High specific capacity α-moo3 negative electrode material and electrode sheet, and preparation method and application thereof
Patent Information
- Application Number
- CN202610941992.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-06-29
- Publication Date
- 2026-10-09
AI Technical Summary
层状α-MoO3具有开放的一维离子扩散通道，理论质子存储容量高，是极具潜力的水系质子电池负极材料，然而，传统方法制备的α-MoO3存在本征电子导电性差、质子扩散动力学缓慢、充放电过程中晶格易畸变坍塌、比表面积与活性位点不足等问题，导致其实际可逆比容量偏低、循环稳定性与倍率性能不佳，难以满足高性能水系质子电池的应用需求；同时，现有制备工艺普遍存在形貌与晶相调控精度不足、反应条件苛刻、难以规模化生产等缺陷，严重制约了α-MoO3基负极材料在水系质子电池中的实际应用与性能提升
[0015]本发明通过水热合成方法，调节反应原料配比、反应温度以及反应时间，合成具有特定晶面配比的α-MoO3材料；硝酸不仅提供酸性环境，还通过调节体系pH与离子强度，影响钼前驱体的水解、缩合与晶核生长速率，进而控制α-MoO3晶体不同晶面的生长速率差异，实现对（020）与（021）晶面暴露比例的定向调控，构建兼具高效离子传输通道与连续电子传导网络的晶体界面结构，使离子嵌入/脱出动力学与电子迁移速率实现动态匹配，从而显著提升材料整体电化学传输性能；
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Abstract
Description
Technical Field
[0001] This invention pertains to battery anode material technology, and particularly relates to a high specific capacity α-MoO3 anode material and electrode sheet, its preparation method, and its application. Background Technology
[0002] With the rapid development of large-scale energy storage and safe electrochemical energy storage technologies, aqueous proton batteries have shown significant application prospects in the energy storage field due to their advantages such as fast proton carrier migration rate, safe and stable aqueous electrolytes, low cost, and environmental friendliness. Layered α-MoO3 possesses open one-dimensional ion diffusion channels and theoretically has a high proton storage capacity, making it a highly promising anode material for aqueous proton batteries. However, α-MoO3 prepared by traditional methods suffers from problems such as poor intrinsic electronic conductivity, slow proton diffusion kinetics, easy lattice distortion and collapse during charge and discharge, and insufficient specific surface area and active sites. This results in low actual reversible specific capacity, poor cycle stability, and poor rate performance, making it difficult to meet the application requirements of high-performance aqueous proton batteries. At the same time, existing preparation processes generally suffer from insufficient precision in morphology and crystal phase control, harsh reaction conditions, and difficulty in large-scale production, which seriously restricts the practical application and performance improvement of α-MoO3-based anode materials in aqueous proton batteries.
[0003] The existing preparation methods mainly include solvothermal methods and high-temperature calcination methods. However, conventional calcination methods are difficult to precisely control the crystal phase, morphology and pore structure of the product. The product is prone to agglomeration, insufficient exposure of active sites and poor affinity with electrolyte. At the same time, some processes have problems such as complicated steps, harsh conditions, poor repeatability and difficulty in large-scale preparation. They cannot achieve high specific capacity, long cycle life and excellent rate performance at the same time, which seriously limits their practical application in high-performance aqueous proton batteries. Summary of the Invention
[0004] The purpose of this invention is to provide a high specific capacity α-MoO3 anode material and its preparation method, aiming to solve the problems mentioned in the background art.
[0005] To achieve the above objectives, the present invention provides the following technical solution:
[0006] On one hand, the present invention provides a method for preparing a high specific capacity α-MoO3 anode material, comprising the following steps:
[0007] S1. Dissolve 1.0 g of ammonium heptamolybdate tetrahydrate in 40 mL of deionized water and stir until completely dissolved. Then, add nitric acid with a concentration of 65% to 68% dropwise while stirring. The molar ratio of nitric acid to ammonium heptamolybdate tetrahydrate is 90:1. Continue stirring after the addition is complete to obtain a mixed solution.
[0008] S2, the mixed solution is transferred to a reaction vessel and hydrothermally reacted at 165~175 ℃ for 2.5~3.5 h. After the reaction is completed, the solution is centrifuged, washed and dried to obtain α-MoO3 nanorods.
[0009] S3, the α-MoO3 nanorods, conductive graphite and polyvinylidene fluoride binder are mixed at a mass ratio of 7:2:1 to obtain the high specific capacity α-MoO3 anode material.
[0010] On the other hand, the present invention provides a high specific capacity α-MoO3 anode material, which is prepared by the above preparation method.
[0011] In another aspect, the present invention provides a method for preparing a high specific capacity α-MoO3 negative electrode sheet, comprising the following steps: S4: adding N-methylpyrrolidone solvent to the high specific capacity α-MoO3 negative electrode material and grinding it evenly to form a slurry, then uniformly coating it on carbon paper and drying it under vacuum to obtain a high specific capacity α-MoO3 negative electrode sheet.
[0012] In another aspect, the present invention provides a high specific capacity α-MoO3 negative electrode sheet, which is prepared by the preparation method described above.
[0013] In another aspect, the present invention provides an application of the high specific capacity α-MoO3 anode material described above in the preparation of aqueous proton batteries.
[0014] Compared with the prior art, the specific beneficial effects of the present invention are as follows:
[0015] This invention synthesizes α-MoO3 materials with specific crystal facet ratios by adjusting the ratio of reactants, reaction temperature, and reaction time through a hydrothermal synthesis method. Nitric acid not only provides an acidic environment but also affects the hydrolysis, condensation, and crystal nucleus growth rate of the molybdenum precursor by adjusting the pH and ionic strength of the system. This controls the difference in growth rate of different crystal faces of α-MoO3 crystals, achieving directional control of the exposure ratio of (020) and (021) crystal faces. It constructs a crystal interface structure that combines efficient ion transport channels and a continuous electron conduction network, enabling dynamic matching of ion insertion / extraction kinetics and electron migration rate, thereby significantly improving the overall electrochemical transport performance of the material.
[0016] This invention improves upon the traditional hydrothermal method, which is simple and safe, and the specific capacitance of α-MoO3 with a specific crystal plane ratio is significantly improved compared to ordinary α-MoO3 samples.
[0017] The negative electrode material prepared using this α-MoO3 has good compatibility with aqueous electrolytes and achieves a higher reversible specific capacity of 350 mAh / g in aqueous proton batteries. It fully leverages the proton storage advantages of the material and can significantly improve the energy density and lifespan of aqueous proton batteries, showing good prospects for practical application and industrialization. Attached Figure Description
[0018] Figure 1 The images show the XRD structural characterization of the three samples provided in the embodiments of the present invention and Comparative Examples 1 and 2.
[0019] Figure 2 For the three samples and Figure 1 Corresponding peak intensity comparison diagram of (021) / (020) crystal planes;
[0020] Figure 3 A 500nm scale scan of MoO3(021)+(020) provided in an embodiment of the present invention;
[0021] Figure 4 A 300nm scale scan of MoO3(021)+(020) provided in an embodiment of the present invention;
[0022] Figure 5 The cyclic voltammetry curves for the three groups of samples are shown below.
[0023] Figure 6 The constant current charge-discharge curves of the three groups of samples are shown below.
[0024] Figure 7 The figure shows the electrochemical galvanostatic intermittent titration (GITT) technique used for the MoO3 (020) sample of Comparative Example 2.
[0025] Figure 8 The figure shows the electrochemical galvanostatic intermittent titration (GITT) technique used for sample MoO3 (021) of Comparative Example 1.
[0026] Figure 9 The figure shows the electrochemical galvanostatic intermittent titration (GITT) technique for MoO3(021)+(020) provided in the embodiments of the present invention.
[0027] Figure 10 The graph shows the performance test results of a single electrode according to an embodiment of the present invention. Detailed Implementation
[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.
[0029] <Example 1>
[0030] A high specific capacity α-MoO3 anode material is prepared by the following steps:
[0031] (1) Take 1.0g of (NH4)6Mo7O 24 • 4H2O (AHM, ammonium heptamolybdate tetrahydrate) was dissolved in 40 mL of deionized water and stirred for 10 minutes to ensure complete dissolution. During stirring, a certain volume of concentrated HNO3 was slowly added dropwise, where n(HNO3):n(AHM) = 90:1, corresponding to a nitric acid volume of 4.56 mL. After the addition was complete, stirring was continued for 10 minutes. The resulting mixed solution was transferred to a reaction vessel and placed in an oven. The reaction was carried out at 165~175 ℃ for 2.5~3.5 h, preferably at 170 ℃ for 3 h. After the reaction was completed, the product was collected by centrifugation, washed three times with anhydrous ethanol and deionized water respectively, and dried overnight in a vacuum drying oven at 60 ℃ for 12 hours to prepare α-MoO3 nanorods. This group of samples was denoted as MoO3(021)+(020).
[0032] (2) The α-MoO3 nanorods, conductive graphite and polyvinylidene fluoride (PVDF) binder were mixed in a mass ratio of 7:2:1. After mixing evenly, N-methylpyrrolidone (NMP) solvent was added and the mixture was ground thoroughly to form a uniformly dispersed slurry. The slurry was then evenly coated onto carbon paper and dried overnight in a vacuum drying oven for 12 hours.
[0033] In this way, a high specific capacity α-MoO3 anode material based on the mixture of α-MoO3 nanorods with conductive agent and binder can be obtained, and further, a high specific capacity α-MoO3 anode sheet based on carbon paper as current collector can be obtained.
[0034] Here, concentrated HNO3 refers to a concentration of 65% to 68% by mass.
[0035] <Comparative Example 1>
[0036] Compared with Example 1, the difference is that the volume of nitric acid was adjusted to 4.05 mL, the reaction time was 48 h, and the prepared sample was denoted as MoO3 (021).
[0037] <Comparative Example 2>
[0038] Compared with Example 1, the difference is that the volume of nitric acid was adjusted to 4.05 mL, the reaction time was 24 h, and the prepared sample was denoted as MoO3(020).
[0039] Performance Testing
[0040] The three groups of samples obtained from Example 1, Comparative Example 1, and Comparative Example 2, namely MoO3(021)+(020), MoO3(021), and MoO3(020), were tested and the results were as follows: Figure 1 The XRD plot shown has the horizontal axis representing angle (degree) and the vertical axis representing intensity (intensity).
[0041] Correspondingly, the peak intensity comparison diagrams of the (021) / (020) crystal planes of the three groups of samples are as follows: Figure 2 As shown, the horizontal axis represents the intensity ratio. MoO3(021) represents the sample with a higher proportion of exposed (021) crystal planes, MoO3(020) represents the sample with a higher proportion of exposed (020) crystal planes, and MoO3(021)+(020) represents the sample with a (021) to (020) crystal plane ratio of 1.5:1.
[0042] exist Figure 3 , Figure 4 The scan images of MoO3(021)+(020) are shown at different scales of 500nm and 300nm. It can be seen that the sample morphology is a hexagonal prism with a length in the range of 1~2μm and a width in the range of 0.16~0.2μm.
[0043] Figure 5 The cyclic voltammetry curves for three samples are shown, where the horizontal axis represents voltage and the vertical axis represents current. Figure 6 The constant current charge-discharge curves for three samples are shown, where the horizontal axis represents specific capacity and the vertical axis represents potential voltage. Figure 5 , Figure 6 It can be seen that the specific capacity of the MoO3(021)+(020) material is significantly improved, and its performance reaches the best. At a current density of 10A / g, its specific capacity is about 350mAh / g.
[0044] More specifically, the α-MoO3 nanorods prepared in Example 1, conductive graphite, and polyvinylidene fluoride (PVDF) binder were mixed in a mass ratio of 7:2:1. After thorough mixing, N-methylpyrrolidone (NMP) solvent was added, and the mixture was thoroughly ground to form a uniformly dispersed slurry. This slurry was then uniformly coated onto carbon paper and dried in a vacuum drying oven for 12 hours. Using the graphite rod as the counter electrode, the calomel electrode (SCE) as the reference electrode, and 8 M H2SO4 solution as the electrolyte, constant current charge-discharge tests were performed with a voltage window of -0.4-0.5V vs SCE. At a current density of 10 A / g, the initial discharge specific capacity was 350 mAh / g; even at a high current density of 200 A / g, the discharge specific capacity still reached approximately 250 mAh / g. Figure 10 As shown, the horizontal axis represents specific capacity, and the vertical axis represents potential voltage.
[0045] The electrochemical galvanostatic intermittent titration technique (GITT) for three samples is shown in the figure below. Figure 7 , 8 As shown in Figures 9 and 1, it can be seen that the ion diffusion coefficient of the MoO3(021)+(020) sample is 10. -8 ~10 -11 cm 2 / s is less than that of MoO3(020) and MoO3(021) samples.
[0046] Since the desolvation of hydrated protons and the subsequent proton insertion step are a continuous process, the desolvation of hydrated protons will affect the hydrogenation reaction of α-MoO3 and the proton transport efficiency in the bulk phase. The proton diffusion kinetics of the MoO3(021)+(020) sample are optimal, providing a more efficient channel for proton bulk diffusion.
[0047] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A method for preparing a high specific capacity α-MoO3 anode material, characterized in that, Includes the following steps: S1. Dissolve 1.0 g of ammonium heptamolybdate tetrahydrate in 40 mL of deionized water and stir until completely dissolved. Then, add nitric acid with a concentration of 65% to 68% dropwise while stirring. The molar ratio of nitric acid to ammonium heptamolybdate tetrahydrate is 90:
1. Continue stirring after the addition is complete to obtain a mixed solution. S2, the mixed solution is transferred to a reaction vessel and hydrothermally reacted at 165~175 ℃ for 2.5~3.5 h. After the reaction is completed, the solution is centrifuged, washed and dried to obtain α-MoO3 nanorods. S3, the α-MoO3 nanorods, conductive graphite and polyvinylidene fluoride binder are mixed at a mass ratio of 7:2:1 to obtain the high specific capacity α-MoO3 anode material.
2. The method for preparing the high specific capacity α-MoO3 anode material according to claim 1, characterized in that, In step S1, the concentration of the nitric acid is 65% by mass.
3. The method for preparing the high specific capacity α-MoO3 anode material according to claim 1, characterized in that, In step S2, the hydrothermal reaction temperature is 170℃ and the time is 3 hours.
4. The method for preparing the high specific capacity α-MoO3 anode material according to claim 1, characterized in that, In step S2, vacuum drying is carried out in a vacuum drying oven for 12 hours.
5. The method for preparing the high specific capacity α-MoO3 anode material according to claim 1, characterized in that, In step S1, 1.0 g of ammonium heptamolybdate tetrahydrate is dissolved in 40 mL of deionized water and stirred for 10 minutes until completely dissolved. Then, 65% nitric acid is added dropwise during the stirring process, with a corresponding volume of 4.56 mL of nitric acid. After the addition is complete, stirring is continued for 10 minutes.
6. The method for preparing the high specific capacity α-MoO3 anode material according to claim 5, characterized in that, In step S2, the mixed solution is transferred to a reaction vessel and placed in an oven for hydrothermal reaction at 165~175 °C for 2.5~3.5 h. After the reaction is completed, the product is collected by centrifugation, washed three times with anhydrous ethanol and deionized water respectively, and dried in a vacuum drying oven at 60 °C for 12 hours to prepare α-MoO3 nanorods.
7. A high specific capacity α-MoO3 anode material, characterized in that, It is prepared by the preparation method described in any one of claims 1 to 6.
8. A method for preparing a high specific capacity α-MoO3 negative electrode sheet, characterized in that, Includes the following steps: S4: N-methylpyrrolidone solvent is added to the high specific capacity α-MoO3 anode material and ground evenly to form a slurry. The slurry is then evenly coated onto carbon paper and dried under vacuum to obtain a high specific capacity α-MoO3 anode sheet.
9. A high specific capacity α-MoO3 negative electrode sheet, characterized in that, It was prepared using the preparation method described in claim 8.
10. The application of the high specific capacity α-MoO3 anode material according to any one of claims 1 to 6 in the preparation of aqueous proton batteries.