阅读说明：本技术 高比能钠离子电池锰基层状正极材料及其制备方法 (Manganese-based layered positive electrode material of high-specific-energy sodium-ion battery and preparation method thereof ) 是由 郭少华 许航 于 2021-08-02 设计创作，主要内容包括：本发明涉及电化学领域,尤其涉及一种钠离子电池高比能锰基层状正极材料。通式为Na-(x)Li-(y)Mn-(1-y-z)M-(z)O-(2),其中M为Ru、Ni、Cu、Zn、Mg或Ti,且0.5≤x≤1,0<y≤0.33,0<z≤0.33。本发明的正极材料中,Li元素占据过渡金属层,Li-O-Na构型引发氧的非杂化能级,触发氧的氧化还原。本发明的钠离子电池高比能锰基层状正极材料,依靠少量其它金属M的均匀掺入,相对于锰与氧形成更强的共价键,从而提高氧附近电子脱出后晶格氧的结构稳定性,从而提高钠离子电池的循环稳定性。(The invention relates to the field of electrochemistry, in particular to a manganese-based layered positive electrode material with high specific energy for a sodium-ion battery. General formula is Na x Li y Mn 1‑y‑z M z O 2 Wherein M is Ru, Ni, Cu, Zn, Mg or Ti, and x is more than or equal to 0.5 and less than or equal to 1 and 0<y≤0.33，0<z is less than or equal to 0.33. In the positive electrode material of the present invention, Li element occupiesThe transition metal layer, Li-O-Na configuration, triggers the non-hybrid energy level of oxygen, and triggers the oxidation reduction of oxygen. The high-specific-energy manganese-based layered cathode material of the sodium-ion battery provided by the invention is uniformly doped with a small amount of other metal M, and forms a stronger covalent bond relative to manganese and oxygen, so that the structural stability of lattice oxygen after electrons near oxygen are removed is improved, and the cycle stability of the sodium-ion battery is improved.)

1. The high-specific-energy manganese-based layered positive electrode material of the sodium-ion battery is characterized in that the general formula of the positive electrode material is Na_xLi_yMn_1-y-zM_zO₂Wherein M is Ru, Ni, Cu, Zn, Mg or Ti, and x is more than or equal to 0.5 and less than or equal to 1 and 0< y≤ 0.33，0< z≤ 0.33。

2. The sodium-ion battery high specific energy manganese-based layered positive electrode material of claim 1, wherein M is Ru; x is more than or equal to 0.5 and less than or equal to 0.75, y is more than or equal to 0.1 and less than or equal to 0.25, and z is more than or equal to 0.1 and less than or equal to 0.25.

3. The high-specific-energy manganese-based layered positive electrode material of the sodium-ion battery as claimed in claim 1, wherein the general formula of the high-specific-energy manganese-based layered positive electrode material of the sodium-ion battery is Na_0.6Li_0.2Mn_0.6Ru_0.2O₂(ii) a The crystal structure of the cathode material belongs to P6₃/mmc or R _{m space}Grouping; the anode material is uniform particles with a layered stacking structure, and the particle size of the anode material is₀.2-5 μm。

4. The method for preparing the high-specific-energy manganese-based layered cathode material of the sodium-ion battery of claim 1, comprising the steps of: and uniformly mixing sodium salt, lithium salt, manganese salt and metal M oxide, tabletting, calcining and cooling to obtain the high-specific-energy manganese-based layered positive electrode material of the sodium-ion battery.

5. The method for preparing the high-specific-energy manganese-based layered cathode material for the sodium-ion battery as claimed in claim 7, wherein the calcination process is a single-step or multi-step calcination at a temperature range of 500-1100 ℃; the oxide of the metal M is selected from RuO₂NiO, CuO, ZnO, MgO and TiO₂One or more of them.

6. The method for preparing the high-specific-energy manganese-based layered cathode material of the sodium-ion battery according to claim 7, wherein the sodium salt is Na₂CO₃、NaNO₃And NaCl; the lithium salt is LiOH or LiOH₂O、Li₂CO₃At least one of; the manganese salt is MnO₂、Mn₂O₃、MnCO₃At least one of (1).

7. The method for preparing the high-specific-energy manganese-based layered cathode material of the sodium-ion battery according to claim 7, wherein the molar ratio of sodium element, lithium element, manganese element and other metal elements in the sodium salt, lithium salt, manganese salt and other metal oxides is 0.5-1: 0.01-0.33: 0.33-0.99: 0.01-0.33.

8. The method for preparing the high-specific-energy manganese-based layered cathode material of the sodium-ion battery according to claim 7, wherein the molar ratio of sodium element, lithium element, manganese element and other metal elements in sodium salt, lithium salt, manganese salt and other metal oxides is 0.5-0.75: 0.1-0.25: 0.5-0.8: 0.1-0.25.

9. The method for preparing the high-specific-energy manganese-based layered cathode material for the sodium-ion battery according to claim 7, wherein the tabletting is performed at 1-50 MPa.

10. The method for preparing the high-specific-energy manganese-based layered cathode material of the sodium-ion battery according to claim 7, wherein the calcination is performed at 1-20 ℃ for min^-1The temperature rise rate is increased from room temperature to the target temperature, and if the step-by-step calcination is needed, the material slices need to be taken out, ground and re-tabletted before the secondary calcination; the calcination is carried out in an oxygen atmosphere or an air atmosphere, and the calcination time is 1-50 h.

Technical Field

The invention relates to the field of electrochemistry, in particular to a manganese-based layered positive electrode material with high specific energy for a sodium-ion battery.

Background

The sodium ion battery has wide application prospect in the fields of large-scale energy storage systems and smart power grids due to rich raw materials and low price. The development of a high specific capacity and stable cycle cathode material is the key for further practicability of the sodium ion battery. Among the cathode materials of sodium ion batteries, layered transition metal oxides have been widely studied due to a series of advantages of high specific capacity, simple synthesis, rich components, controllable structure and the like. The manganese-based layered material also has the advantages of low price, environmental friendliness, valence diversity, capability of adjusting the voltage range of the electrochemical process and the like.

The layered transition metal oxides which are widely studied at present have good electrochemical properties, and most of them rely on transition metal valence change to provide charge compensation in the electrochemical process, i.e. cationic redox. Many of them have approached the theoretical capacity upper limit, and migration, disproportionation, and irreversible phase change during electrochemical cycling of transition metals are also challenges that cannot be ignored.

On the other hand, a number of sodium-ion battery positive electrode materials capable of realizing anion redox are recently reported, and compared with the Li-O-Li configuration of the lithium-rich material reported in the past, the materials have more abundant configuration to form a non-hybridized oxygen 2p state, so that anion redox is initiated, namely, lattice oxygen participates in charge compensation to obtain extra capacity. However, these materials usually have the problems of irreversible first cycle, attenuation or disappearance of subsequent cycle high voltage platform, and oxygen release and rapid capacity potential attenuation caused by structural instability.

Therefore, designing a multi-channel charge compensation and structurally stable cathode material is an effective strategy for achieving high energy density and sustainable cycling of sodium ion batteries, and is also a great challenge.

Disclosure of Invention

The invention aims to solve the technical bottleneck of charge compensation of a single channel at present, break through the upper limit of the traditional theoretical capacity, realize high energy density and sustainable circulation required by the practicability of a sodium-ion battery, and provide a manganese-based layered anode material with high specific energy and a preparation method thereof.

A high specific energy manganese-based layered positive electrode material for sodium ion battery with general formula of Na_xLi_yMn_1-y-zM_zO₂Wherein M is Ru, Ni, Cu, Zn, Mg or Ti, and x is more than or equal to 0.5 and less than or equal to 1 and 0< y≤ 0.33，0< z≤ 0.33。

Preferably, M is Ru.

Preferably, 0.5. ltoreq. x.ltoreq.0.75, 0.1. ltoreq. y.ltoreq.0.25, 0.1. ltoreq. z.ltoreq.0.25.

More preferably, the general formula of the high specific energy manganese-based layered cathode material of the sodium-ion battery is Na_0.6Li_0.2Mn_0.6Ru_0.2O₂。

Preferably, the crystal structure of the cathode material belongs toP6 ₃ /mmcOrR mAnd (4) space group.

Further, the positive electrode material is uniform particles with a layered stacking structure, and the particle size of the positive electrode material is 0.2-5 μm.

The preparation method of the high-specific-energy manganese-based layered positive electrode material of the sodium-ion battery comprises the following steps of:

and uniformly mixing sodium salt, lithium salt, manganese salt and metal M oxide, tabletting, calcining and cooling to obtain the high-specific-energy manganese-based layered positive electrode material of the sodium-ion battery.

Preferably, the calcination process is a single or multiple calcination at a temperature in the range of 500-1100 ℃.

The oxide of the metal M is selected from RuO₂NiO, CuO, ZnO, MgO and TiO₂One or more of them.

Further, the sodium salt is Na₂CO₃、NaNO₃And NaCl.

Further, the lithium salt is LiOH or LiOH₂O、Li₂CO₃At least one of (1).

Further, the manganese salt is MnO₂、Mn₂O₃、MnCO₃At least one of (1).

Furthermore, the molar ratio of sodium element, lithium element, manganese element and other metal elements in the sodium salt, the lithium salt, the manganese salt and other metal oxides is 0.5-1: 0.01-0.33: 0.33-0.99: 0.01-0.33.

Preferably, the molar ratio of the sodium element, the lithium element, the manganese element and other metal elements in the sodium salt, the lithium salt, the manganese salt and other metal oxides is 0.5-0.75: 0.1-0.25: 0.5-0.8: 0.1-0.25.

The ball milling method is adopted in the mixing process, the ball milling speed is 100-^-1The ball milling time is 2-20 h.

Further, tabletting is carried out under 1-50 MPa.

Further, calcining at 1-20 deg.C for min^-1The temperature rise rate of (2) is increased from room temperature to the target temperature, and if the calcination is required step by step, the material slices are taken out and ground before the secondary calcination and then re-tabletted.

Furthermore, the calcination is carried out in an oxygen atmosphere or an air atmosphere, and the calcination time is 1-50 h.

Advantageous effects

(1) The high-specific-energy manganese-based positive electrode material of the sodium-ion battery has a layered crystal structure, Li element occupies a transition metal layer, and Li-O-Na configuration triggers non-hybrid energy level of oxygen to trigger oxidation reduction of the oxygen. The high-specific-energy manganese-based layered cathode material of the sodium-ion battery provided by the invention is uniformly doped with a small amount of other metal M, and forms a stronger covalent bond relative to manganese and oxygen, so that the structural stability of lattice oxygen after electrons near oxygen are removed is improved, and the cycle stability of the sodium-ion battery is improved.

(2) The preparation method is simple, the appearance and the size are uniform, the hexagonal crystal structure is realized, and the ions of the transition metal layer under certain components are orderly arranged in a honeycomb shape.

(3) The super-wide voltage range has the characteristics of super-high specific capacity, high discharge voltage, high energy density and high cycle stability due to the synergetic oxidation reduction of anions and cations (manganese ions and oxygen ions).

(4) The oxygen redox reduces the repulsion between transition metal layers of the material increased by sodium ion separation when the material is charged to a high voltage, so that the material has no phase change in a wide voltage window, and the volume strain in the electrochemical process is very small, thereby having excellent structural stability and cycle stability.

(5) Because the phase change of the sliding of the laminate does not exist, the problem that manganese ions are dissolved in electrolyte due to the Taylor effect of the ginger in the manganese-based material is obviously inhibited, and the electrochemical stability of the material is further improved.

(6) The ball milling method can fully and uniformly mix the sodium salt, the lithium salt, the manganese salt and other metal oxide precursors, thereby facilitating subsequent reaction and fully and uniformly carrying out. In the preparation process of the solid phase method, the precursor mixture can be compacted more compactly by optimizing the tabletting pressure, the distance between particles is smaller, and the reaction between the particles of the precursor mixture is more sufficient and uniform during subsequent heat treatment.

(7) The invention adopts a solid-phase sintering method, the precursor substances of the sample diffuse mutually at high temperature, so that the microscopic discrete particles gradually form a continuous solid-state layered structure, the layered oxide with a cubic crystal structure can be synthesized by controlling the reaction conditions, and the high specific energy can be realized in a wide voltage window.

Drawings

FIG. 1 is an X-ray powder diffraction pattern of a high specific energy manganese-based layered positive electrode material of a sodium-ion battery prepared in example 1 of the present invention;

FIG. 2 is a scanning electron microscope image of a high specific energy manganese-based layered cathode material of a sodium ion battery prepared in example 1 of the present invention;

FIG. 3 shows that the high specific energy manganese-based layered positive electrode material of the sodium-ion battery prepared in example 1 of the invention is 20 mA g^-1The charge-discharge curve of the first three circles under the current density;

FIG. 4 is the rate capability of the high specific energy manganese-based layered positive electrode material of the sodium-ion battery prepared in example 1 of the present invention;

FIG. 5 is a charge-discharge curve of the high specific energy manganese-based layered positive electrode material of the sodium-ion battery prepared in example 1 of the present invention at different current densities;

FIG. 6 shows that the high specific energy manganese-based layered positive electrode material of the sodium-ion battery prepared in example 1 of the invention is 200 mA g^-1Long cycle performance curve at current density;

FIG. 7 is an X-ray powder diffraction pattern of a high specific energy manganese-based layered positive electrode material of a sodium-ion battery prepared in example 14 of the present invention;

FIG. 8 is a scanning electron microscope image of a high specific energy manganese-based layered cathode material of a sodium ion battery prepared in example 14 of the present invention;

FIG. 9 shows that the high specific energy manganese-based layered positive electrode material of the sodium-ion battery prepared in example 14 of the present invention has a density of 20 mA g^-1The charge-discharge curve of the first three circles under the current density;

fig. 10 is a charge-discharge curve of the high specific energy manganese-based layered positive electrode material of the sodium-ion battery prepared in example 14 of the present invention at different current densities;

FIG. 11 shows that the high specific energy manganese-based layered positive electrode material of the sodium-ion battery prepared in example 14 of the present invention has a density of 200 mA g^-1Long cycle performance curve at current density.

Fig. 12 is a cyclic voltammogram of the high specific energy manganese-based layered positive electrode material of the sodium-ion battery prepared in example 14 of the present invention.

Fig. 13 is an X-ray powder diffraction pattern of the positive electrode material prepared in comparative example 1 of the present invention.

FIG. 14 shows the results of comparative example 1 of the present invention in which the positive electrode material was prepared at 20 mA g^-1The charge-discharge curve of the first three circles under the current density.

FIG. 15 shows the results of comparative example 1 of the present invention in which the positive electrode material was prepared at 200 mA g^-1Long cycle performance curve at current density.

Fig. 16 is the rate capability of the high specific energy manganese-based layered positive electrode material of the sodium-ion battery prepared in example 1 of the present invention.

Detailed Description

Example 1

(1) Accurately weighing Na with corresponding mass according to the molar ratio of 0.6:0.2:0.6:0.2₂CO₃(5% excess), LiOH₂O、MnO₂And RuO₂Adding into a ball milling tank, adding ball milling small balls, and processing at 300 r min^-1Ball milling for 15 h under the condition of (1), uniformly mixing the precursors, and drying the uniformly mixed precursors in an oven at 100 ℃ for 12 h.

(2) The ball-milled mixture was pressed into a disk with a diameter of 16 mm under a pressure of 10 MPa.

(3) Placing the sheet sample obtained in the step (2) into a tubular furnace for step-by-step calcination, and carrying out calcination at 5 ℃ for min in air atmosphere^-1Heating to 500 ℃, and calcining for 5 h; cooling to room temperature along with the furnace, grinding, re-tabletting, heating to 700 ℃, and calcining for 7 hours; repeating the above operations, heating to 1100 deg.C, calcining for 11 hr, cooling with furnace, taking out sample, grinding to obtain original powder with molecular formula of Na_0.6Li_0.2Mn_0.6Ru_0.2O₂The particle size of the material particles is 2-10 μm.

The high specific energy manganese-based positive electrode material of the sodium ion battery prepared in the way is characterized, the results are shown in figures 1-2, and figure 1 shows the characteristic curve of the layered oxide, which indicates that the sample hasP63/mmcAnd (3) space group structure. FIG. 2 shows that the material is uniform particles with a layered structure, and the particle size of the particles is 2-10 μm.

Electrochemical performance tests were performed on the prepared high specific energy manganese-based layered positive electrode material for sodium ion batteries, and the results are shown in fig. 3-6. As can be seen from FIG. 3, the material was at 20 mA g^-1The first charging specific capacity under the conditions of current density and 1.5-4.5V voltage is about 130 mAh g^-1The charging curve is a slope without a platform, and the specific discharge capacity is 195 mAh g^-1The discharge curve is smooth. The second time of charging, the curve passes through a slope with manganese valence change leading and a platform with oxygen oxidation reduction leading in a high-voltage area of about 4.4V, and the charging capacity is 225 mAh g^-1. FIG. 4 is a rate performance curve of the material, and FIG. 5 is an electrochemical curve of the material under different current densities at 50 mA g^-1Under the condition, the specific capacity of the nano-silver particles still has 105 mAh g^-1. In fig. 6, the upper curve represents charge-discharge coulombic efficiency, the lower curve represents the specific capacity of the material, and the electrochemical curves for different voltage windows show that the specific capacity of the battery still exceeds 90 mAh g after 100 cycles of long-time charge-discharge cycle^-1And the coulomb efficiency of the battery is kept to be about 97% in the long charge-discharge cycle.

Comparative example 1

The difference from example 1 is that: prepared by using manganese-based material Na not doped with Ru_0.6Li_0.2Mn_0.8O₂。

The preparation method comprises the following steps: (1) accurately weighing Na with corresponding mass according to the molar ratio of 0.6:0.8:0.2₂CO₃(5% excess), MnO₂And RuO₂Adding into a ball milling tank, adding ball milling small balls, and processing at 300 r min^-1Ball milling for 15 h under the condition of (1), uniformly mixing the precursors, and drying the uniformly mixed precursors in an oven at 100 ℃ for 12 h.

(2) The ball-milled mixture was pressed into a disk with a diameter of 16 mm under a pressure of 10 MPa.

(3) Placing the sheet sample obtained in the step (2) into a tubular furnace for step-by-step calcination, and carrying out calcination at 5 ℃ for min in air atmosphere^-1Heating to 500 ℃, and calcining for 5 h; cooling to room temperature along with the furnace, grinding, re-tabletting, heating to 700 ℃, and calcining for 7 hours; repeating the above operations, heating to 900 deg.C, calcining for 11 hr, cooling with the furnace, taking out sample, grinding to obtain original powder with molecular formula of Na_0.6Li_0.2Mn_0.8O₂The particle size of the material particles is 2-10 μm.

The positive electrode material prepared in the above way is characterized, XRD results are shown in figure 13, figure 1 shows a characteristic curve of the layered oxide, and the sample is shown to haveP63/mmcAnd (3) space group structure. FIG. 2 shows that the material is uniform particles with a layered structure, and the particle size of the particles is 2-10 μm.

Electrochemical performance tests were performed on the prepared high specific energy manganese-based layered positive electrode material for sodium ion batteries, and in fig. 15, the specific capacity of the battery was reduced to about 70 mAh g after 20 cycles of long-time charge-discharge cycles^-1The specific capacity of the material in the embodiment 1 is already lower than that of the material after 100 circles, which shows that the addition of Ru forms stronger covalent bonds, so that the structural stability of lattice oxygen after electrons around oxygen are removed is improved, and the cycling stability of the sodium ion battery is improved.

Example 2

Changing the molar ratio of each substance, accurately weighing Na with corresponding mass according to the molar ratio of 0.6:0.05:0.9:0.05₂CO₃、MnO₂And RuO₂The method of steps (1) to (3) in example 1 was followed to prepare a high specific energy manganese-based layered positive electrode material for sodium-ion batteries, the molecular formula of which was Na_0.6Li_0.05Mn_0.9Ru_0.05O₂。

Example 3

Changing the molar ratio of each substance, and accurately weighing Na with corresponding mass according to the molar ratio of 0.6:0.1: 0.8: 0.1₂CO₃、MnO₂And RuO₂The method of steps (1) to (3) in example 1 was followed to prepare a high specific energy manganese-based layered positive electrode material for sodium-ion batteries, the molecular formula of which was Na_0.6Li_0.1Mn_0.8Ru_0.1O₂。

Example 4

Changing the molar ratio of each substance, and accurately weighing Na with corresponding mass according to the molar ratio of 0.6:0.15:0.7:0.15₂CO₃、MnO₂And RuO₂The method of steps (1) to (3) in example 1 was followed to prepare a high specific energy manganese-based layered positive electrode material for sodium-ion batteries, the molecular formula of which was Na_0.6Li_0.15Mn_0.7Ru_0.15O₂。

Example 5

The molar ratio of each substance is changed, and Na with corresponding mass is accurately weighed according to the molar ratio of 0.6:0.25:0.5:0.25₂CO₃、MnO₂And RuO₂The method of steps (1) to (3) in example 1 was followed to prepare a high specific energy manganese-based layered positive electrode material for sodium-ion batteries, the molecular formula of which was Na_0.6Li_0.25Mn_0.5Ru_0.25O₂。

Example 6

The molar ratio of each substance is changed, and Na with corresponding mass is accurately weighed according to the molar ratio of 0.6:0.33:0.34:0.33₂CO₃、MnO₂And RuO₂The method of steps (1) to (3) in example 1 was followed to prepare a high specific energy manganese-based layered positive electrode material for sodium-ion batteries, the molecular formula of which was Na_0.6Li_0.33Mn_0.34Ru_0.33O₂。

Example 7

Changing the molar ratio of each substance, and accurately weighing Na with corresponding mass according to the molar ratio of 0.7:0.15:0.8:0.05₂CO₃、MnO₂And RuO₂The method of steps (1) to (3) in example 1 was followed to prepare a high specific energy manganese-based layered positive electrode material for sodium-ion batteries, the molecular formula of which was Na_0.7Li_0.15Mn_0.8Ru_0.05O₂。

Example 8

Changing the molar ratio of each substance, and accurately weighing Na with corresponding mass according to the molar ratio of 0.7:0.2:0.7:0.1₂CO₃、MnO₂And RuO₂The method of steps (1) to (3) in example 1 was followed to prepare a high specific energy manganese-based layered positive electrode material for sodium-ion batteries, the molecular formula of which was Na_0.7Li_0.2Mn_0.7Ru_0.1O₂。

Example 9

The molar ratio of each substance is changed, and Na with corresponding mass is accurately weighed according to the molar ratio of 0.7:0.25:0.6:0.15₂CO₃、MnO₂And RuO₂The method of steps (1) to (3) in example 1 was followed to prepare a high specific energy manganese-based layered positive electrode material for sodium-ion batteries, the molecular formula of which was Na_0.7Li_0.25Mn_0.6Ru_0.15O₂。

Example 10

RuO in example 1₂The high specific energy manganese-based layered positive electrode material of the sodium-ion battery, the molecular formula of which is Na, is prepared by replacing the NiO with the equal molar quantity according to the steps (1) to (3) in the example 1_0.6Li_0.2Mn_0.6Ni_0.2O₂。

Example 11

RuO in example 1₂The high specific energy manganese-based layered positive electrode material of the sodium-ion battery, the molecular formula of which is Na, was prepared by replacing CuO with equimolar amount according to the method of the steps (1) to (3) in example 1_0.6Li_0.2Mn_0.6Cu_0.2O₂。

Example 12

RuO in example 1₂Replacing ZnO with equimolar amount, and preparing the high-specific-energy manganese-based layered positive electrode material of the sodium-ion battery, wherein the molecular formula of the positive electrode material is Na, according to the method of the steps (1) to (3) in the example 1_0.6Li_0.2Mn_0.6Zn_0.2O₂。

Example 13

RuO in example 1₂The high specific energy manganese-based layered positive electrode material of the sodium-ion battery, the molecular formula of which is Na, was prepared by replacing MgO with an equal molar amount according to the procedures of steps (1) to (3) in example 1_0.6Li_0.2Mn_0.6Mg_0.2O₂。

Example 14

RuO in example 1₂By conversion to equimolar amounts of TiO₂The method of steps (1) to (3) in example 1 was followed to prepare a high specific energy manganese-based layered positive electrode material for sodium-ion batteries, the molecular formula of which was Na_0.6Li_0.2Mn_0.6Ti_0.2O₂。

Example 15

MnO in example 1₂Conversion to equimolar amounts of MnCO₃The method of steps (1) to (3) in example 1 was followed to prepare a high specific energy manganese-based layered positive electrode material for sodium-ion batteries, the molecular formula of which was Na_0.6Li_0.2Mn_0.6Ru_0.2O₂。

Example 16

Na in example 1₂CO₃By conversion to equimolar amounts of NaNO₃Prepared by the method of steps (1) to (3) in example 1The high specific energy manganese-based layered positive electrode material of the sodium-ion battery has a molecular formula of Na_0.6Li_0.2Mn_0.6Ru_0.2O₂。

Example 17

The calcining atmosphere in the example 1 is changed into oxygen, and the high-specific-energy manganese-based layered positive electrode material of the sodium-ion battery, the molecular formula of which is Na, is prepared according to the steps (1) to (3) in the example 1_0.6Li_0.2Mn_0.6Ru_0.2O₂。

In conclusion, the material disclosed by the invention is simple in preparation method, rich in raw materials, low in price and high in practicability, and the synthesized anode material is uniform in particle size, provides charge compensation for anions and cations in a wide voltage range and has no phase change, and uniform particles with a layered stacking structure are provided. The material can obtain excellent energy density and cycle stability when being assembled into a sodium ion battery, so that the material and the preparation method have good application prospects in promoting the practicability of sodium ion battery energy storage devices.