An ammonium-ion battery including a composite current collector and an electric device

Abstract

The application relates to an ammonium ion battery comprising a composite current collector and an electric device. The ammonium ion battery of the application comprises a positive electrode sheet, a negative electrode sheet and a separator interposed between the positive electrode sheet and the negative electrode sheet; the positive electrode sheet comprises a positive electrode composite current collector and a positive electrode active material layer arranged on one side or both sides of the positive electrode composite current collector; the negative electrode sheet comprises a negative electrode composite current collector and a negative electrode active material layer arranged on one side or both sides of the negative electrode composite current collector; at least one of the positive electrode active material layer, the negative electrode active material layer and the separator comprises ammoniated zeolite. By adding ammoniated zeolite in at least one of the positive and negative electrode active material layers and the separator, the electrochemical performance of the ammonium ion battery, such as the rate performance and the cycle performance, is significantly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of batteries, in particular to an ammonium ion battery comprising a composite current collector and an electric device. BACKGROUND

[0002] Ammonium ion (NH4 + ) has a small hydrated ion radius and a relatively light molar mass, and has a fast diffusion speed in aqueous electrolyte, which can realize fast charging and discharging of the battery. In addition, compared with lithium, cobalt, sodium and other metal resources used in traditional batteries, the source of ammonium ion is wide, and the ammonium ion battery has lower cost. Moreover, the ammonium ion battery generally uses aqueous electrolyte, which reduces the safety risk of fire and explosion of the battery compared with organic electrolyte, and is safe and reliable in use and storage. In summary, based on the advantages of ammonium ion battery in charging and discharging speed, cost, safety performance and the like, it has a wider application prospect.

[0003] However, the electrochemical performance of the ammonium ion battery is largely dependent on the deintercalation characteristics of ammonium ions in the electrode material, the migration rate at the interface of the electrolyte, the separator, the electrolyte and the electrode material, and the stability between the electrolyte and the electrode material, which also means that the change of the materials in the battery will have a significant impact on the electrochemical performance of the ammonium ion battery. Therefore, how to improve the compatibility and stability of each component of the ammonium ion battery system to make the ammonium ion battery have good electrochemical performance is a technical problem to be solved in the field. SUMMARY

[0004] Therefore, the present application provides an ammonium ion battery comprising a composite current collector and an electric device. The ammonium ion battery of the present application improves the rate and cycle electrochemical performance of the battery by adding ammoniated zeolite in at least one of the positive electrode active material layer, the negative electrode active material layer and the separator.

[0005] The first aspect of the present application provides an ammonium ion battery comprising a composite current collector, comprising a positive electrode sheet, a negative electrode sheet and a separator spaced between the positive electrode sheet and the negative electrode sheet;

[0006] The positive electrode sheet comprises a positive electrode composite current collector and a positive electrode active material layer arranged on one side or both sides of the positive electrode composite current collector; the negative electrode sheet comprises a negative electrode composite current collector and a negative electrode active material layer arranged on one side or both sides of the negative electrode composite current collector;

[0007] At least one of the positive electrode active material layer, the negative electrode active material layer and the separator comprises ammoniated zeolite;

[0008] The positive electrode composite current collector and the negative electrode composite current collector each comprise a first conductive layer, a second conductive layer and a third conductive layer which are sequentially stacked, and the material of the second conductive layer comprises a polymer.

[0009] In some embodiments of the present application, the ammonium zeolite has a particle size of 50 nm to 500 nm.

[0010] In some embodiments of the present application, the mass content of the ammonium zeolite in the positive electrode active material layer is 2 wt% to 10 wt%;

[0011] And / or, the mass content of the ammonium zeolite in the negative electrode active material layer is 5 wt% to 20 wt%;

[0012] And / or, the mass content of the ammonium zeolite in the separator is 90 wt% to 98 wt%.

[0013] In some embodiments of the present application, the positive electrode active material layer comprises positive electrode active material, conductive agent, binder and ammonium zeolite in a mass ratio of (60-80):(10-20):(5-15):(3-7);

[0014] And / or, the negative electrode active material layer comprises negative electrode active material, conductive agent, binder and ammonium zeolite in a mass ratio of (60-80):(5-15):(5-15):(5-15);

[0015] And / or, the separator comprises a base film and an ammonium zeolite coating layer arranged on one side or both sides of the base film.

[0016] In some embodiments of the present application, the positive electrode active material layer comprises a first coating layer and a second coating layer which are sequentially stacked, the first coating layer comprises positive electrode active material, conductive agent and binder, and the second coating layer comprises ammonium zeolite;

[0017] And / or, the negative electrode active material layer comprises a third coating layer and a fourth coating layer which are sequentially stacked, the third coating layer comprises negative electrode active material, conductive agent and binder, and the fourth coating layer comprises ammonium zeolite.

[0018] In some embodiments of the present application, the positive electrode active material comprises a manganese-based Prussian blue material with a carbon coating layer;

[0019] And / or, the negative electrode active material comprises a two-dimensional transition metal boride.

[0020] In some embodiments of the present application, the second conductive layer comprises a first region and a second region at both ends, and an intermediate region between the first region and the second region;

[0021] The material of the first conductive layer, the third conductive layer and the second conductive layer located in the second region is metal or carbon material.

[0022] The material of the second conductive layer located in the intermediate region comprises a polymer.

[0023] In some embodiments of the present application, the second conductive layer located in the intermediate region comprises N conductive pieces, N≥1; the N conductive pieces are arranged at intervals and the gap between adjacent two conductive pieces is filled with the polymer; the N conductive pieces penetrate the first surface and the second surface of the second conductive layer.

[0024] The first surface is the surface where the second conductive layer and the first conductive layer are in contact, and the second surface is the surface where the second conductive layer and the third conductive layer are in contact.

[0025] In some embodiments of the present application, the N conductive pieces are fixed on a support plate, and the support plate is arranged between the first surface and the second surface of the second conductive layer; the thickness of the support plate is less than the thickness of the second conductive layer.

[0026] The support plate comprises M through holes, M≥1, and the M through holes are filled with the polymer.

[0027] The second aspect of the present application provides an ammonium ion battery comprising the composite current collector provided by the first aspect of the present application.

[0028] The ammonium ion battery provided by the present application comprises a composite current collector, which comprises ammoniated zeolite in at least one of the positive electrode active material layer, the negative electrode active material layer and the separator. When the ammoniated zeolite exists in the positive electrode active material layer and the negative electrode active material layer, the wettability of the electrolyte to the positive electrode sheet and the negative electrode sheet can be improved, the tortuosity of charge transfer is reduced, the ion mobility and electronic conductivity of the positive electrode and the negative electrode are improved, an effective conductive network is formed, and thus the rate and cycle performance of the battery are improved. When the ammoniated zeolite exists in the separator, the high-temperature resistance and mechanical properties of the separator can be improved, and the diffusion of ammonium ions at the separator can be promoted, and the charge and discharge rate performance of the battery is improved. In summary, by introducing ammoniated zeolite into the components of the ammonium ion battery, the electrochemical performance such as the rate performance and the cycle performance of the battery is significantly improved. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 It is a structural schematic diagram of the positive composite current collector and the negative composite current collector in the embodiments of the present application.

[0030] Figure 2 It is a structural schematic diagram of the second conductive layer located in the intermediate region in the embodiments of the present application.

[0031] Figure 3 Another schematic view of the second conductive layer in the middle region in the embodiments of the present application;

[0032] Figure 4 Another schematic view of the second conductive layer in the middle region in the embodiments of the present application; Figure 3 Another schematic view of the second conductive layer in the middle region in the embodiments of the present application;

[0033] Explanation of Reference Signs:

[0034] 101: first conductive layer; 102: second conductive layer; 103: third conductive layer; 104: conductive member; 105: support plate; A: first region; B: second region; C: middle region. DETAILED DESCRIPTION

[0035] In order to facilitate the understanding of the present application, the present application will be described more fully below with reference to the accompanying drawings. In the drawings, preferred embodiments of the present application are shown. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of the present application can be more thoroughly and completely understood.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terminology used in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application.

[0037] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. As used herein, "multiple", "a plurality of", and the like, unless otherwise limited, refer to two or more than two, for example, "one or more" means one, two, or more than two. As used herein, open-ended technical features or technical solutions described by the terms "containing", "including", "comprising", and the like, unless otherwise specified, do not exclude additional members outside the listed members, which can be regarded as providing both closed features or solutions composed of listed members and open features or solutions including additional members outside the listed members.

[0038] In the present application, the sum of the parts of each component in the composition can be 100 parts by weight if not otherwise stated. If not otherwise specified, the basis of the percentage of the present application (including weight percentage) is the total weight of the composition, and in addition, "wt%" herein means mass percentage.

[0039] In the present application, when referring to a numerical interval (i.e., a numerical range), the distribution of the selectable values in the numerical interval is considered continuous and includes both numerical endpoints (i.e., the minimum and maximum values) of the numerical interval and every value between the two numerical endpoints, unless otherwise specified. When a numerical interval refers only to integers within the numerical interval, including both endpoint integers and every integer between the two endpoints, it is equivalent to listing each integer directly, unless otherwise specified. When multiple numerical ranges are provided to describe a feature or characteristic, the numerical ranges can be combined. In other words, unless otherwise indicated, numerical ranges disclosed in the present application are to be understood to include any and all sub-ranges subsumed therein. A "value" in a numerical interval can be any quantitative value, such as a number, a percentage, a ratio, etc. A "numerical interval" is intended to broadly include quantitative intervals such as percentage intervals, ratio intervals, value intervals, etc.

[0040] Ammonium-ion batteries have the advantages of fast charging and discharging speed, safety and reliability, low cost, etc. However, the electrochemical performance of ammonium-ion batteries is greatly dependent on the composition of electrode materials, separators and electrolytes. For example, the strong interaction between the electrode material and the ammonium ion and the low diffusion barrier of the ammonium ion in the electrode material, the separator and the electrolyte are important reasons for the excellent kinetic performance of ammonium-ion batteries, but at the same time, the change of the material composition in the battery system will have an important influence on the electrochemical performance of ammonium-ion batteries. Therefore, how to improve the compatibility and stability of the components in the battery system and improve the electrochemical performance of ammonium-ion batteries is a problem to be solved in the field.

[0041] Based on this, the first aspect of the present application provides an ammonium-ion battery comprising a composite current collector, comprising a positive electrode sheet, a negative electrode sheet and a separator interposed between the positive electrode sheet and the negative electrode sheet;

[0042] The positive electrode sheet comprises a positive electrode composite current collector and a positive electrode active material layer arranged on one side or both sides of the positive electrode composite current collector; the negative electrode sheet comprises a negative electrode composite current collector and a negative electrode active material layer arranged on one side or both sides of the negative electrode composite current collector;

[0043] Among at least one of the positive electrode active material layer, the negative electrode active material layer and the separator, ammoniated zeolite is included;

[0044] The positive electrode composite current collector and the negative electrode composite current collector respectively comprise a first conductive layer, a second conductive layer and a third conductive layer arranged in sequence, and the material of the second conductive layer comprises a polymer.

[0045] The ammoniated zeolite refers to a zeolite formed by replacing the cations in the zeolite with ammonium ions through ion exchange. After ion exchange, the ammonium ions occupy the positions of the original cations in the zeolite, exist in the pores and cavities of the zeolite, and interact with the surrounding framework structures such as silicon-oxygen tetrahedron and aluminum-oxygen tetrahedron, so that the zeolite maintains its original pore structure.

[0046] When the ammoniated zeolite is included in the separator, the good high-temperature resistance, acid and alkali corrosion resistance and mechanical strength of the zeolite itself can improve the mechanical properties and high-temperature stability of the separator, and the ammonium ions in the pores and cavities of the zeolite can promote the diffusion of ammonium ions at the separator, reduce the ammonium ion migration activation energy, improve the ion transport performance of the separator, and further improve the charge-discharge rate performance of the battery; and the good ion transport performance can make the ammonium ions uniformly transmit between the positive and negative electrodes through the separator, avoid the concentration polarization caused by local non-uniform ion concentration, and make the battery maintain good cycle life.

[0047] When the ammoniated zeolite is included in the positive active material layer and the negative active material layer, its rich pore structure improves the wettability of the electrolyte to the positive and negative electrode sheets, reduces the tortuosity of charge transfer, improves the ion mobility and electronic conductivity of the positive and negative electrodes, and forms a more effective conductive network; the ammoniated zeolite itself has rich ammonium ion sites, which can serve as an ammonium ion transport channel, thereby improving the battery rate and cycle electrochemical performance.

[0048] In summary, the present application adds ammoniated zeolite to at least one of the positive active material layer, the negative active material layer and the separator, which can improve the rate and cycle electrochemical performance of the battery.

[0049] In the ammonium ion battery, the current collector mainly plays the role of collecting current, conducting electrons and supporting the active material layer. The positive and negative current collectors of the present application adopt a sandwich structure, that is, the second conductive layer located in the middle position of the current collector includes a polymer, so that the flexibility of the current collector is improved, the weight is reduced, and the electrochemical performance such as energy density and safety performance of the battery is improved.

[0050] The ammoniated zeolite used in the present application can be prepared by mixing the zeolite with an ammonium salt solution and performing ion exchange reaction at a suitable temperature.

[0051] The zeolite can be a zeolite containing exchangeable sodium ions, potassium ions, calcium ions or magnesium ions, etc. It can be a natural zeolite or a synthetic zeolite. Specifically, it can be mordenite or clinoptilolite.

[0052] Further, the ammonium salt solution can be one or more of an ammonium chloride aqueous solution, an ammonium bicarbonate aqueous solution, an ammonium sulfate aqueous solution, and an ammonium carbonate aqueous solution.

[0053] The concentration of the ammonium salt solution will affect the ion exchange degree and ion exchange capacity of the ammoniated zeolite. When the concentration is low, the ion exchange reaction is not sufficient, resulting in a low proportion of cations in the zeolite being replaced by ammonium ions. When the concentration is too high, it may block or damage the pore structure of the zeolite, reducing the ion exchange capacity. To fully ammoniate the zeolite and maintain a high ion exchange capacity, 0.01 mol of zeolite can be placed in an ammonium salt solution with a concentration of 4-8 mol / L for ammoniation.

[0054] After the ion exchange reaction is completed, deionized water can be used for cleaning, followed by drying for standby, to remove the remaining impurities.

[0055] In some embodiments of the present application, the particle size of the ammoniated zeolite is 50-500 nm, preferably 200-400 nm. For example, the particle size of the ammoniated zeolite can be 50 nm, 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, 450 nm, 500 nm, or a range formed by any two of the aforementioned values.

[0056] A smaller particle size of the ammoniated zeolite can provide more ion transport channels, shorten the transport path of lithium ions, and thus improve the ionic conductivity and the rate performance of the battery. In addition, the small particle size of the ammoniated zeolite particles has a larger contact area with the electrolyte, which can better absorb and retain the electrolyte, thereby improving the cycle performance of the battery.

[0057] In some embodiments of the present application, the mass content of the ammoniated zeolite in the positive active material layer is 2-10 wt%, and / or the mass content of the ammoniated zeolite in the negative active material layer is 5-20 wt%. For example, the mass content of the ammoniated zeolite in the positive active material layer can be 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, or a range formed by any two of the aforementioned values; the mass content of the ammoniated zeolite in the negative active material layer can be 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, or a range formed by any two of the aforementioned values. The ammoniated zeolite itself does not have electrochemical reactivity, and a high content of the ammoniated zeolite will occupy too much space in the positive and negative active material layers, reducing the content and proportion of the active material that actually participates in the electrochemical reaction, resulting in a decrease in the capacity of the battery. Therefore, controlling the content of the ammoniated zeolite in the positive and negative active material layers within the above range is beneficial to making the battery have both high capacity and electrochemical performance.

[0058] In some embodiments of the present application, the positive active material layer comprises positive active material, conductive agent, binder and ammoniated zeolite in a mass ratio of (60-80):(10-20):(5-15):(3-7); and / or, the negative active material layer comprises negative active material, conductive agent, binder and ammoniated zeolite in a mass ratio of (60-80):(5-15):(5-15):(5-15).

[0059] The conductive agent in the positive and negative active material layers can establish a good conductive network between active material particles and between active material and current collector, reducing the internal resistance of the battery. An appropriate content of conductive agent is conducive to the rapid transmission of electrons within the electrode sheet, improving the charge and discharge efficiency of the battery. As non-limiting examples, the conductive agent of the present application includes but is not limited to one or more of super-p carbon, acetylene black, carbon black, ketjen black, carbon dots, carbon nanotubes, graphene and carbon nanofibers.

[0060] The main role of the binder is to firmly bond the active material and the conductive agent together and adhere to the current collector, forming a stable electrode structure. An appropriate content of binder can ensure that the electrode does not have problems such as active material falling off and conductive network damage during charging and discharging, maintaining the integrity and stability of the electrode structure, thereby prolonging the service life of the battery. As non-limiting examples, the binder of the present application includes but is not limited to one or more of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, sodium carboxymethyl cellulose, styrene butadiene rubber and fluorine-containing acrylate resin.

[0061] The positive and negative active materials are key substances involved in the electrochemical reaction of the battery, which determines the energy density of the battery. Controlling the mass of the positive and negative active materials in the positive and negative active materials within the above proportion range is conducive to maintaining a high energy density of the battery. When the ammonium ion battery is charged, the ammonium ions in the positive active material are released, migrate to the negative electrode through the electrolyte across the separator, and are embedded in the negative active material layer; when the lithium ion battery is discharged, the ammonium ions in the negative active material are released, return to the positive electrode through the electrolyte across the separator, and are re-embedded in the positive active material.

[0062] In some embodiments of the present application, the positive active material comprises a manganese-based Prussian blue material with a carbon coating layer. Manganese has multiple oxidation states, and in an electrochemical reaction, it can store and release a large amount of electric charge through the transformation between different oxidation states, thereby making the manganese-based Prussian blue material have a high specific capacity, and it has a unique three-dimensional cubic crystal structure, and there are a large number of open channels composed of metal ions and cyanide ions, which have a moderate size and match the size of ammonium ions, and can provide a fast and efficient transmission path for the ammonium ions, so that they can be smoothly deintercalated during the charging and discharging process. However, the electronic conductivity of the manganese-based Prussian blue material itself is relatively low, which will limit the efficiency of electron transmission in the electrochemical reaction, and thus affect the rate performance of the battery. The carbon material has good electrical conductivity, and by coating a carbon material layer on the surface of the manganese-based Prussian blue material, a layer of efficient electron transmission channel is constructed on its surface, thereby improving the electronic conductivity of the manganese-based Prussian blue material.

[0063] The thickness of the carbon coating layer should not be too large, otherwise it will occupy too much space, reduce the loading amount of active material, and cause the energy density of the battery to decrease. Based on the above considerations, the thickness of the carbon coating layer is controlled to be 10 nm to 50 nm. For example, the thickness of the carbon coating layer can be 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, or a range formed by any two of the foregoing values.

[0064] The present application does not particularly limit the formation method of the carbon coating layer, which can be coated by using a conventional coating method in the art. For example, the carbon material can be coated by using a magnetron sputtering method. Specifically, a magnetron sputtering coating machine can be used to vacuum the cavity to (1-6) x 10 -5 Pa, argon gas is introduced at 10-100 sccm, and the coating deposition is carried out in a direct current mode at a working pressure of 0.1-2 Pa and a power of 20-100 W.

[0065] As a non-limiting example, the manganese-based Prussian blue material with a carbon coating layer used in the present application includes but is not limited to one or more of KN-MnHCF, K-FeMnHCF, and N-FeMnHCF.

[0066] The chemical composition of KN-MnHCF is K 1.101 (NH4) 0.533 Mn 0.986 Ni 0.014 [Fe(CN)6] 0.889 ·H2O 0.406 The chemical composition of K-FeMnHCF is K 1.19 Fe 0.35 Mn 0.65 [Fe(CN)6] 0.83• 1.24H2O, the chemical composition of N-FeMnHCF is (NH4) 1.85 Fe 0.33 Mn 0.67 [Fe(CN)6] 0.98 • 0.77H2O.

[0067] In some embodiments of the present application, the negative active material includes a two-dimensional transition metal boride. As a non-limiting example, the two-dimensional transition metal boride includes, but is not limited to, one or more of Mo2B2, V2B2, Mn2B2. The two-dimensional transition metal boride has a typical layered structure, and there is a certain gap between the layers, which provides a spacious channel and storage space for the insertion and extraction of ammonium ions. And research shows that the diffusion barrier of ammonium ions in the two-dimensional transition metal boride is low, which can make the ammonium ions rapidly diffuse inside the material, helping to improve the rate performance of the battery.

[0068] For the positive active material and the negative active material, the present application is not limited to the above materials, and other conventional materials that can be used as positive and negative active materials of ammonium ion batteries can also be added and used in combination with the above materials.

[0069] In the positive and negative active material layers, the ammoniated zeolite can be used as a filler and blended with active materials, conductive agents, and binders, etc. to form positive and negative active material layers, or can be used separately to form a coating.

[0070] In some embodiments of the present application, the positive active material layer includes a first coating layer and a second coating layer arranged in layers, the first coating layer includes a positive active material, a conductive agent, and a binder, and the second coating layer includes an ammoniated zeolite.

[0071] And / or, the negative active material layer includes a third coating layer and a fourth coating layer arranged in layers, the third coating layer includes a negative active material, a conductive agent, and a binder, and the fourth coating layer includes an ammoniated zeolite.

[0072] The present application does not particularly limit the positional relationship between the first coating layer and the second coating layer and the positive composite current collector, and the three can be arranged in layers in the order of the positive composite current collector, the first coating layer, and the second coating layer, or the positive composite current collector, the second coating layer, and the first coating layer. Similarly, the present application does not particularly limit the third coating layer and the fourth coating layer and the negative composite current collector, and the three can be arranged in layers in the order of the negative composite current collector, the third coating layer, and the fourth coating layer, or the negative composite current collector, the fourth coating layer, and the third coating layer.

[0073] When the first coating layer is located between the positive electrode composite current collector and the second coating layer; and / or, when the third coating layer is located between the negative electrode composite current collector and the fourth coating layer, the ammonium zeolite in the positive and negative electrode sheets is located on the contact surface of the positive and negative electrode sheets and the electrolyte, which is equivalent to an artificial CEI film and SEI film, and can allow the rapid transmission of ammonium ions therein, thereby improving the rate performance of the battery. In addition, the good electronic insulation performance of the ammonium zeolite can inhibit the side reaction between the positive and negative electrodes and the electrolyte, thereby improving the cycle life of the battery. At this time, in order to firmly bond the first coating layer and the second coating layer and the third coating layer and the fourth coating layer, a bonding agent can be added to the second coating layer and the fourth coating layer to firmly bond the ammonium zeolite to the first coating layer and the third coating layer, respectively, thereby forming a stable positive and negative electrode structure. At the same time, the thickness of the second coating layer and the fourth coating layer can be further controlled to be not more than 0.5 µm. If the thickness is too large, the transmission path of the ammonium ions in the second coating layer and the fourth coating layer will be too long, and the transmission resistance will be too large, which will be detrimental to the charge and discharge performance of the battery.

[0074] When the second coating layer is located between the positive electrode composite current collector and the first coating layer; and / or, when the fourth coating layer is located between the negative electrode composite current collector and the third coating layer, the ammonium zeolite in the positive and negative electrode sheets is located on the contact surface of the active material layer and the current collector. The high melting point and thermal stability of the ammonium zeolite can effectively inhibit the occurrence of thermal runaway of the electrode sheet during the charge and discharge process of the battery, especially under extreme conditions such as high temperature or high rate charge and discharge. The ammonium zeolite can also act as an insulating barrier layer to prevent the electrode material from directly contacting the current collector due to particle shedding during use, thereby improving the safety performance of the battery. However, the internal resistance of the electrode sheet will also increase accordingly. In order to avoid the energy loss of the battery during the charge and discharge process caused by the increase in internal resistance, a suitable content of a conductive agent and a bonding agent can be added to the second coating layer and the fourth coating layer to firmly bond the second coating layer and the fourth coating layer to the current collector while maintaining a small resistance, so that the charge and discharge rate performance and the safety performance are in a good balance.

[0075] In some embodiments of the present application, when the ammonium zeolite is blended with the positive and negative electrode active materials in the form of a filler to form positive and negative electrode active material layers, the positive and negative electrode sheets can be prepared by the following method:

[0076] The active material, conductive agent, bonding agent and ammonium zeolite are dispersed in a solvent to form a slurry. The slurry is coated on one side or both sides of the surface of the current collector, and after drying and cold pressing processes, the electrode sheet is obtained.

[0077] In some embodiments of the present application, when the ammonium zeolite exists in the positive and negative electrode active material layers in the form of a separate coating layer, the positive and negative electrode sheets can be prepared by the following method:

[0078] The active material, the conductive agent and the binder are dispersed in a solvent to form a first slurry; the ammoniated zeolite and the binder are dispersed in a solvent to form a second slurry; the first slurry and the second slurry are double-coated on one side or both sides of the current collector, and after drying and cold pressing, the pole piece is obtained. Further, the conductive agent can be added to the second slurry to improve the conductivity of the ammoniated zeolite coating.

[0079] It can be understood that double-coating has higher coating efficiency. However, the pole piece can also be formed by layered coating, that is, one layer of slurry is coated first, and after drying and cold pressing, another layer of slurry is coated, and then the pole piece is obtained after secondary drying and cold pressing.

[0080] The two preparation methods of the positive and negative pole pieces given above can use N-methyl pyrrolidone (NMP) or deionized water as the homogenate solvent. When the active material is a positive active material and the current collector is a positive composite current collector, a positive pole piece is prepared; when the active material is a negative active material and the current collector is a negative composite current collector, a negative pole piece is prepared.

[0081] In some embodiments of the present application, the mass content of ammoniated zeolite in the separator is 90wt%-98wt%. Illustratively, the mass content of ammoniated zeolite in the separator can be 90wt%, 91wt%, 92wt%, 93wt%, 94wt%, 95wt%, 96wt%, 97wt%, 98wt%, or a range formed by any two of the foregoing values. Too little content of ammoniated zeolite in the separator will make it difficult to effectively improve the electrochemical performance of the battery. However, too much content of ammoniated zeolite will also adversely affect the performance of the separator. On the one hand, too much ammoniated zeolite will densely accumulate inside the separator, occupy the pore space of the separator, reduce the porosity of the separator, increase the difficulty of electrolyte infiltration in the separator, and affect the cycle performance of the battery; on the other hand, too much ammoniated zeolite will also increase the contact resistance between particles, reduce the overall ionic conductivity of the separator, and affect the rate performance of the battery.

[0082] Further, the separator in the embodiments of the present application includes a base film and an ammoniated zeolite coating layer provided on one side or both sides of the base film. The ammoniated zeolite is provided in the form of a coating layer on the surface of the base film, which not only helps the transmission of ammonium ions by maintaining the original pore structure of the base film, but also improves the mechanical properties and high-temperature stability of the separator, promotes the diffusion of ammonium ions in the separator, and improves the ion transport performance of the separator.

[0083] In some embodiments of the present application, the ammoniated zeolite coating layer includes ammoniated zeolite and a binder in a mass ratio of (90-98):(2-10) to achieve firm adhesion of the ammoniated zeolite coating layer to the base film. The type of the binder can be the same as that of the binder in the positive and negative active material layers described above, which will not be described again here.

[0084] As non-limiting examples, the material of the base film includes, but is not limited to, polypropylene (PP) and / or polyethylene (PE).

[0085] In some embodiments of the present application, the thickness of the base film is 12-20 µm, and / or the thickness of the ammoniated zeolite coating is 0.2-1.0 µm. Controlling the thickness of the base film and the ammoniated zeolite coating within the above ranges is advantageous for the membrane to have excellent mechanical properties, high-temperature stability, and ion transport performance. For example, the thickness of the base film can be 12 µm, 13 µm, 14 µm, 15 µm, 16 µm, 17 µm, 18 µm, 19 µm, 20 µm, or a range defined by any two of the foregoing values, and the thickness of the ammoniated zeolite coating can be 0.2 µm, 0.3 µm, 0.4 µm, 0.5 µm, 0.6 µm, 0.7 µm, 0.8 µm, 0.9 µm, 1.0 µm, or a range defined by any two of the foregoing values.

[0086] Figure 1 For the positive and negative composite current collectors and structures in embodiments of the present application, as shown in FIG. 1, the positive and negative composite current collectors of the present application include a first conductive layer 101, a second conductive layer 102, and a third conductive layer 103 arranged in sequence. Figure 1 The two ends of the current collector usually need to be welded with tabs to connect the current collector with an external circuit. Since the materials of the middle layer and the upper and lower surface layers of the sandwich structure current collector are different, different welding processes are required during welding, and usually different welding methods such as reflow soldering and ultrasonic roll bonding need to be combined to complete the welding of the tabs.

[0087] In some embodiments of the present application, to simplify the welding method of the tabs, the second conductive layer 102 includes a first region A and a second region B at the two ends, and a middle region C between the first region A and the second region B;

[0088] The materials of the first conductive layer 101, the third conductive layer 103, and the second conductive layer 102 in the first region A and the second region B are all metal or all carbon materials.

[0089] The material of the second conductive layer 102 in the middle region C includes a polymer.

[0090] The positive and negative electrode composite current collectors with the above structure, the first region A and the second region B at the end are used for welding the tab. The material of the second conductive layer 102 at the first region A and the second region B is metal or carbon material, which can solve the problem of difficult welding of the sandwich structure composite current collector. The material of the current collector in the welding area is the same or similar, and the process such as transfer welding and ultrasonic roll welding is not needed. The second conductive layer 102 at the first region A and the second region B can form an electrical connection with the first conductive layer 101 and the third conductive layer 103, avoiding the abnormal heating problem of the battery at a large rate caused by the non-conductive polymer in the middle region C, and making the battery have excellent electrochemical performance, energy density and safety performance.

[0091] As non-limiting examples, the metal includes, but is not limited to, one or more of Cu, Ti, Al, Ag and stainless steel, and the carbon material includes, but is not limited to, one or more of carbon black, graphite, carbon fiber, graphene and carbon nanotube.

[0092] As non-limiting examples, the polymer of the second conductive layer 102 in the middle region C includes, but is not limited to, one or more of polyethylene terephthalate (PET), polypropylene (PP) and polyimide (PI).

[0093] In some embodiments of the present application, the thickness of the first conductive layer 101 and the third conductive layer 103 is 0.5-10 μm, and the thickness of the second conductive layer 102 is 4-10 μm. For example, the thickness of the first conductive layer 101 and the third conductive layer 103 can be 0.5 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm or a range formed by any two of the above values; the thickness of the second conductive layer 102 can be 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm or a range formed by any two of the above values. The thickness of each layer can be adjusted within the above range according to the different requirements of the battery conductivity, safety performance and energy density.

[0094] The length of the first region A and the second region B is not particularly limited in the present application, as long as it is sufficient for welding the tab. For example, the length of the first region A and the second region B is equal, and the total length of the two can be 2-8 cm, specifically 2 cm, 3 cm, 4 cm, 5 cm, 6 cm, 7 cm, 8 cm or a range formed by any two of the above values.

[0095] Figure 2 A structure diagram of the second conductive layer in the middle region in the embodiments of the present application is shown in FIG. 1. Figure 2As shown, the second conductive layer 102 located in the middle region C includes N conductive pieces 104, N≥1; the N conductive pieces 104 are arranged at intervals and the gap between adjacent two conductive pieces 104 is filled with polymer; the N conductive pieces 104 penetrate through the first surface and the second surface of the second conductive layer 102;

[0096] The first surface is the surface where the second conductive layer 102 contacts the first conductive layer 101, and the second surface is the surface where the second conductive layer 102 contacts the third conductive layer 103.

[0097] Wherein, the N conductive pieces 104 penetrating through the first surface and the second surface of the second conductive layer 102 means that the thickness of the N conductive pieces 104 is equal to the thickness of the second conductive layer 102 and is flush with the upper and lower surfaces of the second conductive layer 102. By such arrangement, the second conductive layer 102 in the middle region C can be mainly composed of polymer while forming electrical connection with the first conductive layer 101 and the third conductive layer 103, so as to further improve the electrical conductivity of the composite current collector.

[0098] The number of the conductive pieces 104 is not limited in the present application, which can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, etc.

[0099] The shape of the conductive pieces 104 is not particularly limited in the present application, which can be a circular column or a rectangular column, and the side length or diameter of the column can be 20-100 μm. For example, it can be specifically 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm or a range formed by any two of the foregoing values.

[0100] The material of the conductive pieces 104 is not particularly limited in the present application, as long as it has electrical conductivity. The material of the conductive pieces 104 can be the same as or different from that of the first conductive layer 101 and the third conductive layer 103, and the specific type can refer to the material of the first conductive layer 101 and the third conductive layer 103 as described above, which will not be repeated here.

[0101] Further, the N conductive pieces 104 are fixed on the support plate, Figure 3 Another structure diagram of the second conductive layer located in the middle region in the embodiment of the present application is shown in FIG. 3B, which is similar to FIG. 3A, and the difference is that the N conductive pieces 104 are fixed on the support plate 105. Figure 3 As shown, the support plate 105 is arranged between the first surface and the second surface of the second conductive layer 102 for fixing the N conductive pieces 104, and the thickness of the support plate 105 is less than the thickness of the second conductive layer 102.

[0102] Figure 4 Another structure diagram of the second conductive layer located in the middle region in the embodiment of the present application is shown in FIG. 3B, which is similar to FIG. 3A, and the difference is that the N conductive pieces 104 are fixed on the support plate 105. Figure 3 The top view of the support plate of the second conductive layer located in the middle region is shown in FIG. 4B, which is similar to FIG. 4A, and the difference is that the N conductive pieces 104 are fixed on the support plate 105. Figure 4As shown, the support plate 105 includes M through holes, M ≥ 1, and the M through holes are filled with polymers.

[0103] The support plate 105 is used to fix the N conductive members 104, which facilitates the preparation of the composite current collector. The material of the support plate 105 can be the same as that of the first conductive layer 101 and the third conductive layer 103, which is conducive to the electrical connection of the composite current collector, and the material of the first conductive layer 101 and the third conductive layer 103 has higher mechanical strength and better fixing performance than the polymer material.

[0104] Further, a single conductive member 104 can be fixed between two adjacent through holes of the support plate 105, which can avoid occupying the space of the polymer in the through hole while achieving fixation.

[0105] The number of through holes in the support plate 105 is not limited in the present application, which can be 1, 3, 5, 7, 9, 11, 13, 15, etc.

[0106] The thickness of the support plate 105 can be smaller than that of the second conductive layer 102 to avoid excessive occupation of the polymer volume, and the thickness of the support plate 105 is not limited in the present application, as long as it can play a good fixing role. As a non-limiting example, the thickness of the support plate 105 can be 2-3 μm smaller than that of the second conductive layer 102.

[0107] The shape of the M through holes is not limited in the present application, which can be circular or rectangular, the diameter or side length of the through hole can be 50-500 μm, and the distance between two adjacent through holes can be 400-4000 μm. For example, the diameter or side length of the through hole can be 50 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, 500 μm, or a range formed by any two of the above values, and the distance between two adjacent through holes can be 40 μm, 1000 μm, 1500 μm, 2000 μm, 2500 μm, 3000 μm, 3500 μm, 4000 μm, 4500 μm, 5000 μm.

[0108] In some embodiments of the present application, the following methods can be used to prepare the positive and negative composite current collectors:

[0109] The precursor of the second conductive layer 102 is fixed in a mold, and then the molten polymer is poured into the second region C of the second conductive layer 102 to form the second conductive layer 102; the precursor of the second conductive layer 102 is the second conductive layer from which the polymer is removed;

[0110] The second conductive layer 102 is transferred to the cavity of the magnetron sputtering, and the cavity is vacuumed to (2-8) × 10-5 Pa, under 100-300 W power, to form the positive and negative composite current collectors.

[0111] The ammonium-ion battery provided in the present application further comprises an electrolyte, which has the function of conducting ions between the positive electrode sheet and the negative electrode sheet. The type of electrolyte is not particularly limited in the present application, and it can be selected according to the electrolyte commonly used in ammonium-ion batteries as needed, including but not limited to an aqueous solution taking one or more of NH4TFSI, NH4Ac, NH4OTF, (NH4)2SO4, NH4Cl as electrolyte salt, wherein the concentration of ammonium ions in the electrolyte can be 0.5-25 mol / L. For example, the concentration of ammonium ions in the electrolyte can be 0.5 mol / L, 1.0 mol / L, 5 mol / L, 10 mol / L, 15 mol / L, 20 mol / L, 25 mol / L or a range formed by any two of the foregoing values.

[0112] In some embodiments of the present application, the ammonium-ion battery can be prepared in the following way:

[0113] The positive electrode sheet, the separator and the negative electrode sheet are stacked in sequence, and after injecting the electrolyte, they are packaged in an outer packaging shell to obtain the ammonium-ion battery.

[0114] The outer packaging shell can be a hard shell or a soft package. The hard shell includes but is not limited to one or more of a hard plastic layer, an aluminum shell, a steel shell, and the soft package includes but is not limited to one or more of an aluminum plastic film, a PI film, and a PET film.

[0115] The ammonium-ion battery provided in the present application can also form a battery module, which can be composed of one battery monomer or a plurality of battery monomers. Those skilled in the art can select the appropriate number of battery monomers according to the application and capacity of the battery module.

[0116] In the present application, unless otherwise specified, "battery monomer" refers to a basic unit capable of realizing the mutual conversion of chemical energy and electrical energy. Further, in general, it at least includes a set of positive electrode sheet, separator, negative electrode sheet and electrolyte.

[0117] The second aspect of the application also provides a power utilization device, which comprises the ammonium ion battery provided by the application. The ammonium ion battery can be used as a power supply of the power utilization device or as an energy storage unit of the power utilization device. The power utilization device can include a mobile device, an electric vehicle, an electric train, a ship and a satellite, an energy storage system, etc., but is not limited thereto. The mobile device can be a mobile phone, a notebook computer, etc., for example; the electric vehicle can be 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., but is not limited thereto.

[0118] Hereinafter, the ammonium ion battery provided by the application will be described in detail in combination with specific examples. The examples described below are exemplary and are only used to explain the application and cannot be understood as a limitation of the application. If a technology or condition is not specified in the examples, the technology or condition described in the literature in the art or according to the product manual is used. If the reagent or instrument used is not specified by the manufacturer, it is a conventional product that can be obtained by purchase.

[0119] Example 1

[0120] The present example provides an ammonium ion battery, and a preparation method thereof includes the following steps:

[0121] 1. Preparation of ammoniated zeolite

[0122] 0.01 moL of clinoptilolite with a particle size of 200 nm was immersed in a 5 mol / L NH4Cl aqueous solution for 4 h to obtain ammoniated zeolite with a particle size of 200 nm, which was then dried at 80°C for 12 h for standby use.

[0123] 2. Preparation of positive electrode composite current collector

[0124] The positive electrode composite current collector comprises a first conductive layer, a second conductive layer and a third conductive layer which are sequentially stacked, wherein the structure of the second conductive layer is shown in Figure 2 and Figure 3 The materials of the conductive member 104 and the support plate 105 in the first area A, the second area B and the intermediate area C in the second conductive layer 102 are all metal Ag, the material of the part of the second conductive layer 102 in the intermediate area C except the conductive member 104 and the support plate 105 is polymer PET, and the part of the second conductive layer 102 except the polymer in the intermediate area C is the precursor of the second conductive layer 102;

[0125] The Ag metal piece with a width of 135 cm and a thickness of 6 μm is laser etched to form a second conductive layer 102 precursor, wherein the thickness of the conductive piece 104 in the first area A, the second area B and the intermediate area C in the second conductive layer 102 precursor is 6 μm, the length of the first area A and the second area B is 4 cm, the support plate 105 is located at the middle position of the upper and lower surfaces of the second conductive layer 102 precursor, and the thickness is 3 μm, the through hole shape is a circular hole, the circular hole diameter is 200 μm, the spacing between adjacent two holes is 1000 μm, and the conductive piece 104 is arranged at the midpoint between the adjacent two through holes, and the shape of the conductive piece 104 is a cylindrical shape, and the cylindrical diameter is 40 μm;

[0126] The second conductive layer 102 precursor is placed in a mold, and after the PET is melted at 300 ℃, it is poured into the intermediate area C, and after cooling and shaping, the second conductive layer 102 is obtained.

[0127] The second conductive layer 102 is transferred to a magnetron sputtering cavity, the cavity is vacuumed to 4×10 -5 Pa, Ar gas is introduced at 60 sccm, the working pressure is adjusted to 2.5 Pa, the power is 180 W, and Ti metal with a thickness of 1 μm is sputtered on the upper and lower surfaces of the second conductive layer 102 to obtain a positive composite current collector.

[0128] 3. Preparation of negative electrode composite current collector

[0129] The preparation steps of the negative electrode composite current collector are basically the same as those of the positive electrode composite current collector, except that the thickness of the conductive piece 104 in the first area A, the second area B and the intermediate area C in the second conductive layer 102 is 4.5 μm, the thickness of the support plate 105 is 2.5 μm, and the polymer in the intermediate area C of the second conductive layer 102 is PP, and the melting pouring temperature of the PP is 220 ℃.

[0130] The above-mentioned second conductive layer 102 is transferred to a magnetron sputtering cavity, the cavity is vacuumed to 4×10 -5 Pa, Ar gas is introduced at 40 sccm, the working pressure is adjusted to 2 Pa, the power is 220 W, and Cu metal with a thickness of 1 μm is sputtered on the upper and lower surfaces of the second conductive layer 102 to obtain a negative composite current collector.

[0131] 4. Preparation of positive plate

[0132] The surface of the N-FeMnHCF is coated with a conductive carbon material by magnetron sputtering to form a carbon coating layer with a thickness of 20 nm to obtain carbon-coated N-FeMnHCF; wherein the conditions for magnetron sputtering are: the cavity is vacuumed to 4×10 -5Ar gas was introduced at 20 sccm, the working pressure was 0.3 Pa, the power was 35 W, and the coating deposition was carried out in DC mode.

[0133] Carbon-coated N-FeMnHCF, acetylene black, PVDF, and ammonium zeolite prepared in step 1 were mixed in a mass ratio of 70:15:10:5. After adding NMP solvent and homogenizing, the slurry was coated on both sides of the positive electrode composite current collector prepared in step 2. After vacuum drying at 80°C for 24 hours, the positive electrode sheet was obtained.

[0134] 5. Preparation of negative electrode sheet

[0135] Mo2B2, acetylene black, PVDF, and ammonium zeolite prepared in step 1 were mixed in a mass ratio of 70:10:10:10. NMP solvent was added to form a homogenate, which was then coated onto both sides of the negative electrode composite current collector prepared in step 3. After vacuum drying at 80°C for 24 hours, a negative electrode sheet was obtained.

[0136] 6. Preparation of the diaphragm

[0137] The ammonium zeolite and PVDF obtained in step 1 were added to NMP at a mass ratio of 95:5 to form a slurry. The slurry was then coated on both sides of a PE base film with a thickness of 14µm using an extrusion coating method. After drying in a vacuum oven at 100℃ for 24h, a diaphragm with a thickness of 15µm was obtained.

[0138] 7. Preparation of electrolyte

[0139] NH4TFSI was dissolved in deionized water to form an aqueous solution of NH4TFSI with an ammonium ion concentration of 21 mol / L, which was then used as the electrolyte.

[0140] 8. Battery manufacturing

[0141] The positive electrode, separator, and negative electrode are stacked in sequence in the battery casing, with the separator acting as a separator between the positive and negative electrodes. After injecting electrolyte, the battery is encapsulated to obtain an ammonium ion battery.

[0142] Example 2

[0143] The preparation method of the ammonium ion battery in this embodiment is basically the same as that in Embodiment 1. The difference is that the materials of the second conductive layer 102 in the positive and negative current collectors are PET and PP, respectively. There is no need to prepare a precursor for the second conductive layer 102. The PET and PP films of the same thickness can be used directly as the second conductive layer 102, and the first conductive layer 101 and the third conductive layer 103 can be magnetron sputtered on its upper and lower surfaces.

[0144] Example 3

[0145] The preparation method of the ammonium ion battery of the present embodiment is basically the same as that of Embodiment 1, except that the positive electrode active material is replaced from carbon-coated N-FeMnHCF to N-FeMnHCF without carbon coating.

[0146] Embodiment 4

[0147] The preparation method of the ammonium ion battery of the present embodiment is basically the same as that of Embodiment 1, except that in the preparation of the positive electrode sheet, ammoniated zeolite is not added, and the mass ratio of carbon-coated N-FeMnHCF, acetylene black, and PVDF is 75:15:10.

[0148] Embodiment 5

[0149] The preparation method of the ammonium ion battery of the present embodiment is basically the same as that of Embodiment 1, except that in the preparation of the negative electrode sheet, ammoniated zeolite is not added, and the mass ratio of Mo2B2, acetylene black, and PVDF is 80:10:10.

[0150] Embodiment 6

[0151] The preparation method of the ammonium ion battery of the present embodiment is basically the same as that of Embodiment 1, except that a PE-based film with a thickness of 14 µm is directly used as the separator.

[0152] Embodiment 7

[0153] The preparation method of the ammonium ion battery of the present embodiment is basically the same as that of Embodiment 1, except that:

[0154] In the preparation of the positive electrode sheet, carbon-coated N-FeMnHCF, acetylene black, and PVDF are mixed in a mass ratio of 75:15:10, NMP solvent is added for homogenization, and a first positive electrode slurry is formed. The first positive electrode slurry is coated on the two side surfaces of the positive electrode composite current collector, vacuum dried at 80°C for 24h, and a first coating layer is formed. Ammoniated zeolite, CMC, and SBR are mixed in a mass ratio of 95:2:3, deionized water is added for homogenization, and a second positive electrode slurry is formed. The second positive electrode slurry is coated on the surface of the first coating layer, vacuum dried at 80°C for 24h, and a second coating layer with a thickness of 0.5 µm is formed, thereby preparing the positive electrode sheet.

[0155] In the preparation of the negative electrode sheet, Mo2B2, acetylene black and PVDF are mixed in a mass ratio of 80:10:10, NMP solvent is added for homogenization, a first negative electrode slurry is obtained, the first negative electrode slurry is coated on the two side surfaces of the negative electrode composite current collector, vacuum drying is performed at 80°C for 24h, and a third coating layer is formed; ammonium zeolite, CMC and SBR are mixed in a mass ratio of 95:2:3, deionized water is added for homogenization, a second negative electrode slurry is obtained, the second negative electrode slurry is coated on the surface of the third coating layer, vacuum drying is performed at 80°C for 24h, and a fourth coating layer with a thickness of 0.5μm is formed, thereby obtaining the negative electrode sheet.

[0156] Example 8

[0157] The preparation method of the ammonium ion battery of the present example is basically the same as that of Example 7, except that:

[0158] In the preparation of the positive electrode sheet, the second positive electrode slurry is prepared by homogenizing ammonium zeolite, acetylene black and CMC, SBR in a mass ratio of 64:30:3:3, the second positive electrode slurry is first coated on the two side surfaces of the positive electrode composite current collector, vacuum drying is performed at 80°C for 24h, a first coating layer with a thickness of 0.5μm is formed, the first positive electrode slurry is then coated on the first coating layer, vacuum drying is performed at 80°C for 24h, and a second coating layer is formed, thereby obtaining the positive electrode sheet.

[0159] In the preparation of the negative electrode sheet, the second negative electrode slurry is prepared by homogenizing ammonium zeolite, acetylene black and CMC, SBR in a mass ratio of 64:30:3:3, the second negative electrode slurry is first coated on the two side surfaces of the negative electrode composite current collector, vacuum drying is performed at 80°C for 24h, a third coating layer with a thickness of 0.5μm is formed, the first negative electrode slurry is then coated on the third coating layer, vacuum drying is performed at 80°C for 24h, and a fourth coating layer is formed, thereby obtaining the negative electrode sheet.

[0160] Example 9

[0161] The preparation method of the ammonium ion battery of the present example is basically the same as that of Example 1, except that the particle size of the clinoptilolite used in step 1 is 50nm, and the ammonium zeolite prepared has a particle size of 50nm.

[0162] Example 10

[0163] The preparation method of the ammonium ion battery of the present example is basically the same as that of Example 1, except that the particle size of the clinoptilolite used in step 1 is 400nm, and the ammonium zeolite prepared has a particle size of 400nm.

[0164] Example 11

[0165] The preparation method of the ammonium ion battery of the present example is basically the same as that of Example 1, except that the clinoptilolite with a particle size of 500 nm is used as the raw material in step 1, and the ammoniated clinoptilolite with a particle size of 500 nm is prepared.

[0166] Example 12

[0167] The preparation method of the ammonium ion battery of the present example is basically the same as that of Example 1, except that the clinoptilolite with a particle size of 20 nm is used as the raw material in step 1, and the ammoniated clinoptilolite with a particle size of 20 nm is prepared.

[0168] Example 13

[0169] The preparation method of the ammonium ion battery of the present example is basically the same as that of Example 1, except that the clinoptilolite with a particle size of 600 nm is used as the raw material in step 1, and the ammoniated clinoptilolite with a particle size of 600 nm is prepared.

[0170] Comparative Example 1

[0171] The preparation method of the ammonium ion battery of the present example is basically the same as that of Example 1, except that the ammoniated clinoptilolite is not added in the preparation of the positive and negative electrode sheets and the separator. In the preparation of the positive electrode sheet, the mass ratio of carbon-coated N-FeMnHCF, acetylene black and PVDF is 75:15:10; in the preparation of the negative electrode sheet, the mass ratio of Mo2B2, acetylene black and PVDF is 80:10:10; in the preparation of the separator, a PE-based film with a thickness of 14 µm is directly used as the separator.

[0172] Comparative Example 2

[0173] The preparation method of the ammonium ion battery of the present example is basically the same as that of Example 1, except that the ammoniated clinoptilolite is replaced by clinoptilolite with a particle size of 200 nm that is not ammoniated in the preparation of the positive and negative electrode sheets and the separator.

[0174] Test Example

[0175] The ammonium ion batteries prepared in the above examples and comparative examples are tested for the following performances:

[0176] 1. Initial discharge capacity

[0177] At 25℃, the battery is fully charged with 1C current, and then discharged with 1C current, and the initial discharge capacity is recorded.

[0178] 2. Cycle performance

[0179] Test method: at 25℃, the battery capacity is tested for the number of cycles to decay to 80% under the charge-discharge rate of 1C / 1C and the charge-discharge voltage of 0-2.4V.

[0180] 3. Rate discharge performance

[0181] Test method: at 25℃, 1C / 1C charge-discharge, record the discharge capacity C0; then use 1C / 4C for charge-discharge, record the discharge capacity C1, and the rate discharge capacity retention rate is calculated by C1 / C0x100%.

[0182] The test results of the above performances are shown in Table 1.

[0183] Table 1

[0184]

[0185] From Table 1, the following conclusions can be drawn:

[0186] 1) Comparing Comparative Examples 1 and 2, it can be seen that after not adding conductive materials in the second conductive layer 102 of the positive and negative composite current collectors, the battery has poor conductivity, and the first discharge capacity, rate discharge capacity retention rate and cycle performance are all reduced.

[0187] 2) Comparing Comparative Examples 1 and 3, it can be seen that compared to the material without carbon coating, the battery using carbon-coated N-FeMnHCF as the positive material has improved first discharge capacity, rate discharge capacity retention rate and cycle performance, especially the cycle performance is improved more significantly.

[0188] 3) Comparing Comparative Examples 1, 4, 5 and 6, it can be seen that when ammoniated zeolite exists in the positive active material layer, negative active material layer and separator of the battery at the same time, the battery has the most excellent performance in all aspects.

[0189] 4) Comparing Comparative Examples 1, 7 and 8, it can be seen that when ammoniated zeolite is blended with other components to form an active material layer in the positive and negative electrode sheets, the battery has the most excellent first discharge capacity, rate discharge capacity retention rate and cycle performance, and the battery in which the ammoniated zeolite exists in the form of a coating on the surface of the active material layer has the second best performance, and the battery in which the ammoniated zeolite exists as a primer layer in the positive and negative electrode sheets has slightly worse performance than the other two.

[0190] 5) Comparing Comparative Examples 1, 9-13, it can be seen that when the particle size of the ammoniated zeolite is in the range of 50-500 nm, the battery has excellent first discharge capacity, rate discharge capacity retention rate and cycle performance, especially when the particle size is 200 nm and 400 nm, the battery has even better performance, and when the particle size is less than 50 nm and greater than 500 nm, the performance of the battery is reduced.

[0191] 6) By comparing Examples 1-13 with Comparative Examples 1 and 2, it can be seen that when the battery does not contain ammonium zeolite or only contains zeolite that has not been ammoniumized, the battery’s initial discharge capacity, rate discharge capacity retention rate and cycle performance are all poor, especially the battery in Comparative Example 1 that does not contain ammonium zeolite has the worst performance in all aspects.

[0192] The description of the various embodiments above tends to emphasize the differences between the various embodiments. The similarities or similarities between them can be referred to, and for the sake of brevity, they will not be repeated here.

[0193] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. An ammonium-ion battery comprising a composite current collector, characterized in that, It includes a positive electrode, a negative electrode, and a separator between the positive electrode and the negative electrode; The positive electrode sheet includes a positive electrode composite current collector and a positive electrode active material layer disposed on one or both surfaces of the positive electrode composite current collector; the negative electrode sheet includes a negative electrode composite current collector and a negative electrode active material layer disposed on one or both surfaces of the negative electrode composite current collector. At least one of the positive electrode active material layer, the negative electrode active material layer, and the separator includes ammonium zeolite; The positive electrode composite current collector and the negative electrode composite current collector each include a first conductive layer, a second conductive layer and a third conductive layer stacked sequentially, wherein the material of the second conductive layer includes a polymer.

2. The ammonium-ion battery including a composite current collector according to claim 1, characterized in that, The particle size of the ammonium zeolite is 50nm~500nm.

3. The ammonium-ion battery including a composite current collector according to claim 1 or 2, characterized in that, The mass content of ammonium zeolite in the positive electrode active material layer is 2wt%~10wt%; And / or, the mass content of ammonium zeolite in the negative electrode active material layer is 5wt%~20wt%; And / or, the mass content of ammonium zeolite in the diaphragm is 90wt%~98wt%.

4. The ammonium-ion battery including a composite current collector according to claim 3, characterized in that, The positive electrode active material layer comprises a positive electrode active material, a conductive agent, a binder, and ammonium zeolite in a mass ratio of (60~80):(10~20):(5~15):(3~7); And / or, the negative electrode active material layer comprises a negative electrode active material, a conductive agent, a binder, and ammonium zeolite in a mass ratio of (60~80):(5~15):(5~15):(5~15); And / or, the diaphragm includes a base membrane and an ammonium zeolite coating disposed on one or both surfaces of the base membrane.

5. The ammonium-ion battery including a composite current collector according to claim 4, characterized in that, The positive electrode active material layer includes a first coating and a second coating stacked together. The first coating includes a positive electrode active material, a conductive agent and a binder, and the second coating includes ammonium zeolite. And / or, the negative electrode active material layer includes a third coating and a fourth coating stacked together, the third coating including a negative electrode active material, a conductive agent and a binder, and the fourth coating including ammonium zeolite.

6. The ammonium-ion battery including a composite current collector according to claim 4 or 5, characterized in that, The positive electrode active material includes a manganese-based Prussian blue material with a carbon coating layer; And / or, the negative electrode active material includes a two-dimensional transition metal boride.

7. The ammonium-ion battery comprising a composite current collector according to any one of claims 1, 2, 4 or 5, characterized in that, The second conductive layer includes a first region and a second region located at both ends, and an intermediate region located between the first region and the second region; The first conductive layer, the third conductive layer, and the second conductive layer located in the first region and the second region are all made of metal or carbon material; The material of the second conductive layer located in the intermediate region includes a polymer.

8. The ammonium-ion battery including a composite current collector according to claim 7, characterized in that, The second conductive layer located in the intermediate region includes N conductive elements, where N ≥ 1; the N conductive elements are spaced apart and the gap between two adjacent conductive elements is filled with the polymer; the N conductive elements penetrate the first surface and the second surface of the second conductive layer; The first surface is the surface where the second conductive layer and the first conductive layer are in contact, and the second surface is the surface where the second conductive layer and the third conductive layer are in contact.

9. The ammonium-ion battery including a composite current collector according to claim 8, characterized in that, The N conductive components are fixed to the support plate, which is disposed between the first and second surfaces of the second conductive layer; the thickness of the support plate is less than the thickness of the second conductive layer. The support plate includes M through holes, where M ≥ 1, and the M through holes are filled with the polymer.

10. An electrical device, characterized in that, The ammonium-ion battery including the composite current collector as described in any one of claims 1-9.

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