphate, conductive carbon black (Super P), and binder polyvinylidene fluoride (PVDF) were mixed uniformly in an appropriate amount of solvent N-methylpyrrolidone (NMP) at a weight ratio of 8:1:1 to obtain a positive electrode slurry. The positive electrode slurry was coated onto aluminum foil, the positive electrode current collector, and dried to obtain a positive electrode plate. In an argon-protected glove box, the positive electrode plate and the prepared metal foam substrate were assembled into a button cell. The electrolyte salt was LiFSI at a concentration of 1 mol / L, and the solvent was ethylene glycol dimethyl ether (DME). A 12 μm thick PE film was used as the separator.

[0261] Cycling Performance Test: After the assembled button cell is allowed to rest for 12 hours at 25°C, it is charged at a constant current of 0.2C to 3.65V. Then, it is charged at a constant voltage of 3.65V to 0.05C. After the button cell is allowed to rest for 10 minutes, it is discharged at a constant current of 1C to 2V. The button cell is charged and discharged according to the above method, and the number of cycles corresponding to the discharge capacity decaying to 40% of the initial discharge capacity is recorded. The number of button cell samples can be more than 6 during testing, and the test results are averaged.

[0262] Rate Performance Test: After standing for 12 hours at 25°C, assembled button cells were charged to 3.65V at constant currents of 1C and 0.2C, respectively. The 1C and 0.2C charge capacities were measured. The ratio of the 1C to 0.2C charge capacities represents the rate performance of the button cell. The closer this ratio is to 1, the better the rate performance. Six or more button cell samples may be used for testing, and the average of the test results is used.

[0263] Table 2

[0264] From the test results in Table 1 and Table 2, it can be seen that by adjusting the electrochemical active mass specific surface area of ​​the foam metal matrix to 2.5 cm 2 / g-20cm 2 / g, and an electrochemically active volume-to-surface area of ​​22 cm2 / cm 3 -180cm 2 / cm 3 , which can make the battery have both long cycle life and high rate charging capacity retention rate.

[0265] The electrochemically active specific surface area of ​​the foam metal matrix prepared in Comparative Example 1 is too small, and the pore size distribution of the foam metal matrix is ​​uneven, which causes uneven distribution of current density on the surface of the negative electrode, thereby resulting in poor battery cycle performance and high-rate charging capacity retention rate.

[0266] The electrochemically active specific surface area of ​​the foam metal matrix prepared in Comparative Example 2 is too large. At this time, the foam metal matrix contains a large number of small pores. When the battery is charged, the pores on the negative electrode side close to the separator will quickly be blocked by the deposited metal. The ions in the electrolyte will be difficult or even impossible to replenish to the internal position of the negative electrode, thereby reducing the space utilization of the negative electrode. At the same time, it will also cause the electrolyte wettability of the negative electrode to deteriorate, and further lead to poor cycle performance of the battery.

[0267] Next, the battery's first-cycle coulombic efficiency (CEE) was tested. After the assembled button cell was allowed to rest for 12 hours at 25°C, it was charged at a constant current of 0.1C to 3.65V. It was then charged at a constant voltage of 3.65V to 0.05C to obtain the charge capacity. After the button cell was allowed to rest for 10 minutes, it was discharged at a constant current of 0.2C to 2V to obtain the discharge capacity. CEE = discharge capacity / charge capacity. The test results are shown in Table 3.

[0268] Table 3

[0269] The test results in Table 3 show that by further adjusting the electrochemically active mass specific surface area and electrochemically active volume specific surface area of ​​the metal foam matrix, the battery can achieve high coulombic efficiency while maintaining good cycle performance and rate performance. This is because the increase in the electrochemically active surface area of ​​the metal foam matrix consumes more active ions to activate the deposition sites on the negative electrode surface during the battery's first charge, thereby reducing the battery's initial coulombic efficiency.

[0270] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are merely examples, and any embodiments having substantially the same structure and effect as the technical concept within the scope of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the present application, any other embodiments that can be conceived by those skilled in the art and that combine some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A negative electrode current collector, wherein, The negative current collector includes a foam metal matrix, and the electrochemically active mass specific surface area of the foam metal matrix is 2.5 cm 2 / g - 20 cm 2 / g, and the electrochemically active volume specific surface area is 22 cm 2 / cm 3 - 180 cm 2 / cm 3 .

2. The negative electrode current collector according to claim 1, wherein, The electrochemically active mass specific surface area of the foamed metal matrix is 3.2 cm 2 / g - 10 cm 2 / g, and the electrochemically active volume specific surface area is 29 cm 2 / cm 3 - 90 cm 2 / cm 3 .

3. The negative electrode current collector according to claim 2, wherein, The electrochemically active mass specific surface area of the foamed metal matrix is 3.2 cm 2 / g - 5 cm 2 / g, and the electrochemically active volume specific surface area is 29 cm 2 / cm 3 - 45 cm 2 / cm 3 .

4. The negative electrode current collector according to any one of claims 1-3, wherein, The number of pores in the porous metal matrix with pore diameters between 0.5 times the average pore diameter D avg and 1.5 times the average pore diameter D avg is 80%-90% of the total number of pores in the porous metal matrix; and / or, The number of pores with a pore diameter less than 0.5 times the average pore diameter D in the metal foam matrix is 4.5%-12% of the total number of pores in the metal foam matrix; and / or, avg the number of pores with a pore diameter less than 0.5 times the average pore diameter D in the metal foam matrix is 4.5%-12% of the total number of pores in the metal foam matrix; and / or, The number of pores with pore diameters greater than 1.5 times the average pore diameter D in the metal foam matrix is 2% - 12% of the total number of pores in the metal foam matrix. avg ​ 5. The negative electrode current collector according to any one of claims 1-4, wherein, The average pore diameter D of the metallic foam substrate avg is 120 μm - 290 μm; and / or, The maximum pore diameter D of the metal foam matrix max is 200 μm - 500 μm.

6. The negative electrode current collector according to any one of claims 1-5, wherein, The rib width of the foamed metal matrix is 5 μm - 100 μm.

7. The negative electrode current collector according to any one of claims 1-6, wherein, The pore density of the foamed metal matrix is 135 PPI - 200 PPI.

8. The negative electrode current collector according to any one of claims 1-7, wherein, The porosity of the foamed metal matrix is 65% - 91%.

9. The negative electrode current collector according to any one of claims 1-8, wherein, The foamed metal matrix is an open-cell structure, and the open-cell ratio is greater than or equal to 98%.

10. The negative electrode current collector according to any one of claims 1-9, wherein, The thickness of the foamed metal matrix is 80 μm - 1000 μm.

11. The negative electrode current collector according to any one of claims 1-10, wherein, The metal elements in the foamed metal matrix include one or more of copper, nickel, titanium, aluminum, cobalt, iron, manganese, tin, gold, silver, chromium, zinc, cadmium, lead, platinum, antimony, bismuth, gallium, indium, and palladium.

12. The negative electrode current collector according to any one of claims 1-11, wherein, The negative electrode current collector further includes an alkali metal affinity layer located on the surface of the foamed metal matrix.

13. The negative electrode current collector according to claim 12, wherein, The alkali metal affinity layer includes one or more of Cu2O and Li3N; and / or, The thickness of the alkali metal affinity layer is 50 nm - 5 μm.

14. A battery cell, comprising the negative electrode current collector according to any one of claims 1-13.

15. The battery cell according to claim 14, wherein, The battery cell includes at least one of a lithium metal battery cell without a negative electrode and a sodium metal battery cell without a negative electrode.

16. A battery, comprising the battery cell according to any one of claims 14-15.

17. An electrical device, comprising the battery according to claim 16, and the battery is used to provide electrical energy.

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