A lithium-rich manganese-based cathode material with sulfur injection-induced spinel and oxygen vacancies and a preparation method thereof

Abstract

The present invention relates to a lithium-rich manganese-based positive electrode material with sulfur injection-induced spinel and oxygen vacancies and a preparation method thereof, belonging to the technical field of lithium-ion batteries. The material is based on a lithium-rich manganese-based layered positive electrode material, and the surface of the substrate is composed of an S anion doped layer and a spinel layer containing oxygen vacancies from the inside to the outside. The thickness of the spinel layer containing oxygen vacancies is 3nm to 7nm. During preparation, the mixed powder of sulfur powder and the lithium-rich manganese-based positive electrode material is first calcined in an inert gas atmosphere, and the sulfur deposited on the surface simultaneously induces the in-situ generation of spinel and oxygen-vacancy-containing surface, which is then treated with CS2 and calcined to obtain. The S anion doped layer and the spinel layer containing oxygen vacancies on the surface of the material can effectively protect the interface from damage by side reactions during the cycle, and the spinel structure with 3D ion channels is conducive to interfacial lithium ion transmission, and the generation of oxygen vacancies is conducive to reducing the release of lattice oxygen to stabilize the crystal structure of the material.

Description

Technical Field

[0001] The invention relates to a sulfur-injection-induced spinel and oxygen vacancy lithium-rich manganese-based positive electrode material and a preparation method thereof, belonging to the technical field of lithium-ion batteries. Background Art

[0002] With the continuous development of science and technology, people's demand for energy is also increasing. Fossil energy will be exhausted sooner or later, and it is inevitable for mankind to move towards new energy. The cleanness of electricity is the top priority in the development of new energy, and improving battery performance is the most basic goal in the development of electricity. Lithium-ion battery positive electrode materials are the key materials that determine their performance. They are also the main source of lithium ions in current commercial lithium-ion batteries. Their electrochemical properties limit the actual use of batteries. Layered lithium-rich manganese-based positive electrode materials have high capacity and low cost at low rates, but low initial efficiency, severe voltage decay during the cycle, and poor rate performance. These limit their widespread application in the field of power batteries.

[0003] The poor rate performance of lithium-rich manganese-based cathode materials is primarily due to the inherently poor conductivity of the Li2MnO3 phase. Side reactions during cycling damage the CEI membrane, increasing interfacial impedance and hindering the deintercalation and migration of lithium ions. Constructing a spinel structure on the cathode material surface is a common method for reducing interfacial impedance and protecting the interface structure.

[0004] The simplest method to construct spinel structure is acid leaching. The synthesized positive electrode material is immersed in weak acid and + / Li + The exchange forms a surface lithium-deficient structure, which is transformed into a spinel structure during the subsequent calcination process. Although this method can effectively improve the initial efficiency and rate performance, this "acid corrosion" can also easily destroy the crystal structure of the material and reduce the lithium content, which reduces the cycle performance of the material.

[0005] Chinese patent application 201711313310.9 proposes first coating the material with MOFs, then forming metal oxides and carbon through heat treatment, and then carbonizing it to form a spinel structure in situ. Although this method can form spinel in situ without destroying the structure of the positive electrode material, its experimental operation is complicated, and the multiple coating layers (composite layers of spinel layer, metal oxide, and carbon) that are ultimately formed introduce multiple interfaces, which is not conducive to the original purpose of improving rate performance. Summary of the Invention

[0006] In view of this, the object of the present invention is to provide a lithium-rich manganese-based positive electrode material with sulfur injection-induced spinel and oxygen vacancies and a preparation method thereof.

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

[0008] A sulfur-injection-induced spinel and oxygen vacancy lithium-rich manganese-based cathode material, the chemical formula of which is xLi2MnO3·(1-x)LiMO 2-y S y , M is one or more of Ni, Co, and Mn among transition metals; 0<x<1, 0.005<y<0.05; the material is based on a lithium-rich manganese-based layered positive electrode material, and the surface of the substrate is composed of an S anion doped layer and a spinel layer containing oxygen vacancies from the inside to the outside, and the thickness of the spinel layer containing oxygen vacancies is 3nm to 7nm.

[0009] Preferably, 0.01<y<0.03.

[0010] A method for preparing a lithium-rich manganese-based positive electrode material with sulfur injection-induced spinel and oxygen vacancies comprises the following steps:

[0011] (1) dissolving elemental sulfur powder in anhydrous ethanol to obtain solution A; adding a lithium-rich manganese-based positive electrode material to anhydrous ethanol to obtain a suspension B; adding solution A to suspension B, uniformly dispersing by ultrasonication to obtain a suspension, separating the solid and the liquid, and drying the solid to obtain a mixed powder; wherein the amount of elemental sulfur powder used is 0.1% to 5% of the molar amount of the lithium-rich manganese-based positive electrode material;

[0012] (2) placing the mixed powder into a sealed container in an inert gas atmosphere, and calcining at 100° C. to 500° C. for 1 h to 10 h to obtain a calcined material;

[0013] (3) The calcined material is placed in carbon disulfide (CS2) and immersed for 10 minutes to 20 minutes. After solid-liquid separation, the CS2 remaining on the solid surface is removed, and the material is placed in a sealed container with an inert gas atmosphere and calcined at 100°C to 300°C for 1 hour to 5 hours. After the calcination, a lithium-rich manganese-based positive electrode material with sulfur injection-induced spinel and oxygen vacancies is obtained.

[0014] Preferably, in step (1), the amount of elemental sulfur powder used is 2% to 3% of the molar amount of the lithium-rich manganese-based positive electrode material.

[0015] Preferably, in step (2), the calcination temperature is 200° C. to 300° C., the calcination time is 4 h to 8 h, and the heating rate is 1° C. / min to 4° C. / min.

[0016] Preferably, in step (3), the ratio of the calcined material to CS2 is 0.05 g to 0.1 g: 1 mL.

[0017] Preferably, in step (3), when removing the residual CS2 on the solid surface, a method of ventilation and standing for more than 30 minutes is adopted.

[0018] Preferably, in step (3), the calcination temperature is 150° C. to 200° C., the calcination time is 2 h to 3 h, and the heating rate is 1° C. / min to 4° C. / min.

[0019] A lithium-ion battery, wherein the positive electrode material of the battery adopts the lithium-manganese-based positive electrode material with sulfur injection-induced spinel and oxygen vacancies described in the present invention.

[0020] Beneficial effects

[0021] The present invention provides a lithium-rich manganese-based positive electrode material with sulfur-injection-induced spinel and oxygen vacancies. The S anion-doped layer and the spinel layer containing oxygen vacancies on the surface of the material can effectively protect the interface from damage by side reactions during the cycle process. The spinel structure with 3D ion channels is conducive to interfacial lithium ion transport, and the generation of oxygen vacancies is conducive to reducing lattice oxygen release to stabilize the material crystal structure.

[0022] The present invention provides a method for preparing a lithium-rich manganese-based positive electrode material that induces spinel and oxygen vacancies by sulfur injection. First, a mixed powder of sulfur powder and a lithium-rich manganese-based positive electrode material is calcined in an inert gas atmosphere. The sulfur deposited on the surface simultaneously induces the in-situ formation of spinel and oxygen-vacancy surfaces. Subsequently, CS2 treatment is used to form oxygen vacancies that can better protect the interface stability. The sulfur anions formed by internal diffusion can be injected to maintain the bulk stability, ultimately achieving good cycle stability. The synthesis process of the lithium-rich manganese-based positive electrode material that constructs spinel and oxygen vacancies is simple, and the electrochemical performance can be significantly improved at a small sulfur doping amount. It is suitable for large-scale production applications and has low environmental harm. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The X-ray diffraction (XRD) patterns of the materials described in Comparative Example 1 and Examples 1-3 are shown.

[0024] Figure 2 This is a scanning electron microscope (SEM) image of the material described in Example 1.

[0025] Figure 3 This is the electron paramagnetic resonance (EPR) test diagram of the material described in Example 1.

[0026] Figure 4 This is a comparison chart of the discharge capacity of button batteries assembled in Comparative Example 1 and Example 1 after 50 cycles at 30°C and 1C.

[0027] Figure 5 This is the SEM image of the material described in Example 2.

[0028] Figure 6 This is a transmission electron microscope (TEM) image of the material described in Example 2.

[0029] Figure 7 This is a comparison chart of the first week of charge and discharge of the button batteries assembled in Comparative Example 1 and Example 2 at 30°C and 0.1C.

[0030] Figure 8 This is a comparison chart of the rate performance of button batteries assembled in Comparative Example 1 and Example 2.

[0031] Figure 9 is the SEM image of the material described in Example 3.

[0032] Figure 10 This is a comparison chart of the discharge capacity of button batteries assembled in Comparative Example 1 and Example 3 after 50 cycles at 30°C and 5C. DETAILED DESCRIPTION

[0033] The present invention will be further described in detail below with reference to specific embodiments.

[0034] In the following examples and comparative examples:

[0035] (1) X-ray diffractometer: Rigaku Ultima IV-185, Japan.

[0036] (2) SEM testing instrument: FEI Quanta, Netherlands.

[0037] (3) Electron paramagnetic resonance (EPR) test: A300-10 / 12 from Bruker, Germany was used.

[0038] (4) TEM test: JEM-2100F from JEOL Ltd. was used.

[0039] (5) Battery assembly: The material described in the embodiment or comparative example is used as the active material, and the active material is mixed with acetylene black and polyvinylidene fluoride (PVDF) in a mass ratio of 8:1:1. NMP is added and ground into a slurry, which is coated on an aluminum foil with a scraper, dried, and cut into pieces to form a positive electrode sheet; then, a CR2025 button half-cell is assembled in an argon glove box (water <0.01 ppm, oxygen <0.01 ppm), wherein the positive electrode is the above-mentioned positive electrode sheet, the counter electrode is a lithium sheet, the separator is Celgard 2500, and the electrolyte is a solution prepared by using dimethyl carbonate, diethyl carbonate, and ethyl carbonate in a volume ratio of 1:1:1 as solvent and 1 mol / L LiPF6 as solute.

[0040] (6) Battery cycle performance test: LAND CT 2001A tester was purchased from Wuhan Landian Electronics Co., Ltd.

[0041] (7) Inductively coupled plasma atomic emission spectroscopy (ICP-AES): Agilent ICPOES730, USA.

[0042] Comparative Example 1

[0043] Lithium acetate, manganese acetate, and nickel acetate were weighed in a molar ratio of 1.2:0.6:0.2 and then added to distilled water to dissolve to obtain a mixed salt solution; citric acid solution was then added dropwise to the mixed salt solution, with the molar ratio of citric acid to transition metal ions being 1:1; the pH was then adjusted to 7.8 with aqueous ammonia to obtain a mixed solution; the solution was heated at 80°C to a gel state, vacuum dried at 80°C for 40 hours, and then placed in a muffle furnace under an oxygen atmosphere, first heated to 500°C and calcined for 6 hours, then heated to 800°C and calcined for 14 hours, with a heating rate of 5°C / min during calcination. After the calcination, a lithium-rich manganese-based positive electrode material Li 1.2 Mn 0.6 Ni 0.2 O2.

[0044] like Figure 1 As shown, the XRD test results of the material show that the characteristic peak position of the material is consistent with the characteristic peaks of LiNiO2 and Li2MnO3, there is no obvious impurity peak, and the material has a good layered structure.

[0045] The first week discharge capacity of the assembled battery at 30°C and 0.1C is 283.9 mAh / g. Figure 4 As shown, during the 1C rate cycle, the specific capacity in the first week was 175.4 mAh / g, and the capacity after 50 cycles was 126.2 mAh / g, with a retention rate of 71.95%.

[0046] Example 1

[0047] (1) dissolving elemental sulfur powder in anhydrous ethanol to obtain solution A; adding the lithium-rich manganese-based positive electrode material described in Comparative Example 1 to anhydrous ethanol to obtain suspension B; adding solution A to suspension B, ultrasonically dispersing the suspension to obtain a suspension, separating the solid and the liquid, and drying the solid to obtain a mixed powder; wherein the amount of elemental sulfur powder used is 2.5 at% of the lithium-rich manganese-based positive electrode material;

[0048] (2) transferring the mixed powder into a sealed can, introducing argon into the sealed can, and calcining at 300° C. for 4 h at a heating rate of 2° C. / min to obtain a calcined material;

[0049] (3) 0.5 g of the calcined material was taken and placed in 10 mL of CS2 for 10 min, and then placed in a fume hood for 30 min to allow the liquid CS2 to evaporate. The material was then transferred to a sealed can, argon was introduced into the can, and the can was calcined at 175 ° C for 2 h with a heating rate of 2 ° C / min. After the calcination, a sulfur-injection-induced spinel and oxygen vacancy-rich lithium manganese-based positive electrode material was obtained.

[0050] like Figure 1 As shown, the diffraction peaks of the material described in Example 1 are consistent with those of the material described in Comparative Example 1, indicating that the modification did not change its original crystal structure and did not produce impurity phase.

[0051] like Figure 2 As shown, the surface morphology of the material powder is observed by magnifying it 80,000 times, and it can be seen that the primary particles are about 200-300 nm.

[0052] like Figure 3 As shown, the EPR test results of the material show that there are oxygen vacancies on the surface of the material.

[0053] TEM test results show that the surface of the material has a spinel structure with a thickness of 5nm to 7nm.

[0054] ICP-AES analysis showed that the S content was 0.198 at%.

[0055] The material of Example 1 was activated at a rate of 0.1C (1C = 250mA / g) at 2V to 4.8V for 2 weeks, and then charged and discharged at a rate of 1C at 2V to 4.6V. The specific capacity of the material in Example 1 was as high as 292mAh / g in the first week. Figure 4 As shown, the discharge capacity at a 1C rate is 241.9 mAh / g, and the capacity retention rate is 89.21% after 50 cycles. This shows that the constructed spinel and oxygen vacancy layers protect the material structure during cycling. The sulfur injection expands the interlayer spacing, and the surface spinel and oxygen vacancy structures both facilitate lithium ion transport and structural stability, improving capacity while also mitigating capacity decay.

[0056] Example 2

[0057] (1) dissolving elemental sulfur powder in anhydrous ethanol to obtain solution A; adding the lithium-rich manganese-based positive electrode material described in Comparative Example 1 to anhydrous ethanol to obtain suspension B; adding solution A to suspension B, uniformly dispersing by ultrasonication to obtain a suspension, separating the solid and the liquid, and drying the solid to obtain a mixed powder; wherein the amount of elemental sulfur powder used is 2at% of the lithium-rich manganese-based positive electrode material;

[0058] (2) transferring the mixed powder into a sealed can, introducing argon into the sealed can, and calcining at 270° C. for 6 h at a heating rate of 2° C. / min to obtain a calcined material;

[0059] (3) 0.5 g of the calcined material was taken and placed in 5 mL of CS2 for 10 min, and then placed in a fume hood for 30 min to allow the liquid CS2 to evaporate. The material was then transferred to a sealed can, argon was introduced into the can, and the can was calcined at 150 ° C for 1 h at a heating rate of 2 ° C / min. After the calcination, a sulfur-injection-induced spinel and oxygen vacancy-rich lithium manganese-based positive electrode material was obtained.

[0060] like Figure 1 As shown, the diffraction peaks of the material described in Example 1 are consistent with those of the material described in Comparative Example 1, indicating that the modification did not change its original crystal structure and did not produce impurity phase.

[0061] like Figure 5 As shown, the surface morphology of the material powder is observed by magnifying it 80,000 times, and it can be seen that the primary particles are about 200 nm.

[0062] The EPR test results of the material show that there are oxygen vacancies on the surface of the material.

[0063] like Figure 6 As shown, TEM test results show that the surface of the material is a spinel structure with a thickness of 3nm to 5nm.

[0064] ICP-AES analysis showed that the S content was 0.172 at%.

[0065] Figure 7 The button-type battery assembled from Example 2 and Comparative Example 1 was tested at a rate of 0.1C in the voltage range of 2V to 4.8V. It can be seen that the curves have a high degree of fit, indicating that the electrochemical reactions occurring in the modified samples are basically the same. The difference is that there is a small platform at 2.8V discharge in Example 2, which is a sign of the presence of a spinel phase in the material, indicating that a spinel structure has been successfully constructed on the surface of the material. The specific capacity of the first week discharge at a rate of 0.1C (1C = 250mA / g) is 291.6mAh / g. The specific capacity at a rate of 1C is 241.8mAh / g, and the capacity retention rate after 50 cycles is 88.38%.

[0066] Figure 8 The rate performance test results of the battery assembled in Example 2 show that even at a rate of 5C, it still has a specific capacity of 182.4 mAh / g, and the rate performance is significantly better than that of Comparative Example 1.

[0067] Example 3

[0068] (1) dissolving elemental sulfur powder in anhydrous ethanol to obtain solution A; adding the lithium-rich manganese-based positive electrode material described in Comparative Example 1 to anhydrous ethanol to obtain suspension B; adding solution A to suspension B, ultrasonically dispersing the suspension to obtain a suspension, separating the solid and the liquid, and drying the solid to obtain a mixed powder; wherein the amount of elemental sulfur powder used is 2.5 at% of the lithium-rich manganese-based positive electrode material;

[0069] (2) transferring the mixed powder into a sealed can, introducing argon into the sealed can, and calcining at 200° C. for 8 h at a heating rate of 2° C. / min to obtain a calcined material;

[0070] (3) 0.5 g of the calcined material was taken and placed in 10 mL of CS2 for 10 min, and then placed in a fume hood for 30 min to allow the liquid CS2 to evaporate. The material was then transferred to a sealed can, argon was introduced into the can, and the can was calcined at 175 ° C for 2 h with a heating rate of 2 ° C / min. After the calcination, a sulfur-injection-induced spinel and oxygen vacancy-rich lithium manganese-based positive electrode material was obtained.

[0071] like Figure 1 As shown, the diffraction peaks of the material described in Example 1 are consistent with those of the material described in Comparative Example 1. The sharp characteristic peaks indicate good crystallinity, and the obvious splitting of the characteristic peaks indicates that it has a good layered structure, indicating that the modification has not changed its original crystal structure and has not produced impurity phases.

[0072] like Figure 9 As shown, the surface morphology of the material powder was observed by magnifying it 80,000 times, and it can be seen that the primary particles are about 300 nm. The large number of large particles may be due to the long calcination time.

[0073] The EPR test results of the material show that there are oxygen vacancies on the surface of the material.

[0074] TEM test results show that the surface of the material has a spinel structure with a thickness of 5nm to 7nm.

[0075] ICP-AES analysis showed that the S content was 0.193 at%.

[0076] At a rate of 0.1C, the first-week discharge capacity of the assembled button battery is 290.4mAh / g. Figure 10 As shown, the battery assembled in Example 3 can still achieve a specific capacity of 189.4 mAh / g at a high rate of 5C, and after 50 cycles, the capacity retention rate is 90.5%, which is higher than 86.7% in Comparative Example 1. Due to the presence of anion injection and the spinel structure, the structure can be maintained stable at a large current density to provide a higher discharge specific capacity. This shows the effectiveness of the treatment method, which can construct a stable spinel structure, which is conducive to improving rate performance and structural stability.

[0077] Comparative Example 2

[0078] (1) dissolving elemental sulfur powder in anhydrous ethanol to obtain solution A; adding the lithium-rich manganese-based positive electrode material described in Comparative Example 1 to anhydrous ethanol to obtain suspension B; adding solution A to suspension B, ultrasonically dispersing the suspension to obtain a suspension, separating the solid and the liquid, and drying the solid to obtain a mixed powder; wherein the amount of elemental sulfur powder used is 2.5 at% of the lithium-rich manganese-based positive electrode material;

[0079] (2) The mixed powder is transferred to a sealed can, argon is introduced into the sealed can, and the mixed powder is calcined at 200° C. for 8 h at a heating rate of 2° C. / min to obtain a sulfur-injection-induced spinel lithium-rich manganese-based positive electrode material.

[0080] EPR test results show that there are no oxygen vacancies on the surface of the layered structure of the material.

[0081] TEM test results show that the thickness of the spinel structure layer is 10nm to 12nm.

[0082] The assembled battery achieved a first-cycle discharge capacity of 276.87 mAh / g at 30°C and 0.1C. During cycling at a 1C rate, the first-cycle capacity reached 200.3 mAh / g, and after 50 cycles, the capacity was 178.8 mAh / g, with a retention rate of 89.26%. The lower 1C capacity is due to the fact that the synthesized material was not soaked in CS2 to remove residual sulfur, resulting in an excessive inert coating on the surface. Without subsequent CS2 treatment and calcination, no oxygen vacancies were generated on the surface, thus affecting rate performance.

[0083] Comparative Example 3

[0084] (1) dissolving elemental sulfur powder in anhydrous ethanol to obtain solution A; adding the lithium-rich manganese-based positive electrode material described in Comparative Example 1 to anhydrous ethanol to obtain suspension B; adding solution A to suspension B, ultrasonically dispersing the suspension to obtain a suspension, separating the solid and the liquid, and drying the solid to obtain a mixed powder; wherein the amount of elemental sulfur powder used is 2.5 at% of the lithium-rich manganese-based positive electrode material;

[0085] (2) transferring the mixed powder into a sealed can, introducing argon into the sealed can, and calcining at 200° C. for 8 h at a heating rate of 2° C. / min to obtain a calcined material;

[0086] (3) 0.5 g of the calcined material was taken and placed in 50 mL of CS2 and soaked for 10 min, then placed in a fume hood for 30 min to allow the liquid CS2 to evaporate, and then transferred to a sealed can. Argon gas was introduced into the sealed can and calcined at 300 ° C for 6 h with a heating rate of 2 ° C / min. After the calcination, a sulfur-injection-induced spinel and oxygen vacancy-rich lithium manganese-based positive electrode material was obtained.

[0087] EPR test results show that more oxygen vacancies are generated on the surface of the material than in Examples 1-3.

[0088] TEM test results show that the thickness of the spinel structure layer is 10nm to 12nm.

[0089] The assembled battery achieved a first-cycle discharge capacity of 283.79 mAh / g at 30°C and 0.1C. During cycling at a 1C rate, the first-cycle capacity reached 193.54 mAh / g, and after 50 cycles, the capacity reached 133.87 mAh / g, with a retention rate of 69.17%. Due to the large amount of CS2 processed and the calcination time and temperature exceeding the optimal range, a large number of oxygen vacancy layers and spinel structure layers were produced. XRD analysis revealed broadened diffraction peaks and the presence of significant impurity peaks, indicating the formation of impurities. This may be due to the destruction of the material's layered structure caused by the treatment, resulting in poor cycling performance.

[0090] In summary, the invention includes but is not limited to the above embodiments. Any equivalent replacement or partial improvement made under the spirit and principle of the present invention shall be deemed to be within the scope of protection of the present invention.

Claims

1. A lithium-rich manganese-based cathode material with sulfur-injection-induced spinel and oxygen vacancies, characterized by: The chemical formula of the material is xLi2MnO3·(1-x)LiMO 2-y S y , M is one or more of Ni, Co, and Mn among transition metals; 0<x<1, 0.005<y<0.05; the material is based on a lithium-rich manganese-based layered positive electrode material, and the surface of the substrate is sequentially composed of an S anion doped layer and a spinel layer containing oxygen vacancies from the inside out, and the thickness of the spinel layer containing oxygen vacancies is 3nm~7nm; The material is prepared by the following method, comprising the following steps: (1) dissolving elemental sulfur powder in anhydrous ethanol to obtain solution A; adding a lithium-rich manganese-based cathode material to anhydrous ethanol to obtain a suspension B; adding solution A to suspension B, uniformly dispersing by ultrasonication to obtain a suspension, separating the solid and the liquid, and drying the solid to obtain a mixed powder; wherein the amount of elemental sulfur powder used is 0.1% to 5% of the molar amount of the lithium-rich manganese-based cathode material; (2) placing the mixed powder into a sealed container in an inert gas atmosphere, and calcining at 100° C. to 500° C. for 1 h to 10 h to obtain a calcined material; (3) The calcined material is immersed in CS2 for 10 min to 20 min. After solid-liquid separation, the CS2 remaining on the solid surface is removed, and the material is placed in a sealed container under an inert gas atmosphere and calcined at 100° C. to 300° C. for 1 h to 5 h. After the calcination, a lithium-rich manganese-based positive electrode material with sulfur injection-induced spinel and oxygen vacancies is obtained; In step (3), the ratio of the calcined material to CS2 is 0.05 g to 0.1 g: 1 mL.

2. The lithium-rich manganese-based cathode material with sulfur-injection-induced spinel and oxygen vacancies according to claim 1, characterized in that: 0.01＜y＜0.03。 3. The lithium-rich manganese-based cathode material with sulfur-injection-induced spinel and oxygen vacancies according to claim 1, characterized in that: In step (1), the amount of elemental sulfur powder used is 2% to 3% of the molar amount of the lithium-rich manganese-based positive electrode material.

4. The sulfur-implantation-induced spinel and oxygen vacancy lithium-rich manganese-based cathode material according to claim 1, characterized in that: In step (2), the calcination temperature is 200°C to 300°C, the calcination time is 4h to 8h, and the heating rate is 1°C / min to 4°C / min.

5. The lithium-rich manganese-based cathode material with sulfur-injection-induced spinel and oxygen vacancies according to claim 1, characterized in that: In step (3), when removing the residual CS2 on the solid surface, ventilation and standing for more than 30 minutes are adopted.

6. The sulfur-implantation-induced spinel and oxygen vacancy lithium-rich manganese-based cathode material according to claim 1, characterized in that: In step (3), the calcination temperature is 150°C to 200°C, the calcination time is 2h to 3h, and the heating rate is 1°C / min to 4°C / min.

7. The sulfur-implantation-induced spinel and oxygen vacancy lithium-rich manganese-based cathode material according to claim 1, characterized in that: In step (1), the amount of elemental sulfur powder used is 2% to 3% of the molar amount of the lithium-rich manganese-based positive electrode material; In step (2), the calcination temperature is 200°C to 300°C, the calcination time is 4h to 8h, and the heating rate is 1°C / min to 4°C / min; In step (3), the ratio of the calcined material to CS2 is 0.05 g to 0.1 g: 1 mL; when removing the residual CS2 on the solid surface, a ventilation and standing method of more than 30 minutes is adopted; the calcination temperature is 150°C to 200°C, the calcination time is 2h to 3h, and the heating rate is 1°C / min to 4°C / min.

8. A lithium-ion battery, wherein the positive electrode material of the battery is a lithium-manganese-based positive electrode material rich in sulfur-injection-induced spinel and oxygen vacancies according to any one of claims 1 to 7.

Images