A lithium-ion battery electrode material and its preparation method

Abstract

The application discloses a lithium ion battery electrode material and a preparation method thereof, and belongs to the field of lithium ion battery electrode material design and preparation. The lithium ion battery electrode material comprises a negative electrode material and a positive electrode material; the negative electrode material is a NiMnCoO3 nano material, and the NiMnCoO3 nano material is in a sheet structure or a rose flower structure; when the NiMnCoO3 nano material is in the sheet structure, nickel salt, manganese salt, cobalt salt and a complexing agent are used as raw materials, and then hydrothermal treatment and annealing treatment are carried out to obtain the NiMnCoO3 nano material; when the NiMnCoO3 nano material is in the rose flower structure, nickel salt, manganese salt, cobalt salt and a complexing agent are used as raw materials, and then a surfactant and / or foamed nickel are added, and then hydrothermal treatment and annealing treatment are carried out to obtain the NiMnCoO3 nano material; and the positive electrode material is prepared by taking the NiMnCoO3 nano material as a precursor template. The application effectively shortens the transmission distance of lithium ions, increases the contact area of the lithium ions, and significantly improves the electrode dynamics by using the hierarchical structure design.

Description

Technical Field

[0001] This invention relates to the field of lithium-ion battery electrode material design and preparation, and particularly to a lithium-ion battery electrode material and its preparation method. Background Technology

[0002] Lithium-ion batteries, as a green, high-energy portable energy storage technology, are a powerful driving force for the rapid development of industrial sectors such as electronic devices, mobile communications, and electric transportation. They are also an effective means of addressing the depletion of fossil fuels and environmental pollution. However, the ever-evolving demands of the industry place almost stringent requirements and challenges on energy storage systems. Developing high-energy, high-power-density lithium-ion batteries has always been a focus and a challenge for both academia and industry. Currently, for anode materials, commercially available graphite anodes have low capacity (372 mAh g / g). -1 However, silicon-carbon anodes suffer from poor rate performance, making them unsuitable for high-end applications. While silicon-carbon anodes can provide high energy density, their high production cost and low rate capability limit their application. In contrast, transition metal oxides, especially ternary transition metal oxides containing multiple transition metal elements, are considered potential alternative anode materials due to their high capacity. As for cathode materials, commercially available cathode materials such as LiCoO2, LiMn2O4, and LiFePO4 have low capacities, also failing to meet the growing application demands. While high-nickel ternary materials can provide high capacity, their safety issues have been seriously challenged. Among these materials, LiNi... 1 / 3 Co 1 / 3 Mn 1 / 3 O2 has attracted widespread attention due to its high reversible capacity, high energy density, and thermal stability.

[0003] However, regarding anode materials, while transition metal oxide anode materials possess the advantage of high capacity, their low conductivity and large volume changes during cycling lead to performance degradation, significantly limiting their application in high-power environments. Similarly, regarding cathode materials, LiNi... 1 / 3 Co 1 / 3 Mn 1 / 3 O2 cathode materials also face several unresolved issues. Low conductivity, large lattice distortion during lithium insertion and extraction, and significant changes in electrode morphology during cycling all negatively impact LiNi. 1 / 3 Co 1 / 3Mn 1 / 3 Applications of O2 in high-power environments.

[0004] For transition metal oxide (TMO) anode materials, current technologies typically employ micro / nanostructure design and coating techniques to modify these materials. This limits the large volume expansion of the oxide during cycling, resulting in higher rate performance and longer cycle life. However, micro / nanostructure design for TMO anode materials primarily targets mono- or binary TMOs. Designing micro / nanostructures for ternary TMOs containing Mn, Ni, and Co presents significant challenges. Existing fabrication techniques, while ensuring precise micro / nanostructure control, are prone to compositional deviations in the Mn, Ni, and Co elements, and it is difficult to achieve a balance between both.

[0005] For LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 cathode materials, in existing technologies, typically employ doping, coating, and other methods to modify LiNi. 1 / 3 Co 1 / 3 Mn 1 / 3 Modification of O2 cathode materials has been implemented. While these methods have improved the electrochemical performance of the electrode materials to some extent, they cannot completely solve the problems faced by these materials, especially the low-rate performance issue. Numerous studies have shown that micro / nanostructure design of electrode materials is an effective measure to improve their rate performance. However, limitations imposed by the complexity of the material system and key factors such as high sintering temperatures have hindered the development of effective methods for LiNi cathodes. 1 / 3 Co 1 / 3 Mn 1 / 3 The design of micro- and nano-structures for O2 cathode materials has low freedom and limited preparation methods. Summary of the Invention

[0006] To address the above problems, this invention provides a lithium-ion battery electrode material and its preparation method. On one hand, NiMnCoO3 nanomaterials can be used as a negative electrode material, and on the other hand, they can be used as a precursor template for synthesizing LiNi. 1 / 3 Co 1 / 3 Mn 1 / 3 The O2 cathode material and the anode and cathode materials prepared by this invention both have multi-scale hierarchical structures. The hierarchical structure design can effectively shorten the lithium ion transport distance, increase the lithium ion contact area, and significantly improve electrode dynamics.

[0007] This invention provides a lithium-ion battery electrode material, which includes a negative electrode material and a positive electrode material;

[0008] The negative electrode material is NiMnCoO3 nanomaterial, which has a sheet-like structure or a rose-like structure.

[0009] When NiMnCoO3 nanomaterials have a sheet-like structure, they are obtained by hydrothermal treatment and annealing using nickel salts, manganese salts, cobalt salts, and complexing agents as raw materials.

[0010] When NiMnCoO3 nanomaterials have a rose-like structure, they are obtained by using nickel salts, manganese salts, cobalt salts and complexing agents as raw materials, adding surfactants and / or nickel foam, and then performing hydrothermal treatment and annealing.

[0011] The cathode material is LiNi prepared using NiMnCoO3 nanomaterials as a precursor template. 1 / 3 Co 1 / 3 Mn 1 / 3 O2 cathode material.

[0012] In a preferred embodiment of the present invention, the preparation of NiMnCoO3 nanomaterials includes the following steps:

[0013] According to the stoichiometric ratio of NiMnCoO3, the weighed nickel salt, manganese salt and cobalt salt were added to water and dissolved to obtain mixed solution A; the complexing agent A solution was added to mixed solution A and stirred evenly to obtain mixed solution B;

[0014] Mixed solution B was subjected to a hydrothermal reaction at 110℃~140℃ to undergo a complexation precipitation reaction, resulting in hydroxide precursor material;

[0015] The precursor material was annealed at 350℃~500℃ under a protective atmosphere to cause the hydroxide precursor material to decompose and obtain NiMnCoO3 nanomaterials, which have a sheet-like structure.

[0016] For example, the temperature for hydrothermal reactions can be 110℃, 115℃, 120℃, 125℃, 130℃, 135℃, or 140℃, etc.; however, it is not limited to the listed values, and other unlisted values ​​within the above range are also applicable.

[0017] Annealing temperatures can be 350℃, 400℃, 450℃, or 500℃, etc. However, they are not limited to the listed values; other unlisted values ​​within the above range also apply.

[0018] In a preferred embodiment of the present invention, the hydrothermal reaction time is 2 to 6 hours. For example, the hydrothermal reaction time can be 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours, 5 hours, 5.5 hours, or 6 hours. However, it is not limited to the listed values; other unlisted values ​​within the above range are also applicable.

[0019] In a preferred embodiment of the present invention, the annealing time is 2 hours to 4 hours. For example, the annealing time is 2 hours, 2.5 hours, 3 hours, 3.5 hours, or 4 hours, etc. However, it is not limited to the listed values; other unlisted values ​​within the above range are also applicable.

[0020] In a preferred embodiment of the present invention, the molar ratio of cobalt salt to complexing agent A is 0.5:20 to 24; for example, the molar ratio of cobalt salt to complexing agent A is 0.5:20, 0.5:21, 0.5:22, 0.5:23, or 0.5:24; etc. However, it is not limited to the listed values, and other unlisted values ​​within the above range are also applicable.

[0021] Complexing agent A is urea and ammonium fluoride in a molar ratio of 14–16:6–8. For example, the molar ratio of urea to ammonium fluoride can be 14:6, 14:7, 14:8, 15:6, 15:7, 15:8, 16:6, or 16:7, etc. However, it is not limited to the listed values; other unlisted values ​​within the above range also apply.

[0022] In a preferred embodiment of the present invention, a surfactant solution is added to the mixed solution A; the prepared NiMnCoO3 nanomaterial has a rose-like structure.

[0023] The ratio of nickel salt to surfactant is 0.5 mmol:0.1 g to 0.12 g. For example, the ratio of nickel salt to surfactant is 0.5 mmol:0.1 g, 0.5 mmol:0.11 g, or 0.5 mmol:0.12 g, etc. However, it is not limited to the values ​​listed above; other unlisted values ​​within the above range are also applicable.

[0024] In a preferred embodiment of the present invention, nickel foam is added during the hydrothermal reaction; the resulting NiMnCoO3 nanomaterial has a rose-like structure.

[0025] In a preferred embodiment of the present invention, LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 The O2 cathode material was prepared according to the following steps:

[0026] Lithium salt was added to ethanol and mixed thoroughly, and then complexing agent B was added to obtain mixed solution C;

[0027] NiMnCoO3 nanomaterials were used as templates and added to mixed solution C. After mixing evenly, the solvent was evaporated to obtain mixed powder A.

[0028] The mixed powder was annealed under a protective atmosphere to decompose the complex and lithium salt, resulting in mixed powder B.

[0029] LiNi was obtained by sintering mixed powder B in an air atmosphere. 1 / 3 Co 1 / 3 Mn 1 / 3 O2 cathode material.

[0030] In a preferred embodiment of the present invention, the ratio of lithium salt, complexing agent B, and NiMnCoO3 nanomaterials is 0.2g:3ml to 4ml:0.3g. For example, the ratios of lithium salt, complexing agent B, and NiMnCoO3 nanomaterials are 0.2g:3ml:0.3g, 0.2g:3.2ml:0.3g, 0.2g:3.4ml:0.3g, and 0.2g:3.6ml.

[0031] The dosage ranges are 0.3g / ml, 0.2g / 3.8ml / 0.3g, or 0.2g / 4ml / 0.3g, etc. However, they are not limited to the values ​​listed.

[0032] Other values ​​not listed above within the above range also apply.

[0033] In a preferred embodiment of the present invention, the annealing treatment is performed at 350°C to 500°C for 2 to 5 hours; for example, the annealing temperature is 350°C, 400°C, 450°C, or 500°C, etc.; the annealing time is 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours, or 5 hours, etc.; but it is not limited to the listed values, and other unlisted values ​​within the above range are also applicable.

[0034] The sintering process is carried out at 700℃ to 850℃ for 5 to 10 hours. For example, the sintering temperature is 700℃, 750℃, 800℃, or 850℃, and the sintering time is 5 hours, 5.5 hours, 6 hours, 6.5 hours, 7 hours, 7.5 hours, 8 hours, 8.5 hours, 9 hours, 9.5 hours, or 10 hours, etc.; however, it is not limited to the listed values, and other unlisted values ​​within the above range are also applicable.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] (1) This invention discloses a lithium-ion battery electrode material, including a negative electrode material and a positive electrode material. The negative electrode material is NiMnCoO3 nanomaterial, which includes sheet-like and rose-like structures. The sheet-like structure is assembled and stacked by nanoparticles, and the rose-like structure is composed of two-dimensional nanosheets. The positive electrode material is prepared by using NiMnCoO3 nanomaterial as a precursor template based on the sacrificial template method. Both the negative electrode material and the positive electrode material prepared by this invention have multi-scale hierarchical structures. The hierarchical structure design can effectively shorten the lithium-ion transport distance, increase the lithium-ion contact area, and significantly improve electrode dynamics.

[0037] Because NiMnCoO3 nanomaterials can effectively mitigate the volume changes that occur during lithium delithiation / lithiation and prevent the electrode material from pulverizing and deactivating, they can be better used as a negative electrode material.

[0038] Furthermore, unlike traditional solid-phase or liquid-phase methods, this invention uses NiMnCoO3 nanomaterials with a multi-scale hierarchical structure as a precursor template to achieve LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 The complex micro / nano structure design of O2 cathode material, and the preparation of LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 cathode materials can provide up to three lithium-ion transport channels, exhibiting advantages in charging and discharging under high current loads. As an electrode material for lithium-ion batteries, it has important application value for developing high-energy and high-power-density energy storage devices.

[0039] (2) Using the preparation method of the present invention, LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 The O2 material is designed with a mesoporous three-dimensional rose-like structure. This hierarchical structure effectively shortens the lithium-ion transport distance, improves lithium-ion transport efficiency, and significantly enhances the performance of LiNi alloys. 1 / 3 Co 1 / 3 Mn 1 / 3 The rate performance of O2 cathode material is to improve the LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 This lays the foundation for the application value of O2 cathode materials in high-power energy storage devices.

[0040] (3) A class of NiMnCoO3 nanomaterials developed in this invention and their derived LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 The preparation method of O2 cathode material is simple, easy to operate, has low energy consumption, is green and pollution-free, and is easy to promote. Attached Figure Description

[0041] Figure 1 The images shown are scanning electron microscope (SEM) images of the NiMnCoO3 nanomaterials from Example 1, where (a) is magnified at 10k and (b) is magnified at 30k.

[0042] Figure 2 The images shown are scanning electron microscope (SEM) images of the NiMnCoO3 nanomaterials in Example 2, where (a) is magnified to 1k and (b) is magnified to 5k.

[0043] Figure 3 The images shown are scanning electron microscope (SEM) images of NiMnCoO3@nickel foam nanomaterials from Example 4, where (a) is magnified to 400 and (b) is magnified to 10k.

[0044] Figure 4 The images show the X-ray diffraction patterns of the NiMnCoO3 nanomaterials of Example 1, Example 2, and Example 4.

[0045] Figure 5 The graphs show the charge-discharge curves of the NiMnCoO3 nanomaterial at different rates in Example 2.

[0046] Figure 6 The graphs show the charge-discharge curves of NiMnCoO3@foam nickel nanomaterials at different rates in Example 4.

[0047] Figure 7 The cycling rate diagrams are for the NiMnCoO3 nanomaterial of Example 2 and the NiMnCoO3@nickel foam nanomaterial of Example 4.

[0048] Figure 8 LiNi of Example 6 1 / 3 Co 1 / 3 Mn 1 / 3 Scanning electron microscope (SEM) images of the O2 cathode material at 700℃ and 800℃, where (a) is an SEM image at one angle and (b) is an SEM image at another angle.

[0049] Figure 9 LiNi of Example 6 1 / 3 Co 1 / 3 Mn 1 / 3 X-ray diffraction pattern of O2 cathode material.

[0050] Figure 10 LiNi of Example 6 1 / 3 Co 1 / 3 Mn 1 / 3 Charge-discharge curves of O2 cathode material at different rates.

[0051] Figure 11 LiNi of Example 6 1 / 3 Co 1 / 3 Mn 1 / 3 Cycle efficiency diagram of O2 cathode material. Detailed Implementation

[0052] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0053] Low conductivity and large volume changes during cycling have always been key factors restricting the application of transition metal oxide electrode materials, resulting in poor rate performance. According to Fick's rule (J = -D·dC / dx, J: diffusion flux, D: diffusion coefficient, -dC / dx: inverse concentration gradient), it is easy to see that increasing the lithium-ion contact area or reducing the lithium-ion transport distance are effective methods to improve electrode kinetics. Therefore, to reduce the impact of low conductivity of transition metal oxides and improve lithium-ion transport efficiency, the size of the electrode material must be reduced. However, simply reducing the size of the material also brings many problems, such as increased agglomeration, increased nanoparticle and electrolyte side reactions, and decreased vibration density. The most effective way to solve these problems is to increase the size of the electrode material and develop micron-sized materials, but this obviously contradicts the design requirements for improving electrode kinetics. To balance this contradiction, this invention designs a layered structure material with a multi-scale structure. The layered mesoscale structure design not only improves electrode kinetics but also effectively alleviates the large volume changes of the electrode material during cycling, which plays an important role in improving the application of transition metal oxide anode materials under high power loads. This invention effectively solves the problems faced by transition metal oxide electrode materials by designing a three-dimensional nanoflower hierarchical structure.

[0054] In designing the hierarchical structure of three-dimensional nanoflowers, this invention utilizes biomimetic technology to construct hierarchical nanomaterials with unique functions. Roses possess a typical hierarchical structure and can be viewed as three-dimensional nanoflower structures assembled from two-dimensional petals. Based on this, the biomimetic research on the structure and formation process of roses in this invention will provide important guidance for the design and preparation of transition metal oxide nanoflowers.

[0055] In the preparation process of cathode materials, a high phase formation temperature is an obstacle to the formation of LiNi. 1 / 3 Co 1 / 3 Mn 1 / 3 The most critical factor in the micro / nano structure design of O2 cathode materials is the sacrificial template method, which severely restricts research progress in this field. This invention uses NiMnCoO3 nanoflower anode material as a template to avoid structural collapse caused by high-temperature sintering and grain growth. This method successfully prepared LiNi... 1 / 3 Co 1 / 3 Mn 1 / 3 O2 nanoflower cathode materials provide a feasible approach for related research.

[0056] In addition, low electrical conductivity and large morphological changes during cycling are limiting factors for LiNi. 1 / 3 Co 1 / 3 Mn 1 / 3 The key factors for the application of O2 cathode materials in high-power load environments are addressed by this invention through a rose-shaped structural design.

[0057] The specific technical solution is as follows:

[0058] A lithium-ion battery electrode material, characterized in that the lithium-ion battery electrode material comprises a negative electrode material and a positive electrode material;

[0059] The negative electrode material is NiMnCoO3 nanomaterial, which has a sheet-like structure or a rose-like structure.

[0060] When NiMnCoO3 nanomaterials have a sheet-like structure, they are obtained by hydrothermal treatment and annealing using nickel salts, manganese salts, cobalt salts, and complexing agents as raw materials.

[0061] When NiMnCoO3 nanomaterials have a rose-like structure, they are obtained by using nickel salts, manganese salts, cobalt salts and complexing agents as raw materials, adding surfactants and / or nickel foam, and then performing hydrothermal treatment and annealing.

[0062] The cathode material is LiNi prepared using NiMnCoO3 nanomaterials as a precursor template. 1 / 3 Co 1 / 3 Mn 1 / 3 O2 cathode material.

[0063] A method for preparing a lithium-ion battery electrode material, wherein the preparation of NiMnCoO3 nanomaterials includes the following steps:

[0064] According to the stoichiometric ratio of NiMnCoO3, the weighed nickel salt, manganese salt and cobalt salt were added to water and dissolved to obtain mixed solution A; the complexing agent A solution was added to mixed solution A and stirred evenly to obtain mixed solution B;

[0065] Mixed solution B was subjected to hydrothermal treatment at 110℃~140℃ to undergo a complexation precipitation reaction, yielding hydroxide precursor material;

[0066] The hydroxide precursor material was annealed at 350℃~500℃ under a protective atmosphere to induce a decomposition reaction of the hydroxide, yielding NiMnCoO3 nanomaterials. Under these conditions, the prepared NiMnCoO3 nanomaterials were in sheet form.

[0067] It is understood that the present invention does not impose any particular restrictions on nickel salts, manganese salts, and cobalt salts, and any nickel salts, manganese salts, and cobalt salts known to those skilled in the art can be used. Those skilled in the art can select and adjust according to actual application conditions, product quality, and product performance. Preferably, the nickel salt is selected from nickel sulfate, nickel carbonate, and nickel nitrate; the manganese salt is selected from manganese nitrate, manganese sulfate, and manganese carbonate; and the cobalt salt is selected from cobalt nitrate, cobalt sulfate, and cobalt carbonate.

[0068] It is understandable that the hydrothermal reaction time will affect the micro-nano morphology of the hydroxide precursor. Based on this, the preferred hydrothermal reaction time in this invention is 2h-6h.

[0069] Preferably, the annealing time in this invention is 2 to 4 hours. The annealing time changes the size and distribution density of the mesoporous structure on the nanosheets, thereby altering the specific surface area and electrochemical activity of the electrode material, affecting the electrode kinetics, and consequently changing the rate performance of the electrode material.

[0070] Furthermore, the molar ratio of cobalt salt to complexing agent A is 1:20 to 24;

[0071] The complexing agent A used in this invention is urea and ammonium fluoride in a molar ratio of 14-16:6-8. The role of urea is to react with water under hydrothermal conditions to generate NH3, which then reacts with water to hydrolyze and release OH-. - OH - The existence of Ni 2+ Mn 2+ Co 2+ The precipitation provides an alkaline environment. The presence of ammonium fluoride is to regulate the pH of the hydrothermal solution and prevent the urea reaction from generating excessive OH-. - Thus controlling Ni 2+ Mn 2+ Co 2+ The precipitation rate provides sufficient time for the hydroxide precursor to crystallize, ensuring the formation of highly crystalline crystals.

[0072] This also includes adding a surfactant solution to mixed solution A. The surfactant is CTAB.

[0073] The amount of surfactant added is adjusted according to the amount of manganese salt, nickel salt, or cobalt salt used, as well as the amount of hydrothermal solution used. Its concentration and amount are determined through exploratory experiments. Preferably, the ratio of nickel salt to surfactant is 0.5 mmol: 0.1 g to 0.12 g.

[0074] After adding a surfactant, the prepared NiMnCoO3 nanomaterials are rose-shaped. This is because when a surfactant is added to a hydrothermal solution, it becomes a crystal nucleus during the hydrothermal process, resulting in a heterogeneous nucleation reaction. Metal ions aggregate around this nucleus and eventually crystallize into a hydroxide precursor material with a flower-like structure. After annealing in an atmosphere, the hydroxide and surfactant decompose, thus obtaining the NiMnCoO3 rose-shaped nanomaterials.

[0075] In addition to adding surfactants, the process also includes adding nickel foam during the hydrothermal reaction, resulting in NiMnCoO3@nickel foam nanomaterials. During the hydrothermal process, the presence of nickel foam provides attachment sites for the growth of hydroxide nanoflowers, thus obtaining a composite structure of hydroxide nanoflowers and nickel foam. After annealing in an atmosphere, the hydroxides and surfactants decompose, yielding NiMnCoO3@nickel foam nanomaterials, which exhibit a nano-rose-like structure. It is understood that the size of the nickel foam has a certain influence on the micro / nano structure of the hydrothermal products. This invention, through exploratory experiments, obtained relevant process parameters. Preferably, for a 100ml hydrothermal reactor inner liner, the size of the nickel foam should be 1.5cm × 3cm. It should be noted that this invention uses a 100ml hydrothermal reactor inner liner; therefore, the size of the nickel foam was 1.5cm × 3cm during the experiment.

[0076] The NiMnCoO3 nanomaterials prepared by this invention can be used to prepare LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 cathode material, the following section uses the preparation of LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 Taking the O2 nano-rose-shaped cathode material as an example, we will explain in detail:

[0077] Lithium salt was added to ethanol and mixed evenly. Then complexing agent B was added to obtain mixed solution C. Using nano-rose-shaped NiMnCoO3 nanomaterials as templates, they were added to mixed solution C, mixed evenly, and the solvent was evaporated to obtain mixed powder A.

[0078] The mixed powder was annealed under a protective atmosphere to decompose the complex and lithium salt, resulting in mixed powder B.

[0079] Mixed powder B was sintered in an air atmosphere to obtain nano-rose-shaped LiNi. 1 / 3 Co 1 / 3 Mn 1 / 3 O2 cathode material.

[0080] Preparation of nano-rose-shaped LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 In the O2 cathode material process, after coating a layer of lithium salt onto the surface of a rose-shaped NiMnCoO3 nanomaterial and then sintering at high temperature, lithium ions diffuse into the bulk phase of the NiMnCoO3 oxide, resulting in a phase transition and the formation of LiNi. 1 / 3 Co 1 / 3 Mn 1 / 3 O2 ternary phase. Meanwhile, due to the rose-like structure of NiMnCoO3 nanomaterials, the micro-nano morphology of the precursor template is maintained during high-temperature sintering, allowing for a smooth transition to LiNi. 1 / 3 Co 1 / 3 Mn 1 / 3 In the O2 cathode material, a nano-rose-shaped LiNi was finally prepared. 1 / 3 Co 1 / 3 Mn 1 / 3 O2 cathode material

[0081] It is understood that the present invention does not impose any particular limitation on lithium salts, and any lithium salt known to those skilled in the art can be used. Those skilled in the art can select and adjust the lithium salt according to the actual application, product quality and product performance. Preferably, the lithium salt is selected from lithium hydroxide, lithium nitrate and lithium carbonate.

[0082] Complexing agent B is acetylacetone. The presence of acetylacetone can fully disperse the lithium salt, allowing it to be more effectively coated onto the nano-rose-shaped NiMnCoO3 nanomaterial precursor template.

[0083] The ratio of lithium salt, complexing agent B, and nano-rose-shaped NiMnCoO3 nanomaterials was 0.2g:3ml~4ml:0.3g. The annealing treatment was carried out at 350℃~500℃ for 2h~5h.

[0084] The sintering process is carried out at 700℃~850℃ for 5h~10h.

[0085] It is understood that the nano-rose-shaped NiMnCoO3 nanomaterials prepared by this invention can be used as a negative electrode material and nano-rose-shaped LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 cathode materials can be used in high-performance lithium-ion batteries.

[0086] It is understandable that, in addition to preparing nano-rose-shaped LiNi 1 / 3 Co 1 / 3 Mn 1 / 3Besides O2 cathode materials, nanosheet-like LiNi can also be prepared using nanosheet-like NiMnCoO3 nanomaterials as precursor templates. 1 / 3 Co 1 / 3 Mn 1 / 3 The preparation method for O2 cathode materials will not be described in detail here.

[0087] The high-performance lithium-ion battery is manufactured according to the following steps:

[0088] For powder electrode materials, the electrode active material, conductive agent, and binder can be added to a dispersant in a certain proportion and fully dispersed, then coated onto the current collector using a spin-coating process. After drying, it can be cut for later use. For composite electrodes of active material and nickel foam, no coating process is required, and it can be used directly after cutting. Subsequently, the button battery sample is assembled in the following order: positive electrode housing, positive electrode, separator, negative electrode, electrolyte, and negative electrode housing.

[0089] The weight ratio of positive electrode active material, conductive agent, and binder for the powdered positive electrode material is 7:2:1; the weight ratio of negative electrode active material, conductive agent, and binder for the powdered negative electrode material is 6:3:1; the dispersant is NMP; the positive electrode current collector is Al foil; the negative electrode current collector is Cu foil; and the drying conditions are: vacuum, 100℃ for 10-12h.

[0090] The following is a description through specific embodiments.

[0091] Example 1

[0092] The present invention discloses a method for preparing NiMnCoO3 nanomaterials in the form of nanosheets, the specific steps of which are as follows:

[0093] Step 1: Based on the chemical formula of NiMnCoO3, determine that the molar ratio of nickel salt, manganese salt, and cobalt salt is 1:1:1;

[0094] Step 2: Add 0.5 mmol nickel carbonate, 0.5 mmol cobalt carbonate, and 0.5 mmol manganese carbonate to 40 ml of ultrapure water and stir to dissolve to obtain solution A;

[0095] Step 3: Add the complexing agent, namely 15 mmol of urea and 6 mmol of ammonium fluoride, to 30 ml of ultrapure water and stir to dissolve to obtain solution B;

[0096] Step 4: Slowly add solution B to solution A, stir until homogeneous to obtain solution C;

[0097] Step 5: Add solution C to 100ml of hydrothermal reactor and hydrothermally heat at 120℃ for 2 hours to obtain hydrothermal product powder;

[0098] Step six: Place the hydrothermal product powder into a magnetic boat and anneal it at 450°C for 2 hours under an argon atmosphere to obtain nanosheet-like NiMnCoO3 nanomaterials.

[0099] Example 2

[0100] The present invention discloses a method for preparing NiMnCoO3 nanomaterials in the form of nano-roses, the specific steps of which are as follows:

[0101] Step 1: Based on the chemical formula of NiMnCoO3, determine that the molar ratio of nickel salt, manganese salt, and cobalt salt is 1:1:1;

[0102] Step 2: Add 0.5 mmol nickel carbonate, 0.5 mmol cobalt carbonate, and 0.5 mmol manganese carbonate to 30 ml of ultrapure water and stir to dissolve to obtain solution A;

[0103] Step 3: Add the complexing agent, namely 15 mmol of urea and 6 mmol of ammonium fluoride, to 20 ml of ultrapure water and stir to dissolve to obtain solution B;

[0104] Step 4: Add 0.1g of surfactant CTAB to 20ml of ultrapure water and stir to dissolve to obtain solution C;

[0105] Step 5: Slowly add solutions B and C to solution A, and stir until homogeneous to obtain solution D;

[0106] Step 6: Add solution D to 100 ml of hydrothermal reactor and hydrothermally heat at 120°C for 2 hours to obtain hydrothermal product powder.

[0107] Step 7: Place the hydrothermal product powder into a magnetic boat and anneal at 450°C for 2 hours under an argon atmosphere to obtain nano-rose-shaped NiMnCoO3 nanomaterials.

[0108] Example 3

[0109] The present invention discloses a method for preparing NiMnCoO3 nanomaterials in the form of nano-roses, the specific steps of which are as follows:

[0110] Step 1: Based on the chemical formula of NiMnCoO3, determine that the molar ratio of nickel salt, manganese salt, and cobalt salt is 1:1:1;

[0111] Step 2: Add 0.5 mmol nickel nitrate, 0.5 mmol cobalt nitrate, and 0.5 mmol manganese nitrate to 30 ml of ultrapure water and stir to dissolve to obtain solution A;

[0112] Step 3: Add the complexing agent, namely 16 mmol of urea and 7 mmol of ammonium fluoride, to 20 ml of ultrapure water and stir to dissolve to obtain solution B.

[0113] Step 4: Add 0.12g of surfactant CTAB to 20ml of ultrapure water and stir to dissolve to obtain solution C;

[0114] Step 5: Slowly add solutions B and C to solution A, and stir until homogeneous to obtain solution D;

[0115] Step 6: Add solution D to 100 ml of hydrothermal reactor and hydrothermally heat at 120°C for 3 hours to obtain hydrothermal product powder.

[0116] Step 7: Place the hydrothermal product powder into a magnetic boat and anneal at 450°C for 2 hours under an argon atmosphere to obtain nano-rose-shaped NiMnCoO3 nanomaterials.

[0117] Example 4

[0118] The present invention discloses a method for preparing a nano-rose-shaped NiMnCoO3@foam nickel nanomaterial, the specific steps of which are as follows:

[0119] Step 1: Based on the chemical formula of NiMnCoO3, determine that the molar ratio of nickel salt, manganese salt, and cobalt salt is 1:1:1;

[0120] Step 2: Add 0.5 mmol nickel carbonate, 0.5 mmol cobalt carbonate, and 0.5 mmol manganese carbonate to 30 ml of ultrapure water and stir to dissolve to obtain solution A;

[0121] Step 3: Add the complexing agent, namely 15 mmol of urea and 6 mmol of ammonium fluoride, to 20 ml of ultrapure water and stir to dissolve to obtain solution B;

[0122] Step 4: Add 0.1g of surfactant CTAB to 20ml of ultrapure water and stir to dissolve, to obtain solution C;

[0123] Step 5: Slowly add solutions B and C to solution A, and stir until homogeneous to obtain solution D;

[0124] Step 6: Cut the nickel foam into 1.5cm × 3cm pieces, wash them repeatedly, and then place them in a hydrothermal reactor.

[0125] Step 7: Add solution D to 100ml of hydrothermal reactor and hydrothermally heat at 120℃ for 2 hours to obtain hydrothermal product powder;

[0126] Step 8: Place the hydrothermal product powder into a magnetic boat and anneal at 450°C for 2 hours under an argon atmosphere to obtain nano-rose-shaped NiMnCoO3@nickel foam nanomaterials.

[0127] Example 5

[0128] The present invention discloses a method for preparing a nano-rose-shaped NiMnCoO3@foam nickel nanomaterial, the specific steps of which are as follows:

[0129] Step 1: Based on the chemical formula of NiMnCoO3, determine that the molar ratio of nickel salt, manganese salt, and cobalt salt is 1:1:1;

[0130] Step 2: Add 0.5 mmol nickel nitrate, 0.5 mmol cobalt nitrate, and 0.5 mmol manganese nitrate to 30 ml of ultrapure water and stir to dissolve to obtain solution A;

[0131] Step 3: Add the complexing agent, namely 16 mmol of urea and 7 mmol of ammonium fluoride, to 20 ml of ultrapure water and stir to dissolve to obtain solution B.

[0132] Step 4: Add 0.12g of surfactant CTAB to 20ml of ultrapure water and stir to dissolve to obtain solution C;

[0133] Step 5: Slowly add solutions B and C to solution A, and stir until homogeneous to obtain solution D;

[0134] Step 6: Cut the nickel foam into 1.5cm × 3cm pieces, wash them repeatedly, and then place them in a hydrothermal reactor.

[0135] Step 7: Add solution D to 100ml of hydrothermal reactor and hydrothermally heat at 120℃ for 3 hours to obtain hydrothermal product powder.

[0136] Step 8: Place the hydrothermal product powder into a magnetic boat and anneal at 450°C for 2 hours under an argon atmosphere to obtain nano-rose-shaped NiMnCoO3@nickel foam nanomaterials.

[0137] Example 6

[0138] A LiNi of the present invention 1 / 3 Co 1 / 3 Mn 1 / 3 The specific steps for preparing O2 cathode materials are as follows:

[0139] Step 1, based on LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 The chemical formula of O2 is used to calculate the amount of the nano-rose-shaped NiMnCoO3 template, lithium salt, and complexing agent. The nano-rose-shaped NiMnCoO3 used in this example was prepared in Example 3.

[0140] Step 2: Add 0.2g of LiOH·H2O to 10ml of anhydrous ethanol, stir and dissolve evenly to obtain solution D;

[0141] Step 3: Add 3 ml of acetylacetone to solution D, stir and dissolve evenly to obtain solution E;

[0142] Step 4: Using 0.3g of nano-rose-shaped NiMnCoO3 nanomaterial as a template, slowly add it to solution E, and evaporate and stir at 60℃ to ensure complete evaporation of alcohol. After thorough drying, obtain powder F uniformly coated with lithium salt.

[0143] Step 5: Place powder F into a magnetic boat and anneal it at 450°C for 5 hours under an argon atmosphere to fully decompose the complexing agent and inorganic salt, and obtain powder G.

[0144] Step six: Place powder G into a magnetic boat and sinter at 700℃ for 10 hours in air atmosphere to obtain nano-rose-shaped LiNi. 1 / 3 Co 1 / 3 Mn 1 / 3 O2 cathode material.

[0145] Example 7

[0146] A LiNi of the present invention 1 / 3 Co 1 / 3 Mn 1 / 3 The specific steps for preparing O2 cathode materials are as follows:

[0147] Step 1, based on LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 chemical formula, calculate the amount of NiMnCoO3 template, lithium salt, and complexing agent used in the nano-rose-shaped structure;

[0148] Step 2: Add 0.2g of LiNO3 to 10ml of anhydrous ethanol, stir and dissolve evenly to obtain solution D;

[0149] Step 3: Add 3 ml of acetylacetone to solution D, stir and dissolve evenly to obtain solution E;

[0150] Step 4: Using 0.3g of nano-rose-shaped NiMnCoO3 nanomaterial as a template, slowly add it to solution E, and evaporate and stir at 60℃ to ensure complete evaporation of alcohol. After thorough drying, obtain powder F uniformly coated with lithium salt.

[0151] Step 5: Place powder F into a magnetic boat and anneal it at 450°C for 5 hours under an argon atmosphere to fully decompose the complexing agent and inorganic salt, and obtain powder G.

[0152] Step six: Place powder G into a magnetic boat, sinter at 700℃ for 10 hours in air atmosphere, and then continue sintering at 800℃ for 5 hours to obtain nano-rose-shaped LiNi. 1 / 3 Co1 / 3 Mn 1 / 3 O2 cathode material. The purpose of two high-temperature sintering processes is to fully release the large stress / strain caused by nanocrystal growth under high-temperature conditions, prevent the collapse of the flower-like structure of the precursor, and enable the micro / nano structure to smoothly transition to LiNi. 1 / 3 Co 1 / 3 Mn 1 / 3 In the O2 cathode material, a nano-rose-shaped LiNi was finally prepared. 1 / 3 Co 1 / 3 Mn 1 / 3 O2 cathode material.

[0153] It should be noted that step 6 of this embodiment involves two sintering processes. This is to ensure that the LiNi... 1 / 3 Co 1 / 3 Mn 1 / 3 O2 cathode materials have higher phase purity and release the stress / strain generated during sintering in stages, preventing the collapse of the one-dimensional morphology structure.

[0154] Example 8

[0155] The present invention discloses a method for preparing NiMnCoO3 nanomaterials in the form of nano-roses, the specific steps of which are as follows:

[0156] Step 1: Based on the chemical formula of NiMnCoO3, determine that the molar ratio of nickel salt, manganese salt, and cobalt salt is 1:1:1;

[0157] Step 2: Add 0.5 mmol nickel carbonate, 0.5 mmol cobalt carbonate, and 0.5 mmol manganese carbonate to 30 ml of ultrapure water and stir to dissolve to obtain solution A;

[0158] Step 3: Add the complexing agent, namely 14 mmol of urea and 8 mmol of ammonium fluoride, to 20 ml of ultrapure water and stir to dissolve to obtain solution B;

[0159] Step 4: Add 0.11g of surfactant CTAB to 20ml of ultrapure water and stir to dissolve to obtain solution C;

[0160] Step 5: Slowly add solutions B and C to solution A, and stir until homogeneous to obtain solution D;

[0161] Step 6: Add solution D to 100 ml of hydrothermal reactor and hydrothermally heat at 110°C for 6 hours to obtain hydrothermal product powder.

[0162] Step 7: Place the hydrothermal product powder into a magnetic boat and anneal it at 350°C for 4 hours under an argon atmosphere to obtain nano-rose-shaped NiMnCoO3 nanomaterials.

[0163] Example 9

[0164] The present invention discloses a method for preparing NiMnCoO3 nanomaterials in the form of nano-roses, the specific steps of which are as follows:

[0165] Step 1: Based on the chemical formula of NiMnCoO3, determine that the molar ratio of nickel salt, manganese salt, and cobalt salt is 1:1:1;

[0166] Step 2: Add 0.5 mmol nickel carbonate, 0.5 mmol cobalt carbonate, and 0.5 mmol manganese carbonate to 30 ml of ultrapure water and stir to dissolve to obtain solution A;

[0167] Step 3: Add the complexing agent, namely 15 mmol of urea and 7 mmol of ammonium fluoride, to 20 ml of ultrapure water and stir to dissolve to obtain solution B.

[0168] Step 4: Add 0.1g of surfactant CTAB to 20ml of ultrapure water and stir to dissolve to obtain solution C;

[0169] Step 5: Slowly add solutions B and C to solution A, and stir until homogeneous to obtain solution D;

[0170] Step 6: Add solution D to 100 ml of hydrothermal reactor and hydrothermally heat at 140°C for 4 hours to obtain hydrothermal product powder.

[0171] Step 7: Place the hydrothermal product powder into a magnetic boat and anneal at 500°C for 3 hours under an argon atmosphere to obtain nano-rose-shaped NiMnCoO3 nanomaterials.

[0172] Example 10

[0173] A LiNi of the present invention 1 / 3 Co 1 / 3 Mn 1 / 3 The specific steps for preparing O2 cathode materials are as follows:

[0174] Step 1, based on LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 The chemical formula of O2 is used to calculate the amount of the nano-rose-shaped NiMnCoO3 template, lithium salt, and complexing agent. The nano-rose-shaped NiMnCoO3 used in this example was prepared in Example 3.

[0175] Step 2: Add 0.2g of LiOH·H2O to 10ml of anhydrous ethanol, stir and dissolve evenly to obtain solution D;

[0176] Step 3: Add 4 ml of acetylacetone to solution D, stir and dissolve evenly to obtain solution E;

[0177] Step 4: Using 0.3g of nano-rose-shaped NiMnCoO3 nanomaterial as a template, slowly add it to solution E, and evaporate and stir at 60℃ to ensure complete evaporation of alcohol. After thorough drying, obtain powder F uniformly coated with lithium salt.

[0178] Step 5: Place powder F into a magnetic boat and heat-treat it at 350°C for 2 hours under an argon atmosphere to fully decompose the complexing agent and inorganic salt, thus obtaining powder G.

[0179] Step six: Place powder G into a magnetic boat and sinter at 850℃ for 5 hours in air atmosphere to obtain nano-rose-shaped LiNi. 1 / 3 Co 1 / 3 Mn 1 / 3 O2 cathode material.

[0180] Example 11

[0181] A LiNi of the present invention 1 / 3 Co 1 / 3 Mn 1 / 3 The specific steps for preparing O2 cathode materials are as follows:

[0182] Step 1, based on LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 The chemical formula of O2 is used to calculate the amount of the nano-rose-shaped NiMnCoO3 template, lithium salt, and complexing agent. The nano-rose-shaped NiMnCoO3 used in this example was prepared in Example 3.

[0183] Step 2: Add 0.2g of LiOH·H2O to 10ml of anhydrous ethanol, stir and dissolve evenly to obtain solution D;

[0184] Step 3: Add 3.5 ml of acetylacetone to solution D, stir and dissolve evenly to obtain solution E;

[0185] Step 4: Using 0.3g of nano-rose-shaped NiMnCoO3 nanomaterial as a template, slowly add it to solution E, and evaporate and stir at 60℃ to ensure complete evaporation of alcohol. After thorough drying, obtain powder F uniformly coated with lithium salt.

[0186] Step 5: Place powder F into a magnetic boat and anneal it at 500°C for 4 hours under an argon atmosphere to fully decompose the complexing agent and inorganic salt, and obtain powder G.

[0187] Step six: Place powder G into a magnetic boat and sinter at 800℃ for 6 hours in air atmosphere to obtain nano-rose-shaped LiNi. 1 / 3 Co 1 / 3 Mn 1 / 3 O2 cathode material.

[0188] The following examples, namely Examples 1, 2, 4, and 6, illustrate the NiMnCoO3 nanomaterials prepared according to the present invention and their derived LiNi. 1 / 3 Co 1 / 3 Mn 1 / 3 Physical and electrochemical properties of O2 cathode materials. It should be noted that the nanosheet-like NiMnCoO3 nanomaterials prepared in Example 1 are denoted as NiMnCoO3 nanosheets, the nano-rose-shaped NiMnCoO3 nanomaterials prepared in Example 2 are denoted as NiMnCoO3 nanoflowers, the nano-rose-shaped NiMnCoO3@nickel foam nanomaterials prepared in Example 4 are denoted as NiMnCoO3 nanoflowers@nickel foam, and the nano-rose-shaped LiNi nanomaterials prepared in Example 6 are denoted as NiMnCoO3@nickel foam. 1 / 3 Co 1 / 3Mn 1 / 3 The O2 cathode material is designated as LiNi. 1 / 3 Co 1 / 3 Mn 1 / 3 O2 nanoflowers.

[0189] Figure 1 Here are scanning electron microscope (SEM) images of the nanosheet-like NiMnCoO3 nanomaterials prepared in Example 1. Figure 1 It can be clearly observed that NiMnCoO3 nanomaterials exhibit a typical two-dimensional sheet structure, while at a smaller scale, the nanosheet structure is assembled from nanoparticles, and there are abundant mesoporous structures between the nanoparticles.

[0190] Figure 2 Here is a scanning electron microscope (SEM) image of the rose-shaped NiMnCoO3 nanomaterials prepared in Example 2. Figure 2 It can be clearly observed that the NiMnCoO3 nanomaterials exhibit a typical three-dimensional rose-like structure, which is assembled from two-dimensional nanosheets. At a smaller scale, the nanosheet structure is assembled from nanoparticles, with abundant mesoporous structures existing between the nanoparticles. At the same time, large free voids also exist between the nanosheets.

[0191] Figure 3 Scanning electron microscope (SEM) images of the nano-rose-shaped NiMnCoO3@nickel foam nanomaterials prepared in Example 4, from... Figure 3 It can be clearly observed that nano-rose-shaped NiMnCoO3 is uniformly attached to the nickel foam, and its structure is similar to... Figure 2 In comparison, the differences are not significant, both exhibiting a three-dimensional rose-like structure. Due to the introduction of a nickel foam substrate, the nano-rose-like NiMnCoO3@nickel foam nanomaterials can further provide a three-dimensional through-pore structure of nickel foam at a larger micron scale.

[0192] Figure 4 The X-ray diffraction (XRD) patterns of three anode materials are shown: the nanosheet-like NiMnCoO3 nanomaterial prepared in Example 1, the nano-rose-like NiMnCoO3 nanomaterial prepared in Example 2, and the nano-rose-like NiMnCoO3@nickel foam nanomaterial prepared in Example 4. The vertical axis represents X-ray intensity in au, and the horizontal axis represents twice the diffraction angle, denoted as 2-θ, in degrees. Comparison of the XRD patterns reveals that the three materials have the same crystal structure, being a ternary solid solution with a NaCl-type crystal structure formed by the three transition metal elements Mn, Ni, and Co.

[0193] Figure 5 The graphs show the charge-discharge curves of the rose-shaped NiMnCoO3 nanomaterials prepared in Example 2 at different rates. The horizontal axis represents the specific capacity of the material, in mAh / g. The horizontal axis also represents the voltage, in V. Except for the large capacity loss in the first few cycles, the charge-discharge curves of the rose-shaped NiMnCoO3 nanomaterials are basically overlapping, fully demonstrating the effectiveness of the structural design in improving the electrode structure.

[0194] Figure 6 The graphs show the charge-discharge curves of the rose-shaped NiMnCoO3@nickel foam nanomaterials prepared in Example 4 at different rates. The horizontal axis represents the specific capacity of the material, in mAh / g. The horizontal axis also represents the voltage, in V. Compared to NiMnCoO3 nanomaterials, the rose-shaped NiMnCoO3@nickel foam nanomaterials have a flatter charging plateau and higher charging capacity, demonstrating that integrated electrode structure design is an effective measure to improve the electrochemical performance of transition metal oxide electrode materials.

[0195] Figure 7 The graphs show the cycle rates of two anode materials: the nano-rose-shaped NiMnCoO3 nanomaterial prepared in Example 2 and the nano-rose-shaped NiMnCoO3@nickel foam nanomaterial prepared in Example 4. The horizontal axis represents the number of cycles, in laps. The vertical axis represents the discharge specific capacity, in mAh / g. Compared to the nano-rose-shaped NiMnCoO3 powder electrode, the nano-rose-shaped NiMnCoO3@nickel foam electrode exhibits superior rate performance due to its integrated electrode structure design. The NiMnCoO3 nanoflower@nickel foam electrode achieves a rate performance of 5Ag... -1 The capacity is ~840mAh g -1 This is equivalent to 0.1 Ag. -1 It exhibits ~57% of the capacity and high structural stability. In contrast, the nano-rose-shaped NiMnCoO3 powder electrode at 5Ag...-1 The capacity is ~421mAh g. -1 This is equivalent to 0.1 Ag. -1 ~35% of the capacity. It is worth noting that after 0.1Ag... -1 up to 5Ag -1 After rate performance testing, the two electrodes were at 1Ag -1 It can still cycle stably up to 100 times under high current density, fully demonstrating the lithium storage potential of the nano-rose structure design.

[0196] Figure 8 The nano-rose-shaped LiNi prepared in Example 6 1 / 3 Co 1 / 3 Mn 1 / 3 Scanning electron microscope (SEM) images of the O2 cathode material at 700℃ and 800℃. The SEM images clearly show that a nano-rose-shaped LiNi nanomaterial was successfully prepared using NiMnCoO3 nanomaterials as a template. 1 / 3 Co 1 / 3 Mn 1 / 3 O2 cathode material. Nano-rose-shaped LiNi synthesized at 700℃. 1 / 3 Co 1 / 3 Mn 1 / 3 The O2 morphology and structure are relatively complete. As the temperature increases, the nano-rose-shaped LiNi synthesized at 800℃... 1 / 3 Co 1 / 3 Mn 1 / 3 The O2 morphological structure was damaged to some extent. This indicates that LiNi... 1 / 3 Co 1 / 3 Mn 1 / 3 The high phase formation temperature of O2 is a major factor hindering its micro-nano structure design, but the preparation method of this invention can, to a certain extent, accommodate this obstacle of high-temperature sintering.

[0197] Figure 9 Nano-rose-shaped LiNi prepared in Example 6 1 / 3 Co 1 / 3 Mn 1 / 3 X-ray diffraction pattern of O2 cathode material. The vertical axis represents X-ray intensity in au; the horizontal axis represents twice the diffraction angle, denoted as 2-θ, in degrees. A search reveals that the synthesized sample's diffraction peaks point to the hexagonal α-NaFeO2 phase with space group R-3m, corresponding to PDF card 82-1495. Notably, the prepared sample exhibits diffraction peaks of oxide impurities, indicating that the nano-rose-shaped LiNi prepared in this example... 1 / 3 Co 1 / 3 Mn 1 / 3The O2 cathode material has low purity, and further optimization of phase purity is needed to improve its electrochemical performance.

[0198] Figure 10 Nano-rose-shaped LiNi prepared in Example 6 1 / 3 Co 1 / 3 Mn 1 / 3 Charge-discharge curves of the O2 cathode material at different rates. From the charge-discharge curves and the plateau voltage inflection point, it can be seen that LiNi was indeed synthesized in this embodiment. 1 / 3 Co 1 / 3Mn 1 / 3 O2 ternary phase. Nano-rose-shaped LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 The initial discharge capacity of the O2 cathode material is 139.05 mAh g. -1 The initial cycle coulombic efficiency was 78.80%. The significant irreversible capacity loss in the first cycle is largely attributed to the formation of the SEI film. With continued cycling and increasing current density, the discharge capacity decayed rapidly. (Nano-rose-shaped LiNi) 1 / 3 Co 1 / 3 Mn 1 / 3 The capacity of the O2 cathode material electrode at 10C is only 26.23 mAh g. -1 This is equivalent to 18.86% of its capacity at 0.1C, mainly due to low phase purity.

[0199] Figure 11 Nano-rose-shaped LiNi prepared in Example 6 1 / 3 Co 1 / 3 Mn 1 / 3 Cycle efficiency diagram of O2 cathode material. Except for the first cycle, the nano-rose-shaped LiNi... 1 / 3 Co 1 / 3 Mn 1 / 3 The O2 cathode material can be stably cycled 50 times at a current density of 0.5C, with a capacity retention of 67.81% and an average discharge capacity of 77.54 mAh g, respectively. -1 The excellent cycling stability is attributed to the nano-rose structure design.

[0200] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0201] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A lithium-ion battery electrode material, characterized in that, The lithium ion battery electrode material comprises a negative electrode material and a positive electrode material; The negative electrode material is a NiMnCoO3 nanomaterial, and the NiMnCoO3 nanomaterial is in a sheet structure or a rosette structure. When the NiMnCoO3 nanomaterial is in a sheet structure, nickel salt, manganese salt, cobalt salt and a complexing agent are used as raw materials, and hydrothermal treatment and annealing treatment are performed to obtain the NiMnCoO3 nanomaterial. When the NiMnCoO3 nanomaterial is in a rosette structure, nickel salt, manganese salt, cobalt salt and a complexing agent are used as raw materials, and a surfactant is added, and hydrothermal treatment and annealing treatment are performed to obtain the NiMnCoO3 nanomaterial. The positive electrode material is LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 positive electrode material prepared by taking NiMnCoO3 nanomaterial as a precursor template. LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 cathode material is prepared according to the following steps: Lithium salt is added to ethanol to obtain a mixed solution C after mixing uniformly, and then a complexing agent B is added. The NiMnCoO3 nanomaterial is added to the mixed solution C as a template, and the solvent is evaporated after mixing uniformly to obtain a mixed powder A. The mixed powder A is annealed in a protective atmosphere to decompose the complex and the lithium salt to obtain a mixed powder B. The mixed powder B was sintered in air atmosphere to obtain LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 cathode material; Wherein, the NiMnCoO3 nanomaterial is in a sheet structure, the positive electrode material is a nanosheet LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 positive electrode material; LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 cathode material with nano-rose-like structure.

2. The lithium-ion battery electrode material of claim 1, wherein, The amount ratio of the lithium salt, the complexing agent B and the NiMnCoO3 nanomaterial is 0.2 g:3 ml~4 ml:0.3 g.

3. The lithium-ion battery electrode material of claim 1, wherein, In the step of annealing the mixed powder A in a protective atmosphere to decompose the complex and the lithium salt, the annealing is performed at 350 ℃~500 ℃ for 2 h~5 h. The sintering treatment is performed at 700 ℃~850 ℃ for 5 h~10 h.

4. A method of preparing the lithium ion battery electrode material of claim 1, characterized in that, The preparation of the NiMnCoO3 nanomaterial comprises the following steps: Nickel salt, manganese salt and cobalt salt weighed according to the stoichiometric ratio of NiMnCoO3 are dissolved in water to obtain a mixed solution A; and a complexing agent A solution is added to the mixed solution A to obtain a mixed solution B after stirring uniformly. The mixed solution B is subjected to a hydrothermal reaction at 110 ℃~140 ℃ to generate a complex precipitation reaction to obtain a hydroxide precursor material. The precursor material is annealed at 350 ℃~500 ℃ in a protective atmosphere to decompose the hydroxide precursor material to obtain the NiMnCoO3 nanomaterial, and the NiMnCoO3 nanomaterial is in a sheet structure.

5. The method for preparing a lithium-ion battery electrode material according to claim 4, characterized in that, The hydrothermal reaction is performed for 2 h~6 h.

6. The method for preparing a lithium-ion battery electrode material according to claim 4, characterized in that, The annealing treatment is performed for 2 h~4 h.

7. The method of claim 4, wherein the lithium ion battery electrode material is prepared by the steps of: a) mixing the lithium source, the carbon source, and the binder to form a mixture; b) heating the mixture to form a lithium ion battery electrode material; and c) cooling the lithium ion battery electrode material. The amount-of-substance ratio of the cobalt salt to the complexing agent A is 0.5:20~24. The complexing agent A is urea and ammonium fluoride with an amount-of-substance ratio of 14~16:6~8.

8. The method for preparing a lithium-ion battery electrode material according to claim 4, characterized in that, The preparation further comprises adding a surfactant solution to the mixed solution A, and the prepared NiMnCoO3 nanomaterial is in a rosette structure. The amount ratio of the nickel salt to the surfactant is 0.5 mmol:0.1 g~0.12 g.

9. A method for preparing a lithium-ion battery electrode material according to claim 8, characterized in that, The preparation further comprises adding foamed nickel to the hydrothermal reaction, and the prepared NiMnCoO3 nanomaterial is in a rosette structure.

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