阅读说明：本技术 一种室温一步法合成高活性层状锌离子二次电池正极材料的方法 (Method for synthesizing high-activity layered zinc ion secondary battery anode material by one-step method at room temperature ) 是由 迟晓伟 李传强 李卓斌 吕力行 王小荣 来鸣 于 2020-12-09 设计创作，主要内容包括：本发明涉及一种室温一步法合成高活性层状锌离子二次电池正极材料的方法,包括步骤：将螯合二价锰源和碱金属氢氧化物沉淀剂分别加入到去离子水中,高速搅拌至完全溶解,得到两种溶液；将得到的两种溶液进行混合,并在室温下反应。本发明的有益效果是：室温一步法制备正极材料的工艺过程简单,对设备没有特殊要求,成本低廉,容易中试放大生产；制备的正极材料主要成分为高活性的锰氧化物,且具有微观的层状晶体结构；锰氧化物具有良好的结晶性、高比表面积、高活性、可逆性和微纳分级的粉体形貌；将其用于中性或近中性水系锌离子二次电池中,材料的比容量较高,在250mAh/g以上,是很好的锌离子二次电池正极材料,应用前景广阔。(The invention relates to a method for synthesizing a high-activity layered zinc ion secondary battery anode material by a room-temperature one-step method, which comprises the following steps: adding a chelating manganous source and an alkali metal hydroxide precipitator into deionized water respectively, and stirring at a high speed until the chelating manganous source and the alkali metal hydroxide precipitator are dissolved completely to obtain two solutions; the two solutions obtained were mixed and reacted at room temperature. The invention has the beneficial effects that: the process for preparing the cathode material by the room-temperature one-step method is simple, has no special requirements on equipment, is low in cost and is easy for pilot scale production; the main component of the prepared anode material is high-activity manganese oxide and has a microscopic layered crystal structure; the manganese oxide has good crystallinity, high specific surface area, high activity, reversibility and micro-nano graded powder morphology; when the material is used in a neutral or near-neutral water system zinc ion secondary battery, the specific capacity of the material is higher, more than 250mAh/g, the material is a good zinc ion secondary battery anode material, and the application prospect is wide.)

1. A method for synthesizing a high-activity layered zinc ion secondary battery anode material by a room temperature one-step method is characterized by comprising the following steps:

step 1, dissolving raw materials: adding a chelating manganous source and an alkali metal hydroxide precipitator into deionized water respectively, and stirring at a high speed until the chelating manganous source and the alkali metal hydroxide precipitator are dissolved completely to obtain two solutions;

step 2, one-step reaction: mixing the two solutions obtained in the step 1 under the conditions of rapid stirring and oxygen-containing atmosphere introduction, and reacting for 1-5 h at room temperature; the continuous and rapid stirring is ensured in the whole reaction process, and the oxygen-containing atmosphere is continuously introduced;

and 3, separating a product: after the mixed reaction of the two solutions in the step 2 is finished, carrying out vacuum filtration or air filter pressing on a reaction product, and washing the reaction product for 3-5 times by using deionized water and alcohol respectively; and drying the product obtained by suction filtration and washing in an oven for 6-12 h to obtain the high-activity layered zinc ion secondary battery anode material.

2. The method for synthesizing the high-activity layered zinc ion secondary battery cathode material by the room temperature one-step method according to claim 1, is characterized in that: in the step 1, the concentration of manganese ions in deionized water for dissolving and chelating a divalent manganese source is 0.1-2 mol/L, and the concentration of alkali metal ions in deionized water for dissolving an alkali metal hydroxide precipitator is 0.1-8 mol/L; the ratio of the amounts of the chelating divalent manganese source and the alkali metal hydroxide precipitant is (1:2) to (1: 10).

3. The method for synthesizing the high-activity layered zinc ion secondary battery cathode material by the room temperature one-step method according to claim 1, is characterized in that: the chelated divalent manganese source in the step 1 is sodium/potassium manganese ethylenediamine tetraacetate, sodium/potassium manganese hydroxyethyl ethylenediamine tetraacetate, sodium/potassium manganese diethylenetriamine pentaacetate or manganese triphosphate or manganese citrate; the alkali metal hydroxide precipitant is lithium hydroxide, sodium hydroxide, potassium hydroxide or rubidium hydroxide.

4. The method for synthesizing the high-activity layered zinc ion secondary battery cathode material by the room temperature one-step method according to claim 1, is characterized in that: in the step 2, the oxygen-containing atmosphere is air or oxygen.

5. The method for synthesizing the high-activity layered zinc ion secondary battery cathode material by the room temperature one-step method according to claim 1, is characterized in that: the speed of the rapid stirring in the step 2 is 500-3000 r/min.

6. The method for synthesizing the high-activity layered zinc ion secondary battery cathode material by the room temperature one-step method according to claim 1, is characterized in that: the oven temperature in step 3 was 80 ℃.

7. The application of the high-activity layered zinc ion secondary battery cathode material prepared by the method of claim 1 in a zinc ion secondary battery, which is characterized in that: the preparation method comprises the following steps of (60-80): (10-20): (10-20) mixing the components in a mass ratio to obtain slurry; drawing the slurry onto a conductive current collector with a three-dimensional structure to obtain a zinc battery anode with large surface capacity; the zinc ion secondary battery with high specific capacity is assembled by taking metal zinc as a negative electrode and a zinc battery positive electrode with large surface capacity as a positive electrode based on a neutral or near-neutral aqueous zinc ion electrolyte.

8. The application of the high-activity layered zinc ion secondary battery cathode material in the zinc ion secondary battery according to claim 7, wherein the three-dimensional conductive current collector is: stainless steel wire mesh, titanium mesh, or carbon felt.

Technical Field

The invention belongs to the technical field of water-based zinc ion batteries, and particularly relates to a preparation method of a zinc ion battery anode material with a high-activity layered structure and application of the zinc ion battery anode material in a zinc battery.

Background

The zinc ion battery has the technical characteristics of high safety, low cost, environmental protection and the like, and is one of ideal energy storage battery systems. In particular, zinc ion batteries based on manganese-based positive electrode materials have abundant raw material sources and have been receiving much attention since birth. Under the condition of alkaline electrolyte, the reversibility of the zinc-manganese dioxide battery is poor, so the zinc-manganese dioxide battery is used as a primary battery all the time; under neutral and near-neutral conditions, the zinc-manganese dioxide battery has good reversibility, but the manganese oxide positive electrode material prepared by the traditional electrolytic method has large particle size, small specific surface area and low activity, and is difficult to be made into a large-area capacity pole piece for use.

Many methods for synthesizing oxides of manganese are available, but except for electrolytic methods, high-temperature calcination or high-temperature high-pressure conditions are mostly required, for example, in the invention creation of patent No. CN 104211122A, manganese carbonate is prepared by using manganese sulfate and ammonium bicarbonate as raw materials, and then the manganese carbonate is calcined in a suspension decomposition kiln at a high temperature of 400 ℃ to obtain Mn₃O₄. Similarly, patentThe invention of CN 111115688A describes the preparation of MnO by high temperature calcination of manganese carbonate₂The heat treatment temperature is 150-500 ℃, and the product components are complex and closely related to the temperature; longyan Li et al add ammonium persulfate solution and manganese sulfate solution in a hydrothermal reaction kettle, react at 120 ℃ for 12h to obtain beta-MnO₂(Li et al.ACS APPLIED MATERIALS&INTERFACES,2020,12(11):12834-12846), the material has higher activity; but the product purity is not high under the high-temperature calcination condition, the process is complex, and other manganese oxide compounds are easily formed; the high-temperature and high-pressure atmosphere in the hydrothermal reaction is not suitable for industrial production.

Therefore, the search for a simple and feasible synthesis method can generate great promotion effect on the zinc-manganese secondary battery. In addition, the structure of the manganese oxide is also very critical to satisfy the stable storage of zinc ions. Conventional oxides of manganese such as alpha-MnO₂，β-MnO₂，γ-MnO₂The crystal structure is a tunnel structure, although the tunnel structure is stable, the de-intercalation reaction of zinc ions is difficult to realize, and compared with the prior art, the manganese oxide with the layered structure has better prospect in the application field of zinc ion batteries. Therefore, the development of the simple manganese oxide cathode material with the layered structure and the preparation method are very important.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provides a method for synthesizing a high-activity layered zinc ion secondary battery anode material by a one-step method at room temperature.

The method for synthesizing the high-activity layered zinc ion secondary battery anode material by the room temperature one-step method comprises the following steps:

step 1, dissolving raw materials: adding a chelating manganous source and an alkali metal hydroxide precipitator into deionized water respectively, and stirring at a high speed until the chelating manganous source and the alkali metal hydroxide precipitator are dissolved completely to obtain two solutions;

step 2, one-step reaction: mixing the two solutions obtained in the step 1 under the conditions of rapid stirring and oxygen-containing atmosphere introduction, and reacting for 1-5 h at room temperature; the continuous and rapid stirring is ensured in the whole reaction process, and the oxygen-containing atmosphere is continuously introduced;

and 3, separating a product: after the mixed reaction of the two solutions in the step 2 is finished, carrying out vacuum filtration or air filter pressing on a reaction product, and washing the reaction product for 3-5 times by using deionized water and alcohol respectively; and drying the product obtained by suction filtration and washing in an oven for 6-12 h to obtain the high-activity layered zinc ion secondary battery anode material.

Preferably, in the step 1, the concentration of manganese ions in deionized water for dissolving and chelating a divalent manganese source is 0.1-2 mol/L, and the concentration of alkali metal ions in deionized water for dissolving an alkali metal hydroxide precipitator is 0.1-8 mol/L; the ratio of the amounts of the chelating divalent manganese source and the alkali metal hydroxide precipitant is (1:2) to (1: 10).

Preferably, the chelating divalent manganese source in the step 1 is sodium/potassium manganese ethylenediamine tetraacetate, sodium/potassium manganese hydroxyethyl ethylenediamine tetraacetate, sodium/potassium manganese diethylenetriamine pentaacetate or manganese triphosphate or manganese citrate; the alkali metal hydroxide precipitant is lithium hydroxide, sodium hydroxide, potassium hydroxide or rubidium hydroxide.

Preferably, the oxygen-containing atmosphere in step 2 is air or oxygen.

Preferably, the speed of the rapid stirring in the step 2 is 500-3000 r/min.

Preferably, the temperature of the oven in step 3 is 80 ℃.

The high-activity layered zinc ion secondary battery anode material is applied to a zinc ion secondary battery: the preparation method comprises the following steps of (60-80): (10-20): (10-20) mixing the components in a mass ratio to obtain slurry; drawing the slurry onto a conductive current collector with a three-dimensional structure to obtain a zinc battery anode with large surface capacity; the zinc ion secondary battery with high specific capacity is assembled by taking metal zinc as a negative electrode and a zinc battery positive electrode with large surface capacity as a positive electrode based on a neutral or near-neutral aqueous zinc ion electrolyte.

Preferably, the three-dimensional conductive current collector is: stainless steel wire mesh, titanium mesh, or carbon felt.

The invention has the beneficial effects that: (1) the process for preparing the cathode material by the room-temperature one-step method is simple, has no special requirements on equipment, is low in cost and is easy for pilot scale production; (2) the main component of the prepared anode material is high-activity manganese oxide and has a microscopic layered crystal structure; (3) the manganese oxide has good crystallinity, high specific surface area, high activity, reversibility and micro-nano graded powder morphology; (4) when the material is used in a neutral or near-neutral water system zinc ion secondary battery, the specific capacity of the material is higher, more than 250mAh/g, the material is a good zinc ion secondary battery anode material, and the application prospect is wide.

Drawings

Fig. 1 is an XRD pattern of the high-activity layered-structure manganese oxide prepared in example 1.

Fig. 2 is an SEM image of the high activity layered structure manganese oxide prepared in example 1.

FIG. 3 is a BET gas adsorption/desorption curve of the high-activity layered-structure manganese oxide obtained in example 1.

Fig. 4 is a voltage-specific capacity curve diagram of a battery assembled by using the high-activity manganese oxide with a layered structure prepared in example 1 as a positive electrode material and using metal zinc as a negative electrode material.

Fig. 5 is a voltage-specific capacity curve diagram of a battery assembled by using the high-activity manganese oxide with a layered structure prepared in example 2 as a positive electrode material and using metal zinc as a negative electrode material.

Fig. 6 is an XRD pattern of the high-activity layered-structure manganese oxide prepared in example 3.

Fig. 7 is a low-magnification SEM image of the high-activity layered-structure manganese oxide prepared in example 3.

Fig. 8 is a high-magnification SEM image of the high-activity layered-structure manganese oxide obtained in example 3.

Detailed Description

The present invention will be further described with reference to the following examples. The following examples are set forth merely to aid in the understanding of the invention. It should be noted that, for a person skilled in the art, several modifications can be made to the invention without departing from the principle of the invention, and these modifications and modifications also fall within the protection scope of the claims of the present invention.

The invention relates to a preparation method for synthesizing a high-activity layered zinc ion secondary battery anode material by one-step process at room temperature, which adopts chelated divalent manganese ions as a manganese source and alkali metal-based hydroxide as a precipitator, oxidizes the divalent manganese ions into tetravalent manganese ions by one-step reaction in an oxygen-containing atmosphere, and simultaneously precipitates the tetravalent manganese ions from an aqueous solution, and the high-activity layered structure manganese oxide zinc ion secondary battery anode material can be obtained by filtering and washing. The prepared manganese oxide with a layered structure, a carbon material and a binder are uniformly mixed to prepare a high-capacity positive plate through a slurry drawing process, metal zinc is used as a negative electrode, and a zinc ion secondary battery is assembled on the basis of a neutral or near-neutral aqueous zinc ion electrolyte, so that the material can realize high reversible specific capacity of more than 250 mAh/g.

Example 1:

respectively dissolving 0.5mol of ethylene diamine tetraacetic acid manganese sodium powder and 2mol of sodium hydroxide powder in 1L of deionized water, and stirring until the materials are completely dissolved; and then, simultaneously dropwise adding the ethylene diamine tetraacetic acid manganese sodium solution and the sodium hydroxide solution into the reaction kettle, introducing air, stirring at a high speed of 1500 rpm at a speed of 1L/h, stirring for 2h after dropwise addition is finished, and keeping continuous introduction of the air. And (3) carrying out vacuum filtration on the suspension after the reaction, washing the suspension for 3 times by using deionized water and alcohol respectively, and finally placing the suspension in a vacuum oven to dry the suspension for 10 hours at the temperature of 80 ℃ to obtain an expected reaction product.

FIG. 1 is an XRD pattern of the highly active manganese oxide having a layered structure obtained in this example, and it can be seen that the diffraction peaks of the material are well matched with those of the standard card (PDF #43-1456) of manganese oxide having a layered structure, which shows that the synthesized product contains manganese oxide as a main component and has a layered crystal structure; further, it can be seen from the SEM image of the high activity manganese oxide having a layered structure obtained in this example shown in fig. 2 that: the synthesized powder has a micron spherical shape with self-assembled nano scale, and due to the micro-nano hierarchical structure, the material has a relatively high specific surface area which reaches 74.644m²(ii)/g; the BET gas adsorption and desorption curve of the manganese oxide with the high-activity layered structure is shown in figure 3, and the high specific surface area can accelerate ions on the surface interface of the materialThe transport process promotes the electrochemical reaction of zinc ions and realizes high specific capacity.

Based on the manganese oxide powder with the layered structure prepared in the embodiment, a slurry drawing process is adopted to prepare a positive pole piece, and the slurry comprises 70 wt% of manganese oxide, 20 wt% of acetylene black carbon material and 10 wt% of styrene butadiene rubber binder; and (4) pulling the slurry to a titanium mesh conductive current collector, and drying to obtain the positive pole piece. The method comprises the following steps of (1) assembling a battery by using zinc as a negative electrode and 1mol/L zinc sulfate and 0.2mol/L manganese sulfate as electrolytes, and testing, wherein the test result of a voltage-specific capacity curve diagram of the battery is shown in figure 4; the manganese oxide with the layered structure has the specific discharge capacity of 290mAh/g and the specific charge capacity of 302mAh/g, and shows good reversibility.

Example 2:

respectively dissolving 0.5mol of ethylene diamine tetraacetic acid manganese sodium powder and 4mol of sodium hydroxide powder in 1L of deionized water, and stirring until the materials are completely dissolved; and then, simultaneously dropwise adding the ethylene diamine tetraacetic acid manganese sodium solution and the sodium hydroxide solution into the reaction kettle, introducing air, stirring at a high speed of 2000 r/min at a dropwise adding speed of 2L/h, stirring for 2h after dropwise adding is finished, and keeping the continuous introduction of the air. And (3) carrying out vacuum filtration on the suspension after reaction, washing the suspension for 3 times by using deionized water and alcohol respectively, and finally placing the suspension in a vacuum oven to dry the suspension for 10 hours at the temperature of 80 ℃ to obtain an expected reaction product. The pole piece is prepared by adopting the same pole piece technology (slurry drawing technology) as that of the embodiment 1, zinc is used as a negative electrode, 2.5mol/L zinc chloride is used as electrolyte, the battery is assembled for testing, the test result of the voltage-specific capacity curve diagram of the battery is shown in figure 5, the specific capacity of the manganese oxide with the layered structure reaches 275mAh/g, the charging specific capacity is 289mAh/g, and the battery also has better reversibility.

Example 3:

respectively dissolving 0.5mol of ethylene diamine tetraacetic acid manganese sodium powder and 3mol of potassium hydroxide powder in 1L of deionized water, and stirring until the materials are completely dissolved; and then, simultaneously dropwise adding the ethylene diamine tetraacetic acid manganese sodium solution and the potassium hydroxide solution into the reaction kettle, introducing air, stirring at a high speed of 1500 rpm at a speed of 1L/h, stirring for 2h after dropwise addition is finished, and keeping continuous introduction of the air. And (3) carrying out vacuum filtration on the suspension after reaction, washing the suspension for 3 times by using deionized water and alcohol respectively, and finally placing the suspension in a vacuum oven to dry the suspension for 10 hours at the temperature of 80 ℃ to obtain an expected reaction product.

FIG. 6 is an XRD pattern of the highly active manganese oxide with a layered structure prepared in this example, and it can be seen that the diffraction peaks of the material are well matched with those of another standard card (PDF #86-0666) of manganese oxide with a layered structure, which shows that the synthesized product contains manganese oxide as a main component and has a layered crystal structure; further, it can be seen from the low-magnification SEM image of the high-activity layered manganese oxide shown in fig. 7 that the synthesized powder has a micron spherical morphology, and it can be seen from the larger-magnification SEM photograph shown in fig. 8 that the micron sphere surface contains nano flakes, and the existence of the micro-nano hierarchical structure also enables the material to have a relatively high specific surface area, which is helpful for obtaining a high specific capacity.

Example 4:

respectively dissolving 0.2mol of manganese citrate powder and 1.6mol of sodium hydroxide powder in 1L of deionized water, and stirring until the manganese citrate powder and the sodium hydroxide powder are completely dissolved; and then, dropwise adding the manganese citrate solution and the sodium hydroxide solution into the reaction kettle simultaneously, introducing air, stirring at a high speed of 1500 rpm at a speed of 1L/h, stirring for 2h after dropwise addition is finished, and keeping continuous introduction of the air. And (3) carrying out vacuum filtration on the suspension after reaction, washing the suspension for 3 times by using deionized water and alcohol respectively, and finally placing the suspension in a vacuum oven to dry the suspension for 10 hours at the temperature of 80 ℃ to obtain an expected reaction product.

And (4) conclusion:

the synthesis method has the characteristics of simplicity, high efficiency, low cost, mass preparation and the like. The prepared material has high specific surface area, high activity, high specific capacity and reversibility, and is a good anode material of a water system zinc ion secondary battery.