A dodecyl trimethyl ammonium bromide doped manganese dioxide composite material, a preparation method thereof and application thereof in a zinc ion battery
By developing a method for preparing a composite material doped with dodecyltrimethylammonium bromide and manganese dioxide, the problems of conductivity and ion diffusion rate of zinc-ion battery cathode materials were solved, improving the specific capacity and stability of the battery and achieving a high-efficiency performance enhancement of zinc-ion batteries.
Patent Information
- Application Number
- CN202610251891.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-03-03
- Publication Date
- 2026-05-29
AI Technical Summary
The existing zinc-ion battery cathode material, manganese dioxide, has poor conductivity and slow ion diffusion rate, resulting in poor rate performance and poor cycle stability, making it difficult to meet the needs of practical applications.
A method for preparing a composite material doped with dodecyltrimethylammonium bromide and manganese dioxide was adopted. The dodecyltrimethylammonium bromide and manganese dioxide were mixed in isopropanol through a hydrothermal reaction, followed by hydrothermal treatment and vacuum drying to form the composite material.
It significantly improves the conductivity and ion diffusion rate of the material, reduces internal resistance, increases the specific capacity of zinc-ion batteries, and enhances the electrochemical performance and stability of the batteries.
Smart Images
Figure CN122117857A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of battery materials technology, and specifically relates to a dodecyltrimethylammonium bromide-doped manganese dioxide composite material, its preparation method, and its application in zinc-ion batteries. Background Technology
[0002] The escalating global energy crisis and the large-scale development and utilization of renewable energy sources such as solar and wind power have created an increasingly urgent demand for efficient, safe, and low-cost energy storage devices. Renewable energy sources are generally characterized by intermittency and volatility, requiring high-performance energy storage technologies to achieve stable energy output and supply-demand matching. Therefore, energy storage devices have become a core support for promoting the development of the clean energy industry. Among the current mainstream energy storage battery systems, lithium-ion batteries have achieved large-scale application due to their high energy density and long cycle life, widely covering portable electronic devices, new energy vehicles, and other fields. However, the limited global reserves and extremely uneven distribution of lithium resources have led to a continuous rise in raw material costs, severely restricting the application and promotion of large-scale energy storage scenarios. At the same time, the chemically active lithium metal anode and flammable organic electrolyte used in lithium-ion batteries are prone to short-circuit fires, thermal runaway explosions, and other safety hazards, posing significant application risks in scenarios with high safety requirements, such as portable energy storage and home energy storage, further limiting the expansion of their application scope.
[0003] Against this backdrop, water-rechargeable zinc-ion batteries have become an ideal candidate energy storage system to replace lithium-ion batteries due to their inherent safety, lack of combustion and explosion risks, high and uniform zinc resource abundance in the Earth's crust, and simple and easily scalable battery manufacturing process. They have attracted widespread attention from academia and industry. From an electrochemical perspective, the zinc anode has a lower standard redox potential (-0.76 V compared to the standard hydrogen electrode), which can impart a higher output voltage to the battery; more importantly, Zn... 2+ The two-electron transfer reaction mechanism of the Zn redox couple, compared to Li in lithium-ion batteries... + The single-electron transfer of Li can theoretically provide higher specific capacity and energy density, making it promising for applications in portable electronic devices, emergency energy storage, and large-scale grid energy storage. The cathode material is the core of zinc-ion batteries, and its performance directly determines the battery's energy density, rate performance, and cycle stability, representing a key bottleneck restricting industrialization. Manganese dioxide, due to its abundant resources, high theoretical capacity, and suitable redox potential, has become one of the most promising cathode materials for zinc-ion batteries. However, pure-phase manganese dioxide inherently has poor conductivity and a slow ion diffusion rate, and is prone to crystal structure phase transitions and dissolution and loss of active components during charge-discharge cycles, resulting in poor rate performance and cycle stability, making it difficult to meet practical application requirements. Summary of the Invention
[0004] To address the aforementioned technical problems, one objective of this invention is to provide a dodecyltrimethylammonium bromide-doped manganese dioxide composite material and its preparation method.
[0005] The second objective of this invention is to provide the application of dodecyltrimethylammonium bromide-doped manganese dioxide composite material in zinc-ion batteries.
[0006] The technical solution adopted in this invention is: a dodecyltrimethylammonium bromide-doped manganese dioxide composite material, the preparation method of which includes: adding manganese dioxide and dodecyltrimethylammonium bromide into isopropanol, stirring, transferring the resulting mixed solution into a reaction vessel, carrying out a hydrothermal reaction, and after the reaction is completed, vacuum drying the resulting product to obtain the dodecyltrimethylammonium bromide-doped manganese dioxide composite material.
[0007] Furthermore, in a molar ratio, manganese dioxide : dodecyltrimethylammonium bromide = (5-20) : 1.
[0008] Furthermore, the hydrothermal reaction is carried out at 170 ℃~190 ℃ for 12 h~14 h.
[0009] Further, the manganese dioxide is prepared by adding potassium permanganate and manganese sulfate to deionized water, stirring, transferring the resulting mixed solution into a reaction vessel, and carrying out a hydrothermal reaction at 170 ℃~190 ℃ for 12 h~14 h. After the reaction is completed, the product is dried under vacuum to obtain manganese dioxide.
[0010] The present invention relates to the application of dodecyltrimethylammonium bromide-doped manganese dioxide composite material as a positive electrode material in zinc-ion batteries.
[0011] Furthermore, the zinc-ion battery is an aqueous zinc-ion battery.
[0012] An aqueous zinc-ion battery, using the aforementioned dodecyltrimethylammonium bromide-doped manganese dioxide composite material as the positive electrode material, is prepared by the following steps: (1) Preparation of positive electrode: After the dodecyltrimethylammonium bromide-doped manganese dioxide composite material is mixed evenly with binder and conductive material, a small amount of NMP is added as solvent. After mixing evenly, it is directly coated on the substrate, vacuum dried, and taken out to obtain a positive electrode coated with dodecyltrimethylammonium bromide-doped manganese dioxide composite material. (2) Preparation of negative electrode: Zinc sheet is used as negative electrode; (3) Using the positive electrode sheet prepared in step (1) as the positive electrode and the negative electrode sheet prepared in step (2) as the negative electrode, and the electrolyte being a mixed solution of zinc sulfate and manganese sulfate, an aqueous zinc-ion battery is obtained. Further, in step (1), the adhesive is PVDF.
[0013] Further, in step (1), the conductive material is Super-p.
[0014] Furthermore, in step (2), the zinc sheet has a purity of 99% to 99.99%.
[0015] Furthermore, in step (3), the concentration of zinc sulfate in the electrolyte is 1.5 M to 2.5 M; and the concentration of manganese sulfate is 0.1 M to 0.3 M.
[0016] The beneficial effects of this invention are: 1. This invention uses a dodecyltrimethylammonium bromide-doped manganese dioxide composite material as a positive electrode material in zinc-ion batteries, which significantly improves the conductivity and ion diffusion rate of the material and reduces the internal resistance.
[0017] 2. In this invention, a zinc-ion battery is assembled using a dodecyltrimethylammonium bromide-doped manganese dioxide composite material as the positive electrode material. Due to the doping of dodecyltrimethylammonium bromide, the specific capacity of the zinc-ion battery is increased by 219.44 mAh / g, reaching a specific capacity of 517.78 mAh / g.
[0018] 3. The material selected in this invention, dodecyltrimethylammonium bromide, has excellent pseudocapacitive properties and is inexpensive, environmentally friendly, and recyclable. It also possesses a high theoretical specific capacitance and excellent stability. Attached Figure Description
[0019] Figure 1 This is the XRD pattern of the dodecyltrimethylammonium bromide-doped manganese dioxide composite material prepared in Example 3 of this invention.
[0020] Figure 2 This is the SEM spectrum of the dodecyltrimethylammonium bromide-doped manganese dioxide composite material prepared in Example 3 of this invention.
[0021] Figure 3 This is a comparison of the cyclic voltammetry curves of the dodecyltrimethylammonium bromide-doped manganese dioxide zinc-ion battery prepared according to the present invention.
[0022] Figure 4 This is a comparison chart of the specific capacity of the dodecyltrimethylammonium bromide-doped manganese dioxide zinc-ion battery prepared according to the present invention. Detailed Implementation
[0023] Example 1: Dodecyltrimethylammonium bromide-doped manganese dioxide composite material (molar ratio 5:1)
[0024] Preparation method
[0025] Weigh 0.474 g of potassium permanganate and 0.101 g of manganese sulfate monohydrate and dissolve them in 30 mL of deionized water. Stir magnetically for 1 h at room temperature to ensure thorough mixing. Transfer the thoroughly mixed solution to a stainless steel hydrothermal reactor lined with polytetrafluoroethylene and react hydrothermally at 180 °C for 12 h. After the reactor has completely cooled to room temperature, remove the product, wash it three times with deionized water and anhydrous ethanol by centrifugation, and dry it under vacuum at 60 °C for 12 h to obtain pristine manganese dioxide.
[0026] Manganese dioxide and dodecyltrimethylammonium bromide were added to 30 mL of isopropanol at a molar ratio of 5:1 and stirred until the components were completely dissolved. After the solution was stirred evenly, it was transferred to a stainless steel hydrothermal reactor lined with polytetrafluoroethylene and hydrothermally reacted at 180 °C for 12 h. After the reactor was completely cooled to room temperature, the product was removed, washed three times with isopropanol and anhydrous ethanol by centrifugation, and dried under vacuum at 60 °C for 12 h to obtain the dodecyltrimethylammonium bromide-doped manganese dioxide composite material.
[0027] Example 2: Dodecyltrimethylammonium bromide-doped manganese dioxide composite material (molar ratio 10:1)
[0028] Preparation method
[0029] Weigh 0.474 g of potassium permanganate and 0.101 g of manganese sulfate monohydrate and dissolve them in 30 mL of deionized water. Stir magnetically for 1 h at room temperature to ensure thorough mixing. Transfer the thoroughly mixed solution to a stainless steel hydrothermal reactor lined with polytetrafluoroethylene and react hydrothermally at 180 °C for 12 h. After the reactor has completely cooled to room temperature, remove the product, wash it three times with deionized water and anhydrous ethanol by centrifugation, and dry it under vacuum at 60 °C for 12 h to obtain pristine manganese dioxide.
[0030] Manganese dioxide and dodecyltrimethylammonium bromide were added to 30 mL of isopropanol at a molar ratio of 10:1 and stirred until the components were completely dissolved. After the solution was stirred evenly, it was transferred to a stainless steel hydrothermal reactor lined with polytetrafluoroethylene and hydrothermally reacted at 180 °C for 12 h. After the reactor was completely cooled to room temperature, the product was removed, washed three times with isopropanol and anhydrous ethanol by centrifugation, and then dried under vacuum at 60 °C for 12 h to obtain the dodecyltrimethylammonium bromide-doped manganese dioxide composite material.
[0031] Example 3: Dodecyltrimethylammonium bromide-doped manganese dioxide composite material (molar ratio 15:1)
[0032] (I) Preparation method
[0033] Weigh 0.474 g of potassium permanganate and 0.101 g of manganese sulfate monohydrate and dissolve them in 30 mL of deionized water. Stir magnetically for 1 h at room temperature to ensure thorough mixing. Transfer the thoroughly mixed solution to a stainless steel hydrothermal reactor lined with polytetrafluoroethylene and react hydrothermally at 180 °C for 12 h. After the reactor has completely cooled to room temperature, remove the product, wash it three times with deionized water and anhydrous ethanol by centrifugation, and dry it under vacuum at 60 °C for 12 h to obtain raw manganese dioxide, labeled as MO.
[0034] Manganese dioxide and dodecyltrimethylammonium bromide were added to 30 mL of isopropanol at a molar ratio of 15:1 and stirred until the components were completely dissolved. After the solution was stirred evenly, it was transferred to a stainless steel hydrothermal reactor lined with polytetrafluoroethylene and hydrothermally reacted at 180 °C for 12 h. After the reactor was completely cooled to room temperature, the product was removed, washed three times with isopropanol and anhydrous ethanol by centrifugation, and dried under vacuum at 60 °C for 12 h to obtain the dodecyltrimethylammonium bromide-doped manganese dioxide composite material, labeled as DTAB-MO.
[0035] (II) Testing
[0036] Figure 1 These are the XRD patterns of the dodecyltrimethylammonium bromide-doped manganese dioxide composite material and the manganese dioxide material prepared in this embodiment. Figure 1 It is evident that doping with dodecyltrimethylammonium bromide did not produce significant changes; the shift in individual peaks indicates that the doping with dodecyltrimethylammonium bromide was successful.
[0037] Figure 2 This is a SEM image of the dodecyltrimethylammonium bromide-doped manganese dioxide composite material prepared in this embodiment. Figure 2 It is evident that the dodecyltrimethylammonium bromide-doped manganese dioxide composite material is a typical nanoflower structure.
[0038] Example 4: Dodecyltrimethylammonium bromide-doped manganese dioxide composite material (molar ratio 20:1)
[0039] Preparation method
[0040] Weigh 0.474 g of potassium permanganate and 0.101 g of manganese sulfate monohydrate and dissolve them in 30 mL of deionized water. Stir magnetically for 1 h at room temperature to ensure thorough mixing. Transfer the thoroughly mixed solution to a stainless steel hydrothermal reactor lined with polytetrafluoroethylene and react hydrothermally at 180 °C for 12 h. After the reactor has completely cooled to room temperature, remove the product, wash it three times with deionized water and anhydrous ethanol by centrifugation, and dry it under vacuum at 60 °C for 12 h to obtain pristine manganese dioxide.
[0041] Manganese dioxide and dodecyltrimethylammonium bromide were added to 30 mL of isopropanol at a molar ratio of 20:1, and stirred until the components were completely dissolved. After the solution was stirred evenly, it was transferred to a stainless steel hydrothermal reactor lined with polytetrafluoroethylene and hydrothermally reacted at 180 °C for 12 h. After the reactor was completely cooled to room temperature, the product was removed, washed three times each with isopropanol and anhydrous ethanol by centrifugation, and then vacuum dried at 60 °C for 12 h to obtain the dodecyltrimethylammonium bromide-doped manganese dioxide composite material.
[0042] Example 5: Application of dodecyltrimethylammonium bromide-doped manganese dioxide composite material as a cathode material in aqueous zinc-ion batteries.
[0043] (I) Preparation of aqueous zinc-ion batteries
[0044] 1) Preparation of positive electrode: The dodecyltrimethylammonium bromide-doped manganese dioxide composite material prepared in Example 3 was mixed with PVDF and Super-p at a mass ratio of 7:2:1. A small amount of NMP was added as a solvent and mixed evenly. The mixture was then directly coated onto the substrate carbon paper, dried in a vacuum drying oven, and removed to obtain a positive electrode coated with the dodecyltrimethylammonium bromide-doped manganese dioxide composite material. 2) Preparation of negative electrode: The zinc sheet with a thickness of 0.1 mm and a purity of 99.99% is repeatedly polished with sandpaper to remove the oxide layer on the surface. The polished zinc sheet is then cut into a circle with a diameter of 12 mm to serve as the negative electrode.
[0045] 3) Using the positive electrode sheet prepared in step 1) as the positive electrode and the negative electrode sheet prepared in step 2) as the negative electrode, and selecting a mixed solution of 2M zinc sulfate and 0.2M manganese sulfate as the electrolyte, an aqueous zinc-ion battery is obtained.
[0046] Figure 3 The cyclic voltammonia curves of aqueous zinc-ion batteries assembled using the dodecyltrimethylammonium bromide-doped manganese dioxide composite material and manganese dioxide material prepared in Example 3 as positive electrode materials are shown. Figure 3 It can be seen that at 0.2 mVs - ¹Cyclic voltammetry results at scan rate show that dodecyltrimethylammonium bromide-modified manganese dioxide (DTAB-MO) exhibits superior electrochemical performance compared to unmodified manganese dioxide (MO). DTAB-MO shows a significantly increased redox peak current density, sharper and more symmetrical peak shape, and lower polarization, clearly demonstrating that DTAB modification effectively enhances the electrochemical activity, reaction reversibility, and zinc ion insertion / extraction kinetics of the manganese dioxide cathode material.
[0047] Figure 4This is a specific capacity diagram of aqueous zinc-ion batteries assembled using the dodecyltrimethylammonium bromide-doped manganese dioxide composite material and manganese dioxide material prepared in Example 3 as positive electrode materials. Figure 4 It is evident that the zinc-ion battery assembled with dodecyltrimethylammonium bromide-doped manganese dioxide cathode material exhibits a 219.44 mAh / g increase in specific capacity after doping with dodecyltrimethylammonium bromide, reaching a specific capacity as high as 517.78 mAh / g.
[0048] (II) Effect of dodecyltrimethylammonium bromide-doped manganese dioxide composite materials prepared at different molar ratios on the electrochemical performance of aqueous zinc-ion batteries
[0049] 1) Preparation of positive electrode: The dodecyltrimethylammonium bromide-doped manganese dioxide composite materials prepared in Examples 1-4 were mixed with PVDF and Super-p at a mass ratio of 7:2:1. A small amount of NMP was added as a solvent and mixed evenly. The mixture was then directly coated onto a substrate carbon paper, dried in a vacuum drying oven, and removed to obtain positive electrode sheets coated with dodecyltrimethylammonium bromide-doped manganese dioxide composite materials with different molar ratios. 2) Preparation of negative electrode: The zinc sheet with a thickness of 0.1 mm and a purity of 99.99% is repeatedly polished with sandpaper to remove the oxide layer on the surface. The polished zinc sheet is then cut into a circle with a diameter of 12 mm to serve as the negative electrode.
[0050] 3) Using the positive electrode sheet prepared in step 1) as the positive electrode and the negative electrode sheet prepared in step 2) as the negative electrode, a mixed solution of 2M zinc sulfate and 0.2M manganese sulfate was selected as the electrolyte to obtain an aqueous zinc-ion battery and test its electrochemical performance. The results are shown in Table 1.
[0051] Table 1
[0052] As shown in Table 1, different molar ratios of manganese dioxide and dodecyltrimethylammonium bromide significantly affect the electrochemical performance of the prepared dodecyltrimethylammonium bromide-doped manganese dioxide composite material when applied to aqueous zinc-ion batteries. With increasing molar ratio, the specific capacity of the material continuously increases from 319.88 mAh / g to 517.78 mAh / g as the molar ratio of manganese dioxide to dodecyltrimethylammonium bromide gradually increases from 5:1 to 15:1. When the molar ratio further increases to 20:1, the specific capacity drops back to 351.34 mAh / g, showing an overall trend of first increasing and then decreasing. When the amount of dodecyltrimethylammonium bromide added is too high (e.g., molar ratio 5:1), excessive surfactant can easily form an insulating layer on the material surface, blocking ion transport channels or destroying the active structure of manganese dioxide, resulting in limited improvement in specific capacity, only slightly higher than pure manganese dioxide (298.34 mAh / g). When the amount of dodecyltrimethylammonium bromide added is too low (e.g., molar ratio 20:1), the modification effect is insufficient, failing to fully improve the conductivity, ion diffusion kinetics, and structural stability of the material, and the modification effect is not fully realized, with the specific capacity significantly lower than the optimal ratio. As shown in Table 1, the dodecyltrimethylammonium bromide-doped manganese dioxide composite material obtained with a molar ratio of manganese dioxide to dodecyltrimethylammonium bromide of 15:1 exhibits the best electrochemical performance in the prepared aqueous zinc-ion battery. The assembled aqueous zinc-ion battery shows an increase in specific capacity of 219.44 mAh / g, reaching a specific capacity as high as 517.78 mAh / g.
Claims
1. A dodecyltrimethylammonium bromide-doped manganese dioxide composite material, characterized in that, The preparation method includes: adding manganese dioxide and dodecyltrimethylammonium bromide to isopropanol, stirring, transferring the resulting mixed solution into a reaction vessel, carrying out a hydrothermal reaction, and after the reaction is completed, drying the resulting product under vacuum to obtain a dodecyltrimethylammonium bromide-doped manganese dioxide composite material.
2. The dodecyltrimethylammonium bromide-doped manganese dioxide composite material according to claim 1, characterized in that, The molar ratio is manganese dioxide:dodecyltrimethylammonium bromide = (5-20):
1.
3. The dodecyltrimethylammonium bromide-doped manganese dioxide composite material according to claim 1, characterized in that, The hydrothermal reaction is carried out at 170 ℃~190 ℃ for 12 h~14 h.
4. The dodecyltrimethylammonium bromide-doped manganese dioxide composite material according to claim 1, characterized in that, The manganese dioxide is prepared by adding potassium permanganate and manganese sulfate to deionized water, stirring, transferring the resulting mixed solution into a reaction vessel, and carrying out a hydrothermal reaction at 170 ℃~190 ℃ for 12 h~14 h. After the reaction is completed, the product is dried under vacuum to obtain manganese dioxide.
5. The application of the dodecyltrimethylammonium bromide-doped manganese dioxide composite material according to any one of claims 1-4 as a positive electrode material in zinc-ion batteries.
6. The application according to claim 5, characterized in that, The zinc-ion battery is an aqueous zinc-ion battery.
7. An aqueous zinc-ion battery, characterized in that, Using the dodecyltrimethylammonium bromide-doped manganese dioxide composite material according to any one of claims 1-4 as the positive electrode material, the preparation method includes the following steps: (1) Preparation of positive electrode: After the dodecyltrimethylammonium bromide-doped manganese dioxide composite material is mixed evenly with binder and conductive material, a small amount of NMP is added as solvent. After mixing evenly, it is directly coated on the substrate, vacuum dried, and taken out to obtain a positive electrode coated with dodecyltrimethylammonium bromide-doped manganese dioxide composite material. (2) Preparation of negative electrode: Zinc sheet is used as negative electrode; (3) Using the positive electrode sheet prepared in step (1) as the positive electrode and the negative electrode sheet prepared in step (2) as the negative electrode, and the electrolyte is a mixed solution of zinc sulfate and manganese sulfate, an aqueous zinc-ion battery is obtained.
8. The aqueous zinc-ion battery according to claim 7, characterized in that, In step (1), the adhesive is PVDF; the conductive material is Super-p.
9. An aqueous zinc-ion battery according to claim 7, characterized in that, In step (2), the zinc sheet has a purity of 99% to 99.99%.
10. An aqueous zinc-ion battery according to claim 7, characterized in that, In step (3), the concentration of zinc sulfate in the electrolyte is 1.5 M to 2.5 M; the concentration of manganese sulfate is 0.1 M to 0.3 M.