A nickel-metal hydride battery, a positive electrode material, and a preparation method and application thereof

Abstract

The present invention discloses a nickel-metal hydride battery, a positive electrode material thereof, a preparation method and an application thereof. The positive electrode material of the nickel-metal hydride battery comprises a component A and a component B: wherein, the component A includes: a nickel salt; a hydroxy cobalt compound; wherein, the component B includes: a titanium salt; a fluorine-containing polymer; and a solvent. The nickel-metal hydride battery of the present invention has a wide temperature range of use, a high energy density and excellent stability.

Description

Technical Field

[0001] The present invention relates to the technical field of nickel-metal hydride batteries, and particularly to a nickel-metal hydride battery, a positive electrode material thereof, a preparation method thereof, and an application thereof. Background Art

[0002] As an important type of rechargeable battery, nickel-metal hydride (NiMH) batteries have, through years of development and improvement, become an energy storage solution widely used in fields such as consumer electronics, power tools, and hybrid electric vehicles.

[0003] A nickel-metal hydride battery consists of a positive electrode, a negative electrode, an electrolyte, and a separator. Among them, the positive electrode material has a crucial impact on its performance. The traditional positive electrode of a nickel-metal hydride battery mainly uses nickel hydroxide as the active material, and the negative electrode is usually metal hydride. This design enables nickel-metal hydride batteries to have a certain degree of high energy density and good environmental friendliness. Compared with nickel-cadmium batteries, nickel-metal hydride batteries avoid the use of harmful heavy metal cadmium and have a longer cycle life and higher safety.

[0004] However, existing nickel-metal hydride batteries still have some technical limitations in certain aspects. First, the operating temperature range of nickel-metal hydride batteries is relatively narrow, and they perform poorly especially at extreme temperatures (such as low or high temperatures), which limits their use in some specific applications. Second, although they are superior to nickel-cadmium batteries in terms of energy density, compared with lithium-ion batteries, the energy density of nickel-metal hydride batteries is still low, which is insufficient in some applications that require high energy density. In addition, the cycle life and stability of nickel-metal hydride batteries are also limited to a certain extent. Especially during fast charging and discharging and high-rate discharging, performance degradation or safety problems are likely to occur.

[0005] These technical challenges are closely related to the positive electrode material of nickel-metal hydride batteries. The choice of positive electrode material directly affects the energy density, cycle life, and stability of the battery. The traditional positive electrode material of nickel-metal hydride batteries, nickel hydroxide, although able to provide relatively stable electrochemical performance, has poor stability at high temperatures, which easily leads to a shortened battery life or performance degradation. In addition, characteristics such as the hydrogen storage capacity and conductivity of nickel hydroxide also directly affect the power characteristics and cycle life of the battery.

[0006] Based on this, there is an urgent need to develop a new type of positive electrode material for nickel-metal hydride batteries to solve the above problems. Summary of the Invention

[0007] The purpose of the present invention is to provide a positive electrode material and a nickel-metal hydride battery such that the nickel-metal hydride battery has a wide operating temperature range, high energy density, and excellent stability.

[0008] The first aspect of the present invention lies in:

[0009] To provide a positive electrode material for a nickel-metal hydride battery.

[0010] The second aspect of the present invention lies in:

[0011] To provide a preparation method for a positive electrode material for a nickel-metal hydride battery.

[0012] The third aspect of the present invention lies in:

[0013] The application of the positive electrode material for a nickel-metal hydride battery.

[0014] The present invention also provides a nickel-metal hydride battery.

[0015] Specifically, the technical solution adopted according to the first aspect of the present invention is:

[0016] A positive electrode material for a nickel-metal hydride battery, wherein the raw materials of the positive electrode material for a nickel-metal hydride battery include component A and component B:

[0017] Among them, component A includes:

[0018] Nickel salt;

[0019] Hydroxy cobalt compound;

[0020] Among them, component B includes:

[0021] Titanium salt;

[0022] Fluorine-containing polymer;

[0023] Solvent.

[0024] According to an embodiment of the present invention, at least one of the following advantages or beneficial effects is achieved by one of the technical solutions in the technical solution:

[0025] The raw materials of the positive electrode material for a nickel-metal hydride battery according to the present invention include component A and component B. Among them, the nickel salt in component A can store and release charges with high efficiency, thereby providing a high specific capacity. The hydroxy cobalt compound can promote the progress of the electrode reaction, improve the reaction rate and efficiency, and thus enhance the power performance of the battery;

[0026] Among them, the fluorine-containing polymer in component B has excellent chemical inertness and corrosion resistance, can protect the positive electrode material from being eroded by the electrolyte, thereby extending the service life of the battery and improving the stability of the battery. However, the fluorine-containing polymer has a very low surface energy, and some fluorine-containing polymers will cover the surface of the positive electrode material, thus affecting the contact area between the positive electrode material and the electrolyte, resulting in a decrease in the ion diffusion rate, a decrease in the discharge and charge rates of the battery, and an impact on the power output of the battery;

[0027] To compensate for the adverse effects brought by fluorine-containing polymers, the present invention also introduces titanium salts into component B. Titanium salts have good electrical conductivity and chemical stability, which can, to a certain extent, compensate for the problem of reduced contact area caused by the low surface energy of polytetrafluoroethylene, help improve the electron and ion conduction efficiency between the positive electrode material and the electrolyte, thereby improving the discharge and charge rates of the battery and enhancing the power output capacity of the battery.

[0028] According to an embodiment of the present invention, the titanium salt includes titanium dioxide.

[0029] According to an embodiment of the present invention, the titanium dioxide is introduced in-situ into the positive electrode material, so that it can compete with the fluorine-containing polymer for adsorption onto the surface active sites of the positive electrode material, replacing the position of the fluorine-containing polymer on the surface of the positive electrode material, thereby reducing the thickness and mass of the coating layer formed by the fluorine-containing polymer on the surface of the positive electrode material, and thus greatly avoiding the adverse effects brought by the fluorine-containing polymer.

[0030] According to an embodiment of the present invention, the raw materials of the positive electrode material of the nickel-metal hydride battery further include zinc oxide. Zinc oxide can increase the electrical conductivity and the electrochemically active surface area of the electrode, thereby improving the energy density and power density of the battery. Cobalt oxide can provide additional reactive sites during the charge and discharge process of the battery, which helps to enhance the reaction rate and stability of the electrode.

[0031] According to an embodiment of the present invention, the raw materials of the positive electrode material of the nickel-metal hydride battery include component A and component B in the following parts by weight:

[0032] Among them, component A includes the following components in parts by weight:

[0033] Nickel salt, 100 - 120 parts;

[0034] Hydroxy cobalt compound, 20 - 30 parts;

[0035] Among them, component B includes the following components in parts by weight:

[0036] Titanium salt, 10 - 15 parts;

[0037] Fluorine-containing polymer, 20 - 25 parts.

[0038] According to an embodiment of the present invention, the hydroxy cobalt compound includes at least one of cobalt oxyhydroxide, cobalt hydroxy salt, and cobalt hydroxy oxide.

[0039] According to an embodiment of the present invention, the fluorine-containing polymer includes at least one of polytetrafluoroethylene, fluorinated polyethylene, fluorinated polyurethane, fluorinated polyisobutene, and fluorinated polystyrene.

[0040] According to an embodiment of the present invention, the raw materials of the nickel-metal hydride battery cathode material further include component C, and component C includes polyamine carboxylic acid, haloalcohol, alkali, acyl chloride and solvent.

[0041] Since the raw materials of the nickel-metal hydride battery cathode material of the present invention contain hydroxy cobalt compounds, although the hydroxy cobalt compounds can enhance the power performance of the battery, the hydroxy cobalt compounds are not very stable at high temperatures. For example, cobalt oxyhydroxide (CoOOH) will decompose into cobalt oxide (Co3O4) at high temperatures, and this reaction intensifies with the increase of temperature. This decomposition will affect the performance and stability of the battery cathode material. Therefore, component C is introduced to improve this problem.

[0042] Component C contains carboxyl compounds, which can form hydrogen bonds between hydroxyl groups and carboxyl groups with hydroxy cobalt compounds, thereby stabilizing the structure of hydroxy cobalt compounds, reducing the free mobility of hydroxyl groups, and avoiding their decomposition under high temperature conditions. In addition, component C also contains chloroacetyl chloride groups, and the chloroacetyl chloride groups can form stable chemical bonds under high temperature conditions, thereby stabilizing the structure of the cathode material. It can form a protective surface layer by reacting with the oxides on the material surface to prevent further oxidation or structural damage.

[0043] According to an embodiment of the present invention, the polyamine carboxylic acid includes at least one of diethylenetriaminepentaacetic acid, ethylenediaminetetraacetic acid and hydroxyethylethylenediaminetriacetic acid.

[0044] According to an embodiment of the present invention, the preparation method of component C includes the following steps: mixing polyamine carboxylic acid, alkali and haloalcohol in a solvent, heating and reacting to obtain a mixture, and adding acyl chloride to the mixture under a protective atmosphere, heating and reacting to obtain component C.

[0045] According to an embodiment of the present invention, the acyl chloride includes at least one of chloroacetyl chloride, benzoyl chloride, acetyl chloride, isovaleryl chloride, valeryl chloride and butyryl chloride.

[0046] Specifically, the technical solution adopted in the second aspect of the present invention is as follows:

[0047] A method for preparing the nickel-metal hydride battery cathode material includes the following steps:

[0048] S1 Mix nickel salt and hydroxy cobalt compound to obtain a first composite material;

[0049] S2 Mix titanium salt and fluoropolymer in a solvent, heat and react to obtain a first modifier;

[0050] S3 Immerse the first composite material in the first modifier, take it out and dry it to obtain the nickel-metal hydride battery cathode material.

[0051] According to an embodiment of the present invention, at least one of the technical solutions in the technical solution has at least one of the following advantages or beneficial effects:

[0052] The preparation method of the positive electrode material of the nickel-metal hydride battery of the present invention is as follows: First, a first composite material is formed by mixing a nickel salt and a hydroxy cobalt compound, effectively combining nickel and cobalt elements, and providing a basis for the performance of the subsequent positive electrode material of the battery. Secondly, a titanium salt and a fluorine-containing polymer are mixed in a solvent to obtain a first modifier. The first modifier not only helps to adjust the chemical composition and structure of the material, but also improves the electrochemical performance and cycle stability of the material. Finally, the first composite material is immersed in the first modifier, and after drying, the positive electrode material of the nickel-metal hydride battery is obtained. The whole preparation process is simple and efficient, suitable for industrial production requirements, and can mass-produce high-quality positive electrode materials.

[0053] Another aspect of the present invention also provides a nickel-metal hydride battery, including a positive electrode, a negative electrode, and an electrolyte. The positive electrode includes the positive electrode material of the nickel-metal hydride battery as described in the embodiment of the first aspect above. Since this application adopts all the technical solutions of the above-mentioned positive electrode material of the nickel-metal hydride battery, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiments.

[0054] Other features and advantages of the present invention will be described in the subsequent specification, and, in part, will be obvious from the specification, or will be understood by implementing the present invention. Detailed embodiments

[0055] In the description of the present invention, if the first, second, etc. are described only for the purpose of distinguishing technical features, they cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0056] In the description of the present invention, it should be understood that the orientation or positional relationship involved, such as up, down, etc., indicates the orientation or positional relationship based on the orientation or positional relationship shown in the embodiment, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention.

[0057] The terms "preferably", "more preferably", etc. in the present invention refer to embodiments of the present invention that can provide certain beneficial effects in certain cases. However, in the same or other cases, other embodiments may also be preferred. In addition, the description of one or more preferred embodiments does not imply that other embodiments are not available, nor is it intended to exclude other embodiments from the scope of the present invention.

[0058] When a numerical range is disclosed in this text, the above range is considered continuous and includes the minimum and maximum values of the range, as well as each value between such minimum and maximum values. Further, when the range refers to integers, each integer between the minimum and maximum values of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be combined. In other words, unless otherwise specified, all ranges disclosed in this text should be understood to include any and all sub-ranges subsumed therein.

[0059] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of the present invention.

[0060] The reagents, methods, and equipment used in the present invention, unless otherwise specified, are all conventional reagents, methods, and equipment in this technical field.

[0061] Example 1

[0062] A positive electrode material for a nickel-metal hydride battery, comprising component A, component B, and component C:

[0063] Among them, component A includes:

[0064] Nickel salt;

[0065] Hydroxy cobalt compound;

[0066] Among them, component B includes:

[0067] Titanium salt;

[0068] Fluorine-containing polymer;

[0069] Solvent;

[0070] Among them, component C includes:

[0071] Polyamine carboxylic acid;

[0072] Halohydrin;

[0073] Base;

[0074] Acyl chloride;

[0075] Solvent.

[0076] Among them, the nickel salt is nickel hydroxide;

[0077] Among them, the hydroxy cobalt compound is cobalt oxyhydroxide;

[0078] Among them, the titanium salt is titanium chloride;

[0079] Among them, the fluorine-containing polymer is polytetrafluoroethylene;

[0080] Among them, the polyamine carboxylic acid is diethylenetriaminepentaacetic acid;

[0081] Among them, the haloalcohol is 2-bromoethanol;

[0082] Among them, the base is sodium hydroxide;

[0083] Among them, the acyl chloride is chloroacetyl chloride;

[0084] A method for preparing a positive electrode material for a nickel-metal hydride battery, comprising the following steps:

[0085] S1 Mix 100 parts of nickel hydroxide, 15 parts of zinc oxide, 20 parts of cobalt oxyhydroxide and 10 parts of binder to obtain a first composite material;

[0086] S2 Mix titanium chloride and absolute ethanol to obtain a sol with a titanium ion concentration of 0.1 M. While stirring, slowly add sodium hydroxide to the sol, adjust the pH value to 8.0, react at 150 °C for 6 h, cool down, and add 20 parts of polytetrafluoroethylene and 100 parts of tetrafluoroethane to obtain a first modifier;

[0087] S3 Immerse the first composite material in the first modifier, take it out and dry it after 2 h, and perform heat treatment at 500 °C for 2 h to obtain a second composite material;

[0088] S4 Add 28 parts of diethylenetriaminepentaacetic acid, 23 parts of 2-bromoethanol, and 2 parts of sodium hydroxide to 11 parts of dimethyl sulfoxide and 35 parts of acetonitrile, heat up to 65 °C, stir and react for 10 h, extract to obtain a mixture. Under a protective atmosphere, add 21 parts of chloroacetyl chloride and 12 parts of acetone to the mixture, heat up to 60 °C, stir and react for 6 h, extract to obtain a second modifier;

[0089] S5 Mix the second composite material and the second modifier in acetonitrile at a weight ratio of 3:1, remove the solvent after 24 h to obtain the positive electrode material for the nickel-metal hydride battery.

[0090] Example 2

[0091] The difference between Example 2 and Example 1 is that in Example 2, the cobalt oxyhydroxide compound is potassium cobalt oxyhydroxide.

[0092] A positive electrode material for a nickel-metal hydride battery, comprising component A, component B and component C:

[0093] Among them, component A includes:

[0094] Nickel salt;

[0095] Cobalt oxyhydroxide compound;

[0096] Among them, component B includes:

[0097] Titanium salt;

[0098] Fluorine-containing polymer;

[0099] Solvent;

[0100] Among them, component C includes:

[0101] Polyamine carboxylic acid;

[0102] Halohydrin;

[0103] Base;

[0104] Acyl chloride;

[0105] Solvent.

[0106] Among them, the nickel salt is nickel hydroxide;

[0107] Among them, the hydroxy cobalt compound is potassium hydroxycobaltate;

[0108] Among them, the titanium salt is titanium chloride;

[0109] Among them, the fluorine-containing polymer is polytetrafluoroethylene;

[0110] Among them, the polyamine carboxylic acid is diethylenetriaminepentaacetic acid;

[0111] Among them, the halohydrin is 2-bromoethanol;

[0112] Among them, the base is sodium hydroxide;

[0113] Among them, the acyl chloride is chloroacetyl chloride;

[0114] A method for preparing a positive electrode material for a nickel-metal hydride battery includes the following steps:

[0115] S1 Mix 100 parts of nickel hydroxide, 15 parts of zinc oxide, 20 parts of potassium hydroxycobaltate and 10 parts of binder to obtain a first composite material;

[0116] S2 Mix titanium chloride and absolute ethanol to obtain a sol with a titanium ion concentration of 0.1 M. While stirring, slowly add sodium hydroxide to the sol, adjust the pH value to 8.0, react at 150 °C for 6 h, cool down, and then add 20 parts of polytetrafluoroethylene and 100 parts of tetrafluoroethane to obtain a first modifier;

[0117] S3 Immerse the first composite material in the first modifier, take it out and dry it after 2 h, and perform heat treatment at 500 °C for 2 h to obtain a second composite material;

[0118] In S4, 28 parts of diethylenetriaminepentaacetic acid, 23 parts of 2-bromoethanol, and 2 parts of sodium hydroxide were added to 11 parts of dimethyl sulfoxide and 35 parts of acetonitrile. The temperature was raised to 65 °C, and the mixture was stirred and reacted for 10 h. After extraction, a mixture was obtained. Under a protective atmosphere, 21 parts of chloroacetyl chloride and 12 parts of acetone were added to the mixture. The temperature was raised to 60 °C, and the mixture was stirred and reacted for 6 h. After extraction, a second modifier was obtained.

[0119] In S5, the second composite material and the second modifier were mixed in acetonitrile at a weight ratio of 3:1. After 24 h, the solvent was removed to obtain the positive electrode material for nickel-metal hydride batteries.

[0120] Example 3

[0121] The difference between Example 3 and Example 1 is that in Example 3, the titanium salt is titanium acetate.

[0122] A positive electrode material for nickel-metal hydride batteries, comprising component A, component B, and component C:

[0123] Among them, component A includes:

[0124] Nickel salt;

[0125] Hydroxy cobalt compound;

[0126] Among them, component B includes:

[0127] Titanium salt;

[0128] Fluorine-containing polymer;

[0129] Solvent;

[0130] Among them, component C includes:

[0131] Polyamine carboxylic acid;

[0132] Halohydrin;

[0133] Base;

[0134] Acyl chloride;

[0135] Solvent.

[0136] Among them, the nickel salt is nickel hydroxide;

[0137] Among them, the hydroxy cobalt compound is cobalt oxyhydroxide;

[0138] Among them, the titanium salt is titanium acetate;

[0139] Among them, the fluorine-containing polymer is polytetrafluoroethylene;

[0140] Among them, the polyamine carboxylic acid is diethylenetriaminepentaacetic acid;

[0141] Among them, the halohydrin is 2-bromoethanol;

[0142] Among them, the base is sodium hydroxide;

[0143] Among them, the acyl chloride is chloroacetyl chloride;

[0144] A preparation method of a positive electrode material for a nickel-metal hydride battery, comprising the following steps:

[0145] S1 Mix 100 parts of nickel hydroxide, 15 parts of zinc oxide, 20 parts of cobalt oxyhydroxide and 10 parts of binder to obtain a first composite material;

[0146] S2 Mix titanium acetate and absolute ethanol to obtain a sol with a titanium ion concentration of 0.1 M. While stirring, slowly add sodium hydroxide to the sol, adjust the pH value to 8.0, react at 150 °C for 6 h, cool down, and add 20 parts of polytetrafluoroethylene and 100 parts of tetrafluoroethane to obtain a first modifier;

[0147] S3 Immerse the first composite material in the first modifier, take it out and dry it after 2 h, and perform heat treatment at 500 °C for 2 h to obtain a second composite material;

[0148] S4 Add 28 parts of diethylenetriaminepentaacetic acid, 23 parts of 2-bromoethanol, and 2 parts of sodium hydroxide to 11 parts of dimethyl sulfoxide and 35 parts of acetonitrile, heat up to 65 °C, stir and react for 10 h, extract to obtain a mixture. Under a protective atmosphere, add 21 parts of chloroacetyl chloride and 12 parts of acetone to the mixture, heat up to 60 °C, stir and react for 6 h, extract to obtain a second modifier;

[0149] S5 Mix the second composite material and the second modifier in acetonitrile at a weight ratio of 3:1, remove the solvent after 24 h to obtain the positive electrode material for the nickel-metal hydride battery.

[0150] Example 4

[0151] The difference between Example 4 and Example 1 is that in Example 4, the fluoropolymer is fluorinated polyethylene.

[0152] A positive electrode material for a nickel-metal hydride battery, comprising component A, component B and component C:

[0153] Among them, component A includes:

[0154] Nickel salt;

[0155] Cobalt hydroxy compound;

[0156] Among them, component B includes:

[0157] Titanium salt;

[0158] Fluoropolymer;

[0159] Solvent;

[0160] Among them, component C includes:

[0161] Polyamine carboxylic acid;

[0162] Halohydrin;

[0163] Base;

[0164] Acyl chloride;

[0165] Solvent.

[0166] Among them, the nickel salt is nickel hydroxide;

[0167] Among them, the cobalt hydroxy compound is cobalt oxyhydroxide;

[0168] Among them, the titanium salt is titanium chloride;

[0169] Among them, the fluorine-containing polymer is fluorinated polyethylene;

[0170] Among them, the polyamine carboxylic acid is diethylenetriaminepentaacetic acid;

[0171] Among them, the halohydrin is 2-bromoethanol;

[0172] Among them, the base is sodium hydroxide;

[0173] Among them, the acyl chloride is chloroacetyl chloride;

[0174] A method for preparing a positive electrode material for a nickel-metal hydride battery, comprising the following steps:

[0175] S1 Mix 100 parts of nickel hydroxide, 15 parts of zinc oxide, 20 parts of cobalt oxyhydroxide and 10 parts of binder to obtain a first composite material;

[0176] S2 Mix titanium chloride and absolute ethanol to obtain a sol with a titanium ion concentration of 0.1 M. While stirring, slowly add sodium hydroxide to the sol, adjust the pH value to 8.0, react at 150 °C for 6 h, cool down, and add 20 parts of fluorinated polyethylene and 100 parts of tetrafluoroethane to obtain a first modifier;

[0177] S3 Immerse the first composite material in the first modifier, take it out and dry it after 2 h, and perform heat treatment at 500 °C for 2 h to obtain a second composite material;

[0178] S4 Add 28 parts of diethylenetriaminepentaacetic acid, 23 parts of 2-bromoethanol, and 2 parts of sodium hydroxide to 11 parts of dimethyl sulfoxide and 35 parts of acetonitrile, heat up to 65 °C, stir and react for 10 h, extract to obtain a mixture. Under a protective atmosphere, add 21 parts of chloroacetyl chloride and 12 parts of acetone to the mixture, heat up to 60 °C, stir and react for 6 h, extract to obtain a second modifier;

[0179] Mix the second composite material and the second modifier in acetonitrile at a weight ratio of 3:1, and remove the solvent after 24 h to obtain the positive electrode material for nickel-metal hydride batteries.

[0180] Example 5

[0181] The difference between Example 5 and Example 1 is that Example 5 does not contain component C.

[0182] A positive electrode material for nickel-metal hydride batteries, comprising component A and component B:

[0183] Among them, component A includes:

[0184] Nickel salt;

[0185] Hydroxy cobalt compound;

[0186] Among them, component B includes:

[0187] Titanium salt;

[0188] Fluorine-containing polymer;

[0189] Solvent.

[0190] Among them, the nickel salt is nickel hydroxide;

[0191] Among them, the hydroxy cobalt compound is cobalt oxyhydroxide;

[0192] Among them, the titanium salt is titanium chloride;

[0193] Among them, the fluorine-containing polymer is polytetrafluoroethylene;

[0194] A preparation method of a positive electrode material for nickel-metal hydride batteries, comprising the following steps:

[0195] S1 Mix 100 parts of nickel hydroxide, 15 parts of zinc oxide, 20 parts of cobalt oxyhydroxide and 10 parts of binder to obtain the first composite material;

[0196] S2 Mix titanium chloride and absolute ethanol to obtain a sol with a titanium ion concentration of 0.1 M. While stirring, slowly add sodium hydroxide to the sol, adjust the pH value to 8.0, react at 150 °C for 6 h, cool down and add 20 parts of polytetrafluoroethylene and 100 parts of tetrafluoroethane to obtain the first modifier;

[0197] S3 Immerse the first composite material in the first modifier, take it out and dry it after 2 h, and perform heat treatment at 500 °C for 2 h to obtain the positive electrode material for nickel-metal hydride batteries.

[0198] Example 6

[0199] The difference between Example 6 and Example 1 is that the dosage of component A is different.

[0200] A nickel-metal hydride battery positive electrode material, comprising component A, component B and component C:

[0201] Among them, component A includes:

[0202] Nickel salt;

[0203] Hydroxy cobalt compound;

[0204] Among them, component B includes:

[0205] Titanium salt;

[0206] Fluorine-containing polymer;

[0207] Solvent;

[0208] Among them, component C includes:

[0209] Polyamine carboxylic acid;

[0210] Halohydrin;

[0211] Base;

[0212] Acyl chloride;

[0213] Solvent.

[0214] Among them, the nickel salt is nickel hydroxide;

[0215] Among them, the hydroxy cobalt compound is cobalt oxyhydroxide;

[0216] Among them, the titanium salt is titanium chloride;

[0217] Among them, the fluorine-containing polymer is polytetrafluoroethylene;

[0218] Among them, the polyamine carboxylic acid is diethylenetriaminepentaacetic acid;

[0219] Among them, the halohydrin is 2-bromoethanol;

[0220] Among them, the base is sodium hydroxide;

[0221] Among them, the acyl chloride is chloroacetyl chloride;

[0222] A preparation method of a nickel-metal hydride battery positive electrode material, comprising the following steps:

[0223] S1 Mix 100 parts of nickel hydroxide, 20 parts of zinc oxide, 25 parts of cobalt oxyhydroxide and 10 parts of binder to obtain a first composite material;

[0224] S2 Mix titanium chloride and absolute ethanol to obtain a sol with a titanium ion concentration of 0.1 M. While stirring, slowly add sodium hydroxide to the sol, adjust the pH value to 8.0, react at 150 °C for 6 h, cool down and add 20 parts of polytetrafluoroethylene and 100 parts of tetrafluoroethane to obtain a first modifier;

[0225] S3 Immerse the first composite material in the first modifier, take it out and dry it after 2 h, and perform heat treatment at 500 °C for 2 h to obtain the second composite material;

[0226] S4 Add 28 parts of diethylenetriaminepentaacetic acid, 23 parts of 2-bromoethanol, and 2 parts of sodium hydroxide to 11 parts of dimethyl sulfoxide and 35 parts of acetonitrile, heat up to 65 °C, stir and react for 10 h, extract to obtain a mixture. Under a protective atmosphere, add 21 parts of chloroacetyl chloride and 12 parts of acetone to the mixture, heat up to 60 °C, stir and react for 6 h, extract to obtain the second modifier;

[0227] S5 Mix the second composite material and the second modifier in acetonitrile at a weight ratio of 3:1, remove the solvent after 24 h to obtain the positive electrode material for nickel-metal hydride batteries.

[0228] Example 7

[0229] The difference between Example 7 and Example 1 is the amount of component B used.

[0230] A positive electrode material for nickel-metal hydride batteries, comprising component A, component B, and component C:

[0231] Among them, component A includes:

[0232] Nickel salt;

[0233] Hydroxy cobalt compound;

[0234] Among them, component B includes:

[0235] Titanium salt;

[0236] Fluorine-containing polymer;

[0237] Solvent;

[0238] Among them, component C includes:

[0239] Polyamine carboxylic acid;

[0240] Halohydrin;

[0241] Base;

[0242] Acyl chloride;

[0243] Solvent.

[0244] Among them, the nickel salt is nickel hydroxide;

[0245] Among them, the hydroxy cobalt compound is cobalt oxyhydroxide;

[0246] Among them, the titanium salt is titanium chloride;

[0247] Among them, the fluorine-containing polymer is polytetrafluoroethylene;

[0248] Among them, the polyamine carboxylic acid is diethylenetriaminepentaacetic acid;

[0249] Among them, the haloalcohol is 2-bromoethanol;

[0250] Among them, the base is sodium hydroxide;

[0251] Among them, the acyl chloride is chloroacetyl chloride;

[0252] A method for preparing a positive electrode material for a nickel-metal hydride battery, comprising the following steps:

[0253] S1 Mix 100 parts of nickel hydroxide, 15 parts of zinc oxide, 20 parts of cobalt oxyhydroxide and 10 parts of binder to obtain a first composite material;

[0254] S2 Mix titanium chloride and absolute ethanol to obtain a sol with a titanium ion concentration of 0.08 M. While stirring, slowly add sodium hydroxide to the sol, adjust the pH value to 8.0, react at 150 °C for 6 h, cool down, and add 15 parts of polytetrafluoroethylene and 90 parts of tetrafluoroethane to obtain a first modifier;

[0255] S3 Immerse the first composite material in the first modifier, take it out and dry it after 2 h, and perform heat treatment at 500 °C for 2 h to obtain a second composite material;

[0256] S4 Add 28 parts of diethylenetriaminepentaacetic acid, 23 parts of 2-bromoethanol, and 2 parts of sodium hydroxide to 11 parts of dimethyl sulfoxide and 35 parts of acetonitrile, heat up to 65 °C, stir and react for 10 h, extract to obtain a mixture. Under a protective atmosphere, add 21 parts of chloroacetyl chloride and 12 parts of acetone to the mixture, heat up to 60 °C, stir and react for 6 h, extract to obtain a second modifier;

[0257] S5 Mix the second composite material and the second modifier in acetonitrile at a weight ratio of 3:1, remove the solvent after 24 h to obtain the positive electrode material for the nickel-metal hydride battery.

[0258] Example 8

[0259] The difference between Example 8 and Example 1 is that the dosage of component C is different.

[0260] A positive electrode material for a nickel-metal hydride battery, comprising component A, component B and component C:

[0261] Among them, component A includes:

[0262] Nickel salt;

[0263] Hydroxy cobalt compound;

[0264] Among them, component B includes:

[0265] Titanium salt;

[0266] Fluoropolymer;

[0267] Solvent;

[0268] Among them, component C includes:

[0269] Polyamine carboxylic acid;

[0270] Halohydrin;

[0271] Base;

[0272] Acyl chloride;

[0273] Solvent.

[0274] Among them, the nickel salt is nickel hydroxide;

[0275] Among them, the hydroxy cobalt compound is cobalt oxyhydroxide;

[0276] Among them, the titanium salt is titanium chloride;

[0277] Among them, the fluoropolymer is polytetrafluoroethylene;

[0278] Among them, the polyamine carboxylic acid is diethylenetriaminepentaacetic acid;

[0279] Among them, the halohydrin is 2-bromoethanol;

[0280] Among them, the base is sodium hydroxide;

[0281] Among them, the acyl chloride is chloroacetyl chloride;

[0282] A method for preparing a positive electrode material for a nickel-metal hydride battery, comprising the following steps:

[0283] S1 Mix 100 parts of nickel hydroxide, 15 parts of zinc oxide, 20 parts of cobalt oxyhydroxide and 10 parts of binder to obtain a first composite material;

[0284] S2 Mix titanium chloride and absolute ethanol to obtain a sol with a titanium ion concentration of 0.1 M. While stirring, slowly add sodium hydroxide to the sol, adjust the pH value to 8.0, react at 150 °C for 6 h, cool down and add 20 parts of polytetrafluoroethylene and 100 parts of tetrafluoroethane to obtain a first modifier;

[0285] S3 Immerse the first composite material in the first modifier, take it out and dry it after 2 h, and perform heat treatment at 500 °C for 2 h to obtain a second composite material;

[0286] In S4, 28 parts of diethylenetriaminepentaacetic acid, 25 parts of 2-bromoethanol, and 2 parts of sodium hydroxide were added to 13 parts of dimethyl sulfoxide and 40 parts of acetonitrile. The temperature was raised to 65 °C, and the mixture was stirred and reacted for 10 h. After extraction, a mixture was obtained. Under a protective atmosphere, 15 parts of chloroacetyl chloride and 9 parts of acetone were added to the mixture. The temperature was raised to 60 °C, and the mixture was stirred and reacted for 6 h. After extraction, a second modifier was obtained.

[0287] In S5, the second composite material and the second modifier were mixed in a weight ratio of 3:1 in acetonitrile. After 24 h, the solvent was removed to obtain the positive electrode material for nickel-metal hydride batteries.

[0288] Comparative Example 1

[0289] The difference between Comparative Example 1 and Example 1 is that Comparative Example 1 does not contain component B.

[0290] A positive electrode material for nickel-metal hydride batteries, comprising component A and component C:

[0291] Among them, component A includes:

[0292] Nickel salt;

[0293] Hydroxy cobalt compound;

[0294] Among them, component C includes:

[0295] Polyamine carboxylic acid;

[0296] Halohydrin;

[0297] Base;

[0298] Acyl chloride;

[0299] Solvent.

[0300] Among them, the nickel salt is nickel hydroxide;

[0301] Among them, the hydroxy cobalt compound is cobalt oxyhydroxide;

[0302] Among them, the polyamine carboxylic acid is diethylenetriaminepentaacetic acid;

[0303] Among them, the halohydrin is 2-bromoethanol;

[0304] Among them, the base is sodium hydroxide;

[0305] Among them, the acyl chloride is chloroacetyl chloride;

[0306] A preparation method of a positive electrode material for nickel-metal hydride batteries, comprising the following steps:

[0307] In S1, 100 parts of nickel hydroxide, 15 parts of zinc oxide, 20 parts of cobalt oxyhydroxide, and 10 parts of binder were mixed to obtain a first composite material;

[0308] In S2, 28 parts of diethylenetriaminepentaacetic acid, 23 parts of 2-bromoethanol, and 2 parts of sodium hydroxide were added to 11 parts of dimethyl sulfoxide and 35 parts of acetonitrile. The temperature was raised to 65 °C, and the mixture was stirred and reacted for 10 h. After extraction, a mixture was obtained. Under a protective atmosphere, 21 parts of chloroacetyl chloride and 12 parts of acetone were added to the mixture. The temperature was raised to 60 °C, and the mixture was stirred and reacted for 6 h. After extraction, a second modifier was obtained.

[0309] In S3, the first composite material and the second modifier were mixed in acetonitrile at a weight ratio of 3:1. After 24 h, the solvent was removed to obtain the positive electrode material for nickel-metal hydride batteries.

[0310] Comparative Example 2

[0311] The difference between Comparative Example 2 and Example 1 is that in Comparative Example 2, titanium dioxide was not generated by the in-situ hydrothermal method, and titanium dioxide was directly added in step S2.

[0312] A positive electrode material for nickel-metal hydride batteries, comprising component A, component B, and component C:

[0313] Among them, component A includes:

[0314] Nickel salt;

[0315] Hydroxy cobalt compound;

[0316] Among them, component B includes:

[0317] Titanium dioxide;

[0318] Fluorine-containing polymer;

[0319] Solvent;

[0320] Among them, component C includes:

[0321] Polyamine carboxylic acid;

[0322] Halohydrin;

[0323] Base;

[0324] Acyl chloride;

[0325] Solvent.

[0326] Among them, the nickel salt is nickel hydroxide;

[0327] Among them, the hydroxy cobalt compound is cobalt oxyhydroxide;

[0328] Among them, the fluorine-containing polymer is polytetrafluoroethylene;

[0329] Among them, the polyamine carboxylic acid is diethylenetriaminepentaacetic acid;

[0330] Among them, the halohydrin is 2-bromoethanol;

[0331] Among them, the alkali is sodium hydroxide;

[0332] Among them, the acyl chloride is chloroacetyl chloride;

[0333] A method for preparing a positive electrode material of a nickel-metal hydride battery, comprising the following steps:

[0334] S1 Mix 100 parts of nickel hydroxide, 15 parts of zinc oxide, 20 parts of cobalt oxyhydroxide and 10 parts of binder to obtain a first composite material;

[0335] S2 Mix titanium dioxide, absolute ethanol, 20 parts of polytetrafluoroethylene and 100 parts of tetrafluoroethane to obtain a first modifier;

[0336] S3 Immerse the first composite material in the first modifier, take it out and dry it after 2 h, and perform heat treatment at 500 °C for 2 h to obtain a second composite material;

[0337] S4 Add 28 parts of diethylenetriaminepentaacetic acid, 23 parts of 2-bromoethanol and 2 parts of sodium hydroxide to 11 parts of dimethyl sulfoxide and 35 parts of acetonitrile, heat up to 65 °C, stir and react for 10 h, extract to obtain a mixture. Under a protective atmosphere, add 21 parts of chloroacetyl chloride and 12 parts of acetone to the mixture, heat up to 60 °C, stir and react for 6 h, extract to obtain a second modifier;

[0338] S5 Mix the second composite material and the second modifier in acetonitrile at a weight ratio of 3:1, remove the solvent after 24 h to obtain the positive electrode material of the nickel-metal hydride battery.

[0339] Comparative Example 3

[0340] The difference between Comparative Example 3 and Example 1 is that in step S4 of Comparative Example 3, chloroacetyl chloride is not added.

[0341] A positive electrode material of a nickel-metal hydride battery, comprising component A, component B and component C:

[0342] Among them, component A includes:

[0343] Nickel salt;

[0344] Hydroxy cobalt compound;

[0345] Among them, component B includes:

[0346] Titanium salt;

[0347] Fluorine-containing polymer;

[0348] Solvent;

[0349] Among them, component C includes:

[0350] Polyamine carboxylic acid;

[0351] Halohydrin;

[0352] Alkali;

[0353] Solvent.

[0354] Among them, the nickel salt is nickel hydroxide;

[0355] Among them, the hydroxy cobalt compound is cobalt oxyhydroxide;

[0356] Among them, the titanium salt is titanium chloride;

[0357] Among them, the fluorine-containing polymer is polytetrafluoroethylene;

[0358] Among them, the polyamine carboxylic acid is diethylenetriaminepentaacetic acid;

[0359] Among them, the haloalcohol is 2-bromoethanol;

[0360] Among them, the alkali is sodium hydroxide;

[0361] A method for preparing a positive electrode material of a nickel-metal hydride battery, comprising the following steps:

[0362] S1 Mix 100 parts of nickel hydroxide, 15 parts of zinc oxide, 20 parts of cobalt oxyhydroxide and 10 parts of binder to obtain a first composite material;

[0363] S2 Mix titanium chloride and absolute ethanol to obtain a sol with a titanium ion concentration of 0.1 M. While stirring, slowly add sodium hydroxide to the sol, adjust the pH value to 8.0, react at 150 °C for 6 h, cool down and add 20 parts of polytetrafluoroethylene and 100 parts of tetrafluoroethane to obtain a first modifier;

[0364] S3 Immerse the first composite material in the first modifier, take it out and dry it after 2 h, and perform heat treatment at 500 °C for 2 h to obtain a second composite material;

[0365] S4 Add 28 parts of diethylenetriaminepentaacetic acid, 23 parts of 2-bromoethanol, and 2 parts of sodium hydroxide to 11 parts of dimethyl sulfoxide and 35 parts of acetonitrile, heat up to 65 °C, stir and react for 10 h, and extract to obtain a second modifier;

[0366] S5 Mix the second composite material and the second modifier in acetonitrile at a weight ratio of 3:1, remove the solvent after 24 h to obtain the positive electrode material of the nickel-metal hydride battery.

[0367] Performance test:

[0368] The positive electrode materials of the hydrogen batteries prepared in Examples 1-6 and Comparative Examples 1-3 were coated on the surface of nickel foam, and after pressing and drying, the positive electrodes were made. Using a saturated calomel electrode as the reference electrode and a platinum sheet electrode as the counter electrode, 6 mol / L KOH was used as the electrolyte to make a nickel-metal hydride battery. A battery test system and an electrochemical workstation were used to test the electrochemical performance by a three-electrode system, and the test results are shown in Table 1.

[0369] Among them, the cycle test method is as follows:

[0370] The battery prepared above was placed at 60 °C to test its cycle performance. The cycle steps were to repeatedly charge and discharge the lithium-ion battery, and calculate the cycle capacity retention rate of the lithium-ion battery. When the capacity retention rate of the lithium-ion battery was lower than 80%, the cycle test ended, and the number of cycle weeks was recorded.

[0371] Table 1

[0372]

[0373]

[0374] The above are only the embodiments of the present invention, and do not limit the patent scope of the present invention. Any equivalent transformation made using the content of the specification of the present invention, directly or indirectly applied in the relevant technical fields, shall be equally included in the patent protection scope of the present invention.

Claims

1. A positive electrode material for nickel-metal hydride batteries, characterized in that: The raw materials of the positive electrode material of the nickel-metal hydride battery include component A, component B, and component C: Among them, component A includes: Nickel salt; Hydroxy cobalt compound; Among them, component B includes: Titanium salt; Fluorine-containing polymer; Among them, component C includes: Polyamine carboxylic acid, haloalcohol, base, acyl chloride, and solvent.

2. The positive electrode material of a nickel-metal hydride battery according to claim 1, characterized in that: The raw materials of the positive electrode material of the nickel-metal hydride battery include the following parts by weight of component A and component B: Among them, component A includes the following components by weight: Nickel salt, 100 - 120 parts; Hydroxy cobalt compound, 20 - 30 parts; Among them, component B includes the following components by weight: Titanium salt, 10 - 15 parts; Fluorine-containing polymer, 20 - 25 parts.

3. The positive electrode material of a nickel-metal hydride battery according to claim 1, characterized in that: The hydroxy cobalt compound includes at least one of cobalt hydroxyoxide, cobalt hydroxy salt, and cobalt hydroxy oxide.

4. A nickel-metal hydride battery positive electrode material according to claim 1, characterized in that: The fluorine-containing polymer includes at least one of polytetrafluoroethylene, fluorinated polyethylene, fluorinated polyurethane, fluorinated polyisobutene, and fluorinated polystyrene.

5. The positive electrode material of a nickel-metal hydride battery according to claim 1, characterized in that: The polyamine carboxylic acid includes at least one of diethylenetriaminepentaacetic acid, ethylenediaminetetraacetic acid, and hydroxyethylethylenediaminetriacetic acid.

6. The positive electrode material of a nickel-metal hydride battery according to claim 1, characterized in that: The preparation method of component C includes the following steps: Mix polyamine carboxylic acid, base, and haloalcohol in a solvent, and obtain a mixture through heating reaction. Under a protective atmosphere, add acyl chloride to the mixture and obtain component C through heating reaction.

7. The positive electrode material of a nickel-metal hydride battery according to claim 1, wherein: The acyl chloride includes at least one of chloroacetyl chloride, benzoyl chloride, acetyl chloride, isovaleryl chloride, valeryl chloride, and butyryl chloride.

8. A method for preparing a positive electrode material of a nickel-metal hydride battery as described in any one of claims 1 to 7, characterized in that: It includes the following steps: S1 Mix nickel salt and hydroxy cobalt compound to obtain a first composite material; S2 Mix titanium salt and fluorine-containing polymer in a solvent and obtain a first modifier through heating reaction; S3 Immerse the first composite material in the first modifier, take it out and dry it to obtain the positive electrode material of the nickel-metal hydride battery.

9. A nickel-metal hydride battery, characterized in that: It includes a positive electrode, a negative electrode, and an electrolyte. The positive electrode includes a positive electrode material of a nickel-metal hydride battery as described in any one of claims 1 to 7.

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