A sheet-like cobalt-free lithium-rich manganese-based positive electrode material and a preparation method and application thereof

Abstract

The application provides a sheet-layer cobalt-free lithium-rich manganese-based positive electrode material, and a composition formula is as follows: Li x Ni y Mn z O2 formula I; 1.00<=x<=1.25; 0.05<=y<=0.40; 0.50<=z<=0.80; the grain morphology of the sheet-layer cobalt-free lithium-rich manganese-based positive electrode material is porous aggregation, and the primary particles are sheet-layer structures. The method provided by the application uses two-stage solid-phase method to replace traditional co-precipitation method, spray drying method and sol-gel method, and high-purity and high-activity cobalt-free lithium-rich manganese-based positive electrode material is prepared. The synthesis route provided by the application has the advantages of simple method, easy-to-obtain raw materials, energy saving and environmental protection, easy batch production and the like. The cobalt-free lithium-rich manganese-based positive electrode material prepared by the application has high purity and high electrochemical activity, can be used in the current commonly used working voltage, has high compaction density and excellent rate characteristics. The application further provides a preparation method and application of the sheet-layer cobalt-free lithium-rich manganese-based positive electrode material.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of batteries, and particularly relates to a sheet-layered cobalt-free lithium-rich manganese-based positive electrode material and a preparation method and application thereof. BACKGROUND

[0002] Compared with other secondary batteries such as nickel-hydrogen batteries and lead-acid batteries, lithium ion batteries have higher energy density, longer cycle life, lower self-discharge rate and environmental friendliness, and many other advantages, and have become the general power supply for portable devices such as mobile phones, notebook computers and electric tools. In recent years, with the rapid development of the global new energy industry, it has also been widely used in the markets of electric bicycles, electric vehicles, energy storage and the like.

[0003] The positive electrode materials currently used in lithium ion batteries mainly include four categories of lithium cobaltate (LiCoO2), lithium iron phosphate (LiFePO4), lithium manganate (LiMn2O4) and nickel cobalt manganate (NCM ternary) and nickel cobalt aluminum lithium (NCA ternary). The lithium cobaltate material is mainly used in high-end mobile phone batteries and unmanned aerial vehicle batteries because the price of cobalt is relatively high, cobalt has a certain toxicity, and has adverse effects on the environment after being discarded; LiFePO4 has the advantages of structural stability, cheap raw materials, good cycle performance and safety, and less environmental burden, and is currently widely used in electric vehicles and energy storage, but also has problems such as high synthesis cost, low energy density and poor low-temperature performance; NCM ternary and NCA ternary materials have the advantages of high specific capacity, high compaction density and moderate price, and are currently the mainstream positive electrode material in the electric vehicle market, but high-nickel ternary materials have high cost, high difficulty in battery processing and poor battery safety, which cannot fully meet the market demand. Spinel lithium manganate LiMn2O4 has the advantages of good safety, low price, environmental protection and good low-temperature performance, and is also a mainstream positive electrode material at present, but its energy density is relatively low, and the capacity attenuation in the charge and discharge cycle is relatively fast, especially the cycle performance at high temperature is poor, which limits its application in large-scale power lithium ion batteries and energy storage batteries. There are many reasons for the poor high-temperature performance and large-current performance of lithium manganate materials, such as Jahn-Teller distortion effect and manganese dissolution at high temperature, electrolyte decomposition and the like.

[0004] At present, the domestic new energy vehicle industry has reached a critical stage, and users have put forward higher requirements for the safety, price, life, weather resistance and use convenience of new energy vehicles. The demand for developing more low-cost, environmentally friendly and high-performance positive electrode materials is becoming more and more urgent. SUMMARY

[0005] Therefore, the present application aims to provide a sheet-layer cobalt-free lithium-rich manganese-based positive electrode material, a preparation method and application thereof.

[0006] The present application provides a sheet-layer cobalt-free lithium-rich manganese-based positive electrode material, and a preparation method and application thereof.

[0007] Li x Ni y Mn z O2 formula I.

[0008] In formula I, 1.00≤x≤1.25; 0.05≤y≤0.40; 0.50≤z≤0.80.

[0009] The sheet-layer cobalt-free lithium-rich manganese-based positive electrode material has a porous aggregate grain morphology, and the primary particles have a sheet-layer structure.

[0010] Preferably, the sheet-layer structure has a sheet-layer thickness of 50-500 nm and a sheet-layer length of 200-2000 nm.

[0011] The present application provides a preparation method of the sheet-layer cobalt-free lithium-rich manganese-based positive electrode material.

[0012] The manganese source and the nickel source are first mixed to obtain a pre-reaction mixture.

[0013] The pre-reaction mixture is calcined to obtain a spinel-structure precursor.

[0014] The spinel-structure precursor and a lithium source are second mixed and then heat-treated to obtain the sheet-layer cobalt-free lithium-rich manganese-based positive electrode material.

[0015] Preferably, the manganese source is selected from one or more of manganese dioxide, trimanganese tetroxide and manganese carbonate.

[0016] Preferably, the nickel source is selected from one or more of basic nickel carbonate and nickel oxide.

[0017] Preferably, the calcination temperature is 600-1000 DEG C, and the calcination time is 10-24 hours.

[0018] Preferably, the lithium source is selected from one or more of lithium carbonate, lithium hydroxide, lithium acetate and lithium nitrate.

[0019] Preferably, the heat treatment temperature is 700-980 DEG C, and the heat treatment time is 10-24 hours.

[0020] Preferably, the first mixing adopts a ball milling method.

[0021] The second mixing uses a ball mill or a high-speed mixer.

[0022] The application provides a battery, comprising the sheet-layered cobalt-free lithium-rich manganese-based positive electrode material or the sheet-layered cobalt-free lithium-rich manganese-based positive electrode material prepared by the method.

[0023] The application has found that the main features of the lithium-rich manganese-based material are high specific capacity, which can be up to 300 mAh / g, and the main element is manganese, so the material is cheap and friendly to the environment. However, the lithium-rich manganese-based material needs a wide working voltage range (usually 2.0-4.8 volts) to achieve the capacity, and it is difficult to be directly used in the current industry; in addition, the material has low electrochemical activity due to the main elements of manganese and lithium, so the low-temperature and rate characteristics are poor, and the average voltage of the battery decreases after long-term cycling. The current synthesis methods of the lithium-rich manganese-based positive electrode material mainly include spray drying, sol-gel and co-precipitation, and the water and electricity consumption is large in the synthesis process, and the environmental problems such as wastewater treatment need to be solved. Therefore, it is particularly important to develop a lithium-rich manganese-based positive electrode material with low price, which can be used in a low working voltage range and has better specific energy and rate characteristics.

[0024] The method provided by the application uses two-stage solid-phase method to replace the traditional co-precipitation method, spray drying method and sol-gel method to prepare the cobalt-free lithium-rich manganese-based positive electrode material with high purity and high activity; the lithium-rich manganese-based positive electrode material prepared has a porous aggregate grain morphology, and the primary particles have a sheet-layer structure; the sheet-layer thickness of the sheet-layer structure is 50-500 nm; and the sheet-layer length is 200-2000 nm. The lithium-rich manganese-based material prepared by the application is suitable for a non-aqueous secondary battery as a positive electrode. The synthesis route provided by the application has the advantages of simple method, easy-to-obtain raw materials, energy saving and environmental protection, easy batch production and the like. The cobalt-free lithium-rich manganese-based positive electrode material prepared by the application has high purity and high electrochemical activity, can be used in the current commonly used working voltage, has high compaction density and excellent rate characteristics. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 The XRD pattern of ZT-1 prepared in Example 1;

[0026] Figure 2 The SEM pattern of ZT-1 prepared in Example 1;

[0027] Figure 3 The XRD pattern of ZT-3 prepared in Example 1;

[0028] Figure 4 The SEM pattern of ZT-3 prepared in Example 1;

[0029] Figure 5 SEM image of ZT-4 prepared in Example 2;

[0030] Figure 6 SEM image of LX-5 prepared in Example 3;

[0031] Figure 7 First charge-discharge curve of the battery prepared from LX-5 prepared in Example 3 at different voltage ranges;

[0032] Figure 8 Cycle curve of the battery prepared from LX-5 prepared in Example 3 at different rates at different voltage ranges. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0034] The present application provides a sheet-layer cobalt-free lithium-rich manganese-based positive electrode material, and the composition formula is as follows:

[0035] Li x Ni y Mn z O2 Formula I;

[0036] In formula I, 1.00≤x≤1.25; 0.05≤y≤0.40; 0.50≤z≤0.80.

[0037] The grain morphology of the sheet-layer cobalt-free lithium-rich manganese-based positive electrode material is porous aggregation, and the primary particles are sheet-layer structures.

[0038] In the present application, the x is preferably 1.05-1.20, more preferably 1.10-1.15; the y is preferably 0.10-0.30, more preferably 0.15-0.25, and most preferably 0.20; and the z is preferably 0.55-0.75, more preferably 0.60-0.70, and most preferably 0.65.

[0039] In the present application, the sheet-layer thickness of the sheet-layer structure is preferably 50-500 nm, more preferably 100-400 nm, more preferably 200-300 nm, and most preferably 250 nm; and the sheet-layer length is preferably 200-2000 nm, more preferably 500-1500 nm, more preferably 800-1200 nm, and most preferably 1000 nm.

[0040] The application provides a preparation method of the flaky cobalt-free lithium-rich manganese-based positive electrode material.

[0041] The manganese source and the nickel source are first mixed to obtain a pre-reaction mixture;

[0042] The pre-reaction mixture is calcined to obtain a spinel structure precursor;

[0043] The spinel structure precursor and a lithium source are second mixed and then heat-treated to obtain the flaky cobalt-free lithium-rich manganese-based positive electrode material.

[0044] In the application, the manganese source is preferably selected from one or more of manganese dioxide, trimanganese tetroxide and manganese carbonate.

[0045] In the application, the nickel source is preferably selected from one or more of basic nickel carbonate and nickel oxide.

[0046] In the application, the first mixing is preferably uniform mixing by using a ball mill.

[0047] In the application, the calcination temperature is preferably 600-1000 DEG C, more preferably 700-900 DEG C, and most preferably 800 DEG C; the calcination time is preferably 10-24 hours, more preferably 15-20 hours, and most preferably 16-18 hours; and the calcination is preferably followed by natural cooling.

[0048] In the application, the lithium source is preferably selected from one or more of lithium carbonate, lithium hydroxide, lithium acetate and lithium nitrate.

[0049] In the application, the manganese source, the nickel source and the lithium source are used in an amount according to the composition of the flaky cobalt-free lithium-rich manganese-based positive electrode material to be obtained, i.e., according to the composition of formula I.

[0050] In the application, the second mixing is preferably performed by using a ball mill or a high-speed mixer.

[0051] In the application, the heat treatment temperature is preferably 700-980 DEG C, more preferably 750-950 DEG C, more preferably 800-900 DEG C, and most preferably 850 DEG C; the heat treatment time is preferably 10-24 hours, more preferably 15-20 hours, and most preferably 16-18 hours; and the heat treatment is preferably followed by natural cooling.

[0052] In the embodiment of the application, the preparation method of the flaky cobalt-free lithium-rich manganese-based positive electrode material preferably comprises:

[0053] The manganese source (manganese dioxide, trimanganese tetroxide, manganese carbonate, etc.) and the nickel source (basic nickel carbonate, nickel oxide, etc.) are mixed uniformly in a ball mill method according to a stoichiometric ratio to obtain a pre-reaction mixture;

[0054] The pre-reaction mixture is calcined at a high temperature of 600-1000 ℃ to obtain a precursor with a spinel structure;

[0055] The lithium source (lithium carbonate, lithium hydroxide, lithium acetate, lithium nitrate, etc.) and the prepared precursor are mixed by a ball mill or a high-speed mixer according to a certain stoichiometric ratio, and then subjected to secondary heat treatment at 700-980 ℃, so as to finally obtain a lithium-rich manganese-based positive electrode material with high purity, porosity and sheet-like primary particle size.

[0056] The application provides a battery, comprising: the sheet-like cobalt-free lithium-rich manganese-based positive electrode material described in the technical solution, or the sheet-like cobalt-free lithium-rich manganese-based positive electrode material prepared by the method described in the technical solution.

[0057] In the application, the battery is preferably a button cell, such as a CR2032 type button cell.

[0058] In the application, the preparation method of the battery preferably comprises:

[0059] The positive electrode sheet, the negative electrode, the separator and the electrolyte are assembled in a glove box to obtain the button cell.

[0060] In the application, the preparation method of the positive electrode sheet preferably comprises:

[0061] The positive electrode material, the conductive agent, the binder and the solvent are mixed to obtain a slurry;

[0062] The slurry is coated on an aluminum foil and dried to obtain the positive electrode sheet.

[0063] In the application, the positive electrode material is preferably the positive electrode material described in the technical solution.

[0064] In the application, the conductive agent is preferably conductive carbon black, such as super P.

[0065] In the application, the binder is preferably polyvinylidene fluoride (PVDF).

[0066] In the application, the mass ratio of the positive electrode material, the conductive agent and the binder is preferably (6-10):(0.5-2):(0.5-2), more preferably (7-9):(0.8-1.2):(0.8-1.2), and most preferably 8:1:1.

[0067] In the application, the solvent is preferably N-methyl pyrrolidone (NMP).

[0068] In the present application, the temperature of drying is preferably 100-120℃, more preferably 105-115℃, and most preferably 110℃; and the time of drying is preferably 10-15h, more preferably 11-14h, and most preferably 12-13h.

[0069] In the present application, the negative electrode is preferably a lithium metal sheet.

[0070] In the present application, the separator is preferably a polypropylene separator.

[0071] In the present application, the electrolyte in the electrolyte solution is preferably LiPF6, and the solvent preferably includes ethylene carbonate (EC) and diethyl carbonate (DEC); the volume ratio of the ethylene carbonate (EC) and diethyl carbonate (DEC) is preferably (0.5-1.5):(0.5-1.5), more preferably (0.8-1.2):(0.8-1.2), and most preferably 1:1; and the concentration of the electrolyte solution is preferably 0.5-1.5mol / L, more preferably 0.8-1.2mol / L, and most preferably 1.0mol / L.

[0072] In the present application, the assembly is preferably performed in a glove box filled with high-purity argon.

[0073] The synthetic route provided by the present application has the advantages of simple method, easy availability of raw materials, energy saving and environmental protection, and easy batch production. The cobalt-free lithium-rich manganese-based positive electrode material prepared by the present application has high purity and high electrochemical activity, can be used in the current commonly used working voltage, has high compaction density, and has excellent rate characteristics.

[0074] Example 1

[0075] Manganese dioxide and nickel oxide were used as raw materials, and the manganese dioxide and the nickel oxide were weighed according to a molar ratio of Ni:Mn=0.17:0.63, put into a high-energy ball mill, mixed, taken out, loaded into a sagger, and subjected to heat treatment at 780℃ for 12 hours, and then taken out after natural cooling as a precursor (marked as ZT-1);

[0076] Lithium carbonate was used as a raw material, and the lithium carbonate and the precursor were weighed according to a molar ratio of 1.2:1, put into a high-energy ball mill, mixed, taken out, loaded into a sagger, and subjected to heat treatment at 950℃ for 12 hours, and then taken out after natural cooling to obtain a sample (marked as ZT-3).

[0077] The ZT-1 in Example 1 was subjected to XRD detection, and the detection results are shown in FIG. 1, which shows that the nickel-manganese precursor has a typical spinel structure; the ZT-1 was subjected to SEM detection, and the detection results are shown in FIG. 2. Figure 1 Figure 2 ​As shown, it can be seen that the primary particles of the nickel-manganese precursor are granular, and the size is about 200 nm or so.

[0078] The ZT-3 in Example 1 was subjected to XRD detection, and the detection results are shown in Figure 2. Figure 3 As shown, it can be seen that the cobalt-free lithium-rich manganese-based material has a typical layered structure, and a small peak at a 2theta angle of about 21° indicates that it has typical lithium-rich manganese-based characteristics; in addition, no diffraction peak of other phases is found in the XRD spectrum, indicating that the product prepared in Example 1 has very high purity; the ZT-3 was subjected to SEM detection, and the detection results are shown in Figure 3. Figure 4 As shown, it can be seen that the morphology of ZT-3 is a porous aggregate, and the primary particles thereof are lamellar, and the average thickness is about 50-200 nm or so.

[0079] Example 2

[0080] Taking manganese sesquioxide and nickel oxide as raw materials, manganese sesquioxide and nickel oxide were weighed according to a molar ratio of Ni:Mn = 0.17:0.63, put into a high-energy ball mill, crushed and mixed, taken out, loaded into a sagger, and subjected to heat treatment at 780°C for 12 hours, and then taken out after natural cooling as a precursor (marked as ZT-2);

[0081] Taking lithium carbonate as a raw material, lithium carbonate and the precursor were weighed according to a molar ratio of 1.2:1, put into a high-energy ball mill, mixed, taken out, loaded into a sagger, and subjected to heat treatment at 950°C for 12 hours, and then taken out after natural cooling to obtain a sample (marked as ZT-4).

[0082] The ZT-4 was subjected to SEM detection, and the detection results are shown in Figure 6. Figure 5 As shown, it can be seen that the morphology of ZT-4 is a porous aggregate, and the primary particles thereof are lamellar, and the average thickness is about 50-200 nm or so.

[0083] Example 3

[0084] Taking manganese sesquioxide and nickel oxide as raw materials, manganese sesquioxide and nickel oxide were weighed according to a molar ratio of Ni:Mn = 0.17:0.63, put into a high-energy ball mill, crushed and mixed, taken out, loaded into a sagger, and subjected to heat treatment at 780°C for 12 hours, and then taken out after natural cooling as a precursor (marked as ZT-2);

[0085] Taking lithium carbonate as a raw material, lithium carbonate and the precursor were weighed according to a molar ratio of 1.2:1, put into a high-energy ball mill, mixed, taken out, loaded into a sagger, and subjected to heat treatment at 950°C for 12 hours, and then taken out after natural cooling to obtain a sample (marked as ZT-4).

[0086] The LX-5 was subjected to SEM detection, and the detection results are shown in Figure 8. Figure 6As shown, it can be seen that the morphology of LX-5 is a porous aggregate state, and the primary particles thereof are lamellar, with an average thickness of about 50-200 nm.

[0087] Example 4

[0088] ZT-3 prepared in Example 1 was mixed with conductive carbon black super P and binder PVDF in a ratio of 8:1:1, dissolved in N-methyl pyrrolidone (NMP), and coated on an aluminum sheet after uniform stirring to prepare a positive electrode sheet. The prepared positive electrode sheet was dried in a vacuum oven at 110°C for 12 h, and a negative electrode prepared from a lithium metal sheet, a polypropylene separator, and an electrolyte were assembled in a glove box filled with high-purity argon to obtain a CR2032 type button-shaped experimental battery; the electrolyte in the electrolyte was LiPF6, and the solvent was a mixture of ethylene carbonate (EC) and diethyl carbonate (DEC) in a volume ratio of 1:1, and the concentration of the electrolyte was 1 mol / L.

[0089] Example 5

[0090] ZT-4 prepared in Example 2 was mixed with conductive carbon black super P and binder PVDF in a ratio of 8:1:1, dissolved in N-methyl pyrrolidone (NMP), and coated on an aluminum sheet after uniform stirring to prepare a positive electrode sheet. The prepared positive electrode sheet was dried in a vacuum oven at 110°C for 12 h, and a negative electrode prepared from a lithium metal sheet, a polypropylene separator, and an electrolyte were assembled in a glove box filled with high-purity argon to obtain a CR2032 type button-shaped experimental battery; the electrolyte in the electrolyte was LiPF6, and the solvent was a mixture of ethylene carbonate (EC) and diethyl carbonate (DEC) in a volume ratio of 1:1, and the concentration of the electrolyte was 1 mol / L.

[0091] Example 6

[0092] LX-5 prepared in Example 3 was mixed with conductive carbon black super P and binder PVDF in a ratio of 8:1:1, dissolved in N-methyl pyrrolidone (NMP), and coated on an aluminum sheet after uniform stirring to prepare a positive electrode sheet. The prepared positive electrode sheet was dried in a vacuum oven at 110°C for 12 h, and a negative electrode prepared from a lithium metal sheet, a polypropylene separator, and an electrolyte were assembled in a glove box filled with high-purity argon to obtain a CR2032 type button-shaped experimental battery; the electrolyte in the electrolyte was LiPF6, and the solvent was a mixture of ethylene carbonate (EC) and diethyl carbonate (DEC) in a volume ratio of 1:1, and the concentration of the electrolyte was 1 mol / L.

[0093] Performance detection

[0094] The batteries prepared in Examples 4 to 6 were tested at room temperature (25°C), with a charge / discharge voltage range of 3.3 to (4.2 to 4.6) volts, a charging current of 140 mA / g (1C), and 10 cycles at a discharge current of 140 mA / g (1C). The discharge current was then increased to 280 mA / g (2C) for another 10 cycles, and finally, 10 cycles were performed at 700 mA / g (5C). The test results are shown in the table below. Figure 7 and Figure 8 As shown:

[0095]

[0096] As can be seen from the above, ZT-3 has a very low initial discharge capacity due to its low nickel content. However, the discharge capacity will increase with the increase of the charging voltage. ZT-4 uses manganese tetroxide as a raw material, which improves the electrochemical performance compared to the sample using manganese dioxide. However, due to the low nickel content in the sample, the capacity is still low at a lower operating voltage.

[0097] Figure 7 The initial charge-discharge curves of the battery prepared for LX-5 in different voltage ranges show that the discharge capacity in the 3–4.3V range is 113 mA hg. -1 The LX-5 has a discharge capacity of 122 mA hg in the 3–4.4V range. -1 The discharge capacity in the 3-4.5V range is 142mA hg. -1 It exhibits excellent electrochemical performance; Figure 8 Cycling curves of the battery prepared for LX-5 at different rates in different voltage ranges are shown. It can be seen that LX-5 exhibits excellent cycling characteristics in all voltage ranges. In addition, at high rates, the capacity retention and cycling characteristics are very good, indicating that the material prepared using the examples has excellent battery performance.

[0098] The synthetic route provided by this invention has many advantages, including simple method, readily available raw materials, energy saving and environmental protection, and ease of mass production. The cobalt-free lithium-rich manganese-based cathode material prepared by this invention has high purity, high electrochemical activity, can be used within the current commonly used operating voltage range, has high compaction density, and excellent rate capability.

[0099] While the application has been described and illustrated with reference to specific embodiments thereof, those skilled in the art will appreciate that various adaptations, changes, modifications, substitutions, developments, improvements, and permutations can be made in the specific embodiments described without departing from the true spirit and scope of the application as defined by the appended claims. All such modifications are intended to be within the scope of the claims. Although methods disclosed herein have been described with reference to particular operations performed in a particular order, it will be understood that these operations can be combined, sub-divided, or re-ordered to form equivalent methods without departing from the teachings of the present application. Accordingly, unless specifically indicated herein, the order and grouping of operations are not a limitation of this application.

Claims

1. A layered, cobalt-free, lithium-rich manganese-based cathode material, with the following composition: Li x Ni y Mn z O2 of formula I; In Equation I, 1.00 ≤ x ≤ 1.25; 0.05 ≤ y ≤ 0.40; 0.50 ≤ z ≤ 0.80; The grain morphology of the layered cobalt-free lithium-rich manganese-based cathode material is porous aggregated, and the primary particles have a layered structure. The sheet structure has a sheet thickness of 50~500nm and a sheet length of 200~2000nm; The preparation method of the layered cobalt-free lithium-rich manganese-based cathode material includes: The manganese source and the nickel source are first mixed to obtain a pre-reaction mixture; The pre-reaction mixture was calcined to obtain a precursor with a spinel structure; After a second mixing and heat treatment of the spinel-structured precursor and lithium source, a layered cobalt-free lithium-rich manganese-based cathode material is obtained. The preparation method of the layered cobalt-free lithium-rich manganese-based cathode material includes: The manganese source and the nickel source are first mixed to obtain a pre-reaction mixture; The pre-reaction mixture is calcined to obtain a spinel-structured precursor; the calcination temperature is 600~1000℃; the calcination time is 10~24 hours; The spinel-structured precursor and lithium source are mixed in a second process and then heat-treated to obtain a layered cobalt-free lithium-rich manganese-based cathode material; the heat treatment temperature is 700~980℃; the heat treatment time is 10~24 hours. The manganese source is manganese tetroxide; The nickel source is selected from one or more of basic nickel carbonate and nickel oxide; The lithium source is selected from one or more of lithium carbonate, lithium hydroxide, lithium acetate, and lithium nitrate.

2. A method for preparing the layered cobalt-free lithium-rich manganese-based cathode material according to claim 1, comprising: The manganese source and the nickel source are first mixed to obtain a pre-reaction mixture; The pre-reaction mixture is calcined to obtain a spinel-structured precursor; the calcination temperature is 600~1000℃; the calcination time is 10~24 hours; The spinel-structured precursor and lithium source are mixed in a second process and then heat-treated to obtain a layered cobalt-free lithium-rich manganese-based cathode material; the heat treatment temperature is 700~980℃; the heat treatment time is 10~24 hours. The manganese source is manganese tetroxide; The nickel source is selected from one or more of basic nickel carbonate and nickel oxide; The lithium source is selected from one or more of lithium carbonate, lithium hydroxide, lithium acetate, and lithium nitrate.

3. The method according to claim 2, characterized in that, The first mixing is performed using a ball milling method; The second mixing is performed using a ball mill or a high-speed mixer.

4. A battery, comprising: The layered cobalt-free lithium-rich manganese-based cathode material according to claim 1, or the layered cobalt-free lithium-rich manganese-based cathode material prepared by the method according to claim 2.

Images