Battery, ion supplementing material and preparation method thereof, diaphragm and preparation method thereof, and electric device

Abstract

The invention relates to the technical field of batteries, in particular to a battery, an ion supplementing material and a preparation method thereof, a diaphragm and a preparation method thereof, and an electric device. The battery comprises a diaphragm, the diaphragm comprises an ion supplementing material, the ion supplementing material comprises a core layer structure and a coating layer arranged on the surface of the core layer structure, channels are formed in the coating layer, the core layer structure comprises an ion supplementing compound, the chemical formula of the ion supplementing compound is A < 4-d > x M < 1 > x M < 2 > n Z < 2-y > O < y + > (t / 2) n, A comprises at least one of Na and Li, M1 comprises cation elements of an oxide inorganic ceramic material, z comprises at least one of S and Se, M2 comprises at least one of V, Cr, Fe, Co, Ni and Nb, d and t are valence states of M1 and M2 elements respectively, x is larger than or equal to 0.3 and smaller than or equal to 0.5, y is larger than or equal to 0.6 and smaller than or equal to 2, n is larger than or equal to 0 and smaller than or equal to 0.15, and (2-y) and n are not 0 at the same time. The ion supplementing compound can be decomposed to generate A ions and the inorganic ceramic material, and the coating layer can enable the A ions to be slowly released into the electrolyte, so that the cycle performance of the battery is effectively improved.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to a battery, an ion-replenishing material and its preparation method, a separator and its preparation method, and an electrical device. Background Technology

[0002] With the rapid growth of portable electronic devices, electric vehicles, and other technologies, the demand for power batteries is also constantly increasing. Among these, the electrochemical performance of batteries is receiving increasing attention.

[0003] Due to irreversible reactions such as the formation of the solid electrolyte membrane (SEI film) on the negative electrode surface during the first charge-discharge formation process, the positive electrode material will experience ion loss. For example, in sodium-ion batteries, there will be sodium ion loss, which will lead to a decrease in the battery's initial coulombic efficiency and energy density. Summary of the Invention

[0004] The main objective of this invention is to provide a battery, an ion-replenishing material and its preparation method, a separator and its preparation method, and an electrical device, which aim to improve the cycle performance of the battery.

[0005] To achieve the above objectives, the present invention proposes a battery comprising a separator, wherein the separator includes an ion-replenishing material, the ion-replenishing material comprising a core layer structure and a coating layer disposed on the surface of the core layer structure, the core layer structure comprising an ion-replenishing compound, the chemical formula of the ion-replenishing compound being A. 4-dx M1 x M2 n Z 2-y O y+(t / 2)n Wherein, A includes at least one of Na and Li, M1 includes a cationic element of oxide inorganic ceramic material, Z includes at least one of S and Se, M2 includes at least one of V, Cr, Fe, Co, Ni, and Nb, d represents the valence state of the element corresponding to M1, t represents the valence state of the element corresponding to M2, the range of x is 0.3≤x≤0.5, the range of y is 0.6≤y≤2, the range of n is 0≤n≤0.15, and (2-y) and n are not both 0.

[0006] By placing the aforementioned ion-replenishing material in the battery separator, the ion-replenishing compound can decompose to generate A ions and inorganic ceramic materials. M2 and / or Z can catalyze the decomposition of the ion-replenishing compound, and the coating layer can slowly release A ions into the electrolyte, effectively improving the battery's cycle performance.

[0007] Furthermore, the ion-supplementing compound A 4-dx M1 x M2 n Z 2-y O y+(t / 2)nM2 and / or Z in the compound can increase the active sites of the ionized compound and catalyze its decomposition.

[0008] Meanwhile, inorganic ceramic materials have certain heat resistance and hardness, which can improve the heat resistance and puncture resistance of batteries and effectively improve the cycle performance of batteries.

[0009] It is understandable that ionic compound A... 4-dx M1 x M2 n Z 2-y O y+(t / 2)n In this process, Z (at least one of S and Se) replaces part of the O element lattice and coordinates with metal A and M1 elements, increasing the degree of lattice ion mixing. This allows Z to increase the active sites of the ion-complementing compound and enhance its catalytic decomposition performance.

[0010] Ionic compound A 4-dx M1 x M2 n Z 2-y O y+(t / 2)n M2 (at least one of V, Cr, Fe, Co, Ni, Nb) forms atomic clusters, thereby enabling M2 to increase the active sites of the ion compound and catalyze the decomposition of the ion compound.

[0011] It is understandable that Z and M2, which have catalytic effects, can improve the decomposition and conversion rate of ion-complemented compounds, that is, improve the utilization rate of ion-complemented compounds.

[0012] Optionally, the cationic element of the oxide inorganic ceramic material includes at least one of Si, Ti, Zr, Al, and Mg.

[0013] Ionic compound A 4-dx M1 x M2 n Z 2-y O y+(t / 2)n M1 in the formula includes at least one of Si, Ti, Zr, Al, and Mg. During the decomposition of ion-compounds, inorganic ceramic materials containing M1 can be produced, such as alumina, zirconium oxide, magnesium oxide, and silicon dioxide. These inorganic ceramic materials can improve the battery's heat resistance and high-strength puncture resistance.

[0014] Optionally, the pore size of the coating layer ranges from 0.5 nm to 1 nm.

[0015] The pore size of the coating layer ranges from 0.5 nm to 1 nm to allow ions to pass through, enabling A ions generated from the decomposition of the ion-complementing compound in the core layer structure to pass through the coating layer.

[0016] Optionally, the coating layer comprises a polymer material.

[0017] Polymer materials have abundant pores, and when ion-compensating materials are coated onto the membrane, the porosity of the membrane can be improved.

[0018] It is also understandable that ion-compounds can be fully decomposed at a certain potential. Due to the coating of the polymer, the polymer has poor conductivity and a low potential, resulting in a slow decomposition rate of the ion-compounds. To solve this problem, Z and / or M2 are used to increase the active sites of the ion-compounds, thereby catalyzing their full decomposition.

[0019] Optionally, the volume average particle size D50 of the ion-supplementing material ranges from 3 μm to 5 μm.

[0020] Optionally, the volume average particle size D50 of the core layer structure ranges from 0.5 μm to 3 μm.

[0021] Optionally, the coating layer completely covers the surface of the core layer structure.

[0022] The volume average particle size D50 of the ion-replenishing material is in the range of 3 μm to 5 μm. This improves the filtration performance during the preparation of the ion-replenishing slurry, enhances the coating performance, and addresses the issue of reduced rate performance during charge and discharge when large ion-replenishing materials are coated on electrodes or base films. It is understood that larger particle sizes extend the ion transport path, resulting in reduced rate performance.

[0023] In addition, when coating the ion-replenishing material onto the diaphragm, excessively large particle size can affect the diaphragm's air permeability. Using the aforementioned ion-replenishing material with a volume average particle size D50 can improve the diaphragm's air permeability.

[0024] The volume average particle size D50 of the core-layer structure is within the range of 0.5 μm to 3 μm. It is understood that a smaller particle size reduces the ion diffusion path, thereby lowering the ion diffusion time constant. Therefore, a reduced time constant means faster ion diffusion, thus improving the rate of release. The core-layer structure includes a replenishing ion compound. Ions generated from the decomposition of the replenishing ion compound pass through the coating layer and reach the electrolyte. The coating layer allows for the slow release of ions from the decomposition of the replenishing ion compound into the electrolyte. To improve the release rate, the volume average particle size D50 of the core-layer structure is set within the aforementioned range, enabling ions from the decomposition of the replenishing ion compound to quickly reach the vicinity of the coating layer. Ions within the coating layer can quickly respond to the ion concentration gradient outside the coating layer, increasing the release rate, timely replenishing ions consumed in the electrolyte, and improving battery performance.

[0025] In addition, if the particle size is too small, it is easy to agglomerate and have poor dispersibility, which is not conducive to the preparation of ion-supplementing materials with uniform particle size during the preparation process. The volume average particle size D50 of the above-mentioned core layer structure helps to obtain ion-supplementing materials with uniform particle size during the preparation process.

[0026] The coating layer completely covers the surface of the core structure. Theoretically, there is no limitation on how the coating layer is disposed on the surface of the ion-replenishing material. For example, the coating layer can be disposed discontinuously on the surface of the ion-replenishing material. For instance, the coating layer includes multiple shells, which are disposed discontinuously on the surface of the ion-replenishing material. In order to reduce the probability of the ion-replenishing material coming into direct contact with the electrolyte and to reduce the problem of the ion-replenishing material releasing the ions it generates directly into the electrolyte, it is preferable that the coating layer completely covers the surface of the ion-replenishing material.

[0027] Optionally, the polymer material includes at least one of polyvinylidene fluoride, polyamide, polytetrafluoroethylene, polycarbonate, polyethersulfone, and polypropylene.

[0028] Considering the solvent environment of the electrolyte inside the battery, general polymers have poor stability in solvents. To solve this problem, the polymers in this application include at least one of polyvinylidene fluoride, polyamide, polytetrafluoroethylene, polycarbonate, polyethersulfone, and polypropylene. These materials will not react and decompose in electrolyte solvents such as ethylene carbonate, diethyl carbonate, and dimethyl carbonate, and have a semi-permeable membrane function. As the ion-replenishing compound decomposes, when the concentration of ions generated is higher than the concentration of the electrolyte, the ions in the coating layer are replenished into the electrolyte through the pores in the coating layer, playing a role in the slow release of ion replenishment.

[0029] Optionally, the battery includes a positive electrode material, which includes a ternary positive electrode material.

[0030] Understandably, ternary cathode materials consume ions faster during battery cycling and require more ions to replenish them. The ion-replenishing material in this solution can replenish the ions lost in the ternary cathode material over a long period of time, which is beneficial to maintaining the long-term cycle performance of the ternary battery system.

[0031] The ternary cathode material is a layered lithium nickel cobalt manganese (aluminum) oxide composite material.

[0032] Optionally, the battery includes a separator, the separator including a base film and an ion-replenishing layer disposed on at least one side of the base film, the ion-replenishing layer including the ion-replenishing material.

[0033] It is understandable that placing the ion-replenishing material on the separator is more effective than placing it on the positive electrode. Specifically, coating the ion-replenishing material slurry on the positive electrode will affect the ion insertion and extraction of the positive electrode, while coating it on the separator will have a smaller impact. Furthermore, the core layer structure of the ion-replenishing material can decompose to produce inorganic ceramic materials, which can improve the heat resistance and puncture resistance of the separator. In addition, the coating layer of the ion-replenishing material has good air permeability.

[0034] Optionally, the ion-replenishing layer is disposed on the side of the base film facing the positive electrode.

[0035] Theoretically, the ion replenishment layer can be placed on either side of the base film, with preference given to the positive electrode side. The reason why the ion replenishment layer is preferred to be placed on the positive electrode side is that the ion replenishment layer on the positive electrode side is closer to the positive electrode, which is conducive to the rapid arrival of ions released in the ion replenishment layer to the surface of the positive electrode coating, thereby achieving rapid replenishment of ions in the positive electrode material.

[0036] Optionally, the thickness of the ion-supplementing layer is from 0.5 μm to 6 μm.

[0037] When the thickness of the ion replenishing layer is within the above range, it can improve the problem of insufficient ion replenishment when the ion replenishing layer is too thin, and the problem of the ion replenishing layer affecting the membrane performance when the ion replenishing layer is too thick.

[0038] Optionally, this application also provides an ion-replenishing material, the ion-replenishing material comprising a core layer structure and a coating layer disposed on the surface of the core layer structure, the coating layer having channels formed therein, the core layer structure comprising an ion-replenishing compound, the chemical formula of the ion-replenishing compound being A. 4-dx M1 x M2 n Z 2-y O y+(t / 2)n ;

[0039] Wherein, A includes at least one of Na and Li, M1 includes a cationic element of oxide inorganic ceramic material, Z includes at least one of S and Se, M2 includes at least one of V, Cr, Fe, Co, Ni, and Nb, d represents the valence state of the element corresponding to M1, t represents the valence state of the element corresponding to M2, the range of x is 0.3≤x≤0.5, the range of y is 0.6≤y≤2, the range of n is 0≤n≤0.15, and (2-y) and n are not both 0.

[0040] Optionally, the ion-supplementing material satisfies at least one of the following conditions:

[0041] The cationic element of the oxide inorganic ceramic material includes at least one of Si, Ti, Zr, Al, and Mg;

[0042] The aperture of the channel ranges from 0.5 nm to 1 nm;

[0043] The coating layer comprises a polymer material;

[0044] The volume average particle size D50 of the ion-compensating material ranges from 3 μm to 5 μm.

[0045] The volume average particle size D50 of the core layer structure ranges from 0.5 μm to 3 μm;

[0046] The coating layer completely covers the surface of the core layer structure.

[0047] Optionally, the polymer material includes at least one of polyvinylidene fluoride or polyamide.

[0048] Optionally, this application also provides a method for preparing the aforementioned ion-supplementing material, comprising:

[0049] The precursor is prepared by mixing the supplementary ion source, oxide inorganic ceramic material, and catalyst source.

[0050] The precursor was sintered in an inert atmosphere to obtain a core-layer structure;

[0051] A coating layer is prepared on the surface of the core layer structure.

[0052] In the preparation of ion-supplementing materials (A 4-dx M1 x M2 n Z 2-y O y+(t / 2)n In the process, a supplementary ion source, an oxide inorganic ceramic material, and a catalyst source are mixed to prepare a precursor. The precursor is then sintered in an inert atmosphere to obtain a core-layer structure. Through sintering, the supplementary ion source, the oxide inorganic ceramic material, and the catalyst source form a supplementary ion material. The Z element in the catalyst source replaces part of the O element lattice and coordinates with the metal A element and M1 element, increasing the degree of lattice ion mixing. This allows the Z element in the catalyst source of the formed supplementary ion material to catalyze the decomposition of the supplementary ion material.

[0053] It is understandable that simply mixing a supplementary ion source, an oxide inorganic ceramic material, and a catalyst source results in a mixture, in which the catalyst source does not have the effect of catalyzing the decomposition of the supplementary ion source. Furthermore, simply mixing several raw materials to obtain mixed particles, during the process of forming a coating layer on the particle surface, results in either a coating layer covering the supplementary ion source material, a coating layer covering the inorganic ceramic material, a coating layer covering the catalyst source, or a coating layer covering a mixture of several raw materials; the ion-supplementing material of this application cannot be obtained.

[0054] Optionally, the step of preparing the coating layer on the surface of the core layer structure includes: mixing the core layer structure with a polymer solution, adding a coagulant, stirring, heating, filtering and drying to obtain an ion-replenishing material for coating the surface of the core layer structure.

[0055] After mixing the core layer structure with the polymer solution, a coagulant is added so that the polymer forms a coating layer on the surface of the core layer structure under the action of the coagulant. The polymer solution alone does not have the ability to spontaneously coat the core layer.

[0056] Furthermore, the core layer structure needs to be mixed with the polymer solution before adding the coagulant. Mixing first is to ensure that the core layer structure is evenly dispersed in the polymer solution. If the coagulant is added to the core layer structure and the polymer solution together, the core layer structure will begin to coat before it is evenly dispersed, which is not conducive to the formation of a uniform ion-supplementing material.

[0057] A coagulant is a compound that causes polymers to aggregate on the surface of an ion-replenishing compound, forming polymers. Coagulants improve the overall integrity of the polymer coating on the ion-replenishing compound surface, increasing the stability of the coating layer. This makes it difficult for the ion-replenishing compound to be exposed from the coating layer, forcing ions generated from the decomposition of the ion-replenishing compound to pass through the coating layer into the electrolyte, thus allowing ions to slowly replenish the electrolyte.

[0058] In addition, the coagulant does not participate in the network structure formed by the polymer during the polymer film formation process, but is dissolved in the solution and filtered out by filtration.

[0059] Optionally, the polymer solution is a saturated solution.

[0060] The polymer in this application is a saturated solution, which helps to coat the core layer structure surface more fully, for example, it is beneficial to form a fully coated layer structure on the core layer structure surface.

[0061] Optionally, the coagulant includes at least one of aluminum sulfate, ferrous sulfate, alum, and ferric chloride.

[0062] The coagulant in this application includes at least one of aluminum sulfate, ferrous sulfate, alum, and ferric chloride.

[0063] Optionally, in the step of mixing the core layer structure with a polymer solution, adding a coagulant, stirring, heating, filtering and drying to obtain an ion-replenishing material with a coating layer on the surface of the core layer structure, the heating temperature range is 23°C to 27°C, and the heating time range is 2h to 6h.

[0064] The process of forming a coating layer on the surface of the core layer structure includes mixing the core layer structure with a polymer solution, adding a coagulant, stirring, and heating. The heating temperature range is 23°C to 27°C, and the heating time range is 2 hours to 6 hours. Under the above temperature and time range, the polymer can be effectively coated on the surface of the core layer structure under the action of the coagulant.

[0065] Optionally, the supplementary ion source includes at least one of a sodium source or a lithium source, wherein the sodium source includes at least one of Na2CO3, NaNO3, Na2SO4, sodium acetate, sodium formate, sodium acetate, and sodium isopropionate, and the sodium source includes one or more of sodium hydroxide, sodium nitrate, sodium carbonate, sodium acetate, and sodium sulfate.

[0066] Optionally, the oxide inorganic ceramic material includes at least one or more of SiO2, TiO2, ZrO2, Al2O3, and MgO.

[0067] Optionally, the catalyst source includes at least one of Na2S, Li2S, Li2Se, Na2Se, metal oxides of V, metal oxides of Cr, metal oxides of Fe, metal oxides of Co, metal oxides of Ni, and metal oxides of Nb.

[0068] The supplementary ion source in this application includes at least one of sodium source or lithium source. The sodium source includes at least one of Na2CO3, NaNO3, Na2SO4, sodium acetate, sodium formate, sodium acetate, and sodium isopropionate. The sodium source also includes one or more of sodium hydroxide, sodium nitrate, sodium carbonate, sodium acetate, and sodium sulfate.

[0069] The oxide inorganic ceramic materials in this application include at least one or more of SiO2, TiO2, ZrO2, Al2O3, and MgO.

[0070] The catalytic source in this application includes at least one of Na2S, Li2S, Li2Se, Na2Se, metal oxides of V, metal oxides of Cr, metal oxides of Fe, metal oxides of Co, metal oxides of Ni, and metal oxides of Nb.

[0071] Optionally, the molar ratio of ions in the supplementary ion source to cations in the oxide inorganic ceramic material is (4 to 10):1;

[0072] Optionally, the volume average particle size D50 of the oxide inorganic ceramic material ranges from 100 nm to 20 μm.

[0073] In this application, the molar ratio of ions in the supplementary ion source to cations in the oxide inorganic ceramic material is (4 to 10):1.

[0074] In this application, the volume average particle size D50 of the oxide inorganic ceramic material ranges from 100 nm to 20 μm. It is understood that the particle size of the oxide inorganic ceramic material affects the sintering efficiency and uniformity. When the volume average particle size D50 of the oxide inorganic ceramic material is within the above range, the sintering efficiency and the uniformity of the core layer structure preparation can be improved. For example, when the volume average particle size D50 of the oxide inorganic ceramic material is in the range of 500 nm to 10 μm, the sintering efficiency and uniformity are even higher.

[0075] Optionally, the step of sintering the precursor in an inert atmosphere to obtain a core-layer structure includes sintering the precursor in an inert atmosphere at 500°C to 1000°C for 3 to 10 hours, and breaking the sintered product into a core-layer structure with a volume average particle size D50 of 0.5 μm to 3 μm.

[0076] In this application, the precursor sintering step includes sintering the precursor at 500°C to 1000°C for 3 to 10 hours under an inert atmosphere, resulting in the sintering product being broken down into a core-layer structure with a volume average particle size (D50) of 0.5 μm to 3 μm. Furthermore, considering that excessively small particle sizes are prone to agglomeration and poor dispersibility, setting the volume average particle size (D50) of the core-layer structure within the aforementioned range yields a uniformly dispersed core-layer structure, which is beneficial for preparing uniformly sized ion-compensating materials. Moreover, the volume average particle size (D50) of the core-layer structure within this range facilitates the coating of an ion-compensating coating of appropriate thickness onto the membrane. It is understood that when coating the ion-compensating material onto the membrane, a certain thickness is required. If the core-layer structure particle size is too large, it will result in a larger particle size of the ion-compensating material, making it inconvenient to prepare a coating of appropriate thickness when coating the ion-compensating material onto the membrane.

[0077] Optionally, this application also provides a diaphragm, the diaphragm comprising a base membrane and an ion-replenishing layer disposed on at least one side of the base membrane, the ion-replenishing layer being provided with the ion-replenishing material as described above, or the ion-replenishing layer being provided with an ion-replenishing material prepared by the method described above.

[0078] It is understandable that placing the ion-replenishing material on the separator is more effective than placing it on the positive electrode. Specifically, coating the ion-replenishing material slurry on the positive electrode will affect the ion insertion and extraction of the positive electrode, while coating it on the separator will have a smaller impact. Furthermore, the core layer structure of the ion-replenishing material can decompose to produce inorganic ceramic materials, which can improve the heat resistance and puncture resistance of the separator. In addition, the coating layer of the ion-replenishing material has good air permeability.

[0079] Theoretically, the ion replenishment layer can be placed on either side of the base film, with preference given to the positive electrode side. The reason why the ion replenishment layer is preferred to be placed on the positive electrode side is that the ion replenishment layer on the positive electrode side is closer to the positive electrode, which is conducive to the rapid arrival of ions released in the ion replenishment layer to the surface of the positive electrode coating, thereby achieving rapid replenishment of ions in the positive electrode material.

[0080] Optionally, the thickness of the ion-supplementing layer is from 0.5 μm to 6 μm.

[0081] When the thickness of the ion replenishing layer is within the above range, it can improve the problem of insufficient ion replenishment when the ion replenishing layer is too thin, and the problem of the ion replenishing layer affecting the membrane performance when the ion replenishing layer is too thick.

[0082] Optionally, this application also provides a method for preparing the diaphragm as described above, comprising:

[0083] Prepare the ion-compensating material as described above, or prepare the ion-compensating material prepared by the method described above.

[0084] The ion-compensating material, binder, and solvent are mixed and stirred to form a slurry, which is then coated onto a base membrane and dried to obtain a diaphragm.

[0085] A diaphragm can be prepared by coating the ion-supplementing material onto a base membrane.

[0086] Optionally, the mass ratio of the ion-replenishing material to the total mass of the ion-replenishing material and the binder ranges from 88% to 98%.

[0087] Optionally, the adhesive includes at least one of aqueous acrylic emulsion, styrene-butadiene rubber emulsion, and polyacrylic acid.

[0088] The amount of ion-replenishing material and binder used will affect the air permeability of the diaphragm. When the mass of the ion-replenishing material is within the above-mentioned range as a proportion of the total mass of the ion-replenishing material and binder, the air permeability of the diaphragm can be improved.

[0089] The adhesives used in this application include at least one of waterborne acrylic emulsions, styrene-butadiene rubber emulsions, and polyacrylic acids.

[0090] Optionally, this application also provides a battery, the battery comprising the ion-replenishing material as described above;

[0091] Alternatively, the battery may comprise an ion-compensating material prepared by the method described above.

[0092] Alternatively, the battery may include a separator as described above;

[0093] Alternatively, the battery may comprise a separator prepared by the method described above.

[0094] Optionally, this application also provides an electrical device, which includes the battery as described above.

[0095] The battery of this application includes a separator, which includes an ion-replenishing material. The ion-replenishing material includes a core layer structure and a coating layer disposed on the surface of the core layer structure. The core layer structure includes an ion-replenishing compound with the chemical formula A.4- dx M1 x M2 n Z 2-y O y+(t / 2)n Wherein, A includes at least one of Na and Li, M1 includes a cationic element of the oxide inorganic ceramic material, Z includes at least one of S and Se, M2 includes at least one of V, Cr, Fe, Co, Ni, and Nb, d represents the valence state of the element corresponding to M1, t represents the valence state of the element corresponding to B, x ranges from 0.3 to 0.5, y ranges from 0.6 to 2, n ranges from 0 to 0.15, and (2-y) is not simultaneously 0 with n. The ion-replenishing compound can decompose to produce A ions and inorganic ceramic materials. The coating layer allows A ions to be slowly released into the electrolyte. At the same time, M2 and / or Z can increase the active sites of the ion-replenishing compound and catalyze its decomposition. The inorganic ceramic material has certain heat resistance and hardness, which can improve the heat resistance and puncture resistance of the battery and effectively improve the cycle performance of the battery. Attached Figure Description

[0096] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0097] Figure 1 This is a schematic diagram of the structure of the ion-supplementing material according to one embodiment of this application;

[0098] Figure 2 This is a schematic diagram of the diaphragm structure according to one embodiment of this application;

[0099] Figure 3 This is a schematic diagram of the structure of a battery cell according to one embodiment of this application;

[0100] Figure 4 yes Figure 3 An exploded view of a battery cell according to one embodiment of this application is shown.

[0101] Figure 5 This is a schematic diagram of a battery module according to one embodiment of this application;

[0102] Figure 6 This is a schematic diagram of a battery pack according to one embodiment of this application;

[0103] Figure 7 yes Figure 6 An exploded view of a battery pack according to one embodiment of this application is shown;

[0104] Figure 8 This is a schematic diagram of an electrical device in which a single battery cell is used as a power source according to one embodiment of this application.

[0105] Explanation of icon numbers:

[0106]

[0107]

[0108] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0109] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0110] The following detailed description, with appropriate reference to the accompanying drawings, discloses the ion-supplementing material and its preparation method, the separator and its preparation method, the battery, and the power supply device of this application. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repetitive descriptions of practically identical structures may be omitted. This is to avoid unnecessarily lengthy descriptions and to facilitate understanding by those skilled in the art. Furthermore, the accompanying drawings and the following description are provided for the purpose of enabling those skilled in the art to fully understand this application and are not intended to limit the subject matter of the claims.

[0111] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also included. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this article; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0112] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0113] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0114] Unless otherwise specified, all steps in this 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 it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0115] Due to irreversible reactions such as the formation of the solid electrolyte membrane (SEI film) on the negative electrode surface during the first charge-discharge formation process, the positive electrode material will experience ion loss. For example, in sodium-ion batteries, there will be sodium ion loss, which will lead to a decrease in the battery's initial coulombic efficiency and energy density.

[0116] To address the aforementioned technical problems, this application provides a battery including a separator containing an ion-replenishing material, aimed at improving the battery's cycle performance. It is understood that ion loss occurs in the electrolyte during battery formation, and the ion-replenishing material described in this application can be used to replenish ions in the electrolyte.

[0117] The ion-supplementing material comprises a core layer structure and a coating layer disposed on the surface of the core layer structure. The coating layer contains channels. The core layer structure includes an ion-supplementing compound with the chemical formula A. 4-dx M1 x M2 n Z 2-y O y+(t / 2)n Wherein, A includes at least one of Na and Li, M1 includes a cationic element of oxide inorganic ceramic material, Z includes at least one of S and Se, M2 includes at least one of V, Cr, Fe, Co, Ni, and Nb, d is the valence state of the element corresponding to M1, t represents the valence state of the element corresponding to B, the range of x is 0.3≤x≤0.5, the range of y is 0.6≤y≤2, the range of n is 0≤n≤0.15, and (2-y) and n are not both 0.

[0118] The core layer structure is shown below. Figure 1 As shown, an ion-supplementing material 10 has a core-layer structure 12 located within the coating layer 11.

[0119] The coating layer, a substance placed on the surface of the core layer structure, has a coating function. That is, the coating layer has pores that allow ions to pass through, allowing ions to diffuse in and out of the coating layer. In other words, ions generated by the decomposition of the ion-replenishing compound can reach the electrolyte through the pores, thus achieving the slow release and replenishment of ions.

[0120] M1 includes the cationic elements in oxide inorganic ceramic materials; for example, the chemical formula of oxide inorganic ceramic materials is M1. d / 2 O d d represents the valence state of the element corresponding to M1, O represents the anion, and M1 represents the cation.

[0121] Considering that excessive ion replenishment during battery ion replenishment can lead to excessively high ion content, further affecting electrolyte kinetics, while insufficient ion content does not significantly improve long-term battery performance, the ion replenishment material of this application has a coating layer on the surface of the core layer structure. The coating layer contains channels, and the core layer structure includes an ion replenishment compound. During battery formation and cycling, the ion replenishment compound decomposes to generate A ions (A includes at least one of Na and Li) and inorganic ceramic materials. The A ions replenish ions lost in the battery. Based on the coating layer, the ions generated by the decomposition of the ion replenishment compound are slowly released into the electrolyte. Specifically, for example, taking sodium ions as an example, when the concentration of sodium ions from the decomposition of the ion replenishment compound is higher than the concentration of sodium ions in the electrolyte, the sodium ions within the coating layer are replenished into the electrolyte through the coating layer, playing a role in slow-release sodium replenishment, extending the replenishment time of ions in the electrolyte, and mitigating the problem of excessively high ion content affecting electrolyte kinetics.

[0122] Furthermore, the ion-supplementing compound A 4-dx M1 x M2 n Z 2-y O y+(t / 2)n M2 and / or Z in the compound can increase the active sites of the ion-complement compound, catalyze the decomposition of the ion-complement compound, and improve the utilization rate of the ion-complement compound.

[0123] Meanwhile, inorganic ceramic materials possess certain heat resistance and hardness, which can improve the battery's heat resistance and puncture resistance, effectively enhancing its cycle performance. Specifically, inorganic ceramic materials include at least one of the traditional heat-resistant and high-strength puncture-resistant materials such as alumina, zirconium oxide, magnesium oxide, and silicon dioxide; inorganic ceramic materials derived from the decomposition products of ionized compounds can improve the high-temperature shrinkage performance and dendrite puncture resistance of the separator, thereby improving battery safety performance.

[0124] It is understandable that ionic compound A... 4-dx M1 x M2 n Z 2-y O y+(t / 2)n The Z element in the lattice replaces part of the O element and coordinates with the metal A and M elements, increasing the degree of lattice ion mixing. This allows Z to increase the active sites of the ion-complementing compound and enhance its catalytic decomposition performance.

[0125] Ionic compound A 4-dx M1 x M2 n Z 2-y O y+(t / 2)n M2 forms atomic clusters, thereby enabling M2 to increase the active sites of the ionized compound and catalyze the decomposition of the ionized compound.

[0126] In the above 0.3≤x≤0.5, the values ​​include the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Specific examples include, but are not limited to, the point values ​​in the embodiments, as well as 0.3, 0.4, 0.5, etc., and the range values ​​between any two of the above point values.

[0127] In the above 0.6≤y≤1, the values ​​include the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Specific examples include, but are not limited to, the point values ​​in the embodiments, as well as 0.6, 0.7, 0.8, 0.9, 1, etc., and the range values ​​between any two of the above point values.

[0128] In one embodiment, the cationic element of the oxide inorganic ceramic material includes at least one of Si, Ti, Zr, Al, and Mg.

[0129] Ionic compound A 4-dx M1 x M2 n Z 2-y O y+(t / 2)n M1 in the formula includes at least one of Si, Ti, Zr, Al, and Mg. During the decomposition of ion-compounds, inorganic ceramic materials containing M1 can be produced, such as alumina, zirconium oxide, magnesium oxide, and silicon dioxide. These inorganic ceramic materials can improve the battery's heat resistance and high-strength puncture resistance.

[0130] In one embodiment, the pore size of the coating layer channels ranges from 0.5 nm to 1 nm.

[0131] The pore size of the coating layer is in the range of 0.5 nm to 1 nm to allow ions to pass through, so that A ions generated by the decomposition of the ion-complementing compound in the core layer structure can pass through the coating layer.

[0132] Understandably, a scanning electron microscope (SEM) can be used to measure the pore size of the coating layer. The instrument model used is a field emission SEM: SU8010 (HITACHI, Japan). The testing procedure is as follows: SEM images are captured, and the working distance of the field emission SEM is set to 8.5 mm. Because the coating material is non-conductive and exhibits significant charging, different accelerating voltages and gold sputtering methods are used to obtain clear, uncharged images. Three accelerating voltages were selected: 20, 25, and 30 kV. The ion sputtering conditions were a platinum target, a sputtering current of 150 mA, and a sputtering time of 300 s. After ion sputtering, the same three accelerating voltages were used to observe the sample. To analyze the pore size of the sample, ImageJ software was used to analyze the obtained SEM image. The specific analysis steps are as follows: Open the obtained SEM image in ImageJ software, select the original image for size calibration, enter the measured unit and size in the size settings, then select the area on the original image that does not include equipment information and scale, and click crop to obtain the image to be analyzed; When performing surface pore size analysis, first click the analysis option in the toolbar, set the measurement value, then click the image in the toolbar to adjust the threshold, then click the analysis option to analyze the particle settings, and finally obtain the pore size result of the sample through "Ferret" analysis.

[0133] The values ​​in the range of 0.5nm to 1nm include the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Specific examples include, but are not limited to, the point values ​​in the embodiments, and 0.5nm, 0.6nm, 0.7nm, 0.8nm, 0.9nm, 1nm, etc., as well as the range values ​​between any two of the above point values.

[0134] In one embodiment, the coating layer comprises a polymer material.

[0135] Polymer materials have abundant pores, and when ion-compensating materials are coated onto the membrane, the porosity of the membrane can be improved.

[0136] It is also understandable that ion-compounds can be fully decomposed at a certain potential. Due to the coating of the polymer, the polymer has poor conductivity and a low potential, resulting in a slow decomposition rate of the ion-compounds. To solve this problem, Z and / or M2 are used to increase the active sites of the ion-compounds, thereby catalyzing their full decomposition.

[0137] In one embodiment, the polymer material includes at least one selected from polyvinylidene fluoride, polyamide, polytetrafluoroethylene, polycarbonate, polyethersulfone, and polypropylene.

[0138] Considering the solvent environment of the electrolyte inside the battery, general polymers have poor stability in solvents. To solve this problem, the polymers in this application include at least one of polyvinylidene fluoride, polyamide, polytetrafluoroethylene, polycarbonate, polyethersulfone, and polypropylene. These materials will not react and decompose in electrolyte solvents such as ethylene carbonate, diethyl carbonate, and dimethyl carbonate, and have a coating layer function. As the ion-replenishing compound decomposes, when the concentration of ions generated is higher than the concentration of the electrolyte, the ions in the coating layer are replenished into the electrolyte through the pores of the coating layer, playing a role in slow-release ion replenishment.

[0139] In one embodiment, the volume average particle size D50 of the ion-supplementing material ranges from 3 μm to 5 μm; and / or, the volume average particle size D50 of the core-layer structure ranges from 0.5 μm to 3 μm; and / or, the coating layer completely covers the surface of the core-layer structure.

[0140] The volume average particle size D50 of the ion-replenishing material is in the range of 3 μm to 5 μm. This improves the filtration performance during the preparation of the ion-replenishing slurry, enhances the coating performance, and addresses the issue of reduced rate performance during charge and discharge when large ion-replenishing materials are coated on electrodes or base films. It is understood that larger particle sizes extend the ion transport path, resulting in reduced rate performance.

[0141] In addition, when coating the ion-replenishing material onto the diaphragm, excessively large particle size can affect the diaphragm's air permeability. Using the aforementioned ion-replenishing material with a volume average particle size D50 can improve the diaphragm's air permeability.

[0142] The volume average particle size D50 of the core-layer structure is within the range of 0.5 μm to 3 μm. It is understood that a smaller particle size reduces the ion diffusion path, thereby lowering the ion diffusion time constant. Therefore, a reduced time constant means faster ion diffusion, thus improving the rate of release. The core-layer structure includes a replenishing ion compound. Ions generated from the decomposition of the replenishing ion compound pass through the coating layer and reach the electrolyte. The coating layer allows for the slow release of ions from the decomposition of the replenishing ion compound into the electrolyte. To improve the release rate, the volume average particle size D50 of the core-layer structure is set within the aforementioned range, enabling ions from the decomposition of the replenishing ion compound to quickly reach the vicinity of the coating layer. Ions within the coating layer can quickly respond to the ion concentration gradient outside the coating layer, increasing the release rate, timely replenishing ions consumed in the electrolyte, and improving battery performance.

[0143] In addition, if the particle size is too small, it is easy to agglomerate and have poor dispersibility, which is not conducive to the preparation of ion-supplementing materials with uniform particle size during the preparation process. The volume average particle size D50 of the above-mentioned core layer structure helps to obtain ion-supplementing materials with uniform particle size during the preparation process.

[0144] The coating layer completely covers the surface of the core structure. Theoretically, there is no limitation on how the coating layer is disposed on the surface of the ion-replenishing material. For example, the coating layer can be disposed discontinuously on the surface of the ion-replenishing material. For instance, the coating layer includes multiple shells, which are disposed discontinuously on the surface of the ion-replenishing material. In order to reduce the probability of the ion-replenishing material coming into direct contact with the electrolyte and to reduce the problem of the ion-replenishing material releasing the ions it generates directly into the electrolyte, it is preferable that the coating layer completely covers the surface of the ion-replenishing material.

[0145] D50 is the particle size at which the cumulative particle size distribution percentage of a sample reaches 50%. Physically, it means that 50% of the particles are larger than D50, and 50% are smaller. D50 is also called the median diameter or median particle size. D50 is often used to represent the average particle size of powders.

[0146] The values ​​in the range of 3μm to 5μm include the minimum and maximum values ​​of this range, as well as every value between the minimum and maximum values. Specific examples include, but are not limited to, the point values ​​in the embodiments, as well as 3μm, 3.5μm, 4μm, 4.5μm, 5μm, etc., and the range values ​​between any two of the above point values.

[0147] The values ​​in the range of 0.5μm to 3μm include the minimum and maximum values ​​of this range, as well as every value between the minimum and maximum values. Specific examples include, but are not limited to, the point values ​​in the embodiments, and 0.5μm, 0.7μm, 0.9μm, 1μm, 1.5μm, 2μm, 2.5μm, 3μm, etc., as well as the range values ​​between any two of the above point values.

[0148] In one embodiment, the battery includes a positive electrode material, which includes a ternary positive electrode material.

[0149] Understandably, ternary cathode materials consume ions faster during battery cycling and require more ions to replenish them. The ion-replenishing material in this solution can replenish the ions lost in the ternary cathode material over a long period of time, which is beneficial to maintaining the long-term cycle performance of the ternary battery system.

[0150] The ternary cathode material is a layered lithium nickel cobalt manganese (aluminum) oxide composite material.

[0151] In one embodiment, the battery includes a separator, the separator including a base film and an ion-replenishing layer disposed on at least one side of the base film, the ion-replenishing layer including the ion-replenishing material.

[0152] It is understandable that placing the ion-replenishing material on the separator is more effective than placing it on the positive electrode. Specifically, coating the ion-replenishing material slurry on the positive electrode will affect the ion insertion and extraction of the positive electrode, while coating it on the separator will have a smaller impact. Furthermore, the core layer structure of the ion-replenishing material can decompose to produce inorganic ceramic materials, which can improve the heat resistance and puncture resistance of the separator. In addition, the coating layer of the ion-replenishing material has good air permeability.

[0153] In one embodiment, the ion replenishing layer is disposed on the side of the base film facing the positive electrode.

[0154] Theoretically, the ion replenishment layer can be placed on either side of the base film, with preference given to the positive electrode side. The reason why the ion replenishment layer is preferred to be placed on the positive electrode side is that the ion replenishment layer on the positive electrode side is closer to the positive electrode, which is conducive to the rapid arrival of ions released in the ion replenishment layer to the surface of the positive electrode coating, thereby achieving rapid replenishment of ions in the positive electrode material.

[0155] In one embodiment, the thickness of the ion-supplementing layer is 0.5 μm to 6 μm.

[0156] When the thickness of the ion replenishing layer is within the above range, it can improve the problem of insufficient ion replenishment when the ion replenishing layer is too thin, and the problem of the ion replenishing layer affecting the membrane performance when the ion replenishing layer is too thick.

[0157] In one embodiment, this application also provides an ion-replenishing material, which includes a core layer structure and a coating layer disposed on the surface of the core layer structure. The coating layer has channels formed therein. The core layer structure includes an ion-replenishing compound with the chemical formula A. 4-dx M1 x M2 n Z 2-y O y+(t / 2)n Wherein, A includes at least one of Na and Li, M1 includes a cationic element of oxide inorganic ceramic material, Z includes at least one of S and Se, M2 includes at least one of V, Cr, Fe, Co, Ni, and Nb, d represents the valence state of the element corresponding to M1, t represents the valence state of the element corresponding to M2, the range of x is 0.3≤x≤0.5, the range of y is 0.6≤y≤2, the range of n is 0≤n≤0.15, and (2-y) and n are not both 0.

[0158] In one embodiment, the ion-replenishing material satisfies at least one of the following conditions: the cationic element of the oxide inorganic ceramic material includes at least one of Si, Ti, Zr, Al, and Mg; the pore size ranges from 0.5 nm to 1 nm; the coating layer includes a polymer material; the volume average particle size D50 of the ion-replenishing material ranges from 3 μm to 5 μm; the volume average particle size D50 of the core layer structure ranges from 0.5 μm to 3 μm; and the coating layer completely covers the surface of the core layer structure.

[0159] In one embodiment, the polymer material includes at least one of polyvinylidene fluoride or polyamide.

[0160] In one embodiment, a method for preparing a supplementary ion material is also provided, comprising: mixing a supplementary ion source, an oxide inorganic ceramic material, and a catalyst source to obtain a precursor; sintering the precursor under an inert atmosphere to obtain a core-layer structure; and preparing a coating layer on the surface of the core-layer structure.

[0161] A supplementary ion source is used to introduce supplementary ion elements into the core structure, for example, to form a supplementary ion compound A. 4-dx M1 x M2 n Z 2-y O y+(t / 2)n Element A in the text.

[0162] Oxide inorganic ceramic materials are used to introduce cationic elements into the core layer structure of oxide inorganic ceramic materials, for example, to form ion-complementing compound A. 4-dx M1 x M2 n Z 2-y O y+(t / 2)n The M1 element in the text.

[0163] A catalytic source, used to introduce catalytic elements into the core structure, for example, to form an ion-complementing compound A. 4- dx M1 x M2 n Z 2-y O y+(t / 2)n The M2 and / or Z elements in the dataset.

[0164] In the preparation of ion-supplementing materials (A 4-dx M1 x M2 n Z 2-y O y+(t / 2)n In the process of preparation, a supplementary ion source, an oxide inorganic ceramic material, and a catalyst source are mixed to obtain a precursor. The precursor is then sintered in an inert atmosphere to obtain a core-layer structure. Through sintering, the supplementary ion source, inorganic ceramic material, and catalyst source form a supplementary ion material. The Z element in the catalyst source replaces part of the O element lattice and coordinates with the metal A element and M1 element, increasing the degree of lattice ion mixing. This allows the Z element in the catalyst source in the formed supplementary ion material to catalyze the decomposition of the supplementary ion material. Alternatively, the M2 element in the catalyst source forms atomic clusters, thereby increasing the active sites of the supplementary ion compound, improving the performance of catalyzing the decomposition of the supplementary ion compound, and increasing the utilization rate of the supplementary ion compound.

[0165] It is understandable that simply mixing a supplementary ion source, an oxide inorganic ceramic material, and a catalyst source results in a mixture, in which the catalyst source does not have the effect of catalyzing the decomposition of the supplementary ion source. Furthermore, simply mixing several raw materials to obtain mixed particles, during the process of forming a coating layer on the particle surface, results in either a coating layer covering the supplementary ion source material, a coating layer covering the oxide inorganic ceramic material, a coating layer covering the catalyst source, or a coating layer covering a mixture of several raw materials; the material described in this application cannot be obtained.

[0166] In one embodiment, the step of preparing a coating layer on the surface of a core layer structure includes: mixing the core layer structure with a polymer solution, adding a coagulant, stirring, heating, filtering and drying to obtain an ion-replenishing material for coating the surface of the core layer structure.

[0167] After mixing the core layer structure with the polymer solution, a coagulant is added so that the polymer forms a coating layer on the surface of the core layer structure under the action of the coagulant. The polymer solution alone does not have the ability to spontaneously coat the core layer.

[0168] Furthermore, the core layer structure needs to be mixed with the polymer solution before adding the coagulant. Mixing first is to ensure that the core layer structure is evenly dispersed in the polymer solution. If the coagulant is added to the core layer structure and the polymer solution together, the core layer structure will begin to coat before it is evenly dispersed, which is not conducive to the formation of a uniform ion-supplementing material.

[0169] A coagulant is a compound that causes polymers to aggregate on the surface of an ion-replenishing compound, forming polymers. Coagulants improve the overall integrity of the polymer coating on the ion-replenishing compound surface, increasing the stability of the coating layer. This makes it difficult for the ion-replenishing compound to be exposed from the coating layer, forcing ions generated from the decomposition of the ion-replenishing compound to pass through the coating layer into the electrolyte, thus allowing ions to slowly replenish the electrolyte.

[0170] In addition, the coagulant does not participate in the network structure formed by the polymer during the polymer film formation process, but is dissolved in the solution and filtered out by filtration.

[0171] In one embodiment, the polymer solution is a saturated solution. The saturated polymer solution in this application facilitates a more thorough coating layer on the surface of the core-layer structure, for example, it is beneficial for forming a fully coated layer structure on the surface of the core-layer structure.

[0172] In one embodiment, the coagulant includes at least one selected from aluminum sulfate, ferrous sulfate, alum, and ferric chloride.

[0173] In one embodiment, in the step of mixing the core layer structure with a polymer solution, adding a coagulant, stirring, heating, filtering and drying to obtain the ion-replenishing material with a coating layer on the surface of the core layer structure, the heating temperature range is 23°C to 27°C, and the heating time range is 2h to 6h.

[0174] The process of forming a coating layer on the surface of the core layer structure includes mixing the core layer structure with a polymer solution, adding a coagulant, stirring, and heating. The heating temperature range is 23°C to 27°C, and the heating time range is 2 hours to 6 hours. Under the above temperature and time range, the polymer can be effectively coated on the surface of the core layer structure under the action of the coagulant.

[0175] In one embodiment, the supplementary ion source includes at least one of a sodium source or a lithium source. The sodium source includes at least one of Na2CO3, NaNO3, Na2SO4, sodium acetate, sodium formate, sodium acetate, and sodium isopropionate. The sodium source also includes one or more of sodium hydroxide, sodium nitrate, sodium carbonate, sodium acetate, and sodium sulfate. And / or, the oxide inorganic ceramic material includes at least one or more of SiO2, TiO2, ZrO2, Al2O3, and MgO. And / or, the catalytic source includes at least one of Na2S, Li2S, Li2Se, Na2Se, metal oxides of V, metal oxides of Cr, metal oxides of Fe, metal oxides of Co, metal oxides of Ni, and metal oxides of Nb.

[0176] The supplementary ion source in this application includes at least one of sodium source or lithium source. The sodium source includes at least one of Na2CO3, NaNO3, Na2SO4, sodium acetate, sodium formate, sodium acetate, and sodium isopropionate. The sodium source also includes one or more of sodium hydroxide, sodium nitrate, sodium carbonate, sodium acetate, and sodium sulfate.

[0177] The oxide inorganic ceramic materials in this application include at least one or more of SiO2, TiO2, ZrO2, Al2O3, and MgO.

[0178] The catalytic source in this application includes at least one of Na2S, Li2S, Li2Se, Na2Se, metal oxides of V, metal oxides of Cr, metal oxides of Fe, metal oxides of Co, metal oxides of Ni, and metal oxides of Nb.

[0179] In one embodiment, the molar ratio of ions in the supplementary ion source to cations in the oxide inorganic ceramic material is (4 to 10):1; and / or, the volume average particle size D50 of the oxide inorganic ceramic material ranges from 100 nm to 20 μm.

[0180] In this application, the molar ratio of ions in the supplementary ion source to cations in the oxide inorganic ceramic material is (4 to 10):1. Furthermore, the catalytic element in the catalytic source is added in excess.

[0181] In this application, the volume average particle size D50 of the oxide inorganic ceramic material ranges from 100 nm to 20 μm. It is understood that the particle size of the oxide inorganic ceramic material affects the sintering efficiency and uniformity. When the volume average particle size D50 of the oxide inorganic ceramic material is within the above range, the sintering efficiency and the uniformity of the core layer structure preparation can be improved.

[0182] The polymer in this application is a saturated solution, which helps to form a fully encapsulated coating structure during the process of coating the core layer structure surface.

[0183] In the above (4 to 10):1, the values ​​include the minimum and maximum values ​​of the range, as well as every value between such minimum and maximum values. Specific examples include, but are not limited to, the point values ​​in the embodiments and 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, etc., as well as the range values ​​between any two of the above point values.

[0184] The values ​​in the range of 100nm to 20μm include the minimum and maximum values ​​of this range, as well as every value between the minimum and maximum values. Specific examples include, but are not limited to, the point values ​​in the embodiments, and 100nm, 200nm, 500nm, 800nm, 1μm, 2μm, 5μm, 10μm, 12μm, 15μm, 18μm, 20μm, etc., as well as the range values ​​between any two of the above point values.

[0185] In one embodiment, the step of sintering the precursor in an inert atmosphere to obtain a core-layer structure includes sintering the precursor in an inert atmosphere at 500°C to 1000°C for 3 to 10 hours, and breaking the sintered product into a core-layer structure with a volume average particle size D50 of 0.5 μm to 3 μm.

[0186] In this application, the precursor sintering step includes sintering the precursor at 500°C to 1000°C for 3 to 10 hours under an inert atmosphere, resulting in the sintering product being broken down into a core-layer structure with a volume average particle size (D50) of 0.5 μm to 3 μm. Furthermore, considering that excessively small particle sizes are prone to agglomeration and poor dispersibility, setting the volume average particle size (D50) of the core-layer structure within the aforementioned range yields a uniformly dispersed core-layer structure, which is beneficial for preparing uniformly sized ion-compensating materials. Moreover, the volume average particle size (D50) of the core-layer structure within this range facilitates the coating of an ion-compensating coating of appropriate thickness onto the membrane. It is understood that when coating the ion-compensating material onto the membrane, a certain thickness is required. If the core-layer structure particle size is too large, it will result in a larger particle size of the ion-compensating material, making it inconvenient to prepare a coating of appropriate thickness when coating the ion-compensating material onto the membrane.

[0187] The values ​​in the range of 500℃ to 1000℃ include the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Specific examples include, but are not limited to, the point values ​​in the embodiments, and 500℃, 600℃, 700℃, 800℃, 900℃, 1000℃, etc., as well as the range values ​​between any two of the above point values.

[0188] The values ​​in the range 3h to 10h include the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Specific examples include, but are not limited to, the point values ​​in the embodiments, as well as 3h, 4h, 5h, 6h, 7h, 8h, 9h, 10h, etc., and the range values ​​between any two of the above point values.

[0189] The values ​​in the range of 0.5μm to 3μm include the minimum and maximum values ​​of this range, as well as every value between the minimum and maximum values. Specific examples include, but are not limited to, the point values ​​in the embodiments, and 0.5μm, 0.7μm, 0.9μm, 1μm, 1.5μm, 2μm, 2.5μm, 3μm, etc., as well as the range values ​​between any two of the above point values.

[0190] In one embodiment, in the step of mixing the core layer structure with a polymer solution, adding a coagulant, stirring, heating, filtering and drying to obtain the ion-replenishing material with a coating layer on the surface of the core layer structure, the heating temperature range is 23°C to 27°C, and the heating time range is 2h to 6h.

[0191] The process of forming a coating layer on the surface of the core layer structure includes mixing the core layer structure with a polymer solution, adding a coagulant, stirring, and heating. The heating temperature range is 23°C to 27°C, and the heating time range is 2 hours to 6 hours. Under the above temperature and time range, the polymer can be effectively coated on the surface of the core layer structure under the action of the coagulant.

[0192] The values ​​in the range of 23°C to 27°C include the minimum and maximum values ​​of this range, as well as every value between the minimum and maximum values. Specific examples include, but are not limited to, the point values ​​in the embodiments, as well as 23°C, 24°C, 25°C, 26°C, 27°C, etc., and the range values ​​between any two of the above point values.

[0193] In one embodiment, this application also provides a diaphragm, the diaphragm including a base membrane and an ion-replenishing layer disposed on at least one side of the base membrane, the ion-replenishing layer being provided with an ion-replenishing material as described above, or the ion-replenishing layer being provided with an ion-replenishing material prepared by the method described above for preparing ion-replenishing materials.

[0194] In battery structure, the separator is one of the key internal components. The performance of the separator determines the battery's interface structure, internal resistance, and other characteristics, directly affecting its capacity, cycle life, and safety. A high-performance separator plays a crucial role in improving the overall performance of the battery. The main function of the separator is to separate the positive and negative electrodes, preventing short circuits caused by contact between them. Additionally, it allows electrolyte ions to pass through.

[0195] It is understandable that placing the ion-replenishing material on the diaphragm is more effective than placing it on the positive electrode. Specifically, coating the ion-replenishing material slurry on the positive electrode will affect the ion insertion and extraction of the positive electrode, while coating it on the diaphragm has a smaller impact. Furthermore, the core layer structure of the ion-replenishing material can decompose to produce inorganic ceramic materials, which can improve the heat resistance and puncture resistance of the diaphragm. In addition, the coating layer of the ion-replenishing material has good air permeability, which can improve the air permeability of the diaphragm.

[0196] Theoretically, the ion replenishment layer can be placed on either side of the base film, with preference given to the positive electrode side. The reason why the ion replenishment layer is preferred to be placed on the positive electrode side is that the ion replenishment layer on the positive electrode side is closer to the positive electrode, which is conducive to the rapid arrival of ions released in the ion replenishment layer to the surface of the positive electrode coating, thereby achieving rapid replenishment of ions in the positive electrode material.

[0197] like Figure 2 The diagram shown is a schematic diagram of a diaphragm structure according to an embodiment of this application. The diaphragm 100 includes a base membrane 30 and an ion replenishment layer 20 disposed on at least one side of the base membrane 30.

[0198] In one embodiment, the thickness of the ion-supplementing layer is 0.5 μm to 6 μm.

[0199] When the thickness of the ion replenishing layer is within the above range, it can improve the problem of insufficient ion replenishment when the ion replenishing layer is too thin, and the problem of the ion replenishing layer affecting the membrane performance when the ion replenishing layer is too thick.

[0200] The values ​​in the range of 0.5μm to 6μm include the minimum and maximum values ​​of this range, as well as every value between the minimum and maximum values. Specific examples include, but are not limited to, the point values ​​in the embodiments, and 0.5μm, 0.7μm, 0.9μm, 1μm, 2μm, 3μm, 4μm, 5μm, 6μm, etc., as well as the range values ​​between any two of the above point values.

[0201] In one embodiment, this application also provides a method for preparing a diaphragm, comprising: preparing an ion-replenishing material as described above, or preparing an ion-replenishing material prepared by the method described above; mixing and stirring the ion-replenishing material, binder and solvent to form a slurry, coating it on a base membrane, and drying it to obtain a diaphragm.

[0202] Adhesives are materials with adhesive properties used to bond different substances together.

[0203] The base membrane, or organic microporous membrane, refers to a membrane structure with micropores made of organic materials.

[0204] A diaphragm can be prepared by coating the ion-supplementing material onto a base membrane.

[0205] In one embodiment, the mass ratio of the ion-replenishing material to the total mass of the ion-replenishing material and the binder ranges from 88% to 98%; and / or, the binder includes at least one of aqueous acrylic emulsion, styrene-butadiene rubber emulsion, and polyacrylic acid.

[0206] The amount of ion-replenishing material and binder used will affect the air permeability of the diaphragm. When the mass of the ion-replenishing material accounts for the total mass of the ion-replenishing material and binder within the above range, the air permeability of the diaphragm can be improved, especially in the range of 93% to 97%.

[0207] The adhesives used in this application include at least one of waterborne acrylic emulsions, styrene-butadiene rubber emulsions, and polyacrylic acids.

[0208] The values ​​in the range of 88% to 98% include the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Specific examples include, but are not limited to, the point values ​​in the embodiments, and 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, etc., as well as the range values ​​between any two of the above point values.

[0209] In addition, the battery secondary battery, battery module, battery pack and power device of this application will be described below with appropriate reference to the accompanying drawings.

[0210] In one embodiment of this application, a secondary battery is provided.

[0211] Typically, a secondary battery includes a positive electrode, a negative electrode, an electrolyte, and a separator. During charging and discharging, active ions move back and forth between the positive and negative electrodes, inserting and releasing. The electrolyte acts as a conductor of ions between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, primarily prevents short circuits between the electrodes while allowing ions to pass through. The separator described above is the type used in this application.

[0212] The positive electrode includes a positive current collector and a positive electrode film layer disposed on at least one surface of the positive current collector.

[0213] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive electrode film layer is disposed on either or both of the two opposite surfaces of the positive current collector.

[0214] In some embodiments, the positive current collector may be a metal foil or a composite current collector. For example, aluminum foil may be used as the metal foil. The composite current collector may include a polymer substrate and a metal layer formed on at least one surface of the polymer substrate. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0215] In some embodiments, when the secondary battery is a lithium-ion battery, the positive electrode active material may be a positive electrode active material known in the art for lithium-ion batteries. As an example, the positive electrode active material may include at least one of the following materials: lithium phosphates with an olivine structure, lithium transition metal oxides, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as battery positive electrode active materials may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium transition metal oxides include, but are not limited to, lithium cobalt oxides (such as LiCoO2), lithium nickel oxides (such as LiNiO2), lithium manganese oxides (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxides, lithium manganese cobalt oxides, lithium nickel manganese oxides, and lithium nickel cobalt manganese oxides (such as LiNi). 1 / 3 Co 1 / 3Mn 1 / 3 O2 (also known as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM) 523 LiNi 0.5 Co 0.25Mn 0.25 O2 (also known as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM) 622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 ), lithium nickel cobalt aluminum oxide (such as LiNi) 0.85 Co 0.15 Al 0.05 At least one of O2 and its modified compounds. Examples of lithium phosphates with an olivine structure include, but are not limited to, lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium manganese iron phosphate, and lithium manganese iron phosphate and carbon composites.

[0216] During the charging and discharging process of a battery, Li undergoes insertion / extraction and consumption, resulting in varying molar Li content at different discharge states. In the examples of cathode materials in this application, the molar Li content refers to the initial state of the material, i.e., the state before feeding. When the cathode material is applied to the battery system, the molar Li content changes after charge-discharge cycles.

[0217] In the examples of cathode materials in this application, the molar content of O is only a theoretical value. Oxygen release from the crystal lattice will cause changes in the molar content of oxygen, and the actual molar content of O will fluctuate.

[0218] In some embodiments, the positive electrode film layer may optionally include a binder. As an example, the binder may include at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), PVDF-tetrafluoroethylene-propylene terpolymer, PVDF-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and fluorinated acrylate resin.

[0219] In some embodiments, the positive electrode film may optionally include a conductive agent. As an example, the conductive agent may include at least one selected from superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0220] In some embodiments, the positive electrode sheet can be prepared by dispersing the above-mentioned components for preparing the positive electrode sheet, such as positive active material, conductive agent, binder and any other components, in a solvent (e.g., N-methylpyrrolidone) to form a positive electrode slurry; coating the positive electrode slurry onto the positive electrode current collector, and then obtaining the positive electrode sheet after drying, cold pressing and other processes.

[0221] The negative electrode sheet includes a negative current collector and a negative electrode film layer disposed on at least one surface of the negative current collector, the negative electrode film layer including a negative electrode active material.

[0222] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode film layer is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0223] In some embodiments, the negative electrode current collector may be a metal foil or a composite current collector. For example, copper foil may be used as the metal foil. The composite current collector may include a polymer material substrate and a metal layer formed on at least one surface of the polymer material substrate. The composite current collector may be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0224] In some embodiments, the negative electrode active material may be a negative electrode active material known in the art for use in batteries. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, etc. Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials, and other conventional materials that can be used as negative electrode active materials for batteries may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0225] In some embodiments, the negative electrode film layer may optionally include a binder. The binder may be selected from at least one of styrene-butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA), and carboxymethyl chitosan (CMCS).

[0226] In some embodiments, the negative electrode film may optionally include a conductive agent. The conductive agent may be selected from at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0227] In some embodiments, the negative electrode film may optionally include other additives, such as thickeners (e.g., sodium carboxymethyl cellulose (CMC-Na)).

[0228] In some embodiments, the negative electrode sheet can be prepared by dispersing the components used to prepare the negative electrode sheet, such as the negative electrode active material, conductive agent, binder and any other components, in a solvent (e.g., deionized water) to form a negative electrode slurry; coating the negative electrode slurry onto the negative electrode current collector, and then obtaining the negative electrode sheet after drying, cold pressing and other processes.

[0229] The electrolyte acts as a conductor of ions between the positive and negative electrodes. This application does not specify any particular type of electrolyte; it can be selected according to requirements.

[0230] In some embodiments, the electrolyte is an electrolyte solution. The electrolyte solution includes an electrolyte salt and a solvent.

[0231] In some embodiments, the electrolyte may optionally include additives. For example, additives may include negative electrode film-forming additives, positive electrode film-forming additives, and may also include additives that can improve certain battery performance, such as additives that improve battery overcharge performance, additives that improve battery high-temperature or low-temperature performance, etc.

[0232] In some implementations, the positive electrode, negative electrode, and separator can be fabricated into an electrode assembly using a winding or stacking process.

[0233] In some embodiments, the battery cell may include an outer packaging. This outer packaging can be used to encapsulate the electrode assembly and electrolyte described above.

[0234] In some embodiments, the outer packaging of the battery cell can be a rigid shell, such as a hard plastic shell, an aluminum shell, or a steel shell. The outer packaging of the battery cell can also be a flexible package, such as a pouch. The material of the flexible package can be plastic; examples of plastics include polypropylene, polybutylene terephthalate, and polybutylene succinate.

[0235] This application does not impose any particular limitation on the shape of the battery cell; it can be cylindrical, square, or any other arbitrary shape. For example, Figure 2 The example shown is a square-structured battery cell 5.

[0236] In some implementations, refer to Figure 4The outer packaging may include a housing 51 and a cover 53. The housing 51 may include a base plate and side plates connected to the base plate, the base plate and side plates forming a receiving cavity. The housing 51 has an opening communicating with the receiving cavity, and the cover 53 can be placed over the opening to close the receiving cavity. The positive electrode, negative electrode, and separator may be formed into an electrode assembly 52 by a winding process or a stacking process. The electrode assembly 52 is encapsulated within the receiving cavity. Electrolyte is immersed in the electrode assembly 52. ​​The number of electrode assemblies 52 contained in a single battery cell 5 may be one or more, which can be selected by those skilled in the art according to specific practical needs.

[0237] In some implementations, individual battery cells can be assembled into a battery module. The number of individual battery cells contained in a battery module can be one or more, and the specific number can be selected by those skilled in the art based on the application and capacity of the battery module.

[0238] Figure 5 This is battery module 4, used as an example. (See reference...) Figure 5 In battery module 4, multiple battery cells 5 can be arranged sequentially along the length of battery module 4. Of course, they can also be arranged in any other manner. Furthermore, these multiple battery cells 5 can be fixed in place using fasteners.

[0239] Optionally, the battery module 4 may also include a housing with a receiving space in which multiple battery cells 5 are received.

[0240] In some embodiments, the battery modules described above can also be assembled into a battery pack, and the number of battery modules contained in the battery pack can be one or more, the specific number of which can be selected by those skilled in the art according to the application and capacity of the battery pack.

[0241] Figure 6 and Figure 7 This is battery pack 1 as an example. (See reference...) Figure 6 and Figure 7 The battery pack 1 may include a battery box and multiple battery modules 4 disposed within the battery box. The battery box includes an upper body 2 and a lower body 3, with the upper body 2 covering the lower body 3 to form a closed space for accommodating the battery modules 4. The multiple battery modules 4 can be arranged in any manner within the battery box.

[0242] In addition, this application also provides an electrical device, which includes at least one of the secondary battery, battery module, or battery pack provided in this application. The secondary battery, battery module, or battery pack can be used as the power source of the electrical device or as the energy storage unit of the electrical device. The electrical device may include, but is not limited to, mobile devices (e.g., mobile phones, laptops, etc.), electric vehicles (e.g., pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc.

[0243] As an electrical device, you can choose individual battery cells, battery modules, or battery packs according to your usage requirements.

[0244] Figure 8 This is an example of an electrical device. The device could be 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 individual battery cells, a battery pack or battery module can be used.

[0245] Another example device could be a mobile phone, tablet, or laptop. These devices typically require a slim and lightweight design and can use a single battery cell as their power source.

[0246] Example

[0247] Example 1

[0248] Preparation of the precursor: Deionized water was used as a solvent, and sodium nitrate (supplementary ion source) and silicon dioxide (oxide inorganic ceramic material with D50 of 2 μm) were added to it in a molar ratio of 6:1. The deionized water was used to submerge the material to mix it. After mixing evenly, sodium sulfide (catalytic source, the mass of added sodium sulfide accounts for 10% of the mass of silicon dioxide) was added. The mixture was placed in a ball mill jar and stirred and ball milled. The slurry was placed in a forced-air drying oven and baked at 80°C for 10 hours. After drying, it was crushed and sieved to obtain the precursor.

[0249] Preparation of the core layer structure: The precursor was sintered at 750℃ for 6 hours under a nitrogen atmosphere. After natural cooling, the sample was taken out, ball-milled and sieved to obtain a core layer structure with a D50 of 1 μm.

[0250] Preparation of the coating layer on the surface of the core layer structure: The core layer structure was mixed with a saturated polyamide solution (the mass ratio of the core layer structure to the saturated polyamide solution was 1:8), and an appropriate amount of aluminum sulfate (the mass ratio of the core layer structure to the core layer structure was 1:1) was added. The mixture was stirred at room temperature for 2 hours, filtered, and dried to form the ion-replenishing material (D50 of 3.5 μm) for the surface coating layer.

[0251] Preparation of slurry coating on the diaphragm: The above-mentioned ion-replenishing material and styrene-butadiene rubber latex are mixed with deionized water (the mass ratio of deionized water to ion-replenishing material and styrene-butadiene rubber latex is 70:95:5) at a mass ratio of 95:5 to form a uniform slurry. The slurry is then coated onto the base film using a microgravure plate and dried to obtain a diaphragm with an ion-replenishing layer on the base film (the thickness of the ion-replenishing layer is 3.5 μm).

[0252] Preparation of positive electrode sheet: Na3V2(PO4)2F3 positive electrode active material, PVDF binder and acetylene black conductive agent are dispersed and dissolved in NMP solvent at a mass ratio of 88:2:5:5 to form a uniformly dispersed slurry. The slurry is then uniformly coated on aluminum foil current collector, and then dried, cold pressed and cut to obtain positive electrode sheet.

[0253] Preparation of negative electrode sheet: The active material artificial graphite, conductive agent carbon black, binder styrene-butadiene rubber (SBR), and thickener sodium carboxymethyl cellulose (CMC) are dissolved in deionized water at a weight ratio of 96.2:0.8:0.8:1.2 and mixed evenly to prepare a negative electrode slurry; the negative electrode slurry is uniformly coated on the negative electrode current collector copper foil once or multiple times, and then dried, cold-pressed, and slit to obtain the negative electrode sheet.

[0254] Electrolyte preparation: In an argon atmosphere glove box (H2O<0.1ppm, O2<0.1ppm), ethylene carbonate (EC) / ethyl methyl carbonate (EMC) organic solvents were mixed evenly at a volume ratio of 3 / 7. 12.5% ​​NaPF6 sodium salt was added and dissolved in the organic solvent and stirred evenly.

[0255] Polypropylene film is used as the base film.

[0256] Battery fabrication: The positive electrode, separator, and negative electrode are stacked in sequence, with the separator positioned between the positive and negative electrodes to provide isolation. The cells are then wound to obtain a bare cell. Tabs are welded to the bare cell, which is then placed in an aluminum casing and baked at 60°C to remove moisture. Electrolyte is then injected and the casing is sealed, resulting in a non-charged battery. The non-charged battery then undergoes a series of processes including settling, hot and cold pressing, formation, shaping, and capacity testing to obtain the sodium-ion battery product of Example 1.

[0257] Example 2

[0258] Except for replacing sodium nitrate and silicon dioxide (in a molar ratio of 6:1) with sodium acetate and zirconium dioxide, the other steps in Example 2 are the same as in Example 1.

[0259] Example 3

[0260] Except for replacing sodium sulfide with sodium selenide, the other steps in Example 3 are the same as in Example 1.

[0261] Example 4

[0262] Except for replacing the molar ratio of sodium nitrate and silicon dioxide from 6:1 to 4:1, the other steps in Example 4 are the same as in Example 1.

[0263] Example 5

[0264] Except for replacing the molar ratio of sodium nitrate and silicon dioxide from 6:1 to 9.3:1, the other steps in Example 5 are the same as in Example 1.

[0265] Example 6

[0266] Except for replacing the slurry containing the ion-replenishing material and styrene-butadiene rubber latex at a mass ratio of 95:5 with a slurry at a mass ratio of 90:10, the other steps in Example 6 are the same as in Example 1.

[0267] Example 7

[0268] Based on Example 1, the precursor was prepared as follows: Deionized water was used as a solvent, and sodium nitrate (supplementary ion source) and silicon dioxide (oxide inorganic ceramic material with D50 of 2 μm) were added to it in a molar ratio of 3:1. The deionized water was used to submerge the material to mix it. After mixing evenly, sodium sulfide and V2O5 (catalytic source, the mass of added sodium sulfide accounts for 10% of the mass of silicon dioxide, and the mass of added V2O5 accounts for 5% of the mass of silicon dioxide) were added. The mixture was placed in a ball mill jar and stirred and ball-milled. The slurry was placed in a forced-air drying oven and baked at 80°C for 10 hours. After drying, it was crushed and sieved to obtain the precursor.

[0269] Example 8

[0270] Based on Example 1, the precursor was prepared as follows: Deionized water was used as a solvent, and sodium nitrate (supplementary ion source) and silicon dioxide (oxide inorganic ceramic material with D50 of 2 μm) were added to it in a molar ratio of 3:1. The deionized water was used to submerge the material to mix it. After mixing evenly, V2O5 (catalytic source, the mass of added V2O5 accounted for 10% of the mass of silicon dioxide) was added. The mixture was placed in a ball mill jar and stirred and ball milled. The slurry was placed in a forced-air drying oven and baked at 80°C for 10 hours. After drying, it was crushed and sieved to obtain the precursor.

[0271] Comparative Example 1

[0272] Except for replacing the slurry containing the ion-replenishing material and styrene-butadiene rubber latex at a mass ratio of 95:5 with a slurry containing Na2O and styrene-butadiene rubber latex at a mass ratio of 95:5, the other steps in Comparative Example 1 are the same as in Example 1.

[0273] Performance testing

[0274] Volume average particle size D50 test: Equipment model: Malvern 2000 (MasterSizer 2000) laser particle size analyzer; Reference standard procedure: GB / T19077-2016 / ISO 13320:2009; Specific test procedure: Take an appropriate amount of the sample to be tested (the sample concentration should be 8% to 12% light-blocking degree), add 20ml of deionized water, and simultaneously incubate for 5 minutes (53KHz / 120W) to ensure that the sample is completely dispersed. Then, measure the sample according to the standard GB / T19077-2016 / ISO 13320:2009.

[0275] Tests on the air permeability and heat shrinkage properties of the diaphragm: Referring to standard ISO 14616-1997 "Heat shrinkage films of polyethylene, ethylene copolymers and mixtures thereof - Determination of shrinkage stress", the FST-02 film heat shrinkage rate tester was used. The sample was cut into strips of 15mm × 130mm, and the heat shrinkage rate of the diaphragm after heat treatment at 130℃ for 30min was tested.

[0276] Battery capacity retention rate test: Taking Example 1 as an example, the battery capacity retention rate test process is as follows: At 25°C, the battery corresponding to Example 1 is charged to 4.3V at a constant current of 1 / 3C, then charged to a current of 0.05C at a constant voltage of 4.3V, rested for 5 minutes, and then discharged to 2.8V at 1 / 3C. The resulting capacity is recorded as the initial capacity C0. The above steps are repeated for the same battery, and the discharge capacity Cn of the battery after the nth cycle is recorded. Then, the battery capacity retention rate Pn after each cycle is Pn = Cn / C0 * 100%. In this test process, the first cycle corresponds to n = 1, the second cycle corresponds to n = 2, ..., the 200th cycle corresponds to n = 200. The battery capacity retention rate data corresponding to the examples and comparative examples in Tables 1 and 2 are the data measured after 600 cycles under the above test conditions.

[0277] Table 1 List of Examples

[0278]

[0279]

[0280] Table 2 Performance List

[0281]

[0282] As can be seen from the table above, comparing Example 1 and Comparative Example 1, the membrane permeability, membrane thermal shrinkage rate, and capacity retention rate after 600 cycles of Comparative Example 1 are all inferior to those of Example 1. This indicates that by adopting the scheme of this application, based on the coating layer covering the core structure, the sodium ions generated by the decomposition within the core structure can be slowly released to replenish the sodium ions in the electrolyte, thereby improving the cycle performance of the battery. Simultaneously, the inorganic ceramic material generated by the decomposition of the ion-replenishing compound helps to improve the thermal shrinkage rate of the membrane. Furthermore, comparing Example 1 and Example 6, it can be seen that the amount of ion-replenishing material and binder affects the membrane permeability. Excessive binder will clog the membrane pores, leading to a decrease in permeability. When the mass of the ion-replenishing material accounts for 93% to 97% of the total mass of the ion-replenishing material and binder, the membrane permeability is better.

[0283] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural transformations made using the contents of the specification and drawings of the present invention under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the scope of patent protection of the present invention.

Claims

1. A battery, characterized in that, The battery includes a separator, the separator comprising an ion-replenishing material, the ion-replenishing material comprising a core layer structure and a coating layer disposed on the surface of the core layer structure, the coating layer having channels formed therein, and the core layer structure comprising an ion-replenishing compound having the chemical formula A. 4-dx M1 x M2 n Z 2-y O y+(t / 2)n ; Wherein, A includes at least one of Na and Li, M1 includes a cationic element of oxide inorganic ceramic material, Z includes at least one of S and Se, M2 includes at least one of V, Cr, Fe, Co, Ni, and Nb, d represents the valence state of the element corresponding to M1, t represents the valence state of the element corresponding to M2, the range of x is 0.3≤x≤0.5, the range of y is 0.6≤y≤2, the range of n is 0≤n≤0.15, and (2-y) and n are not both 0.

2. The battery as described in claim 1, characterized in that, At least one of the following conditions must be met: The cationic element of the oxide inorganic ceramic material includes at least one of Si, Ti, Zr, Al, and Mg; The aperture of the channel ranges from 0.5 nm to 1 nm; The coating layer comprises a polymer material; The volume average particle size D50 of the ion-compensating material ranges from 3 μm to 5 μm. The volume average particle size D50 of the core layer structure ranges from 0.5 μm to 3 μm; The coating layer completely covers the surface of the core layer structure.

3. The battery as described in claim 2, characterized in that, The polymer material includes at least one of polyvinylidene fluoride, polyamide, polytetrafluoroethylene, polycarbonate, polyethersulfone, and polypropylene.

4. The battery as described in any one of claims 1 to 3, characterized in that, The battery includes a positive electrode material, which includes a ternary positive electrode material.

5. The battery as described in any one of claims 1 to 4, characterized in that, The diaphragm includes a base membrane and an ion-replenishing layer disposed on at least one side of the base membrane, wherein the ion-replenishing layer includes an ion-replenishing material.

6. The battery as described in claim 5, characterized in that, At least one of the following conditions must be met: The ion replenishing layer is disposed on the side of the base film facing the positive electrode; The thickness of the ion-supplementing layer is 0.5 μm to 6 μm.

7. An ion-compensating material, characterized in that, The ion-compensating material comprises a core layer structure and a coating layer disposed on the surface of the core layer structure. The coating layer has channels formed therein. The core layer structure comprises an ion-compensating compound with the chemical formula A. 4-dx M1 x M2 n Z 2-y O y+(t / 2)n ; Wherein, A includes at least one of Na and Li, M1 includes a cationic element of oxide inorganic ceramic material, Z includes at least one of S and Se, M2 includes at least one of V, Cr, Fe, Co, Ni, and Nb, d represents the valence state of the element corresponding to M1, t represents the valence state of the element corresponding to M2, the range of x is 0.3≤x≤0.5, the range of y is 0.6≤y≤2, the range of n is 0≤n≤0.15, and (2-y) and n are not both 0.

8. The ion-compensating material as described in claim 7, characterized in that, At least one of the following conditions must be met: The cationic element of the oxide inorganic ceramic material includes at least one of Si, Ti, Zr, Al, and Mg; The aperture of the channel ranges from 0.5 nm to 1 nm; The coating layer comprises a polymer material; The volume average particle size D50 of the ion-compensating material ranges from 3 μm to 5 μm. The volume average particle size D50 of the core layer structure ranges from 0.5 μm to 3 μm; The coating layer completely covers the surface of the core layer structure.

9. The ion-compensating material as described in claim 8, characterized in that, The polymer material includes at least one of polyvinylidene fluoride or polyamide.

10. A method for preparing an ion-compensating material as described in any one of claims 1 to 9, characterized in that, include: The precursor is prepared by mixing the supplementary ion source, oxide inorganic ceramic material, and catalyst source. The precursor was sintered in an inert atmosphere to obtain a core-layer structure; A coating layer is prepared on the surface of the core layer structure.

11. The method for preparing the ion-compensating material as described in claim 10, characterized in that, The step of preparing a coating layer on the surface of the core layer structure includes: The core layer structure is mixed with a polymer solution, a coagulant is added, the mixture is stirred, heated, filtered, and dried to obtain an ion-replenishing material with a coating layer on the surface of the core layer structure.

12. The method for preparing the ion-compensating material as described in claim 11, characterized in that, At least one of the following conditions must be met: The polymer solution is a saturated solution; The coagulant includes at least one of aluminum sulfate, ferrous sulfate, alum, and ferric chloride; In the step of mixing the core layer structure with a polymer solution, adding a coagulant, stirring, heating, filtering and drying to obtain an ion-replenishing material with a coating layer on the surface of the core layer structure, the heating temperature range is 23°C to 27°C, and the heating time range is 2h to 6h.

13. The method for preparing the ion-compensating material according to any one of claims 10 to 12, characterized in that, At least one of the following conditions must be met: The supplementary ion source includes at least one of sodium source or lithium source, wherein the sodium source includes at least one of Na2CO3, NaNO3, Na2SO4, sodium acetate, sodium formate, sodium acetate, and sodium isopropionate, and wherein the sodium source includes one or more of sodium hydroxide, sodium nitrate, sodium carbonate, sodium acetate, and sodium sulfate. The oxide inorganic ceramic material includes at least one or more of SiO2, TiO2, ZrO2, Al2O3, and MgO; The catalyst source includes at least one of Na2S, Li2S, Li2Se, Na2Se, metal oxides of V, metal oxides of Cr, metal oxides of Fe, metal oxides of Co, metal oxides of Ni, and metal oxides of Nb. The molar ratio of ions in the supplementary ion source to cationic elements in the oxide inorganic ceramic material is (4 to 10): 1; The volume average particle size D50 of the oxide inorganic ceramic material ranges from 100 nm to 20 μm. The step of sintering the precursor in an inert atmosphere to obtain a core-layer structure includes sintering the precursor in an inert atmosphere at 500°C to 1000°C for 3 to 10 hours, and breaking the sintered product into a core-layer structure with a volume average particle size D50 of 0.5 μm to 3 μm.

14. A diaphragm, characterized in that, The diaphragm includes a base membrane and an ion-replenishing layer disposed on at least one side of the base membrane. The ion-replenishing layer contains an ion-replenishing material as described in any one of claims 7 to 9, or the ion-replenishing layer contains an ion-replenishing material prepared by the method for preparing the ion-replenishing material as described in any one of claims 10 to 13.

15. The diaphragm as claimed in claim 14, characterized in that, The thickness of the ion-supplementing layer is 0.5 μm to 6 μm.

16. A method for preparing a diaphragm as described in claim 14 or 15, characterized in that, include: Prepare an ion-compensating material as described in any one of claims 7 to 9, or prepare an ion-compensating material prepared by the method for preparing an ion-compensating material as described in any one of claims 10 to 13; The ion-compensating material, binder, and solvent are mixed and stirred to form a slurry, which is then coated onto a base membrane and dried to obtain a diaphragm.

17. The method for preparing the diaphragm as described in claim 16, characterized in that, At least one of the following conditions must be met: The mass ratio of the ion-replenishing material to the total mass of the ion-replenishing material and the binder ranges from 88% to 98%. The adhesive includes at least one of water-based acrylic emulsion, styrene-butadiene rubber emulsion, and polyacrylic acid.

18. An electrical appliance, characterized in that, The electrical device includes a battery as described in any one of claims 1 to 9.

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