Layered metal oxide containing interstitial carbon atoms and preparation method thereof

Abstract

The invention relates to a layered metal oxide containing interstitial carbon atoms and a preparation method thereof, and belongs to the technical field of lithium / sodium ion battery electrode materials.The preparation method comprises the steps that polyphenol organic ligands and metal are weighed at the room temperature, and the molar ratio ranges from 1: 6 to 1: 300; adding the raw materials into a solvent, mechanically grinding for 1-3 hours, and drying to obtain a precursor product; and calcining the precursor at the temperature of 700 to 1050 DEG C for 10 to 17 hours. According to the method, carbon atoms are doped between lattice laminates of the layered metal oxide in situ in the process of precursor synthesis and high-temperature heat treatment, and repulsive force between the transition metal laminates is reduced through generated lattice attractive force, so that the unit cell volume is reduced; the structural strain is greatly reduced in the electrochemical energy storage process, and the electrochemical performance under ultrahigh rate and long cycle is greatly improved.

Description

Technical Field

[0001] This invention belongs to the technical field of electrode materials for lithium / sodium-ion batteries in electrochemical energy storage, specifically relating to a layered metal oxide containing interstitial carbon atoms and its preparation method. Background Technology

[0002] Layered metal oxides are a common type of metal oxide material, consisting of stacked octahedral cells of several transition metals. Their transition metal active centers possess high redox potentials, significantly enhancing electrochemical capacity. However, transition metal oxides are structurally unstable, facing challenges such as irreversible phase transitions, irreversible redox reactions of lattice oxygen, and ordered / disordered changes in active sites / vacancies during charge-discharge cycling (ACS Nano 2024, 18, 18834−18851). This leads to drastic volume changes during long electrochemical cycles, causing strain accumulation at phase boundaries, which can further induce cracks or structural deterioration, making it impossible to maintain structural stability. Furthermore, carrier insertion and extraction cross different energy storage active sites; these stable intermediate states make it difficult for diffusion barriers to overlap, resulting in slow kinetics during cycling and failing to meet the demands of long-life, high-power applications (Interdisciplinary Materials, 2024, 1–28).

[0003] Currently, the main methods for synthesizing layered metal oxides are solid-state methods, room-temperature co-precipitation methods, and sol-gel methods. Furthermore, these methods are often supplemented with nickel / manganese-rich substrates by metal doping, non-metal doping, or carbon / inorganic layer coating. For example, Yang et al. used Zn to replace Na sites, disrupting the Na / vacancy arrangement and establishing a strengthened "pillar" effect within the layered framework. Ultimately, after 500 cycles at 10C, the capacity retention remained close to 100% (Adv. Funct. Mater, 2024, 34, 2315437). Liu et al. used F... - Replace O 2- This site enhances the average valence state of the oxygen layer, thereby promoting the reversibility of the electrochemical reaction, ultimately reaching 16 mA g. -1 148mAh g was obtained under the current. -1The initial capacity was maintained, and 53.4% ​​of the capacity was retained even after a 100-fold increase in current density (Adv. Mater. 2024, 2407519). However, high-entropy alloys are prone to misalignment, introducing distortion into the layered structure and causing structural disorder. Sun et al. coated the surface of the layered oxide with a Na-free inert coating to suppress structural degradation and excessive SEI growth. After exposure to humid air for 4 days, only a small amount of Na2CO3 impurities were observed on the cathode surface (Small 2024, 2404593). Although carbon coating enhances the stability of the material, the thick inert coating also hinders ion transport under high current, thereby reducing energy density and ion diffusion rate, making it difficult for the battery to be used in high-rate and high-power applications.

[0004] Interstitial carbon atom doping is a novel and highly effective modification strategy. Embedding carbon atoms into the lattice spaces alters the interstitial spacing through the micro-stress they generate on lattice oxygen, optimizing bond lengths and angles, and enhancing the structure's resistance to strain, thus significantly improving structural stability. Furthermore, the introduction of interstitial carbon atoms also helps improve the self-forming properties of the crystal, greatly increasing crystallinity, thereby reducing the high-energy barrier for charge carriers to cross grain boundaries, improving the dynamic characteristics of charge carriers, and enhancing the high-rate performance of the material. For example, Yang et al., during Bi nucleation, encapsulated interstitial carbon atoms in situ within Bi nanoparticles to stabilize the structure, resulting in a high-rate performance as an anode material at 10 A g. -1 Capacity can reach 215 mAh g at current density -1 And in 10A g -1 Under certain conditions, the capacity retention rate reached 83.8% after 6000 cycles (Adv. Sci. 2025, 12, 2416742). Zhang et al. spontaneously doped carbon atoms into the Pd-Au lattice, while maintaining the alloy size, metallic state, and alloy composition, and significantly reduced the conduction band center, thereby weakening the adsorption of acetate and greatly improving the catalytic performance (J. Am. Chem. Soc. 2023, 145, 5, 2985–2998).

[0005] However, current research on interstitial carbon doping mainly focuses on battery anode materials, and studies on interstitial carbon doping in cathode materials remain lacking. Therefore, in order to further improve the crystallographic structure, stability, and electrochemical performance of layered metal oxides, it is crucial to develop a technique that can dope trace amounts of carbon atoms in the interlayer spaces of layered metal oxides. Summary of the Invention

[0006] The purpose of this invention is to address the problems of poor structural stability and slow kinetics in layered metal oxides by providing a layered metal oxide containing interstitial carbon atoms and its preparation method. This invention utilizes the coordination of polyphenol small molecules with metal ions in metal salts to form layered metal oxides through the calcination and thermal decomposition of the precursor, introducing carbon atoms into the interlayer gaps. The introduction of interstitial carbon not only optimizes the bond length and bond angle between metal and oxygen atoms through micro-stress, thereby enhancing the stability of the cathode material structure, but also improves the self-forming properties of the material, significantly increasing its crystallinity, thus reducing the potential barrier for carrier transport, improving the rate performance of the material, and exhibiting good electrochemical activity and stability.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows:

[0008] A layered metal oxide containing interstitial carbon atoms, wherein the lattice of the layered metal oxide is doped with interstitial carbon atoms, and the content of the interstitial carbon atoms accounts for 0.1 to 5% of the total molar fraction of metal elements.

[0009] Furthermore, the layered metal oxide has a hexagonal crystal structure with space group P63-mmc, and interstitial carbon atoms are located within the oxide lattice.

[0010] Furthermore, the layered metal oxide exhibits stronger X-ray diffraction peaks and narrower full width at half maximum (FWHM) compared to layered metal oxides without interstitial carbon atoms; it also displays a single-crystal diffraction pattern under a high-resolution electron microscope.

[0011] A method for preparing layered metal oxides containing interstitial carbon atoms includes the following steps:

[0012] The polyphenol organic ligand and metal salt were mixed in a molar ratio of 1:6 to 1:300, added to a solvent and mechanically ground for 1-3 hours, and then dried to obtain the precursor.

[0013] The precursor was calcined at 700~1050 °C for 10~17 hours to obtain layered metal oxides containing interstitial carbon atoms.

[0014] Furthermore, the polyphenol ligand is selected from at least one of gallic acid, pyrogallol, ellagic acid, tannic acid, quercetin, kaempferol, and catechin.

[0015] Furthermore, the layered metal oxide is Na. 0.67 Ni 0.33 Mn 0.67 O2, Na 0.67 Ni 0.5 Mn 0.5 O2, NaNi 0.33 Fe 0.33 Mn0.33 O2, LiNi 0.8 Co 0.1 Mn 0.1 O2 or Li 1.2 Mn 0.53 Ni 0.2 Co 0.07 O2.

[0016] Furthermore, the layered metal oxide is also doped with 0.1 to 5 mol% of at least one of Ca, Cu, Zn, Mg, Al, Fe, and Te.

[0017] Furthermore, the metal salt is selected from at least one of acetate, carbonate, citrate, nitrate, halide, sulfate, and phosphate; the solvent is at least one of deionized water, ethanol, and N,N-dimethylformamide.

[0018] The application of a layered metal oxide containing interstitial carbon atoms in lithium / sodium-ion batteries achieves a discharge capacity of 86.3 mAh g at a 20C rate. -1 -145.8mAh g -1 And after 1200 cycles, the capacity retention rate is 62%-85%.

[0019] A lithium / sodium-ion battery comprising the aforementioned layered metal oxide cathode material.

[0020] Beneficial effects:

[0021] This invention provides a layered metal oxide containing interstitial carbon atom doping and its preparation method. It utilizes the polyphenol-metal complexation and segmented weightless decomposition of small organic molecules during precursor synthesis and high-temperature heat treatment to in-situ dope carbon atoms at the interlayer gaps in the crystal lattice during the synthesis of the layered metal oxide. The features and advantages of this invention are:

[0022] (1) First, suitable small organic polyphenol molecules and corresponding reaction solvents were screened to ensure the full dissolution and chelation of polyphenol molecules with metal salts, thus synthesizing stable precursor materials. Subsequently, interstitial carbon atom doping was carried out during the synthesis of layered metal oxides using a high-temperature heat treatment process.

[0023] (2) Select appropriate high-temperature heat treatment steps, temperatures and times to ensure sufficient chelation-assisted crystallization of small organic polyphenol molecules and sufficient pyrolysis after crystallization, so as to synthesize layered metal oxides with high crystallinity.

[0024] (3) The interstitial carbon atom-doped layered metal oxides prepared exhibit good electrochemical stability and comprehensive performance when used as energy storage cathode materials.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] (1) This method involves in-situ doping of atomic carbon into the interlayer of the lattice of layered metal oxides during precursor synthesis and high-temperature heat treatment. The generated lattice micro-stress optimizes the lattice spacing of the material, improves the atomic bond length and bond angle, and enhances the stability of the structure.

[0027] (2) This method utilizes the introduction of interstitial carbon to enhance the self-forming properties of the material, thereby greatly increasing the crystallinity, reducing the barrier to carrier transport, improving rate performance, and thus exhibiting good electrochemical activity and stability in the field of energy storage.

[0028] (3) This method utilizes the introduction of interstitial carbon to change the coordination environment of redox active centers, thereby changing the electronic configuration inside the material, constructing interconnected electronic pathways, thereby reducing the energy barrier for free electron transitions, which is beneficial to obtaining electrochemical performance with ultra-high rate and lifetime.

[0029] (4) The preparation process of this method is simple, the raw materials are widely available, and the cost is low. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention.

[0031] Figure 2 This is a schematic diagram of the (100) and (001) plane crystal structures of Embodiment 1 of the present invention.

[0032] Figure 3 This is a schematic diagram of the (100) and (001) plane crystal structures of Comparative Example 1 of the present invention.

[0033] Figure 4 This is the refined XRD Rietveld pattern of Embodiment 1 of the present invention.

[0034] Figure 5 This is the refined XRD Rietveld pattern of Comparative Example 1 of the present invention.

[0035] Figure 6 This is a scanning electron microscope image of Embodiment 1 of the present invention.

[0036] Figure 7 This is a scanning electron microscope image of Comparative Example 1 of the present invention.

[0037] Figure 8 The images shown are projection electron microscope images and partial magnified views of Embodiment 1 of the present invention.

[0038] Figure 9 This is a projection electron microscope image and a partial magnified view of Comparative Example 1 of the present invention.

[0039] Figure 10 The thermogravimetric analysis diagrams for Embodiment 1 and Comparative Example 1 of the present invention are shown.

[0040] Figure 11 This is the X-ray photoelectron spectrum of Embodiment 1 of the present invention.

[0041] Figure 12 This is the EDS Mapping diagram of Embodiment 1 of the present invention.

[0042] Figure 13 The electrochemical rate test results are shown for Example 1 and Comparative Example 1 of this invention.

[0043] Figure 14 The images show the electrochemical lifetime test results of Example 1 and Comparative Example 1 of this invention. Detailed Implementation

[0044] The specific embodiments of the present invention will now be described in conjunction with the accompanying drawings and examples to provide a better understanding of the invention.

[0045] Example 1:

[0046] In this example 1, a manganese-rich layered metal oxide (Na) containing interstitial carbon was used. 0.67 Ni 0.33 Mn 0.67 The preparation method of O2 as a positive electrode material for sodium-ion batteries involves the following steps: gallic acid and metal salt are added to deionized water at a molar ratio of 1:30 (the specific ratio is gallic acid: nickel acetate: manganese acetate: sodium carbonate = 1:6:12:6), and mechanically ground for 2 hours. After drying, a precursor product is obtained. The precursor product is heated to 950°C and calcined for 15 hours to obtain a layered metal oxide containing interstitial carbon doping.

[0047] Example 2:

[0048] In Example 2, a nickel-rich layered metal oxide (LiNi) containing interstitial carbon was used. 0.8 Co 0.1 Mn 0.1 The preparation method of O2 as a positive electrode material for lithium-ion batteries involves the following steps: pyrogallic acid and metal salt are added to deionized water at a molar ratio of 1:30 (the specific ratio is pyrogallic acid: nickel acetate: manganese acetate: cobalt acetate: sodium carbonate = 2:24:3:3:15), and mechanically ground for 2 hours. After drying, a precursor product is obtained. The precursor product is then heated to 750°C and calcined for 12 hours to obtain a layered metal oxide containing interstitial carbon doping.

[0049] Example 3:

[0050] In Example 3, the manganese-rich layered metal oxide (Na) containing interstitial carbon0.67 Ni 0.45 Ca 0.05 Mn 0.5 The preparation method of O2 as a positive electrode material for sodium-ion batteries involves the following steps: ellagic acid and metal salt are added to anhydrous ethanol at a molar ratio of 1:300 (the specific ratio is ellagic acid: nickel chloride: manganese chloride: calcium chloride: sodium carbonate = 1:81:90:9:60), and mechanically ground for 2 hours. After drying, a precursor product is obtained. The precursor product is heated to 950°C and calcined for 15 hours to obtain a layered metal oxide containing interstitial carbon doping.

[0051] Example 4:

[0052] In Example 4, a manganese-rich layered metal oxide (NaNi) containing interstitial carbon was used. 0.33 Fe 0.33 Mn 0.33 The preparation method of O2 as a positive electrode material for sodium-ion batteries involves the following steps: Quercetin and metal salt are added to anhydrous ethanol at a molar ratio of 1:6 (the specific ratio is quercetin: nickel citrate: iron citrate: manganese citrate: sodium carbonate = 5:6:6:6:6), and mechanically ground for 3 hours. After drying, a precursor product is obtained. The precursor product is heated to 700°C and calcined for 17 hours to obtain a layered metal oxide containing interstitial carbon doping.

[0053] Example 5:

[0054] In Example 5, the manganese-rich layered metal oxide (Na) containing interstitial carbon is used. 0.67 Ni 0.33 Mn 0.67 The preparation method of O2 as a positive electrode material for sodium-ion batteries involves the following steps: adding kaempferol and metal salt in a molar ratio of 1:30 (specifically, the ratio of kaempferol: nickel phosphate: manganese phosphate: sodium carbonate = 1:6:12:6) to N,N-dimethylformamide and mechanically grinding for 1 hour, followed by drying to obtain a precursor product; heating the above precursor product to 1050℃ and calcining it for 10 hours to obtain a layered metal oxide containing interstitial carbon doping.

[0055] Example 6:

[0056] In Example 6, the manganese-rich layered metal oxide (Na) contains interstitial carbon. 0.67 Ni 0.33 Mn 0.67The preparation method of O2 as a positive electrode material for sodium-ion batteries involves the following steps: adding catechin and metal salt in a molar ratio of 1:30 (specifically, the ratio of catechin:nickel carbonate:manganese carbonate:sodium carbonate = 1:6:12:6) to N,N-dimethylformamide and mechanically grinding for 2 hours, followed by drying to obtain a precursor product; heating the above precursor product to 950°C and calcining it for 15 hours to obtain a layered metal oxide containing interstitial carbon doping.

[0057] Comparative Example 1:

[0058] In Comparative Example 1, the manganese-rich layered metal oxide (Na) 0.67 Ni 0.33 Mn 0.67 The preparation method of sodium-ion battery cathode material using O2 is as follows: Nickel acetate, manganese acetate, and sodium carbonate are added to a solvent in a molar ratio of 1:2:1 and mechanically ground for 2 hours, then dried to obtain a precursor product; the precursor product is heated to 950℃ and calcined for 15 hours to obtain Na2. 0.67 Ni 0.33 Mn 0.67 O2 layered metal oxides.

[0059] Comparative Example 2:

[0060] In Comparative Example 2, nickel-rich layered metal oxides (LiNi) 0.8 Co 0.1 Mn 0.1 The preparation method of O2 as a positive electrode material for lithium-ion batteries involves the following steps: nickel acetate, manganese acetate, cobalt acetate, and lithium carbonate are added to a solvent in a molar ratio of 8:1:1:5 and mechanically ground for 2 hours, followed by drying to obtain a precursor product; the precursor product is then heated to 750℃ and calcined for 12 hours to obtain LiNi. 0.8 Co 0.1 Mn 0.1 O2 layered metal oxides.

[0061] Comparative Example 3:

[0062] In Comparative Example 3, the manganese-rich layered metal oxide (NaNi) 0.33 Fe 0.33 Mn 0.33 The preparation method of O2 as a positive electrode material for sodium-ion batteries involves the following steps: nickel acetate, ferric acetate, manganese acetate, and sodium carbonate are ball-milled in a molar ratio of 1:1:1:1 for 7 hours to obtain a precursor product; the precursor product is then heated to 950℃ and calcined for 15 hours to obtain NaNi. 0.33 Fe 0.33 Mn 0.33 O2 layered metal oxides.

[0063] Table 1 shows the interstitial carbon content and electrochemical performance results of Examples 1-6 and Comparative Examples 1-3 of the present invention. It can be seen that after the introduction of the polyphenol organic ligand, interstitial carbon was successfully doped between the lattice layers, leading to an increase in carbon content, which accounts for 0.1-5% of the total metal element molar fraction. Furthermore, the improved nickel-rich / manganese-based layered metal oxide not only exhibits better rate performance but also significantly improved cycle stability.

[0064] Table 1. Interstitial carbon content and electrochemical performance of Examples 1-6 and Comparative Examples 1-3

[0065] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention. Figure 1 As can be seen, carbon atoms are doped in atomic form between the layers of the layered metal oxide lattice. The crystal structure and cell parameters of the corresponding material are obtained by performing powder XRD tests on the synthesized material and then applying Rietveld precision fitting to the test results. A schematic diagram of the crystal structure and interlayer spacing in Example 1 of this invention is shown below. Figure 2 As shown in the figure. Where a, b, and c (coordinates in Tables 2 and 3) are the side lengths of the unit cell along the x, y, and z axes, respectively, and the atomic coordinates are the atomic sites of different elements within the lattice.

[0066] Testing revealed that the crystal structure of Example 1 belongs to the hexagonal crystal system, with space group P63-mmc. The interstitial carbon atoms are located at triangular prism-shaped active sites. The specific cell parameters are shown in Table 2.

[0067] Table 2. XRD Rietveld refinement parameters for Example 1

[0068] The crystal structure and schematic diagram of Comparative Example 1 are shown below. Figure 3 As shown in the figure, the interlayer spacing increased significantly due to the absence of carbon doping. Testing revealed that the crystal structure of Comparative Example 1 also belongs to the hexagonal crystal system with space group P63-mmc, but the cell parameters differ. Specific parameters are shown in Table 3.

[0069] Table 3. XRD Rietveld refinement parameters for Comparative Example 1

[0070] Figure 4 and Figure 5 These are the refined XRD patterns of Embodiment 1 and Comparative Example 1 of the present invention. (From...) Figure 4 and Figure 5It can be seen that after doping with interstitial carbon, the number and shape of the XRD peaks of the material did not change, but their positions shifted slightly. This proves that its crystal form is still a P2-type layered metal oxide, but the interlayer spacing and cell size have changed. This indicates that the interstitial carbon did not change the original crystal structure, but was doped in small quantities in the form of atoms between the lattice layers.

[0071] Figure 6 and Figure 7 These are scanning electron microscope images of Embodiment 1 and Comparative Example 1 of the present invention. Figure 6 and Figure 7 Scanning electron microscopy images show that carbon doping significantly improves the crystallinity of the layered structure. The lamellae expand from irregular small particles to smooth and uniform thick lamellar structures, with a size of 2–10 μm and a thickness of 0.5–3 μm. This indicates that the introduction of interstitial carbon enhances the self-forming properties of the material.

[0072] Figure 8 and Figure 9 These are transmission electron microscope images of Embodiment 1 and Comparative Example 1 of the present invention. Figure 8 and Figure 9 The projection electron microscope images clearly show the lattice difference. Interstitial carbon doping optimizes the lattice spacing of the material through the generated lattice microstress, improving atomic bond lengths and bond angles, and enhancing structural stability. Simultaneously, it significantly increases crystallinity, thereby reducing the potential barrier for carrier transport.

[0073] Figure 10 The thermogravimetric analysis (TGA) curves for Embodiment 1 and Comparative Example 1 of the present invention are shown. These curves further illustrate that the organic small molecule ligands underwent cleavage during precursor synthesis and heat treatment, thereby doping carbon atoms into the interlayer spaces of the layered metal oxide. In contrast, the comparative example without the addition of organic small molecule ligands only experienced nucleation and growth of the metal unit cells.

[0074] Figure 11 This is the X-ray photoelectron spectrum of Embodiment 1 of the present invention. The spectrum further illustrates that interstitial carbon atoms were successfully introduced between the lattice layers and bonded to lattice oxygen, forming a stable carbon-doped structure.

[0075] Figure 12 This is the EDS mapping spectrum of Example 1 of the present invention. This spectrum further illustrates the successful preparation of the P2-type layered metal oxide material, along with the successful doping of a small amount of interstitial carbon atoms (C, Na, Ni, Mn, and O). The content is approximately 0.1% to 5% of the content of other metal elements. Figure 12 The first row, from left to right, contains HADDF (high-angle annular dark field, i.e., the control), C, and Na. The second row, from left to right, contains Ni, Mn, and O.

[0076] Figure 13 and Figure 14 This document presents the electrochemical rate performance and electrochemical lifetime performance of Example 1 and Comparative Example 1 of the present invention. Layered metal oxide materials, as positive electrode materials for electrochemical energy storage, not only require high rate performance, but more importantly, good cycle stability to further enhance their practical application value. Figure 13 and Figure 14 As can be seen, the cathode material prepared in Example 1 of this invention still exhibits a current density of nearly 100 mAh g⁻¹ at an ultra-high current density of 20C. -1 The specific capacity of the cathode material is significantly higher than that of the cathode material prepared in Comparative Example 1. Furthermore, it retains 75% of its capacity after 1200 cycles at a current density of 20C. In contrast, the cathode material prepared in Comparative Example 1 only exhibits a capacity of 55 mAh g⁻¹ at 20C. -1 The capacity was achieved, and after 1200 cycles at this current density, the retention rate was only 48%. This indicates that the introduction of interstitial carbon not only improved the rate performance of the layered metal oxide but also significantly enhanced its cycling stability.

[0077] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A layered metal oxide containing interstitial carbon atoms, characterized in that, The layered metal oxide is doped with interstitial carbon atoms in its crystal lattice, and the content of the interstitial carbon atoms accounts for 0.1 to 5% of the total molar fraction of metal elements.

2. The layered metal oxide containing interstitial carbon atoms according to claim 1, characterized in that, The layered metal oxide has a hexagonal crystal structure with space group P63-mmc, and interstitial carbon atoms are located within the oxide lattice.

3. A method for preparing the layered metal oxide containing interstitial carbon atoms as described in claim 1 or 2, characterized in that, Includes the following steps: The polyphenol organic ligand and metal salt were mixed in a molar ratio of 1:6 to 1:300, added to a solvent and mechanically ground for 1-3 hours, and then dried to obtain the precursor. The precursor was calcined at 700~1050℃ for 10~17 hours to obtain a layered metal oxide containing interstitial carbon atoms.

4. The method according to claim 3, characterized in that, The polyphenol organic ligand is selected from at least one of gallic acid, pyrogallol, ellagic acid, tannic acid, quercetin, kaempferol, and catechin.

5. The method according to claim 3, characterized in that, The layered metal oxide is Na. 0.67 Ni 0.33 Mn 0.67 O2, Na 0.67 Ni 0.5 Mn 0.5 O2, NaNi 0.33 Fe 0.33 Mn 0.33 O2, LiNi 0.8 Co 0.1 Mn 0.1 O2 or Li 1.2 Mn 0.53 Ni 0.2 Co 0.07 O2.

6. The method according to claim 3, characterized in that, The metal salt is selected from at least one of acetate, carbonate, citrate, nitrate, halide, sulfate, and phosphate; the solvent is at least one of deionized water, ethanol, and N,N-dimethylformamide.

7. A lithium / sodium-ion battery, characterized in that, It includes the layered metal oxide cathode material as described in claim 1 or 2.

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