Lithium nickel manganese spinel material and method for producing the same

Abstract

The present invention provides a spinel-type lithium nickel manganese oxide material, wherein the condition satisfied in the XRD spectrum of the spinel-type lithium nickel manganese oxide material is 0<(A(43.7°) / A(18.8°)). 1 / 2 ≦0.2. The spinel-type lithium nickel manganese oxide material of the present invention can reduce oxygen defects, improve the stability of the crystal structure, and reduce the content of rock salt phase.

Description

Technical Field

[0001] The present invention relates to the field of electrochemistry, and particularly to a spinel-type lithium nickel manganate material and a method for manufacturing the same.

Background Art

[0002] The discharge voltage platform of spinel-type lithium nickel manganate is as high as 4.7 V (vs Li / Li + ), and since the theoretical discharge specific capacity (147 mAh / g) is high, the theoretical specific energy density (690 Wh / kg) is high. Currently, the specific energy density of spinel-type lithium nickel manganate actually used in the full cell with graphite negative electrode is also higher than 590 Wh / kg, much higher than that of lithium iron phosphate (≤460 Wh / kg), close to that of ternary nickel cobalt manganese (≥650 Wh / kg), and there is still much room for improvement in spinel-type lithium nickel manganate. The contents of Li and Ni in spinel-type lithium nickel manganate are both significantly lower than those in ternary nickel cobalt manganese, and since the manufacturing process is simple, when used in the full cell with graphite negative electrode, the cost per watt-hour of the battery is much lower than that of ternary nickel cobalt manganese and close to that of lithium iron phosphate. Furthermore, since the thermal stability of spinel-type lithium nickel manganate is high and the allowable overcharge and overdischarge range is large, the safety of using the spinel-type lithium nickel manganate system is significantly superior to that of the ternary nickel cobalt manganese system.

[0003] As described above, spinel-type lithium nickel manganate is a positive electrode material with sufficient potential for low cost and high energy density because it has high energy density, low cost, and high safety.

[0004] However, this material itself has the following defects, which greatly affect its use in battery cells. The synthesis of spinel-type lithium nickel manganate under high-temperature conditions is likely to generate oxygen vacancies in the material. As a result, a large number of oxygen vacancies and rock salt phases are generated, the structural stability of the material decreases, and the cycle performance may deteriorate further.

[0005] Also, under the working conditions of high temperature and high pressure, Mn in the spinel-type lithium nickel manganate 3+ is prone to disproportionation reaction, and Mn 2+ dissolves in the electrolyte and deposits on the negative electrode. At the same time, a large number of side reactions occur between the material surface and the electrolyte, deteriorating the overall battery performance.

[0006] Therefore, the current research focus is to reduce the oxygen vacancies in the spinel-type lithium nickel manganate, enhance the stability of the crystal structure, and reduce the content of the rock salt phase, thereby improving the rate performance, cycle performance, and storage performance of the cathode material, and thus improving the energy density and long cycle life of the battery using the cathode material.

Summary of the Invention

Problems to be Solved by the Invention

[0007] This application is made in view of the above technical problems, and aims to provide a spinel-type lithium nickel manganate material and its manufacturing method, a secondary battery, a battery module, a battery pack, and an electrical device including the spinel-type lithium nickel manganate material. The spinel-type lithium nickel manganate material of this application can reduce oxygen vacancies, enhance the stability of the crystal structure, and reduce the content of the rock salt phase.

Means for Solving the Problems

[0008] To achieve the above object, the first aspect of this application provides a spinel-type lithium nickel manganate material, The condition satisfied by the XRD spectrum of the spinel-type lithium nickel manganate material is 0 < (A(43.7°) / A(18.8°)) 1 / 2is ≦ 0.2, and preferably, the satisfied condition is 0 < (A(43.7°) / A(18.8°)) 1 / 2 is ≦ 0.1, Here, A(43.7°) indicates the peak area of the diffraction peak appearing near 43.7° in the XRD spectrum, and A(18.8°) indicates the peak area of the diffraction peak appearing near 18.8° in the XRD spectrum.

[0009] (A(43.7°) / A(18.8°)) in the XRD spectrum of the spinel-type lithium nickel manganate material 1 / 2 By establishing the relationship between the specific range of and oxygen defects, the reduction of oxygen defects in the spinel-type lithium nickel manganate material can be determined by measuring the XRD spectrum of the spinel-type lithium nickel manganate material.

[0010] In some embodiments, the chemical formula of the spinel-type lithium nickel manganate material is Li x (Ni 0.5 Mn 1.5 ) n M m O4, provided that M is one or more elements selected from W, P, B, Nb, Mo, and Ta, and as stoichiometric numbers, n + m = 1, x = 0.95 to 1.1, and m = 0.001 to 0.015. By doping the spinel-type lithium nickel manganate with one or more elements selected from W, P, B, Nb, Mo, and Ta, the above stoichiometric range is reached, and thereby, the crystal structure of the obtained spinel-type lithium nickel manganate material is ensured to satisfy the conditions within the specific range of the above (A(43.7°) / A(18.8°)), thereby determining the reduction of oxygen defects in the crystal structure. 1 / 2

[0011] In some embodiments, the spinel-type lithium nickel manganate material is a single crystal and an octahedron with blunt corners. By doping the above elements in specific amounts to modify the spinel-type lithium nickel manganate, the obtained spinel-type lithium nickel manganate material is formed in a single crystal form of an octahedron with blunt corners. The blunt corners can reduce the surface activity of the spinel-type lithium nickel manganate and decrease the contact area with the electrolyte. As a result, side reactions can be reduced. The single crystal form can effectively reduce the cracking phenomenon during cold pressing and the use of battery cells, and improve the overall performance of the battery cells.

[0012] In some embodiments, the average particle size Dv50 of the volume distribution of the spinel-type lithium nickel manganate material is 5 μm to 15 μm, preferably 5 μm to 10 μm. By setting the average particle size Dv50 of the volume distribution of the nickel manganese spinel material of the present invention within the above range, since the particle size of the primary particles is large, the side reaction between the nickel manganese spinel material and the electrolyte can be effectively reduced.

[0013] In some embodiments, the distance between particle sizes (Dv90 - Dv10) / Dv50 of the volume distribution of the spinel-type lithium nickel manganate material particles is 1.0 or less. By setting (Dv90 - Dv10) / Dv50 of the nickel manganese spinel material of the present invention within the above range, since the particle consistency is good, the side reaction between the nickel manganese spinel material and the electrolyte can be effectively reduced.

[0014] In some embodiments, the BET of the nickel manganese spinel material is 0.3 m 2 / g to 1.0 m 2 / g, preferably 0.3 m 2 / g to 0.5 m 2 / g. By setting the BET of the nickel manganese spinel material of the present invention within the above range, since the BET is small, the side reaction between the nickel manganese spinel material and the electrolyte can be effectively reduced.

[0015] The second aspect of the present application provides a method for manufacturing a spinel-type lithium nickel manganate material described in the first aspect, The manufacturing method is as follows, Step S1: Put a lithium salt, a nickel manganese hydroxide precursor, and an M-containing compound into a mixer and mix them to obtain a mixture; Step S2: Heat up the mixture obtained in step S1 in an oxygen-enriched atmosphere to perform primary sintering. After the primary sintering is completed, naturally cool it to room temperature, and then perform ball milling to obtain a powder; Step S3: Heat up the powder obtained in step S2 again in an oxygen-enriched atmosphere to perform secondary sintering. After the secondary sintering is completed, keep it warm, and then naturally cool it to room temperature. Next, perform ball milling to obtain a spinel-type lithium nickel manganate material.

[0016] The spinel-type lithium nickel manganate material of the invention obtained by the above manufacturing method has few oxygen defects, side reactions, and Mn elution, and has excellent comprehensive electrochemical performance.

[0017] In some embodiments, in step S1, regarding the mixing ratio of the lithium salt and the nickel manganese hydroxide, the Li / (Ni + Mn) molar ratio is (0.45 to 0.55):1, where (Ni + Mn) is the total metal molar number of nickel and manganese, and regarding the doping amount of the M-containing compound, the Li / M molar ratio is 1:(0.001 to 0.01), preferably, the Li / M molar ratio is 1:(0.003 to 0.007). By setting the doping amount of the M-containing compound within the above range and setting the mixing ratio of the lithium salt and the nickel manganese hydroxide within the above range, the crystal form of the spinel-type lithium nickel manganate material can be effectively adjusted, the side reaction between the oxygen defects, the spinel-type lithium nickel manganate material and the electrolyte can be effectively reduced, the structural stability of the spinel-type lithium nickel manganate material can be improved, and the Mn elution can be reduced.

[0018] In some embodiments, in step S1, the mixer is a planetary mixer, a high-speed mixer or an inclined mixer. By using these mixers, the mixing efficiency can be effectively improved.

[0019] In some embodiments, in steps S2 and S3, the heating rate during primary sintering and secondary sintering is 5 °C / min or less, preferably 3 °C / min or less. Since the heating rate affects the heating of the material during the crystallization process, by setting the heating rate within the above range, it is ensured that the primary particles become more uniform.

[0020] In some embodiments, in step S2, the primary sintering temperature is 500 °C to 1200 °C, preferably 600 °C to 1200 °C, and in step S3, the secondary sintering temperature is 400 °C to 700 °C, preferably 500 °C to 700 °C. By the two sinterings, the secondary sintering annealing of the spinel-type lithium nickel manganate material compensates for the oxygen defects in the primary sintering annealing process, and can further reduce the oxygen defects of the material. At the same time, the content of Mn in the material can be effectively reduced, and Mn elution can be reduced. In order to dope spinel-type lithium nickel manganate with one or more elements selected from W, P, B, Nb, Mo and Ta, the primary sintering temperature and the secondary sintering temperature can be synthesized within the above low temperature ranges respectively. 3+ The content of can be effectively reduced, and Mn elution can be reduced. In order to dope spinel-type lithium nickel manganate with one or more elements selected from W, P, B, Nb, Mo and Ta, the primary sintering temperature and the secondary sintering temperature can be synthesized within the above low temperature ranges respectively.

[0021] In some embodiments, in steps S2 and S3, as the oxygen-enriched atmosphere, the oxygen content is greater than 60%, preferably 80% to 100%. By setting the oxygen-enriched atmosphere within the above range, the content of small particles in the spinel-type lithium nickel manganate material can be effectively reduced, and the content of oxygen defects in the spinel-type lithium nickel manganate material can be reduced.

[0022] In some embodiments, in steps S2 and S3, the pressure in the sintering furnace is 0.02 MPa to 0.08 MPa relative to atmospheric pressure, preferably 0.02 MPa to 0.04 MPa. By setting the pressure in the sintering furnace within the above range relative to atmospheric pressure, the content of small particles in the spinel-type lithium nickel manganate material can be effectively reduced, and the content of oxygen defects in the spinel-type lithium nickel manganate material can be reduced.

[0023] In some embodiments, in step S3, the heat preservation time is 5 h to 40 h, preferably 15 h to 30 h. By setting the heat preservation time within the above range, the oxygen defects of the material can be further reduced, and at the same time, the content of Mn 3+ in the material can be effectively reduced, and Mn elution can be reduced.

[0024] The third aspect of the present application provides a secondary battery including the spinel-type lithium nickel manganate material described in the first aspect of the present application.

[0025] The fourth aspect of the present application provides a battery module including the secondary battery described in the third aspect of the present application.

[0026] The fifth aspect of the present application provides a battery pack including the battery module described in the fourth aspect of the present application.

[0027] The sixth aspect of the present application provides an electrical device including at least one of the secondary battery described in the third aspect of the present application, the battery module described in the fourth aspect of the present application, and the battery pack described in the fifth aspect of the present application.

Advantages of the Invention

[0028] According to the spinel-type lithium nickel manganate material of the present invention, as a cathode material, the oxygen defect content of the spinel-type lithium nickel manganate material is low, the stability of the crystal structure is strong, the content of the rock salt phase is low, and further, the secondary battery using the cathode material has a high energy density and a long cycle life, and the problem of gas generation during the cycle process is effectively suppressed.

Brief Description of the Drawings

[0029]

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Embodiments for Carrying Out the Invention

[0030] Hereinafter, embodiments specifically disclosing the positive electrode sheet, secondary battery, battery module, battery pack, and electric device of the present application will be described in detail with appropriate reference to the drawings. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and duplicate descriptions of actually identical structures may be omitted. This is to avoid making the following description unnecessarily long and to facilitate the understanding of those skilled in the art. Note that the drawings and the following description are provided for those skilled in the art to fully understand the present application and do not limit the subject matter described in the claims.

[0031] The "range" disclosed in this application is limited in the form of a lower limit and an upper limit. A predetermined range is limited by selecting one lower limit and one upper limit, and the boundary of a specific range is limited by the selected lower limit and upper limit. The range thus limited may or may not include the boundary values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form one range. For example, if ranges of 60 - 120 and 80 - 110 are listed for a specific parameter, ranges of 60 - 110 and 80 - 120 are also understood to be expected. In addition, if the minimum range values 1 and 2, and the maximum range values 3, 4, and 5 are listed, the following ranges, 1 - 3, 1 - 4, 1 - 5, 2 - 3, 2 - 4, and 2 - 5 can all be expected. In this application, unless otherwise explained, the numerical range "a - b" represents an abbreviated expression of any combination of real numbers from a to b, and both a and b are real numbers. For example, the numerical range "0 - 5" represents all real numbers between "0 - 5" listed in this specification, and "0 - 5" is just an abbreviated expression of the combination of these numerical values. Also, if a certain parameter indicates an integer ≧2, it is equivalent to disclosing that the parameter is an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0032] Unless otherwise specified, all embodiments and preferred embodiments of this application can be combined with each other to form new technical solutions.

[0033] Unless otherwise specified, all technical features and preferred technical features of this application can be combined with each other to form new technical solutions.

[0034] Unless otherwise specified, the "comprising" and "including" mentioned in this application indicate that they may be either non - limiting or limiting. For example, the above "comprising" and "including" can further comprise or include other components not listed, or can comprise or include only the listed components.

[0035] Unless otherwise specified, the term "or" in this application is inclusive. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, any of the following conditions where A is true (or exists) and B is false (or does not exist), A is false (or does not exist) but B is true (or exists), or both A and B are true (or exist) satisfies the condition "A or B".

[0036] Spinel-type lithium nickel manganate material The condition satisfied by the XRD spectrum of the spinel-type lithium nickel manganate material of this application is 0 < (A(43.7°) / A(18.8°)) 1 / 2 ≦ 0.2, and preferably, the satisfied condition is 0 < (A(43.7°) / A(18.8°)) 1 / 2 ≦ 0.1, where A(43.7°) represents the peak area of the diffraction peak that appears near 43.7° in the XRD spectrum, and A(18.8°) represents the peak area of the diffraction peak that appears near 18.8° in the XRD spectrum.

[0037] As shown in FIGS. 1a, 1b, and 1c, the spinel-type lithium nickel manganate material of the present invention has a diffraction peak near 43.7° and a diffraction peak near 18.8°. Thereby, the peak area of the diffraction peak that appears near 43.7° and the peak area of the diffraction peak that appears near 18.8° are obtained. Furthermore, (A(43.7°) / A(18.8°)) of the spinel-type lithium nickel manganate material of the present invention 1 / 2 is calculated.

[0038] When heating spinel-type lithium nickel manganate (LiNi 0.5 Mn 1.5 O4) to a certain temperature or higher, LiNi 0.5 Mn 1.5 O4 loses oxygen and disproportionates into spinel and Li x Ni 1-x O, and the reaction is LiNi 0.5 Mn 1.5 O4 → αLix Ni 1-x O + βLiNi 0.5+y Mn 1.5 O4 + γO2, and Li x Ni 1-x O belongs to the rock salt phase. In the XRD spectrum, 2θ = 37.6, and there is a one-segment peak expression at 43.7° and 63.5°. As can be seen from the chemical formula, the more the rock salt phase, the more oxygen deficiency, and thus the larger the oxygen defect. Therefore, in the XRD spectrum, the diffraction peak expressions at 2θ = 37.6°, 43.7°, and 63.5° are shown as the content of oxygen defects. Since the diffraction peak intensities at 37.6° and 63.5° are extremely low, the oxygen defect content is defined at 43.7°. Also, the reference peak is defined at 18.8°.

[0039] Also, the chemical formula of the spinel-type lithium nickel manganate material of the present application is Li x (Ni 0.5 Mn 1.5 ) n M m O4, where M is one or more elements selected from W, P, B, Nb, Mo, and Ta. As stoichiometric numbers, n + m = 1, x = 0.95 - 1.1, and m = 0.001 - 0.015.

[0040] By using one or more elements selected from W, P, B, Nb, Mo, and Ta as doping elements, the synthesis temperature is reduced, and the above reaction is decreased, thereby reducing its oxygen defects. In the above chemical formula, by controlling an appropriate doping amount, if the doping amount is too low, the effect is low, and if the doping amount is too high, it will affect the capacity of the spinel-type lithium nickel manganate material.

[0041] The doping of element M effectively affects the particle morphology, so that the perfect octahedral corners are blunt. As shown in FIGS. 2a and 2b, it is shown that the spinel-type lithium nickel manganate material of the present invention is in the form of a single crystal and an octahedron with blunt corners.

[0042] Furthermore, the average particle size Dv50 of the volume distribution of the spinel-type lithium nickel manganate material of the present application is 5 μm to 15 μm, preferably 5 μm to 10 μm. The size of Dv50 mainly affects the contact surface between the material and the electrolyte, thus affecting the side reaction between the material and the electrolyte. However, the size of Dv50 is affected by the primary sintering temperature and the secondary sintering temperature. When the temperature rises, DV50 increases. Therefore, a large Dv50 needs to be synthesized at a high temperature. However, when the temperature rises, its oxygen defects also increase. Therefore, Dv50 should not be too large. If Dv50 is too small, the side reaction will increase and the electrical performance will deteriorate.

[0043] Furthermore, the interparticle distance (Dv90 - Dv10) / Dv50 of the volume distribution of the particles of the spinel-type lithium nickel manganate material is 1.0 or less. The interparticle distance (Dv90 - Dv10) / Dv50 of the volume distribution of the particles indicates the difference in size between each particle in the material. The smaller the difference, the smaller the value. Also, this value mainly affects the side reaction between the material and the electrolyte.

[0044] Furthermore, the BET of the nickel manganese spinel material is 0.3 m 2 / g to 1.0 m 2 / g, preferably 0.3 m 2 / g to 0.5 m 2 / g. BET mainly affects the capacity display and side reaction of the spinel-type lithium nickel manganate material. A large BET provides a high capacity, but the side reactions that occur increase. Therefore, BET should not be too large or too small. Furthermore, BET also affects the coating of the spinel-type lithium nickel manganate material.

[0045] Manufacturing method of spinel-type lithium nickel manganate material The manufacturing method of the present invention is as follows: S1: putting a lithium salt, a nickel manganese hydroxide precursor, and an M-containing compound into a mixer and mixing them to obtain a mixture; The mixture obtained in S1 is heated in an oxygen-enriched atmosphere to perform primary sintering. After the primary sintering is completed, it is naturally cooled to room temperature, and then ball milling is performed to obtain powder in S2. The powder obtained in S2 is heated again in an oxygen-enriched atmosphere to perform secondary sintering. After the secondary sintering is completed, it is kept warm and then naturally cooled to room temperature, and then ball milling is performed to obtain a spinel-type lithium nickel manganate material in S3. It includes S3.

[0046] The spinel-type lithium nickel manganate material of the invention obtained by the above manufacturing method has few oxygen defects, side reactions and Mn elution, and has excellent comprehensive electrochemical performance.

[0047] In step S1 of the manufacturing method of the present invention, regarding the mixing ratio of the lithium salt and nickel manganese hydroxide, the Li / (Ni+Mn) molar ratio is (0.45~0.55):1, where (Ni+Mn) is the total metal molar number of nickel and manganese, and regarding the doping amount of the M-containing compound, the Li / M molar ratio is 1:(0.001~0.01), preferably, the Li / M molar ratio is 1:(0.003~0.007).

[0048] Examples of the lithium salt include lithium carbonate and lithium hydroxide. Examples of the nickel manganese hydroxide include Ni 0.5 Mn 1.5 (OH)7. Examples of the M-containing compound include M-containing chlorides, M-containing carbonates, M-containing sulfates, etc., that is, chlorides, carbonates, and sulfates of these elements such as W, P, B, Nb, Mo, and Ta.

[0049] Furthermore, by setting the doping amount of the M-containing compound within the above Li / M molar ratio range and setting the mixing ratio of the lithium salt and nickel manganese hydroxide within the above Li / (Ni+Mn) molar ratio range, when the doping element M enters the crystal lattice, it occupies the positions and vacancies of the transition metals, so the elution of the transition metal Mn in the material is effectively reduced, and the stability of the material structure is enhanced. The two are in a positive correlation, but if the M doping amount is too much, it will greatly affect the electrical performance of the material, and if it is too little, the effect will not appear.

[0050] At the same time, since the selected doping element can effectively increase the growth of primary particles, the material can complete secondary sintering at a low temperature, and the low secondary sintering temperature can effectively reduce the presence of oxygen defects.

[0051] In step S1 of the manufacturing method of the present invention, the mixer can use a mixer commonly used in this field. Specifically, a Coulter mixer, a high mixer, or an inclined mixer can be mentioned.

[0052] In some embodiments, in steps S2 and S3, the heating rate during sintering is 5 °C / min or less, preferably 3 °C / min or less. By controlling the heating rate, each particle is heated more uniformly during the growth process, whereby the interparticle distance (Dv90 - Dv10) / Dv50 of the particle volume distribution is smaller, and Dv50 is mainly related to the doping element and the initial firing temperature of the primary sintering.

[0053] In some embodiments, in step S2, the primary sintering temperature is 500 °C to 1200 °C, preferably 600 °C to 1200 °C, and in step S3, the secondary sintering temperature is 400 °C to 700 °C, preferably 500 °C to 700 °C. Here, the primary sintering in step S2 is the crystallization process of the spinel-type lithium nickel manganate material. The form, Dv50, and electrical performance of the spinel-type lithium nickel manganate material are basically shaped in step S2. However, if the temperature is high during the primary sintering process, the oxygen defects will increase. Furthermore, the secondary sintering in step S3 is the annealing process of the spinel-type lithium nickel manganate material, which can compensate for the oxygen defects caused by the primary sintering process in step S2 and further improve the performance of the spinel-type lithium nickel manganate material.

[0054] In some embodiments, in steps S2 and S3, as an oxygen-enriched atmosphere, the oxygen content is greater than 60%, preferably 80% - 100%. Since the oxygen-enrichment conditions affect the oxygen defect content of the material, it is necessary to control the oxygen content within the above range.

[0055] In some embodiments, in steps S2 and S3, the pressure in the sintering furnace is 0.02 MPa - 0.08 MPa relative to atmospheric pressure, preferably 0.02 MPa - 0.04 MPa. If the pressure in the furnace is too high or too low, a large number of small particles will be generated in the material, resulting in a decrease in Dv50, an increase in the diameter interval distance (Dv90 - Dv10) / Dv50 of the particle volume distribution, and an impact on the air flow exchange, leading to an increase in the oxygen defect content.

[0056] In some embodiments, in step S3, the heat preservation time is 5 h - 40 h, preferably 15 h - 30 h. The secondary sintering temperature is related to the heat preservation time. When secondary sintering is performed within the range of step S3, the oxygen defects and the Mn 3+ content of the spinel-type lithium nickel manganate material can be effectively reduced. Since Mn 3+ undergoes a disproportionation reaction, resulting in the elution of Mn in the spinel-type lithium nickel manganate material, the decrease in the Mn 3+ content can reduce the elution of Mn.

[0057] Within the range that does not affect the effects of the present invention, in step S3, organic substances and / or inorganic substances commonly used in this field can also be added for coating, reducing the occurrence of side reactions between the spinel-type lithium nickel manganate material and the electrolyte when the spinel-type lithium nickel manganate material is used in a secondary battery.

[0058] Also, the secondary battery, battery module, battery pack, and electrical device of the present application will be described with appropriate reference to the drawings.

[0059] Secondary battery

[0060] In one embodiment of the present application, a secondary battery is provided.

[0061] In general, a secondary battery includes a positive electrode sheet, a negative electrode sheet, an electrolyte, and a separator. During the charge and discharge process of the battery, active ions adsorb and desorb reciprocally between the positive electrode sheet and the negative electrode sheet. The electrolyte plays a role in conducting ions between the positive electrode sheet and the negative electrode sheet. The separator is provided between the positive electrode sheet and the negative electrode sheet, mainly playing a role in preventing short - circuit between the positive and negative electrodes, and at the same time, allowing ions to pass through.

[0062] [Positive electrode sheet] The positive electrode sheet includes a positive electrode current collector and a positive electrode film layer provided on at least one surface of the positive electrode current collector, and the positive electrode film layer includes a spinel - type lithium nickel manganate material according to the first aspect of the present application as a positive electrode active material.

[0063] For example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode film layer is provided on either one or both of the two opposing surfaces of the positive electrode current collector.

[0064] In some embodiments, a metal foil sheet or a composite current collector can be adopted for the positive electrode current collector. For example, as the metal foil sheet, aluminum foil can be used. The composite current collector includes a polymer material base layer and a metal layer formed on at least one surface of the polymer material base layer. The composite current collector can be formed by forming a metal material (such as aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material base (such as a base of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0065] In some embodiments, in addition to the spinel-type lithium nickel manganate material according to the first aspect of the present application, other cathode active materials may be included. As the cathode active materials, cathode active materials for batteries well-known in the art can be adopted. By way of example, the cathode active material can include at least one of materials such as olivine-structured lithium-containing phosphates, lithium transition metal oxides, and their respective modified compounds. The present application is not limited to these materials, and conventional materials that can be used as other battery cathode active materials may also be used. These cathode active materials may be used alone or in combination of two or more. Examples of lithium transition metal oxides include lithium cobalt oxide (e.g., LiCoO2), lithium nickel oxide (e.g., LiNiO2), lithium manganate (e.g., LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganate, lithium nickel cobalt manganate (e.g., LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (which can also be abbreviated as NCM 333 ), LiNi 0.5 Co 0.2 Mn 0.3 O2 (which can also be abbreviated as NCM 523 ), LiNi 0.5 Co 0.25 Mn 0.25 O2 (which can also be abbreviated as NCM 211 ), LiNi 0.6 Co 0.2 Mn 0.2 O2 (which can also be abbreviated as NCM 622 ), LiNi 0.8 Co 0.1 Mn 0.1 O2 (which can also be abbreviated as NCM 811 ), lithium nickel cobalt aluminum oxide (e.g., LiNi 0.85 Co 0.15 Al 0.05It includes, but is not limited to, at least one of O2) and its modified compounds, etc. Examples of lithium-containing phosphates with olivine structure include lithium iron phosphate (for example, LiFePO4 (which can also be abbreviated as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (for example, LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and at least one of a composite material of lithium manganese iron phosphate and carbon, but is not limited to these.

[0066] In some embodiments, the positive electrode film layer preferably further includes a binder. As an example, the binder can include at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and fluorine-containing acrylate resin.

[0067] In some embodiments, the positive electrode film layer preferably further includes a conductive agent. As an example, the conductive agent can include at least one of superconducting carbon, acetylene black, carbon black, ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0068] In some embodiments, the positive electrode sheet can be manufactured as follows. The above components for manufacturing the positive electrode sheet, such as the positive electrode active material, conductive agent, binder, and any other components, are dispersed in a solvent (for example, N-methylpyrrolidone) to form a positive electrode slurry. After coating the positive electrode slurry on the positive electrode current collector and undergoing processes such as drying and cold pressing, the positive electrode sheet can be obtained.

[0069] [Negative electrode sheet] The negative electrode sheet includes a negative electrode current collector and a negative electrode film layer provided on at least one surface of the negative electrode current collector, and the negative electrode film layer includes a negative electrode active material.

[0070] As an example, the negative electrode current collector has two surfaces facing each other in its thickness direction, and the negative electrode film layer is provided on one or both of the two opposing surfaces of the negative electrode current collector.

[0071] In some embodiments, a metal foil sheet or a composite current collector can be employed for the negative electrode current collector. For example, a copper foil can be used as the metal foil sheet. The composite current collector can include a polymer material base layer and a metal layer formed on at least one surface of the polymer material base layer. The composite current collector can be formed by forming a metal material (such as copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material base (such as a base of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0072] In some embodiments, a negative electrode active material well-known in the art for use in batteries can be employed for the negative electrode active material. As an example, the negative electrode active material can include at least one of materials such as artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate. The silicon-based material can be selected from at least one of silicon alone, silicon oxide, silicon-carbon composite, silicon-nitrogen composite, and silicon alloy. The tin-based material can be selected from at least one of tin alone, stannic acid compound, and tin alloy. However, the present application is not limited to these materials, and other conventional materials that can be used as the negative electrode active material of the battery may also be used. These negative electrode active materials can be used alone or in combination of two or more.

[0073] In some embodiments, the negative electrode film layer preferably further contains a binder. The binder can be selected from at least one of styrene butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA), and carboxymethyl chitosan (CMCS).

[0074] In some embodiments, the negative electrode film layer preferably further contains a conductive agent. The conductive agent can be selected from at least one of superconducting carbon, acetylene black, carbon black, ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0075] In some embodiments, the negative electrode film layer preferably further contains other auxiliary agents such as a thickener (for example, sodium carboxymethyl cellulose (CMC-Na)).

[0076] In some embodiments, the negative electrode sheet can be manufactured as follows. The above components for manufacturing the negative electrode sheet, such as the negative electrode active material, the conductive agent, the binder, and any other components, are dispersed in a solvent (for example, deionized water) to form a negative electrode slurry. The negative electrode slurry is coated on the negative electrode current collector, and after processes such as drying and cold pressing, the negative electrode sheet can be obtained.

[0077] [Electrolyte] The electrolyte plays a role in conducting ions between the positive electrode sheet and the negative electrode sheet. The present application is not specifically limited to the type of electrolyte and can be selected as needed. For example, the electrolyte can be liquid, gelled, or all-solid.

[0078] In some embodiments, the electrolyte uses an electrolytic solution. The electrolytic solution contains an electrolyte salt and a solvent.

[0079] In some embodiments, the electrolyte salt can be selected from one or more of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluoroborate oxalate, lithium bis(oxalate)borate, lithium difluoro bis(oxalate)phosphate, and lithium tetrafluoroborate phosphate.

[0080] In some embodiments, the solvent can be selected from one or more of ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethylene propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4 - butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone.

[0081] In some embodiments, it is preferable that the electrolyte further contains an additive. For example, the additive can include a negative electrode film - forming additive and a positive electrode film - forming additive, and may also include additives that can improve certain performances of the battery, such as additives for improving the overcharge performance of the battery, additives for improving the high - temperature or low - temperature performance of the battery.

[0082] [Separator] In some embodiments, the secondary battery further includes a separator. The present application is not particularly limited to the type of the separator, and any known porous - structure separator having good chemical stability and mechanical stability can be selected.

[0083] In some embodiments, the material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator is not particularly limited and may be a single-layer thin film or a multi-layer composite thin film. When the separator is a multi-layer composite thin film, the material of each layer is not particularly limited and may be the same or different.

[0084] In some embodiments, the positive electrode sheet, the negative electrode sheet, and the separator can be used to manufacture an electrode assembly by a winding process or a lamination process.

[0085] In some embodiments, the secondary battery may include an exterior. The exterior can be used to seal the above electrode assembly and electrolyte.

[0086] In some embodiments, the exterior of the secondary battery may be a hard shell such as a hard plastic shell, an aluminum shell, or a steel shell. The exterior of the secondary battery may be a soft bag such as a pouch soft bag. The material of the soft bag may be plastic, and examples of the plastic include polypropylene, polybutylene terephthalate, and polybutylene succinate.

[0087] The present application is not particularly limited to the shape of the secondary battery, and it may be cylindrical, rectangular, or any other arbitrary shape. For example, FIG. 3 is an example of a rectangular-structured secondary battery 5.

[0088] In some embodiments, referring to FIG. 4, the exterior can include a housing 51 and a cover plate 53. The housing 51 can include a bottom plate and side plates connected to the bottom plate, and the bottom plate and the side plates can surround to form a storage chamber. The housing 51 has an opening communicating with the storage chamber, and the cover plate 53 can be covered on the opening to close the storage chamber. The positive electrode sheet, the negative electrode sheet, and the separator can form an electrode assembly 52 by a winding process or a lamination process. The electrode assembly 52 is sealed in the storage chamber. The electrolyte infiltrates into the electrode assembly 52. The number of electrode assemblies 52 included in the secondary battery 5 can be one or more, and those skilled in the art can select according to specific actual requirements.

[0089] Battery module In some embodiments, the secondary battery can be assembled as a battery module, and the number of secondary batteries included in the battery module can be one or more. Regarding the specific number, those skilled in the art can select according to the application and capacity of the battery module.

[0090] FIG. 5 is an example of the battery module 4. Referring to FIG. 5, in the battery module 4, a plurality of secondary batteries 5 are sequentially arranged and installed along the length direction of the battery module 4. Of course, they can be distributed in any other manner. Further, the plurality of secondary batteries 5 can be fixed with fasteners.

[0091] Preferably, the battery module 4 may further include an external case having a storage space, and the plurality of secondary batteries 5 are stored in the storage space.

[0092] Battery pack In some embodiments, the above battery module can also be further assembled as a battery pack, and the number of battery modules included in the battery pack can be one or more. Regarding the specific number, those skilled in the art can select according to the application and capacity of the battery module.

[0093] Figs. 6 and 7 are an example of the battery pack 1. Referring to Figs. 6 and 7, the battery pack 1 may include a battery box and a plurality of battery modules 4 provided in the battery box. The battery box includes an upper box body 2 and a lower box body 3. The upper box body 2 can be covered by the lower box body 3 to form a closed space for housing the battery modules 4. The plurality of battery modules 4 can be distributed in the battery box in any manner.

[0094] Electrical device In addition, the present application further provides an electrical device, which includes at least one of the secondary battery, battery module, or battery pack provided by the present application. The secondary battery, battery module, or battery pack can be used as the power source of the electrical device and can also be used as the energy storage unit of the electrical device. Examples of the electrical device include, but are not limited to, mobile devices (such as mobile phones, notebook computers, etc.), electric vehicles (such as pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), trains, ships, satellites, energy storage systems, etc.

[0095] As the electrical device, a secondary battery, battery module, or battery pack can be selected according to the usage requirements.

[0096] Fig. 8 is an example of an electrical device. The electrical device is a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, etc. In order to meet the requirements of high output and high energy density of the secondary battery of the electrical device, a battery pack or a battery module can be used.

[0097] As other examples of the device, it may be a mobile phone, a tablet, a notebook computer, etc. The device usually requires thinning and can use a secondary battery as the power source.

[0098] Embodiment The embodiments of the present application will be described below. The embodiments described below are merely illustrative and are only used for interpreting the present application and should not be understood as limiting the present application. When specific technologies or conditions are not indicated in the embodiments, it is necessary to follow the technologies or conditions described in the literature in this field or the product specifications. When the manufacturer of the reagents or equipment used is not indicated, they are conventional products that can be purchased commercially.

[0099] <Example 1> The spinel-type lithium nickel manganate material of Example 1 is manufactured according to the following steps S1 to S3.

[0100] In step S1, lithium carbonate (lithium salt), nickel manganese hydroxide with a particle size of 3.5 μm (nickel manganese hydroxide precursor), and niobium oxide (M-containing compound) are put into an inclined mixer (mixer) and mixed to obtain a mixture. Here, it is ensured that the Li / (Ni + Mn) molar ratio is within the range of 0.53:1, where (Ni + Mn) is the total metal molar number of nickel and manganese, and for the doping amount of Nb, the Li / M molar ratio is 1:0.004.

[0101] In step S2, the mixture obtained in step S1 is heated to 1000°C at a heating rate of 1°C / min in an oxygen-enriched atmosphere with an oxygen content of 95% and a furnace pressure of 0.03 Mpa for 30 h of primary sintering. After the primary sintering is completed, it is naturally cooled to room temperature, and then ball milling is performed to obtain a powder.

[0102] In step S3, the powder obtained in step S2 is heated to 700°C at a heating rate of 1°C / min in an oxygen-enriched atmosphere with an oxygen content of 95% and a furnace pressure of 0.03 Mpa for 10 h of secondary sintering. After the secondary sintering is completed, it is held at this temperature for 10 h, then naturally cooled to room temperature, and then ball milling is performed to obtain a spinel-type lithium nickel manganate material.

[0103] It was confirmed that the chemical formula of the spinel-type lithium nickel manganate material is Li(Ni0.5 Mn 1.5 ) 0.996 M 0.004 is O4, and the diffraction peaks that appeared near 43.7° and the diffraction peaks that appeared near 18.8° in the spinel-type lithium nickel manganate material obtained in Example 1 are shown in FIGS. 9a, 9b, and 9c. Accordingly, the peak area of the diffraction peak that appeared near 43.7° and the peak area of the diffraction peak that appeared near 18.8° were obtained, and thereby, (A(43.7°) / A(18.8°)) of the spinel-type lithium nickel manganate material obtained in Example 1 1 / 2 was calculated and is within the scope of the present invention.

[0104] In addition, the specific conditions in the manufacturing process of Example 1, and the specific chemical formula, crystal structure, physicochemical data, and electrical performance of the manufactured spinel-type lithium nickel manganate material are shown in Table 1 and Table 2, respectively.

[0105] <Examples 2 to 12> In Examples 2 to 12, the same manufacturing method as in Example 1 was used, and the difference is that the specific conditions in the manufacturing process were changed respectively. Specifically, as shown in Table 1, and the specific chemical formula, crystal structure, physicochemical data, electrical performance, etc. of the manufactured spinel-type lithium nickel manganate material are also shown in Table 1 and Table 2, respectively.

[0106] <Comparative Examples 1 to 12> In Comparative Examples 1 to 12, the same manufacturing method as in Example 1 was used, and the difference is that the specific conditions in the manufacturing process were changed respectively. Specifically, as shown in Table 1, and the specific chemical formula, crystal structure, physicochemical data, electrical performance, etc. of the manufactured spinel-type lithium nickel manganate material are also shown in Table 1 and Table 2, respectively.

[0107] Moreover, for the spinel-type lithium nickel manganate material obtained in Comparative Example 1, the diffraction peaks appearing around 43.7° and the diffraction peaks appearing around 18.8° are shown in FIGS. 10a, 10b, and 10c. Thus, by obtaining the peak area of the diffraction peak appearing around 43.7° and the peak area of the diffraction peak appearing around 18.8°, (A(43.7°) / A(18.8°)) of the spinel-type lithium nickel manganate material obtained in Comparative Example 1 1 / 2 is calculated and does not fall within the scope of the present invention.

[0108] Hereinafter, the test processes of the related parameters regarding Examples 1 to 12 and Comparative Examples 1 to 12 of the present application will be described in detail.

[0109] I. XRD Spectrum of Spinel-Type Lithium Nickel Manganate Material

[0110] Equipment model: Bruker X-ray diffractometer D8 DISCOVER, reference standard procedure: General rules for X-ray diffraction analysis method of JIS / K0131-1996.

[0111] Specific procedures: (1) Sample preparation: Preparation of a sample with a sample groove having a depth of 1 mm and a diameter of 25 mm by the flat sample preparation method, (2) Test: Starting angle 15°, ending angle 70°, step size 0.01671°, time per step 0.24 s, (3) Fixing of core parameters: Voltage: 40 KV, current: 40 mA, anti-scattering slit: 1 mm. According to the above specific procedures (1) to (3), the spinel-type lithium nickel manganate materials obtained in Examples 1 to 12 and Comparative Examples 1 to 12 are measured.

[0112] Next, the data is processed with X′Pert HighScore Plus to obtain A(43.7°) (that is, the peak area of the diffraction peak appearing around 43.7° in the XRD spectrum) and A(18.8°) (that is, the peak area of the diffraction peak appearing around 18.8° in the XRD spectrum), and thereby, (A(43.7°) / A(18.8°)) 1 / 2 can be calculated.

[0113] II. Test of Median Diameter (D50)

[0114] Equipment Model: Malvern 3000 (MasterSizer 3000) Laser Particle Size Analyzer, Reference Standard Procedure: GB / T 19077-2016 / ISO 13320:2009, Specific Test Procedure: Take an appropriate amount of the sample to be measured (the sample concentration should ensure a light shielding rate of 8-12%), add 20 ml of deionized water, and at the same time perform external ultrasonic vibration for 5 min (53 KHz / 120 W) to ensure that the sample is completely dispersed. Then, measure the spinel-type lithium nickel manganate materials obtained in Examples 1-12 and Comparative Examples 1-12 according to the standard of GB / T 19077-2016 / ISO 13320:2009. The measurement results are shown in Table 2.

[0115] III. Calculation of the Distance between Particle Volume Distribution Diameters (Dv90 - Dv10) / Dv50) When testing the above median diameter (D50), obtain Dv90 and Dv10 simultaneously, and then calculate this value according to the formula (Dv90 - Dv10) / Dv50. The measurement results are shown in Table 2.

[0116] IV. Test of the Particle Morphology of Spinel-Type Lithium Nickel Manganate Materials Test the spinel-type lithium nickel manganate materials obtained in Examples 1-12 and Comparative Examples 1-12 respectively with a ZEISS sigma 300 scanning electron microscope, and then refer to the standard JY / T010-1996 for testing and observe the sample morphology. The measurement results are shown in Table 2.

[0117] V. BET Surface Area Test Take about 7 g of the sample from the spinel-type lithium nickel manganate materials obtained in Examples 1-12 and Comparative Examples 1-12, put it into a long tube with a 9 cc ball, degas it at 150 °C for 15 min, and then put it into the host machine for testing to obtain BET data with an American Micromeritics fully automatic specific surface area and porosity analyzer Gemini VII 2390. The measurement results are shown in Table 2.

[0118] VI. Battery Performance Test For the spinel-type lithium nickel manganate materials obtained in Examples 1 to 12 and Comparative Examples 1 to 12, the following battery performance tests are carried out. The test results are shown in Table 2.

[0119] Assembly of Button-Type Half-Cell The spinel-type lithium nickel manganate materials produced in Examples 1 to 12 and Comparative Examples 1 to 12 are mixed with conductive carbon black and PVDF in a weight ratio of 90:5:5 as the positive electrode active material, an appropriate amount of N-methylpyrrolidinone is added, and the mixture is stirred uniformly to obtain a positive electrode slurry. The positive electrode slurry is coated on an aluminum foil, dried after coating, and a positive electrode sheet is obtained. The loading amount of the positive electrode active material in the positive electrode sheet is 0.015 g / cm 2 is

[0120] A mixed solution containing 1 mol / L of LiPF6, such as carbonate ester and phosphate ester, is used as the electrolyte.

[0121] A polypropylene film (Φ16 mm) with a thickness of 12 μm is used as the separator. A lithium sheet, a separator, and a positive electrode sheet are sequentially placed, and the separator is positioned between the metal lithium sheet and the composite negative electrode sheet to play a role in isolation. The electrolyte is injected, assembled into a CR2030 button-type battery, and left standing for 24 h to obtain a button-type half-cell.

[0122] (1) Discharge Capacity of Button-Type Half-Cell At 25 °C, the button-type half-cells manufactured using the spinel-type lithium nickel manganate materials produced in Examples 1 to 12 and Comparative Examples 1 to 12 as the positive electrode active material are charged at a constant current of 0.1 C until the voltage reaches 4.95 V, then charged at a constant voltage of 4.95 V until the current reaches 0.05 C, left standing for 5 min, and then discharged at a constant current of 0.1 C until the voltage reaches 3.5 V.

[0123] Fabrication of Graphite Soft Pack Battery The spinel-type lithium nickel manganate materials produced in Examples 1 to 12 and Comparative Examples 1 to 12 were mixed with conductive carbon black and PVDF at a weight ratio of 96:2.5:1.5 as the positive electrode active material, an appropriate amount of N-methylpyrrolidinone was added, and they were uniformly stirred to obtain a positive electrode slurry. The positive electrode slurry was applied to an aluminum foil, dried after application, and a positive electrode sheet was obtained. The loading amount of the positive electrode active material in the positive electrode sheet is 0.02 g / cm 2 is.

[0124] Graphite, conductive carbon black, and carboxymethyl cellulose were mixed at a weight ratio of 96:1:3, an appropriate amount of pure water was added, and they were uniformly stirred to obtain a negative electrode slurry. The negative electrode slurry was applied to a copper foil, dried after application, and a negative electrode sheet was obtained. The loading amount of graphite in the negative electrode sheet is 0.008 g / cm 2 is.

[0125] A mixed solution containing 1 mol / L of LiPF6, such as carbonic acid ester and phosphoric acid ester, was used as the electrolyte.

[0126] Using a 12-μm-thick polypropylene film (Φ16 mm) as the separator, the above-prepared positive electrode sheet, separator, and negative electrode sheet were sequentially placed, with the separator positioned between the positive and negative electrode sheets to play a role of isolation, wound and formed, and packaged with an aluminum foil pack. After injecting the electrolyte and sealing, it was formed to obtain the capacity, and a graphite soft pack battery was manufactured.

[0127] (2) 25°C cycle 300 cls / % of the soft pack The graphite soft pack batteries manufactured using the spinel-type lithium nickel manganate materials produced in Examples 1 to 12 and Comparative Examples 1 to 12 as the positive electrode active material were used as the test objects.

[0128] At 25°C, the graphite soft-pack battery is charged at a constant current of 0.3C until the voltage reaches 4.9V, then charged at a constant voltage of 4.9V until the current reaches 0.05C. After standing for 5 minutes, the graphite soft-pack battery is discharged at a constant current of 0.33C until the voltage reaches 3.5V. This is one charge-discharge cycle process, and this discharge capacity is the discharge capacity of the first cycle. After performing a charge-discharge test of 300 cycles on the entire battery according to the above method, the remaining reversible discharge capacity is recorded.

[0129] (3) 45°C cycle of soft pack 200 cls / % The graphite soft-pack batteries manufactured using the spinel-type lithium nickel manganate materials produced in each of Examples 1 to 12 and Comparative Examples 1 to 12 as the positive electrode active material are the test objects.

[0130] At 45°C, the graphite soft-pack battery is charged at a constant current of 0.3C until the voltage reaches 4.9V, then charged at a constant voltage of 4.9V until the current reaches 0.05C. After standing for 5 minutes, the graphite soft-pack battery is discharged at a constant current of 0.33C until the voltage reaches 3.5V. This is one charge-discharge cycle process, and this discharge capacity is the discharge capacity of the first cycle. After performing a charge-discharge test of 200 cycles on the entire battery according to the above method, the remaining reversible discharge capacity is recorded.

[0131] (4) 45°C full charge storage of soft pack (d) The graphite soft-pack batteries manufactured using the spinel-type lithium nickel manganate materials produced in each of Examples 1 to 12 and Comparative Examples 1 to 12 as the positive electrode active material are the test objects.

[0132] At 25°C, the graphite soft-pack battery is charged at a constant current of 0.3C until the voltage reaches 4.9V, and then charged at a constant voltage of 4.9V until the current reaches 0.05C. Next, the soft-pack battery is left at 45°C, and after performing a discharge process every 5 days, it is fully charged again and continuously stored in an environment of 45°C. The discharge capacity value is extracted until the discharge capacity decays to 80% of the initial value, and the storage ends. The total time of storage at 45°C after full charge is the high-temperature full-charge storage time. The charge-discharge process is the same as the charge-discharge process of the full battery capacity test in (5).

[0133] (5) Full battery capacity Graphite soft-pack batteries manufactured using spinel-type lithium nickel manganate materials produced in each of Examples 1 to 12 and Comparative Examples 1 to 12 as the positive electrode active material are the test subjects.

[0134] At 25°C, the graphite soft-pack battery is charged at a constant current of 0.3C until the voltage reaches 4.9V, and then charged at a constant voltage of 4.9V until the current reaches 0.05C. After standing for 5 minutes, the graphite soft-pack battery is discharged at a constant current of 0.33C until the voltage reaches 3.5V, and this discharge capacity is the full battery capacity of the soft-pack.

[0135]

Table 1

[0136]

Table 2

[0137] It can be seen from Table 1 and Table 2 as follows.

[0138] As can be seen from Examples 1, 2, 3 and Comparative Examples 1, 2, if the doping amount is too large, it will have a great impact on the full battery capacity and button-type battery capacity of the material, and will also have a certain impact on its cycle. If the doping amount is too small, it will have a great impact on its structural stability, and the effect of passivating the octahedron will decrease, side reactions will increase, and it will be reflected in the decline of its storage and cycle performance.

[0139] As can be seen from Examples 1 and 4 and Comparative Examples 1 and 3, if the heating rate is too high, the consistency of the particle size is low, that is, the (Dv90 - Dv10) / Dv50 value becomes large, the side reaction between the material and the electrolyte increases, and if the heating rate is too high, the oxygen defect content increases during the particle growth process, and its structural stability deteriorates, thereby deteriorating the storage and cycle performance.

[0140] As can be seen from Examples 1 and 5 and Comparative Examples 1 and 4, the oxygen content mainly affects the oxygen defect content of the material. Since a low oxygen content causes a large oxygen defect content, it affects its storage and cycle performance.

[0141] As can be seen from Examples 1, 6, and 7 and Comparative Examples 1, 5, and 6, the pressure in the furnace mainly affects the (Dv90 - Dv10) / Dv50 value and the BET size of the material. If the pressure in the furnace is too high or too low, the small particles increase and the (Dv90 - Dv10) / Dv50 and BET are too large, thereby increasing the side reaction of the material.

[0142] As can be seen from Examples 1, 8, and 9 and Comparative Examples 1, 7, and 8, the secondary sintering process is a process of compensating for oxygen defects. If the secondary sintering temperature and the annealing temperature are too low, the effect is extremely low. If the secondary sintering temperature is too high, the oxygen defects increase.

[0143] As can be seen from Examples 1, 10, and 11 and Comparative Examples 1, 9, and 10, if the heat preservation time after secondary sintering is too short, similarly, there is no effect of compensating for oxygen defects. Even if the heat preservation time is extended outside the range, the oxygen defects are not further reduced, but instead the process cost increases.

[0144] As can be seen from Examples 1 and 12 and Comparative Examples 1, 11, and 12, except for the doping elements within the range, other elements cannot exert effects such as octahedral passivation and promotion of the growth of primary particles, cannot enhance the structural stability of the material, and cannot exert the effect of reducing the oxygen defect content, side reactions, and elution of transition metal Mn.

[0145] Furthermore, as can be seen from the comparison between FIGS. 11a, 11b and FIGS. 12a, 12b, FIGS. 11a, 11b are lithium nickel manganese oxide materials doped with Zr of Comparative Example 11, and FIGS. 12a, 12b are lithium nickel manganese oxide materials not doped with other elements. Even if other elements are doped into the lithium nickel manganese oxide material, since the doped elements are other elements (for example, Zr) outside the scope of the present invention, the effects such as octahedral passivation and promotion of primary particle growth are still not exerted.

[0146] As described above, as can be seen from the comparison between Examples 1 to 12 and Comparative Examples 1 to 12, the oxygen defect content of the spinel-type lithium nickel manganese oxide material of the present application is low, the stability of the crystal structure is strong, the rock salt phase content is low, and furthermore, the secondary battery using the spinel-type lithium nickel manganese oxide material has a high energy density and a long cycle life, and the gas generation problem during the cycle is effectively suppressed.

[0147] It should be noted that the present application is not limited to the above embodiments. The above embodiments are merely examples, and any embodiments having substantially the same configuration as the technical idea within the scope of the technical solution of the present application and exhibiting the same operational effects are included in the technical scope of the present application. In addition, within the scope not departing from the gist of the present application, various modifications that those skilled in the art can conceive, and other forms constructed by combining some components of the embodiments are also included in the scope of the present application.

Explanation of Reference Numerals

[0148] 1 Battery Pack 2 Upper Box Body 3 Lower Box Body 4 Battery Module 5 Secondary Battery 51 Housing 52 Electrode Assembly 53 Top Cover Assembly

Claims

1. A spinel-type lithium nickel manganate material, The condition satisfied in the XRD spectrum of the spinel-type lithium nickel manganate material is 0 < (A(43.7°) / A(18.8°)) １／２ ≤ 0.2, where A(43.7°) represents the peak area of the diffraction peak appearing near 43.7° in the XRD spectrum, and A(18.8°) represents the peak area of the diffraction peak appearing near 18.8° in the XRD spectrum, The chemical formula of the spinel-type lithium nickel manganate material is Li ｘ (Ni ０．５ Mn １．５ ) ｎ M ｍ O ４ and provided that M is a W or Nb element, stoichiometrically, n + m = 1, x = 0.95 to 1.1, and m = 0.001 to 0.015, A spinel-type lithium nickel manganate material in which the distance between particle size diameters (Dv90 - Dv10) / Dv50 of the volume distribution of the spinel-type lithium nickel manganate material is 1.0 or less. A spinel-type lithium nickel manganate material.

2. 0 < (A(43.7°) / A(18.8°)) １／２ The spinel-type lithium nickel manganate material according to claim 1, wherein 0 < (A(43.7°) / A(18.8°)) ≤ 0.

1.

3. The spinel-type lithium nickel manganate material according to claim 1, wherein the spinel-type lithium nickel manganate material is a single crystal and an octahedron with rounded corners.

4. The spinel-type lithium nickel manganate material according to claim 1, wherein the average particle size Dv50 of the volume distribution of the spinel-type lithium nickel manganate material is 5 μm to 15 μm.

5. The spinel-type lithium nickel manganate material according to claim 4, wherein the average particle size Dv50 of the volume distribution of the spinel-type lithium nickel manganate material is 5 μm to 10 μm.

6. The BET of the nickel manganese spinel material is 0.3 m ２ / g to 1.0 m ２ / g, and the lithium nickel manganese spinel material according to Claim 1.

7. The BET of the nickel manganese spinel material is 0.3 m ２ / g to 0.5 m ２ / g. The lithium nickel manganese spinel material according to claim 6

8. A method for manufacturing a spinel-type lithium nickel manganate material according to any one of claims 1 to 7, wherein the manufacturing method comprises: Step S1: putting a lithium salt, a nickel manganese hydroxide precursor, and an M-containing compound into a mixer and mixing to obtain a mixture; Step S2: heating the mixture obtained in step S1 in an oxygen-enriched atmosphere to perform primary sintering, and after the primary sintering is completed, naturally cooling to room temperature, and then performing ball milling to obtain a powder; Step S3: heating the powder obtained in step S2 again in an oxygen-enriched atmosphere to perform secondary sintering, holding the temperature after the secondary sintering is completed, and then naturally cooling to room temperature, and then performing ball milling to obtain a spinel-type lithium nickel manganate material.

9. In step S1, regarding the mixing ratio of the lithium salt and the nickel manganese hydroxide, the Li / (Ni + Mn) molar ratio is (0.45 to 0.55):1, provided that (Ni + Mn) is the total metal molar number of nickel and manganese. And, regarding the doping amount of the M-containing compound, the method for producing a lithium nickel manganate spinel material according to claim 8, wherein the Li / M molar ratio is 1:(0.001 to 0.01).

10. The method for producing a lithium nickel manganate spinel material according to claim 9, wherein regarding the doping amount of the M-containing compound, the Li / M molar ratio is 1:(0.003 to 0.007).

11. In step S1, the mixer is a Coulter mixer, a high mixer, or an inclined mixer, and the method for producing a lithium nickel manganate spinel material according to claim 8.

12. In steps S2 and S3, the heating rate during primary sintering and secondary sintering is 5 °C / min or less, and the method for producing a lithium nickel manganate spinel material according to claim 8.

13. In steps S2 and S3, the heating rate during primary sintering and secondary sintering is 3 °C / min or less, and the method for producing a lithium nickel manganate spinel material according to claim 12.

14. In steps S2 and S3, as an oxygen-enriched atmosphere, the oxygen content is greater than 60%, and the method for producing a lithium nickel manganate spinel material according to claim 8.

15. In steps S2 and S3, as an oxygen-enriched atmosphere, the oxygen content is 80% to 100%, and the method for producing a lithium nickel manganate spinel material according to claim 14.

16. In steps S2 and S3, the pressure in the sintering furnace is 0.02 MPa to 0.08 MPa with respect to atmospheric pressure, and the method for producing a lithium nickel manganate spinel material according to claim 8.

17. In steps S2 and S3, the pressure in the sintering furnace is 0.02 MPa to 0.04 MPa with respect to atmospheric pressure, and the method for producing a lithium nickel manganate spinel material according to claim 16.

18. In step S2, the primary sintering temperature is 500 °C to 1200 °C, and in step S3, the secondary sintering temperature is 400 °C to 700 °C, and the method for producing a lithium nickel manganate spinel material according to claim 8.

19. In step S2, the primary sintering temperature is 600 °C to 1200 °C, and in step S3, the secondary sintering temperature is 500 °C to 700 °C, and the method for producing a lithium nickel manganate spinel material according to claim 17.

20. The manufacturing method of the spinel-type lithium nickel manganate material according to claim 8, wherein in step S3, the heat preservation time is 5 h to 40 h.

21. The manufacturing method of the spinel-type lithium nickel manganate material according to claim 20, wherein in step S3, the heat preservation time is 15 h to 30 h.

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