Modified lithium-rich manganese-based positive electrode material, preparation method and application thereof

Abstract

The application discloses a modified lithium-rich manganese-based positive electrode material and a preparation method and application thereof, and belongs to the technical field of positive electrode materials. The modified lithium-rich manganese-based positive electrode material comprises a lithium-rich manganese-based positive electrode material core doped with S and Se, and a composite material coated on at least part of the surface of the core, wherein the composite material is composed of MS and MSe, and M is one or two of Ni, Mn and Co. In the application, the lithium-rich manganese-based positive electrode is doped with S and Se, the doping of S and Se can reduce the oxygen defects of the lithium-rich manganese-based positive electrode, improve the structural stability, and reduce the band gap of the lithium-rich manganese-based positive electrode. In the application, the lithium-rich manganese-based positive electrode material is coated with the composite material composed of MS and MSe, which can significantly improve the conductivity of the lithium-rich manganese-based positive electrode, introduce lithium defects on the lithium-rich manganese-based positive electrode, inhibit the disproportionation reaction of Mn and reduce the oxygen escape phenomenon, and further significantly improve the reaction kinetics and chemical stability of the lithium-rich manganese-based material.

Description

Technical Field

[0001] This invention belongs to the field of cathode material technology, specifically relating to a modified lithium-rich manganese-based cathode material, its preparation method, and its application. Background Technology

[0002] Lithium-ion batteries have been applied to various aspects of society, including portable electronic products, electric vehicles, and grid energy storage. The development of lithium-ion battery technology is limited by its energy density. To break through the current energy density of lithium-ion batteries, cathode materials with higher capacity are needed. Lithium-rich manganese-based cathode materials have attracted great attention from the academic community due to their high specific capacity (>250 mAh / g), high operating voltage, low cost, and environmental friendliness, making them a highly promising next-generation lithium-ion battery cathode material. However, lithium-rich manganese-based cathode materials suffer from poor conductivity and structural stability, making the assembled batteries prone to polarization, which in turn reduces the battery's specific capacity and cycle stability. Summary of the Invention

[0003] Therefore, the purpose of this invention is to provide a modified lithium-rich manganese-based cathode material, its preparation method, and its application.

[0004] In a first aspect, the present invention provides a modified lithium-rich manganese-based cathode material, comprising: an S and Se-doped lithium-rich manganese-based cathode material core, and a composite material coating at least a portion of the surface of the core, wherein the composite material is composed of MS and MSe, wherein M is one or two of Ni, Mn, and Co.

[0005] Preferably, the chemical formula of the lithium-rich manganese-based cathode material is Li 1+m Mn 1-m O2, where 0 <m≤0.2。

[0006] Preferably, the chemical formula of the S and Se-doped lithium-rich manganese-based cathode material core is Li. 1+m Mn 1-m O 2-a- b S a Se b , of which: 0 <m≤0.2,0.001≤a≤0.005,0.001≤b≤0.005。

[0007] Secondly, the present invention provides a method for preparing a modified lithium-rich manganese-based cathode material, comprising the following steps: Metal oxide MO is mechanically mixed with lithium-rich manganese-based cathode material to obtain mixed powder; the mixed powder is placed in a sintering furnace and sintered in an atmosphere of coexisting H2S and H2Se to obtain modified lithium-rich manganese-based cathode material; wherein: M is one or two of Ni, Mn and Co.

[0008] Preferably, the mass ratio of the metal oxide MO to the lithium-rich manganese-based cathode material is (0.01~0.06):1.

[0009] Preferably, the volume ratio of H2S to H2Se is (1~10):(1~10).

[0010] Preferably, the ratio of the number of moles of M in the metal oxide MO to the total number of moles of H2S and H2Se introduced is 1:(3.5~10).

[0011] Preferably, the sintering temperature is 600~800℃ and the sintering time is 0.5~2h.

[0012] Preferably, the preparation method of the lithium-rich manganese-based cathode material includes the following steps: S1: Dissolve manganese salt in deionized water to form a metal salt solution. Then, under a nitrogen atmosphere, continuously pass the metal salt solution into the reactor, and continuously pass in a precipitant solution and a complexing agent solution. Adjust the pH of the solution to 10-11. After a set reaction time, a lithium-rich manganese-based precursor is obtained. S2: After mechanically mixing the lithium-rich manganese-based precursor with a lithium source, sintering is performed to obtain the lithium-rich manganese-based cathode material Li. 1+m Mn 1-m O2.

[0013] Preferably, in step S1, the manganese salt is one or both of manganese nitrate and manganese sulfate; the concentration of the metal salt solution is 1~3 mol / L; the precipitant solution is sodium hydroxide solution or potassium hydroxide solution, and the concentration of the precipitant solution is 3~5 mol / L; the complexing agent solution is an ammonia solution, and the concentration of the complexing agent solution is 15~40 wt%.

[0014] Preferably, in step S1, the time is set to 30~50h.

[0015] Preferably, in step S2, the lithium source is one or more of lithium oxide, lithium carbonate, lithium hydroxide, lithium nitrate, and lithium acetate; the molar ratio of Mn in the lithium-rich manganese-based precursor to Li in the lithium source is (0.7~0.9):(1.12~1.38).

[0016] Preferably, in step S2, the sintering temperature is 900~1100℃ and the sintering time is 10~30h.

[0017] Thirdly, the present invention provides a lithium battery comprising the aforementioned modified lithium-rich manganese-based cathode material.

[0018] Compared with the prior art, one or more of the above technical solutions can achieve at least one of the following beneficial effects: In this invention, sulfur (S) and selenium (Se) are used to dope the lithium-rich manganese-based cathode. The doping of sulfur and selenium reduces oxygen defects in the lithium-rich manganese-based cathode, improving its structural stability. Furthermore, the doping of sulfur and selenium reduces its band gap, further enhancing reaction kinetics. This invention also employs a composite material composed of sulfur (MS) and selenium (MSe) to coat the lithium-rich manganese-based cathode material. This not only forms a protective layer but also significantly improves the conductivity of the lithium-rich manganese-based cathode. It also introduces lithium defects into the lithium-rich manganese-based cathode, suppressing the disproportionation reaction of manganese (Mn) and reducing oxygen escape, thereby significantly improving the reaction kinetics and chemical stability of the lithium-rich manganese-based material. Through the synergistic modification of doping and coating, this invention significantly improves the overall electrochemical performance of the lithium-rich manganese-based cathode material. Attached Figure Description

[0019] Figure 1 This is a STEM image of the modified lithium-rich manganese-based cathode material prepared in Example 1.

[0020] Figure 2 EDS image of the cross-section of the modified lithium-rich manganese-based cathode material particles prepared in Example 1.

[0021] Figure 3 The diagram shows the cycle performance of batteries assembled from the cathode materials prepared in Examples 1-6 and Comparative Examples 1-3 of this invention. Detailed Implementation

[0022] To facilitate understanding of the present invention, the invention will be described more fully and in detail below with reference to the accompanying drawings and preferred embodiments, but the scope of protection of the present invention is not limited to the following specific embodiments.

[0023] As mentioned above, in a first aspect, the present invention provides a modified lithium-rich manganese-based cathode material, comprising: an S and Se-doped lithium-rich manganese-based cathode material core, and a composite material coating at least a portion of the surface of the core, wherein the composite material is composed of MS and MSe, wherein M is one or two of Ni, Mn, and Co.

[0024] In this invention, the doping of S and Se can occupy the oxygen defects generated during the preparation of lithium-rich manganese-based cathodes and can partially replace oxygen elements, causing slight distortion of the crystal structure and thus improving the structural stability of lithium-rich manganese-based cathodes. Furthermore, the doping of sulfur and selenium can reduce its band gap, further improving reaction kinetics. This invention also uses a composite material composed of MS and MSe to coat the lithium-rich manganese-based cathode material. MS and MSe have good conductivity, which can improve the conductivity of the lithium-rich manganese-based cathode. Moreover, the synergistic coating of MS and MSe also induces lithium defects in the lithium-rich manganese-based cathode material, inhibiting the disproportionation reaction of Mn and reducing oxygen escape, thereby significantly improving the reaction kinetics and chemical stability of the material. Through the synergistic modification of doping and coating, this invention can significantly improve the overall electrochemical performance of lithium-rich manganese-based cathode materials.

[0025] Preferably, the chemical formula of the lithium-rich manganese-based cathode material is Li 1+m Mn 1-m O2, where 0 <m≤0.2。

[0026] Preferably, the chemical formula of the S and Se-doped lithium-rich manganese-based cathode material core is Li. 1+m Mn 1-m O 2-a- b S a Se b , of which: 0 <m≤0.2,0.001≤a≤0.005,0.001≤b≤0.005。

[0027] Secondly, the present invention provides a method for preparing a modified lithium-rich manganese-based cathode material, comprising the following steps: Metal oxide MO is mechanically mixed with lithium-rich manganese-based cathode material to obtain mixed powder; the mixed powder is placed in a sintering furnace and sintered in an atmosphere of coexisting H2S and H2Se to obtain modified lithium-rich manganese-based cathode material; wherein: M is one or two of Ni, Mn and Co.

[0028] The preparation method of this invention uses H2S and H2Se as sulfur and selenium sources, respectively, which can simultaneously achieve the sulfidation of the coating layer and the doping of sulfur and selenium in the lithium-rich manganese-based cathode material. The process is simple and easy to realize industrial production.

[0029] Furthermore, during doping and sulfidation / selenization, sulfur and selenium exist in their divalent form. When sulfur powder and selenium powder are used as sulfur and selenium sources, a redox reaction is required. This reaction affects the structure of the coating layer and the lithium-rich manganese-based cathode material, and sulfur and selenium powder residues may remain, affecting the electrochemical performance of the lithium-rich manganese-based cathode. In this invention, H2S and H2Se are used as sulfur and selenium sources. Compared to using sulfur or selenium, they do not undergo a redox reaction, reducing the impact of the reaction process on the coating layer and the lithium-rich manganese-based cathode material, and eliminating residues.

[0030] In this invention, H2S and H2Se are used as sulfur and selenium sources, respectively. During the sulfidation and selenization processes with MO, water vapor is generated. At high temperatures, the water vapor causes slight precipitation of Li at the interface of the lithium-rich manganese-based cathode. At the same time, the surface Li will undergo slight volatilization under high temperature conditions, which synergistically creates lithium defects. The presence of lithium defects can suppress the disproportionation reaction of Mn and reduce oxygen escape, thereby significantly improving the chemical stability of lithium-rich manganese-based materials.

[0031] Preferably, the mass ratio of the metal oxide MO to the lithium-rich manganese-based cathode material is (0.01~0.06):1, including but not limited to: 0.01:1, 0.02:1, 0.03:1, 0.04:1, 0.05:1, 0.06:1, etc.

[0032] Preferably, the volume ratio of H2S to H2Se is (1~10):(1~10), including but not limited to: 1:10, 3:10, 5:10, 8:10, 10:10, 10:8, 10:5, 10:3, 10:1, etc.

[0033] Preferably, the ratio of the number of moles of M in the metal oxide MO to the total number of moles of S+Se in H2S and H2Se is 1:(3.5~10), including but not limited to: 1:3.5, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, etc.

[0034] Preferably, the sintering temperature is 600~800℃, including but not limited to: 600℃, 650℃, 700℃, 750℃, 800℃, etc.; the sintering time is 0.5~2h, including but not limited to: 0.5h, 1h, 1.5h, 2h, etc.

[0035] Thirdly, the present invention provides a lithium battery comprising the aforementioned modified lithium-rich manganese-based cathode material.

[0036] Examples 1 and 2 illustrate the preparation of lithium-rich manganese-based cathode materials.

[0037] Preparation Example 1 MnSO4·H2O was dissolved in deionized water to prepare a 2 mol / L metal ion solution. This solution was then continuously added to a continuously stirred tank reactor under a nitrogen atmosphere, while a 4 mol / L NaOH precipitant solution and a 20 wt% NH3·H2O complexing agent solution were continuously introduced to maintain the pH within the range of 10-11. After a complete reaction of 40 h, the solution was filtered, washed with water, washed with alcohol, and dried to obtain Mn(OH)2. Mn(OH)2 was mechanically mixed with lithium hydroxide at a molar ratio of Mn to Li of 1:1.23 to obtain a mixed powder. This powder was then sintered in a muffle furnace at 980 °C for 20 h to finally obtain Li. 1.1 Mn 0.9 O2.

[0038] Preparation Example 2 MnSO4·H2O was dissolved in deionized water to prepare a 1 mol / L metal ion solution. This solution was then continuously added to a continuously stirred tank reactor under a nitrogen atmosphere, while a 3 mol / L NaOH precipitant solution and a 15 wt% NH3·H2O complexing agent solution were continuously introduced to maintain the pH of the solution within the range of 10-11. After a complete reaction of 50 h, the solution was filtered, washed with water, washed with alcohol, and dried to obtain Mn(OH)2. Mn(OH)2 was mechanically mixed with lithium hydroxide at a molar ratio of Mn to Li of 1:1.54 to obtain a mixed powder. This powder was then sintered in a muffle furnace at 900 °C for 30 h to finally obtain Li. 1.2 Mn 0.8 O2.

[0039] Example 1 In this embodiment, the modified lithium-rich manganese-based cathode material comprises: an S and Se-doped lithium-rich manganese-based core and a composite material coating at least a portion of the surface of the core, wherein the composite material is NiS and NiSe. The specific preparation method is as follows: NiO was combined with Li prepared in Preparation Example 1 1.1 Mn 0.9 O2 (NiO and Li) 1.1 Mn 0.9 After ball milling solid-phase mixing with O2 at a mass ratio of 0.03:1, a mixed powder was obtained. The mixed powder was placed in a sealed sintering furnace, and H2S and H2Se gases were introduced according to the volume ratio of H2S to H2Se of 1:5 and the ratio of the molar number of NiO to the total molar number of H2S and H2Se of 1:4. The temperature was then raised to 700℃ and sintered for 1 hour to obtain a modified lithium-rich manganese-based cathode material. The modified lithium-rich manganese-based cathode material prepared in this embodiment has a lithium-deficient surface, is doped with S and Se anions, and has a coating layer composed of a composite material of NiS and NiSe.

[0040] The STEM image of the modified lithium-rich manganese-based cathode material prepared in this embodiment is shown below. Figure 1 As shown in the figure, it can be seen that there are obvious Li defects.

[0041] The EDS image of the cross-section of the modified lithium-rich manganese-based cathode material particles prepared in this embodiment is shown below. Figure 2 As shown, S and Se elements are present inside the particles, indicating that S and Se doping has been achieved.

[0042] Comparative Example 1 Li prepared directly using Preparation Example 1 1.1 Mn 0.9 O2 is used as the positive electrode material.

[0043] Comparative Example 2 In this embodiment, the modified lithium-rich manganese-based cathode material includes: an S-doped lithium-rich manganese-based core and a composite material coating at least a portion of the surface of the core, wherein the composite material is NiS. The specific preparation method is as follows: NiO was combined with Li prepared in Preparation Example 1 1.1 Mn 0.9 O2 (NiO and Li) 1.1 Mn 0.9 After ball milling solid-phase mixing with O2 at a mass ratio of 0.03:1, a mixed powder was obtained. The mixed powder was placed in a sealed sintering furnace, and H2S gas was introduced at a molar ratio of NiO to H2S of 1:4. The temperature was then raised to 700℃ and sintered for 1 hour to obtain a modified lithium-rich manganese-based cathode material. The modified lithium-rich manganese-based cathode material has a lithium-deficient surface, is doped with S anions, and has a NiS coating layer.

[0044] Comparative Example 3 In this embodiment, the modified lithium-rich manganese-based cathode material includes: a Se-doped lithium-rich manganese-based core and a composite material coating at least a portion of the surface of the core, wherein the composite material is NiSe. The specific preparation method is as follows: NiO was combined with Li prepared in Preparation Example 1 1.1 Mn 0.9 O2 (NiO and Li) 1.1 Mn 0.9 After ball milling solid-phase mixing with O2 at a mass ratio of 0.03:1, a mixed powder was obtained. The mixed powder was placed in a sealed sintering furnace, and H2Se gas was introduced at a molar ratio of NiO to H2Se of 1:4. The temperature was then raised to 700℃ and sintered for 1 hour to obtain a modified lithium-rich manganese-based cathode material. The modified lithium-rich manganese-based cathode material has a lithium-deficient surface, is doped with Se anions, and has a NiSe coating layer.

[0045] Example 2 In this embodiment, the modified lithium-rich manganese-based cathode material comprises: an S and Se-doped lithium-rich manganese-based core and a composite material coating at least a portion of the surface of the core, wherein the composite material is NiS and NiSe. The specific preparation method is as follows: NiO was combined with Li prepared in Preparation Example 1 1.1 Mn 0.9 O2 (NiO and Li) 1.1 Mn 0.9 After ball milling solid-phase mixing with O2 at a mass ratio of 0.03:1, a mixed powder was obtained. Then, sulfur powder and selenium powder at a mass ratio of 1.539:18.22 were added, and the ratio of the molar number of NiO to the total molar number of sulfur powder and selenium powder was 1:4. After mixing evenly, mixed powder 1 was obtained. Mixed powder 1 was added to a sintering furnace and heated to 700℃, and sintered for 1 hour to obtain a modified lithium-rich manganese-based cathode material.

[0046] The modified lithium-rich manganese-based cathode material is doped with S and Se anions, and the coating layer is a composite material composed of NiS and NiSe.

[0047] Example 3 This embodiment is basically the same as Embodiment 1, except that the ratio of the number of moles of NiO to the total number of moles of H2S and H2Se is 1:2.5.

[0048] Example 4 This embodiment is basically the same as Embodiment 1, except that the ratio of the number of moles of NiO to the total number of moles of H2S and H2Se is 1:10.

[0049] Example 5 The modified lithium-rich manganese-based cathode material in this embodiment includes: an S and Se-doped lithium-rich manganese-based core and a composite material coating at least a portion of the surface of the core, wherein the composite material is CoS and CoSe. The specific preparation method is as follows: CoO was combined with Li prepared in Preparation Example 2 1.2 Mn 0.8 O2 (CoO and Li) 1.2 Mn 0.8 After ball milling solid-phase mixing with O2 at a mass ratio of 0.01:1, a mixed powder was obtained. The mixed powder was placed in a sealed sintering furnace, and H2S and H2Se gases were introduced according to the volume ratio of H2S to H2Se of 5:5 and the ratio of the molar number of CoO to the total molar number of H2S and H2Se of 1:6. The temperature was then raised to 600℃ and sintered for 2 hours to obtain a modified lithium-rich manganese-based cathode material. The modified lithium-rich manganese-based cathode material has a lithium-deficient surface, is doped with S and Se anions, and has a coating layer composed of a composite material of CoS and CoSe.

[0050] Example 6 In this embodiment, the modified lithium-rich manganese-based cathode material comprises: an S and Se-doped lithium-rich manganese-based core and a composite material coating at least a portion of the surface of the core, wherein the composite material is MnS and MnSe. The specific preparation method is as follows: MnO was combined with Li prepared in Preparation Example 3 1.1 Mn 0.9 O2 (MnO and Li) 1.1 Mn 0.9 After ball milling solid-phase mixing with O2 at a mass ratio of 0.06:1, a mixed powder was obtained. The mixed powder was placed in a sealed sintering furnace, and H2S and H2Se gases were introduced according to the volume ratio of H2S to H2Se of 8:3 and the molar ratio of MnO to the total molar ratio of H2S and H2Se of 1:5. The temperature was then raised to 800℃ and sintered for 0.5 h to obtain a modified lithium-rich manganese-based cathode material. The modified lithium-rich manganese-based cathode material has a lithium-deficient surface, is doped with S and Se anions, and has a coating layer composed of a composite material of MnS and MnSe.

[0051] Performance testing: The positive electrode materials prepared in Examples 1-6 and Comparative Examples 1-3 were assembled into batteries. The positive electrode material, conductive graphite, and PVDF were weighed and ground according to a mass ratio of 8:1:1. Then, an appropriate amount of N-methylpyrrolidone (NMP) was added, and grinding and stirring were continued to form a uniform slurry. The slurry was then uniformly coated onto aluminum foil using a mold to a thickness of 200 μm, and placed in a drying oven at 90°C for 10 hours. The coated foil was then cut into 12 mm diameter discs. The discs were used as the positive electrode, and lithium foil as the negative electrode. The electrolyte consisted of a solvent and LiPF6, with a LiPF6 concentration of 1 mol / L. The electrolyte solvent was a mixture of EC, DEC, and DMC in a volume ratio of 1:1:1. The batteries were assembled in a glove box according to the coin cell assembly sequence. The assembled batteries were subjected to performance testing. The assembled batteries, which had been left to stand overnight, were placed in a LAND2001CT battery test chamber for charge-discharge testing. The test was conducted at 25℃, 1C, and a cycle voltage of 2~4V, with 100 cycles. The test results are shown below. Figure 3 See Table 1.

[0052] Table 1 As can be seen from the data in Table 1, the battery assembled with cathode material without doping and coating in Comparative Example 1 has poor cycle stability; the battery assembled with cathode material only doped with S and coated with NiS in Comparative Example 2 has a slightly improved cycle stability compared to Comparative Example 1; the battery assembled with cathode material only doped with Se and coated with NiSe in Comparative Example 3 has a slightly improved cycle stability compared to Comparative Example 1; the battery assembled with cathode material doped with S and Se and coated with NiS and NiSe in Example 1 has significantly better cycle stability than Comparative Examples 1-3, possibly because the synergistic effect of S and Se significantly improves the stability of the cathode material. In Example 2, S and Se powders were used as raw materials for doping and coating, and the cycle stability of the battery assembled with its cathode material was significantly lower than that of Example 1. This may be because the doping and reaction of S and Se powders affected the cathode stability, or it may be that S and Se cannot introduce lithium defects, thus leading to a significant decrease in cycle stability. In Examples 3 and 4, the ratio of the molar amount of NiO to the total molar amount of H2S and H2Se was adjusted. The cycle stability of the batteries assembled with the corresponding cathodes showed some fluctuation compared to Example 1, indicating that the amount of H2S and H2Se has a certain impact on the performance of the cathode material. In Examples 5 and 6, the process parameters were adjusted, and the batteries assembled with the corresponding cathode materials showed some fluctuation, but overall, they all exhibited good electrochemical performance.

[0053] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a modified lithium-rich manganese-based cathode material, characterized in that, Includes the following steps: Metal oxide MO is mechanically mixed with lithium-rich manganese-based cathode material to obtain a mixed powder; the mixed powder is placed in a sintering furnace and sintered in an atmosphere of coexisting H2S and H2Se to obtain a modified lithium-rich manganese-based cathode material; wherein: M is one or two of Ni, Mn, and Co; The modified lithium-rich manganese-based cathode material comprises: an S and Se-doped lithium-rich manganese-based cathode material core, and a composite material coating at least a portion of the surface of the core, wherein the composite material is composed of MS and MSe, wherein M is one or two of Ni, Mn, and Co.

2. The method for preparing the modified lithium-rich manganese-based cathode material as described in claim 1, characterized in that, The chemical formula of the lithium-rich manganese-based cathode material is Li 1+m Mn 1-m O2, where 0 <m≤0.2。 3. The method for preparing the modified lithium-rich manganese-based cathode material as described in claim 1, characterized in that, The mass ratio of the metal oxide MO to the lithium-rich manganese-based cathode material is (0.01~0.06):

1.

4. The method for preparing the modified lithium-rich manganese-based cathode material as described in claim 1, characterized in that, The volume ratio of H2S to H2Se is (1~10):(1~10).

5. The method for preparing the modified lithium-rich manganese-based cathode material as described in claim 1, characterized in that, The ratio of the number of moles of M in the metal oxide MO to the total number of moles of H2S and H2Se introduced is 1:(3.5~10).

6. The method for preparing the modified lithium-rich manganese-based cathode material as described in claim 1, characterized in that, The sintering temperature is 600~800℃, and the sintering time is 0.5~2h.

7. The method for preparing the modified lithium-rich manganese-based cathode material as described in claim 1, characterized in that, The preparation method of the lithium-rich manganese-based cathode material includes the following steps: S1: Dissolve manganese salt in deionized water to form a metal salt solution. Then, under a nitrogen atmosphere, continuously pass the metal salt solution into the reactor, and continuously pass in a precipitant solution and a complexing agent solution. Adjust the pH of the solution to 10-11. After a set reaction time, a lithium-rich manganese-based precursor is obtained. S2: After mechanically mixing the lithium-rich manganese-based precursor with a lithium source, sintering is performed to obtain the lithium-rich manganese-based cathode material Li. 1+ m Mn 1-m O2.

8. A lithium battery, characterized in that, include: The modified lithium-rich manganese-based cathode material prepared by the method according to any one of claims 1 to 7.

Images