Electrode material, positive electrode material for lithium battery, lithium battery, and electric device

Abstract

The application relates to the technical field of batteries, and discloses an electrode material, a positive electrode material for a lithium battery, a lithium battery and a power utilization device. x TM y O 4‑z F z ; wherein 2.5<=x+y<=4, 0<=z<=1, and TM includes one or more redox-active transition metals. The number of cations in the electrode material provided by the application is less than the number of anions, and a long-range disordered and locally ordered composite structure electrode material is further formed. The electrochemical performance of the disordered rock salt material can be significantly improved by the locally ordered unit, the lithium ion transmission can be controlled, and the capacity and rate capability of the obtained electrode material can be improved. Meanwhile, the introduction of the locally ordered unit can also reduce the lithium ion migration barrier, effectively connect the percolation network of the lithium ion migration from an octahedron-tetrahedron-octahedron, and improve the lithium ion migration rate to achieve an effect comparable to that after high-energy ball milling.

Description

Technical Field

[0001] The present application relates to the field of energy storage technology, for example, to an electrode material, a positive electrode material for a lithium battery, a lithium battery, and an electrical device. Background Art

[0002] Continuously improving the performance of cathode materials is a key factor in improving the overall performance of lithium batteries. In related technologies, lithium-rich transition metal oxides (Li x TM y O2) type positive electrode materials and lithium-rich cation disordered rock salt materials were selected due to their high specific energy.

[0003] During implementation, the application of the above two materials has the following problems:

[0004] Structurally ordered lithium-rich transition metal oxides (Li x TM y O2) type positive electrode materials, the structural instability during the cycle causes the material's rate performance to be less than ideal, the voltage attenuation phenomenon is more serious and other problems. x TM y The main factors causing the instability of the structure of O2-type cathode materials are as follows: (1) High-capacity operation triggers the migration of transition metals or lithium ions, which results in structural symmetry changes or phase transitions. x TM y High-capacity operation of O2 is always accompanied by continuous phase evolution, such as the T1 / T2 phase transition from layered phase structure to spinel phase, layered phase structure to rock salt phase, and cubic phase to tetragonal phase in spinel phase structure during high-capacity operation. These complex phase transition processes are the main factors leading to the unsatisfactory cycle stability and rate performance of most high-capacity positive electrodes. (2) During the electrochemical cycle, uneven lithium ion deintercalation and heterogeneous electrochemical reactions often occur in the positive electrode, resulting in structural imbalance at the macro and micro levels, which is specifically manifested as anisotropic volume changes and volume mechanical strain in some materials. This problem is an important cause of mechanical degradation of materials, such as secondary particle rupture. It is this heterogeneous structural dynamics that determines the global generation of nanoscale strain, significantly affecting the structural stability of the material and exacerbating oxygen release. The formation of microcracks in secondary particles has a destructive effect on the performance of such materials. This behavior is coupled with the phase transition involving transition metals in the materials described in (1), exacerbating the problem of poor structural stability. (3) During the cycle, Li x TM y The high specific capacity of O2 is related to the redox reaction of anions (mainly oxygen ions) occurring at a potential higher than 4.45 V. However, the redox reaction of oxygen is irreversible when accompanied by the release of oxygen, which will lead to rapid capacity decay. Studies have found that the oxidation of surface oxygen will cause O2 gas to irreversibly flow from the Lix TM y O2 escapes or reacts violently with the electrolyte, leaving oxygen vacancies in the surface and subsurface regions and generating an interface layer with poor conductivity. These oxygen vacancies promote the migration of transition metals, triggering phase changes that cause voltage decay during extended cycles.

[0005] The application of the lithium-rich cation-disordered rock salt material has the following problems. (1) In the lithium-rich cation-disordered rock salt material, the performance of the material has a strong dependence on the short-range ordered structure of the cation. Studies have shown that the short-range ordered structure is crucial to controlling the lithium ion transport and the capacity and rate capability of the positive electrode of the lithium-rich cation-disordered rock salt material, and the regulation of the short-range ordered structure is still in the initial stage in the current process. (2) Studies have found that the lithium ion migration in the positive electrode of the lithium-rich cation-disordered rock salt material undergoes an octahedral-tetrahedral-octahedral transition state, and the migration energy barrier of this transition state structure is extremely dependent on the local structure around it, and the connectivity of its percolation network is built on this basis. This unique lithium ion migration channel leads to an unsatisfactory migration rate of lithium ions in the material.

[0006] It should be noted that the information disclosed in the above background section is only used to strengthen the understanding of the background of the present application, and therefore can include information that does not constitute prior art known to those of ordinary skill in the art. SUMMARY

[0007] To provide a simple overview of some aspects of the disclosed embodiments the following description is given. The outline is not an exhaustive overview of all aspects of the embodiments. It is therefore not intended to identify key / critical elements or determine the scope of the embodiments. The following outline is intended only to provide a brief overview of some aspects of the embodiments.

[0008] The embodiments of the present disclosure provide an electrode material, a positive electrode material for a lithium battery, a lithium battery and an electric device, which improve the electrochemical performance of the disordered rock salt material, facilitate the control of lithium ion transport and improve the capacity and rate capability of the electrode of the disordered rock salt material.

[0009] In some embodiments, an electrode material is provided, the electrode material having a general chemical formula of Li x TM y O 4- z F z ; wherein 2.5≤x+y≤4, 0≤z≤1, and TM includes one or more redox-active transition metals.

[0010] In some embodiments, a positive electrode material for a lithium battery is provided, comprising: the electrode material according to any one of the above embodiments.

[0011] In some embodiments, a lithium battery is provided, comprising: the electrode material as described above; or the positive electrode material for a lithium battery as described in any of the above embodiments.

[0012] In some embodiments, an electric device is provided, comprising: the lithium battery as described in any of the above embodiments.

[0013] The electrode material, the positive electrode material for a lithium battery, the lithium battery and the electric device provided by the embodiments of the present disclosure can achieve the following technical effects:

[0014] The number of cations in the electrode material provided by the present disclosure is less than the number of anions, and a composite structure electrode material with long-range disorder and local order is further formed. The electrochemical performance of the disordered rock salt material can be significantly improved by the local ordered unit, which is conducive to controlling the lithium ion transmission and improving the capacity and rate capability of the obtained electrode material. At the same time, the introduction of the local ordered unit can also reduce the lithium ion migration barrier, thereby effectively connecting the percolation network of lithium ion migration from octahedron-tetrahedron-octahedron, and improving the lithium ion migration rate to achieve an effect comparable to high-energy ball milling.

[0015] The foregoing general description and the following description are only exemplary and explanatory, and are not used to limit the present application. BRIEF DESCRIPTION OF DRAWINGS

[0016] One or more embodiments are exemplarily illustrated by corresponding drawings, which do not constitute limitation on the embodiments, elements with the same reference numerals in the drawings are shown as similar elements, the drawings do not constitute proportional limitation, and wherein:

[0017] Figure 1 is a schematic diagram of the preparation method for the electrode material provided by an embodiment of the present disclosure;

[0018] Figure 2 is a schematic diagram of the preparation method for the electrode material provided by another embodiment of the present disclosure;

[0019] Figure 3 is a schematic diagram of the method for proton exchange treatment on the initial disordered rock salt material provided by an embodiment of the present disclosure;

[0020] Figure 4 is a schematic diagram of the method for proton exchange treatment on the initial disordered rock salt material provided by another embodiment of the present disclosure;

[0021] Figure 5 is a schematic diagram of the preparation method for the electrode material provided by another embodiment of the present disclosure;

[0022] Figure 6is a schematic diagram of a preparation method of an initial disordered rock salt material provided by one embodiment of the present disclosure;

[0023] Figure 7 is a schematic diagram of a preparation method of an initial disordered rock salt material provided by another embodiment of the present disclosure;

[0024] Figure 8 is a schematic diagram of a preparation method of an electrode material provided by yet another embodiment of the present disclosure;

[0025] Figure 9 is an XRD pattern of a composite positive electrode material obtained by proton exchange treatment with tetrafluoroboric acid (HBF4) in one embodiment of the present disclosure;

[0026] Figure 10 is an XRD pattern of a composite positive electrode material obtained by proton exchange treatment with boric acid (H3BO3) in one embodiment of the present disclosure;

[0027] Figure 11 is an XRD pattern of a composite positive electrode material obtained by proton exchange treatment with oleic acid in one embodiment of the present disclosure;

[0028] Figure 12 is a Li 1.2 Mn 0.6 Ti 0.2 O2 positive electrode material and a comparison schematic diagram of charge-discharge curves of a composite positive electrode material thereof;

[0029] Figure 13 is an XRD pattern of a composite positive electrode material obtained by proton exchange treatment with boric acid (H3BO3) in one embodiment of the present disclosure;

[0030] Figure 14 is an XRD pattern of a composite positive electrode material obtained by proton exchange treatment with tetrafluoroboric acid (HBF4) in one embodiment of the present disclosure;

[0031] Figure 15 is an XRD pattern of a composite positive electrode material obtained by proton exchange treatment with tetrafluoroboric acid (HBF4) in one embodiment of the present disclosure;

[0032] Figure 16 is an XRD pattern of a composite positive electrode material obtained by proton exchange treatment with tetrafluoroboric acid (HBF4) in one embodiment of the present disclosure;

[0033] Figure 17 is an XRD pattern of a composite positive electrode material obtained based on nitric acid treatment in one embodiment of the present disclosure;

[0034] Figure 18 is a Li 1.05 Mn0.85 Ti 0.1 The first cycle charge-discharge curve of the O2-based composite cathode material;

[0035] Figure 19 LiMnO4 material obtained in Comparative Example 1; 1.05 Mn 0.85 Ti 0.1 XRD pattern of the O2 cathode material;

[0036] Figure 20 LiMnO4 material obtained in Comparative Example 1; 1.05 Mn 0.85 Ti 0.1 The first cycle charge-discharge curve of the O2-based composite cathode material;

[0037] Figure 21 LiMnO4 material obtained in Comparative Example 2; 1.80 Ti 0.2 XRD pattern of the O4 material;

[0038] Figure 22 LiMnO4 material obtained in Comparative Example 2; 1.80 Ti 0.2 The first cycle charge-discharge curve of the O4-spinel cathode material. DETAILED DESCRIPTION

[0039] In order to enable a more detailed understanding of the features and technical content of the embodiments of the present disclosure, the implementation of the embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings, which are for reference only and do not limit the embodiments of the present disclosure. In the following technical description, for the purpose of easy explanation, through multiple details, a sufficient understanding of the disclosed embodiments is provided. However, one or more embodiments can still be implemented without these details. In other cases, well-known structures and devices can be simplified to show.

[0040] The terms "first", "second", and the like in the specification and claims of the embodiments of the present disclosure and the above-described drawings are used to distinguish similar objects, and do not necessarily have to describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present disclosure described herein can be implemented. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion.

[0041] In the embodiments of the present disclosure, the terms "upper", "lower", "inside", "middle", "outside", "front", "back" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. These terms are mainly intended to better describe the embodiments of the present disclosure and their embodiments, and are not intended to limit the indicated devices, elements or components to having a specific direction, or to be constructed and operated in a specific direction. Moreover, in addition to being used to indicate directions or positional relationships, some of the above terms may also be used to indicate other meanings. For example, the term "upper" may also be used to indicate a certain dependency or connection relationship in certain circumstances. For those of ordinary skill in the art, the specific meanings of these terms in the embodiments of the present disclosure can be understood according to specific circumstances.

[0042] Furthermore, the terms "disposed," "connected," and "fixed" should be interpreted broadly. For example, "connected" can mean a fixed connection, a removable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection, an indirect connection through an intermediary, or an internal connection between two devices, elements, or components. Those skilled in the art will understand the specific meanings of these terms in the embodiments of this disclosure based on the specific circumstances.

[0043] Unless otherwise stated, the term "plurality" means two or more.

[0044] In the embodiment of the present disclosure, the character " / " indicates that the preceding and following objects are in an "or" relationship. For example, A / B means: A or B.

[0045] The term "and / or" describes an association between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or A and B.

[0046] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present disclosure can be combined with each other.

[0047] In some embodiments, an electrode material is provided, wherein the electrode material has the following chemical formula: Li x TM y O 4- z F z , 2.5≤x+y≤4, 0≤z≤1, TM includes one or more redox-active transition metals.

[0048] The electrode material provided by the present disclosure has a number of cations less than a number of anions, and further forms a composite structure electrode material with long-range disorder and local order. The local order unit can significantly improve the electrochemical performance of the disordered rock salt material, and is conducive to controlling lithium ion transmission and improving the capacity and rate capability of the obtained electrode material. At the same time, the introduction of the local order unit can also reduce the lithium ion migration barrier, thereby effectively connecting the percolation network of lithium ion migration from octahedral-tetrahedral-octahedral, and improving the lithium ion migration rate to achieve an effect comparable to that after high-energy ball milling.

[0049] Optionally, the redox-active transition metal includes Mn, Ni, Fe, Co, Cr, Mo, V, Ru, or Rh.

[0050] Optionally, the TM further includes one or more non-redox-active transition metals.

[0051] Optionally, the non-redox-active transition metal includes Ti, Nb, Zr, Ta, Sn, Sb, W, Te, Hf, Na, K, Ca, Mg, Zn, Ga, or Al.

[0052] Optionally, 0.25≤x≤2.75, 1≤y≤2.5.

[0053] In this embodiment, by reasonably setting the value range of x and y, the ion ratio of the electrode material is met, the electrochemical performance is improved, and the capacity and rate capability of the electrode material are improved.

[0054] Optionally, the single particle of the electrode material is a composite phase structure.

[0055] In this embodiment, the electrode material is a composite phase structure, and the electrochemical performance of a single structure system is enhanced and the rate performance of the disordered rock salt electrode material is improved by adopting a double / multi-structure composite design.

[0056] Optionally, the composite phase structure includes two or three of a disordered rock salt phase structure, a spinel phase structure, and a layered phase structure.

[0057] In this embodiment, the composite phase structure is at least two of a disordered rock salt phase structure, a spinel phase structure, and a layered phase structure. Compared with the single-phase structure of the disordered rock salt material in the related art, the composite structure electrode material Li x TM y O 4-z F z(2.5≤x+y≤4, 0.25≤x≤2.75, 1≤y≤2.5, 0≤z≤1). The local order significantly improves the electrochemical performance, which is beneficial to control the lithium ion transport and improve the capacity and rate capability of the disordered rock salt material. At the same time, without the help of high-energy ball milling, the introduction of local order can also reduce the lithium ion migration barrier, thereby effectively connecting the percolation network of lithium ion migration from octahedral-tetrahedral-octahedral, and improving the lithium ion migration rate to achieve the effect comparable to high-energy ball milling. On the other hand, for the traditional structure ordered spinel material (Li x TM 3-x O4(1≤x≤2)) with excellent rate performance, i.e. high energy density, the introduction of local disorder can effectively inhibit the harmful phase transition from cubic symmetry to tetragonal symmetry of the traditional ordered spinel material due to the John-Teller effect of manganese ions during long-term cycling, resulting in poor capacity retention. By adopting the design of double / multiple structure composite to enhance the electrochemical performance of a single structure system, the spinel component with high rate performance is introduced into the disordered rock salt material matrix structure, which can hinder the undesirable phase transition of the spinel cathode material and improve the rate performance of the disordered rock salt material cathode material.

[0058] Optionally, the ratio of cations to anions in the disordered rock salt phase structure is 1:1; the ratio of cations to anions in the spinel phase structure is 3:4; and the ratio of cations to anions in the layered phase structure is 1:1.

[0059] In this embodiment, by adopting the ratio of cations to anions in the disordered rock salt phase structure is 1:1; the ratio of cations to anions in the spinel phase structure is 3:4; and the ratio of cations to anions in the layered phase structure is 1:1, and then by preparing the electrode material with a composite structure.

[0060] In some embodiments, a cathode material for a lithium battery is provided, comprising: the electrode material as described in any of the above embodiments.

[0061] The cathode material for a lithium battery adopted by the present disclosure adopts the electrode material provided by any of the above embodiments. By adopting the electrode material of any of the above embodiments as the cathode material of a lithium battery, the electrochemical performance of the disordered rock salt material can be significantly improved, which is beneficial to control the lithium ion transport and improve the capacity and rate capability of the obtained electrode material.

[0062] In some embodiments, a lithium battery is provided, comprising: the electrode material as described in any of the above embodiments.

[0063] The electrode material provided by any one of the above embodiments is used in the lithium battery adopted by the present disclosure. By using the electrode material of any one of the above embodiments, the electrochemical performance of the disordered rock salt material can be significantly improved, the lithium ion transmission can be controlled, and the capacity and rate capability of the obtained electrode material can be improved.

[0064] In some embodiments, a lithium battery is provided, comprising: the positive electrode material for a lithium battery as described in any one of the above embodiments.

[0065] The positive electrode material for a lithium battery adopted by the present disclosure uses the electrode material provided by any one of the above embodiments. By using the electrode material of any one of the above embodiments as the positive electrode material of the lithium battery, the electrochemical performance of the disordered rock salt material can be significantly improved, the lithium ion transmission can be controlled, and the capacity and rate capability of the obtained electrode material can be improved.

[0066] In some embodiments, an electric device is provided, comprising: the lithium battery as described in any one of the above embodiments.

[0067] The electric device provided by the present disclosure comprises the lithium battery provided by any one of the above embodiments, and therefore has all the beneficial effects of the lithium battery described above, which will not be repeated here.

[0068] In some embodiments, in combination with Figure 1 As shown in the drawings, a preparation method for an electrode material is provided, the electrode material described in any one of the above embodiments is prepared by the preparation method provided by the present disclosure, and the preparation method comprises:

[0069] S101, performing proton exchange treatment on the initial disordered rock salt material.

[0070] S102, after completing the proton exchange treatment, obtaining a delithiated disordered rock salt material.

[0071] S103, annealing the obtained delithiated disordered rock salt material to obtain an electrode material.

[0072] In the preparation method for the electrode material adopted by the present disclosure, the initial disordered rock salt material prepared is subjected to proton exchange treatment to perform proton exchange, i.e., hydrogen ions in the solution are exchanged with lithium ions in the material, so as to form local lithium-poor phase regions and lithium-rich phase regions. Then, the disordered rock salt material after drying is subjected to annealing, so that the hydrogen ions substituted into the crystal interior in the process of proton exchange leave the particles in the form of H2O, leaving cation vacancies, and thermodynamically driven structural relaxation occurs in the heating process, local ordered units are established, and a long-range disordered and locally ordered composite structure electrode material is formed. The local ordered units can significantly improve the electrochemical performance of the disordered rock salt material, are conducive to controlling lithium ion transmission, and improve the capacity and rate capability of the obtained electrode material. At the same time, under the condition of not relying on high-energy ball milling, the introduction of the local ordered units can also realize the reduction of the lithium ion migration barrier, thereby effectively connecting the percolation network of the lithium ion migration from octahedron-tetrahedron-octahedron, improving the lithium ion migration rate to achieve an effect comparable to high-energy ball milling, and thus being able to replace the high-energy ball milling preparation method to realize batch production.

[0073] In some embodiments, in combination with Figure 2 As shown in FIG. 1, a preparation method for an electrode material is provided, comprising:

[0074] S201, preparing an initial disordered rock salt material.

[0075] S202, adding the initial disordered rock salt material into a proton solution with a preset concentration to obtain a mixed solution.

[0076] S203, treating the mixed solution by using a preset treatment method to obtain a suspension.

[0077] S204, cleaning the suspension until the supernatant is neutral.

[0078] S205, after completing the proton exchange treatment, performing drying treatment to obtain a disordered rock salt material after delithiation and drying.

[0079] S206, annealing the obtained disordered rock salt material after delithiation to obtain an electrode material.

[0080] The preparation method adopted by the embodiments of the present disclosure first prepares the preparation material, prepares the initial disordered rock salt material for the preparation of the electrode material. Then the prepared initial disordered rock salt material is soaked in a proton solution with a preset concentration, and the acid solution after adding the initial rock salt material is treated by a preset treatment method to obtain a suspension. Further, the suspension is washed until the supernatant is neutral, and the proton exchange treatment of the initial rock salt material is completed. Through the proton exchange treatment of the initial rock salt material, a proton exchange reaction is carried out in the proton exchange treatment process, so that the hydrogen ions in the acid solution are exchanged with the lithium ions in the material, thereby forming a local lithium-poor phase region and a lithium-rich phase region. Then, by annealing the dried disordered rock salt material, the hydrogen ions that replace the lithium ions into the crystal interior in the proton exchange process leave the particles in the form of H2O, leaving cation vacancies, and thermodynamic-driven structural relaxation occurs in the heating process, establishing local ordered units and forming a composite structure electrode material with long-range disorder and local order.

[0081] Optionally, the proton solution includes an acid solution or an alcohol solution. The protons in the acid solution or the alcohol solution are exchanged with the initial rock salt material.

[0082] Optionally, the acid solution includes an inorganic acid solution or an organic acid solution. By selecting different types of acids, the concentration is determined according to the characteristics of the selected acid to achieve acid treatment of the initial rock salt material. Here, no one is exemplified. The inorganic acid includes but is not limited to nitric acid, hydrochloric acid, tetrafluoroboric acid, sulfuric acid, boric acid, phosphoric acid, etc. The organic acid includes but is not limited to oxalic acid, citric acid, acetic acid, oleic acid, etc.

[0083] Optionally, the preset concentration of the inorganic acid solution is 1% to 30%. The specific value of the preset concentration includes 1%, 3%, 5%, 10%, 12%, 15%, 20%, 25% or 30%.

[0084] Optionally, the preset concentration of the inorganic acid solution is 1% to 15%. The specific value of the preset concentration includes 1%, 3%, 5%, 10%, 12% or 15%.

[0085] Optionally, the preset concentration of the organic acid solution is 10% to 90%. The specific value of the preset concentration includes 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80% or 90%.

[0086] Optionally, the preset concentration of the organic acid solution is 30% to 90%. The specific value of the preset concentration includes 30%, 40%, 50%, 60%, 70%, 80% or 90%.

[0087] Optionally, the proton exchange treatment can also use an alcohol solution to perform the proton exchange reaction. Specifically, all alcohol solutions capable of proton exchange with lithium ions are within the scope of the present application, and are not listed here.

[0088] Optionally, after the proton exchange treatment is completed, the step of obtaining the delithiated disordered rock salt material includes: drying the material after the proton exchange treatment to obtain a dried delithiated disordered rock salt material. The drying method includes, but is not limited to, high-temperature evaporation drying or centrifugal drying.

[0089] In some embodiments, in combination with Figure 3 As shown in FIG. 1, a method for acid treatment of an initial disordered rock salt material is provided, including:

[0090] S301, adding the initial disordered rock salt material to an acid solution of a preset concentration to obtain a mixed solution.

[0091] S302, treating the mixed solution with ultrasound for a preset treatment time to obtain a suspension.

[0092] S303, sequentially using deionized water and ethanol to centrifugally wash the suspension.

[0093] S304, repeatedly performing centrifugal washing until the supernatant is neutral.

[0094] In the embodiments of the present disclosure, the prepared initial disordered rock salt material is soaked in an acid solution of a preset concentration, and the mixed solution is treated with ultrasound for a preset treatment time to assist the proton exchange treatment reaction. Then, the suspension after the reaction is centrifugally washed. Specifically, deionized water and ethanol are sequentially used to repeatedly perform centrifugal washing until the supernatant is neutral.

[0095] Optionally, the washing of the suspension can also use acetone to centrifugally wash the suspension, and repeatedly perform centrifugal washing until the supernatant is neutral.

[0096] Optionally, the preset treatment time ranges from 0.5h to 8h. The preset treatment time includes 0.5h, 1h, 2h, 3h, 4h, 5h, 6h, 7h, or 8h.

[0097] In some embodiments, in combination with Figure 4 As shown in FIG. 1, a method for acid treatment of an initial disordered rock salt material is provided, including:

[0098] S401, adding the initial disordered rock salt material to an acid solution of a preset concentration to obtain a mixed solution.

[0099] S402, using a water bath heating method or an oil bath heating method, treating the mixed solution at a preset heating temperature for a preset treatment duration.

[0100] S403, sequentially using deionized water and ethanol to centrifugally wash the suspension.

[0101] S404, repeatedly performing centrifugal washing until the supernatant is neutral.

[0102] In the embodiments of the present disclosure, the prepared initial disordered rock salt material is soaked in an acid solution with a preset concentration, and the mixed solution is heated to a preset heating temperature by a water bath heating method or an oil bath heating method, and the heating is continued for a preset treatment duration. Then, the suspension after reaction is centrifugally washed. Specifically, deionized water and ethanol are sequentially used to repeatedly perform centrifugal washing until the supernatant is neutral.

[0103] Optionally, the preset treatment duration has a value range of 10 min to 8 h. The preset treatment duration has a value of 10 min, 20 min, 0.5 h, 1 h, 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, or 8 h. The preset heating temperature has a value range of 60°C to 200°C. The preset heating temperature has a value of 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, or 200°C.

[0104] Optionally, the preset treatment duration has a value range of 0.5 h to 8 h. The preset treatment duration has a value of 0.5 h, 1 h, 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, or 8 h. The preset heating temperature has a value range of 80°C to 160°C. The preset heating temperature has a value of 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, or 160°C.

[0105] In some embodiments, in combination with Figure 5 As shown in FIG. 1, a method for preparing an electrode material is provided, comprising:

[0106] S501, preparing an initial disordered rock salt material.

[0107] S502, performing proton exchange treatment on the initial disordered rock salt material.

[0108] S503, after completing the proton exchange treatment, performing drying treatment to obtain a dried delithiated disordered rock salt material.

[0109] S504, placing the obtained delithiated disordered rock salt material in a high-temperature furnace, and maintaining at a preset annealing temperature for a preset annealing duration.

[0110] In the preparation method for the electrode material adopted by the present disclosure, a proton exchange reaction is carried out by subjecting the prepared initial disordered rock salt material to a proton exchange treatment, i.e., hydrogen ions in a solution are exchanged with lithium ions in the material, thereby forming local lithium-poor phase regions and lithium-rich phase regions. Then, the dried delithiated disordered rock salt material is placed in a high-temperature furnace, and subjected to annealing at a preset annealing temperature for a preset annealing time, so that the hydrogen ions that replace the lithium ions in the proton exchange process and enter the crystal interior leave the particles in the form of H2O, leaving cation vacancies, and a thermodynamically driven structural relaxation occurs in the heating process, local ordered units are established, and a composite structure electrode material with long-range disorder and local order is formed. The local ordered units can significantly improve the electrochemical performance of the disordered rock salt material, facilitate the control of lithium ion transmission, and improve the capacity and rate capability of the obtained electrode material. At the same time, under the condition of not relying on high-energy ball milling, the introduction of local ordered units can also reduce the lithium ion migration barrier, thereby effectively connecting the percolation network of lithium ion migration from octahedral-tetrahedral-octahedral, improving the lithium ion migration rate to achieve an effect comparable to high-energy ball milling, and thus being able to replace the high-energy ball milling preparation method to realize mass production.

[0111] Optionally, the preset annealing temperature is in a range of 100°C to 700°C. The preset annealing temperature can be 100°C, 150°C, 200°C, 300°C, 400°C, 500°C, 600°C, or 700°C. The preset annealing time is in a range of 1 min to 10 h. The preset annealing time can be 1 min, 15 min, 0.5 h, 2 h, 4 h, 6 h, 8 h, or 10 h.

[0112] Optionally, the preset annealing temperature is in a range of 150°C to 600°C. The preset annealing temperature can be 150°C, 200°C, 300°C, 400°C, 500°C, or 600°C. The preset annealing time is in a range of 0.5 h to 10 h. The preset annealing time can be 0.5 h, 2 h, 4 h, 6 h, 8 h, or 10 h.

[0113] Optionally, the high-temperature furnace is filled with argon, nitrogen, or air.

[0114] In this embodiment, the delithiated disordered rock salt material is placed in an argon atmosphere, a nitrogen atmosphere, or an air atmosphere, and subjected to annealing at a preset annealing temperature for a preset annealing time.

[0115] In some embodiments, the step of preparing the initial disordered rock salt material includes: using a preset preparation method to process the preparation material to obtain a precursor. The precursor is placed in a high-temperature furnace for high-temperature treatment to obtain the initial disordered rock salt material. The chemical formula of the initial disordered rock salt material is Li 1+a TM 1-a O 2-bF b , a > 0, b ≥ 0, TM comprises one or more high valence metal ions.

[0116] In this embodiment, the prepared preparation material is treated by a preset preparation method to obtain a precursor. Further, the precursor is placed in a high-temperature furnace, and high-temperature treatment is performed to obtain an initial disordered rock salt material. The chemical general formula of the initial disordered rock salt material is: Li 1+a TM 1-a O 2-b F b , a > 0, b ≥ 0, TM comprises one or more high valence metal ions. The lithium-rich cation disordered rock salt material has the characteristics of high specific energy, and makes full use of low-cost and earth-abundant elements, for example, TM includes manganese and titanium. Compared with the ordered materials of traditional structure ordered lithium ion cathode (for example, layered, spinel and olivine cathode), the disordered rock salt material has the characteristics of high disorder within the cation sublattice, and lithium transport is achieved through the mutual penetration of unique near-statistical "0-TM" local structures connected approximately. This unique isotropic structure ensures that the structure change of the positive electrode material is inhibited during the cycle process, so that the phase transition phenomenon and the intercrystalline stress in the material are not obvious. The high capacity of the disordered rock salt material electrode is due to the close coupling of the transition metal and anion redox process, so that the working voltage of the material is higher.

[0117] In some embodiments, in combination Figure 6 As shown in FIG. 6, a preparation method of an initial disordered rock salt material is provided, which includes

[0118] S601, using a solid phase method, the preparation material is added to a precursor according to a preset molar ratio, and a mixing ball is added.

[0119] S602, planetary ball milling is performed at a preset rotating speed, and the operation is continued for a preset running time to obtain a precursor.

[0120] S603, the precursor is placed in a high-temperature furnace, and the operation is continued at a preset temperature for a preset time to obtain an initial disordered rock salt material.

[0121] The chemical general formula of the initial disordered rock salt material is: Li 1+a TM 1-a O 2-b F b , a > 0, b ≥ 0, TM comprises one or more high valence metal ions.

[0122] In the embodiment, the preparation material is added into the precursor in a preset molar ratio by using a solid phase method, and mixed balls are added. Planetary ball milling is performed at a preset rotating speed, and the process is continued for a preset running time to obtain a precursor. The precursor is placed in a high-temperature furnace, and is subjected to a preset temperature for a preset time to obtain an initial disordered rock salt material. The disordered rock salt structure material is obtained by using a solid phase method, and the process method is simple and easy to implement.

[0123] Optionally, the preset temperature is in a range from 700 DEG C to 1500 DEG C, and the preset temperature includes 700 DEG C, 900 DEG C, 1100 DEG C, 1300 DEG C or 1500 DEG C. The preset time is in a range from 1 min to 20 h, and the preset time includes 1 min, 30 min, 1 h, 5 h, 10 h, 15 h or 20 h.

[0124] Optionally, the preset temperature is in a range from 900 DEG C to 1200 DEG C. The preset temperature includes 900 DEG C, 1000 DEG C, 1100 DEG C or 1200 DEG C. The preset time is in a range from 5 min to 20 h, and the preset time includes 5 min, 30 min, 1 h, 5 h, 10 h, 15 h or 20 h.

[0125] Optionally, the preset rotating speed is in a range from 150 rpm to 2000 rpm, and the preset rotating speed includes 150 rpm, 300 rpm, 500 rpm, 1000 rpm, 1500 rpm or 2000 rpm.

[0126] The material of the mixed ball includes stainless steel or zirconium oxide. The diameter of the mixed ball can be selected in multiple sizes to improve the ball milling effect. The specific value of the preset rotating speed depends on the revolution radius of the planetary ball mill.

[0127] In some embodiments, the method for preparing the initial disordered rock salt material comprises the following steps. Figure 7 As shown in the figure, a method for preparing an initial disordered rock salt material is provided, which comprises the following steps.

[0128] S701, a sol-gel method is used to dissolve and stir the preparation material in ethanol according to a preset molar ratio to obtain a precursor liquid, and the precursor liquid is aged at room temperature to obtain a precursor gel.

[0129] S702, the precursor gel is pre-calcined at a first temperature.

[0130] S703, the initial disordered rock salt material is obtained by constant temperature treatment at a second temperature in a high-temperature furnace for a preset constant temperature time.

[0131] In this embodiment, the preparation material is dissolved in ethanol by adopting a sol-gel method according to a preset molar ratio, stirred to obtain a precursor liquid, and the precursor liquid is aged at room temperature to obtain a precursor gel. Subsequently, the precursor gel is precalcined at a first temperature, and then is kept at a second temperature in a high-temperature furnace for a preset constant-temperature duration to obtain an initial disordered rock salt material.

[0132] Optionally, the first temperature is in a range of 200-700°C, and the first temperature includes 200°C, 400°C, 500°C, 600°C or 700°C. The second temperature is in a range of 700-1500°C. The second temperature includes 700°C, 900°C, 1100°C, 1300°C or 1500°C. The preset constant-temperature duration is in a range of 1 min-20 h. The preset constant-temperature duration includes 1 min, 15 min, 30 min, 1 h, 5 h, 10 h, 15 h or 20 h.

[0133] Optionally, the first temperature is in a range of 300-600°C. The first temperature includes 300°C, 400°C, 500°C or 600°C. The second temperature is in a range of 900-1200°C. The second temperature includes 900°C, 1100°C, 1300°C or 1200°C. The preset constant-temperature duration is in a range of 5 min-20 h. The preset constant-temperature duration includes 5 min, 15 min, 30 min, 1 h, 5 h, 10 h, 15 h or 20 h.

[0134] In some embodiments, in combination with Figure 8 As shown in FIG. 1, a preparation method for an electrode material is provided, including:

[0135] S801, a solid-phase method or a sol-gel method is adopted to process a preparation material to obtain a precursor.

[0136] S802, the precursor is placed in a high-temperature furnace for high-temperature treatment to obtain an initial disordered rock salt material.

[0137] The chemical general formula of the initial disordered rock salt material is Li 1+a TM 1-a O 2-b F b , a>0, b≥0, TM includes one or more high-valence metal ions.

[0138] S803, the initial disordered rock salt material is added to an acid solution with a preset concentration to obtain a mixed liquid.

[0139] S804, the mixed liquid is processed by adopting a preset processing method to obtain a suspension.

[0140] S805, the suspension is sequentially washed by centrifugation using deionized water and ethanol.

[0141] S806, repeating the centrifugal washing until the supernatant is neutral.

[0142] S807, after the proton exchange treatment is completed, drying treatment is performed to obtain a dried delithiated disordered rock salt material.

[0143] S808, the obtained delithiated disordered rock salt material is placed in a high-temperature furnace, and an annealing temperature is set for a preset annealing time to obtain an electrode material.

[0144] In the preparation method for the electrode material adopted by the present disclosure, the initial disordered rock salt material prepared is subjected to proton exchange treatment with an acid or alcohol solution, that is, the hydrogen ions in the acid or alcohol solution are exchanged with the lithium ions in the material, thereby forming a local lithium-poor phase region and a lithium-rich phase region. Then, the disordered rock salt material after drying is subjected to annealing, so that the hydrogen ions that replace the lithium ions into the crystal interior in the proton exchange process leave the particles in the form of H2O, leaving cation vacancies, and thermodynamic driving structural relaxation occurs in the heating process, establishing a local ordered unit and forming a long-range disordered and locally ordered composite structure electrode material. The local ordered unit can significantly improve the electrochemical performance of the disordered rock salt material, is conducive to controlling lithium ion transport, and improves the capacity and rate capability of the obtained electrode material. At the same time, without relying on high-energy ball milling, the introduction of the local ordered unit can also reduce the lithium ion migration barrier, thereby effectively connecting the percolation network of lithium ion migration from octahedral-tetrahedral-octahedral, improving the lithium ion migration rate to achieve an effect comparable to high-energy ball milling, thereby being able to replace the high-energy ball milling preparation method to realize mass production.

[0145] Specifically, the following examples are used in the preparation method for the electrode material provided by the present disclosure:

[0146] Example 1:

[0147] Prepare the preparation material, which includes lithium carbonate, manganese sesquioxide, manganese dioxide, and titanium dioxide.

[0148] Use the solid phase method to planetary ball mill lithium carbonate, manganese sesquioxide, manganese dioxide, and titanium dioxide in a molar ratio of 0.6:0.2:0.2:0.2, and add mixed balls of different sizes of stainless steel or zirconium oxide, and uniformly mix the balls at any speed between 150 rpm and 2000 rpm to obtain an oxide mixed precursor.

[0149] Put the obtained oxide mixed precursor into a high-temperature furnace, and treat it at a constant temperature for any length of time between 5 min and 20 h at any temperature between 900°C and 1200°C to obtain Li 1.2 Mn 0.6 Ti0.2 O2 material.

[0150] Li 1.2 Mn 0.6 Ti 0.2 O2 material is soaked in an inorganic acid solution with a mass fraction of 1% to 45% or an organic acid with a mass fraction of 30% to 90%, and is treated by ultrasonic or water / oil bath (temperature between 80°C and 160°C) for 0.5h to 8h. The type and concentration of the acid solution can be specifically selected according to requirements.

[0151] The treated suspension is repeatedly washed and centrifuged with deionized water and ethanol in sequence until the supernatant is neutral, and after drying, the acid-treated Li 1.2 Mn 0.6 Ti 0.2 O2 material is obtained.

[0152] The acid-treated Li 1.2 Mn 0.6 Ti 0.2 O2 material is treated at a constant temperature of 150°C to 600°C in an argon atmosphere, a nitrogen atmosphere, or an air atmosphere in a high-temperature furnace for 0.5h to 10h to obtain a Li 1.2 Mn 0.6 Ti 0.2 O2-based composite cathode material. The number of ions in the composite cathode material obtained is different according to different types of acid solutions and the length of time for constant temperature treatment during annealing, which is not exemplified here, and the specific test can be specifically set according to requirements.

[0153] Figure 9 The XRD pattern (X-ray diffraction pattern) of the composite cathode material obtained by proton exchange treatment with tetrafluoroboric acid (HBF4) is shown;

[0154] Figure 10 The XRD pattern (X-ray diffraction pattern) of the composite cathode material obtained by proton exchange treatment with boric acid (H3BO3) is shown;

[0155] Figure 11 The XRD pattern (X-ray diffraction pattern) of the composite cathode material obtained by proton exchange treatment with oleic acid is shown;

[0156] In combination with Figures 9 to 11 The XRD pattern shown can be seen that the composite material is composed of disordered rock salt phase and spinel phase.

[0157] Further, the Li 1.2 Mn 0.6 Ti 0.2The electrodes are made of O2-based composite positive electrode materials and assembled with lithium sheets into button batteries. Figure 12 As shown, lines l1 and l2 in the figure are Li 1.2 Mn 0.6 Ti 0.2 The charge and discharge curves of the electrode made of O2 material, lines L1 and L2 in the figure are the Li 1.2 Mn 0.6 Ti 0.2 The charge and discharge curves of the electrode made of O2-based composite positive electrode material. Figure 12 As shown, Li 1.2 Mn 0.6 Ti 0.2 The O2-based composite cathode material has a charge and discharge current density of 248 mAh g at a charge and discharge current density of 50 mA / g. -1 The specific capacity and 658Wh·kg -1 The energy density is much higher than that of Li 1.2 Mn 0.6 Ti 0.2 77.3mAh·g of O2 cathode material -1 The specific capacity and 244.6Wh·kg -1 Energy density. It can be seen that the introduction of the localized ordered phase can effectively reduce the diffusion barrier of Li+ in the bulk phase and significantly improve the capacity and energy density of the disordered rock salt material.

[0158] Example 2:

[0159] Prepare the preparation materials, which include lithium carbonate, manganese trioxide and titanium dioxide oxide.

[0160] Using a solid-phase method, lithium carbonate, manganese trioxide and titanium dioxide oxide are planetarily ball-milled in a molar ratio of 0.6:0.2:0.4, and stainless steel or zirconium oxide mixing balls of different sizes are added. The mixed balls are evenly milled at any speed between 150 rpm and 2000 rpm to obtain an oxide mixed precursor.

[0161] The obtained oxide mixed precursor is placed in a high temperature furnace and treated at any temperature between 900°C and 1100°C for any time between 5 minutes and 20 hours to obtain Li 1.2 Mn 0.4 Ti 0.4 O2 material.

[0162] Li 1.2 Mn 0.4 Ti 0.4The O2 material is soaked in a boric acid or tetrafluoroboric acid solution with a mass fraction of 1% to 45%, and is treated by ultrasonic or water / oil bath (temperature between 80°C and 160°C) for 0.5h to 8h. The heating temperature and treatment time can be set according to the specific type of acid solution and the test requirements, and will not be exemplified here.

[0163] The treated suspension is repeatedly washed and centrifuged with deionized water and ethanol, respectively, until the supernatant is neutral, and then dried to obtain the acid-treated Li 1.2 Mn 0.4 Ti 0.4 O2 material.

[0164] The acid-treated Li 1.2 Mn 0.4 Ti 0.4 O2 material is treated at a constant temperature of 150°C to 600°C in a high-temperature furnace under an air atmosphere for 0.5h to 10h to obtain a Li 1.2 Mn 0.4 Ti 0.4 O2-based composite cathode material. The number of ions in the composite cathode material obtained is different according to the different types of acid solution and the constant temperature treatment time of annealing, which will not be exemplified here, and the specific test can be set according to the requirements.

[0165] Figure 13 The XRD pattern of the composite cathode material obtained by proton exchange treatment with boric acid (H3BO3) is shown;

[0166] Figure 14 The XRD pattern of the composite cathode material obtained by proton exchange treatment with tetrafluoroboric acid (HBF4) is shown;

[0167] The XRD patterns shown in Figure 13 and Figure 14 It can be seen that the composite material is composed of disordered rock salt phase and spinel phase.

[0168] Example Three:

[0169] Prepare the preparation material, which includes lithium carbonate, manganese sesquioxide, manganese dioxide, and titanium dioxide.

[0170] Using the solid phase method, lithium carbonate, manganese sesquioxide, manganese dioxide, and titanium dioxide are planetary ball milled in a molar ratio of 0.575:0.275:0.2:0.1, and different sizes of stainless steel or zirconium oxide mixed balls are added, and the mixed balls are uniformly milled at any speed between 150rpm and 2000rpm to obtain an oxide mixture precursor.

[0171] The obtained oxide mixed precursor is placed in a high-temperature furnace, and is treated at any temperature ranging from 900°C to 1200°C for any time ranging from 5 min to 20 h, to obtain Li 1.15 Mn 0.75 Ti 0.1 O2 material.

[0172] The Li 1.15 Mn 0.75 Ti 0.1 O2 material is soaked in 1% to 45% mass fraction of tetrafluoroboric acid (HBF4), and is treated by ultrasonic or water / oil bath (temperature between 80°C and 160°C) for 0.5 h to 8 h.

[0173] The treated suspension is repeatedly washed and centrifuged with deionized water and ethanol in sequence until the supernatant is neutral, and after drying, the acid-treated Li 1.15 Mn 0.75 Ti 0.1 O2 material is obtained.

[0174] The acid-treated Li 1.15 Mn 0.75 Ti 0.1 O2 material is treated in a high-temperature furnace at any temperature ranging from 150°C to 600°C in an air atmosphere for 0.5 h to 10 h, to obtain Li 1.15 Mn 0.75 Ti 0.1 O2-based composite cathode material. Depending on the length of the annealing treatment, the number of ions in the composite cathode material obtained is different, which is not exemplified here, and the specific test can be set according to the requirement.

[0175] Figure 15 The XRD pattern of the composite cathode material obtained by proton exchange treatment with tetrafluoroboric acid (HBF4) is shown; in combination with the XRD pattern shown in FIG. 1, it can be seen that the composite material is composed of disordered rock salt phase and spinel phase. Figure 15

[0176] Example Four:

[0177] The material is prepared, and the material includes lithium carbonate, manganese sesquioxide, and titanium dioxide.

[0178] The lithium carbonate, manganese sesquioxide, and titanium dioxide are mixed by planetary ball milling in a solid phase method, and different sizes of stainless steel or zirconium oxide mixed balls are added, and the mixed balls are uniformly ball milled at any speed ranging from 150 rpm to 2000 rpm, to obtain an oxide mixed precursor. ​

[0179] The obtained oxide mixed precursor is placed in a high-temperature furnace, and is treated at any temperature ranging from 900 to 1200°C for any time ranging from 5 minutes to 20 hours, to obtain Li 1.05 Mn 0.85 Ti 0.1 O2 material.

[0180] The Li 1.05 Mn 0.85 Ti 0.1 O2 material is soaked in 1% to 45% tetrafluoroboric acid (HBF4) by mass fraction, and is treated by ultrasonic or water bath / oil bath (temperature between 80 to 160°C) for 0.5 to 8 hours.

[0181] The treated suspension is repeatedly washed and centrifuged with deionized water and ethanol in sequence until the supernatant is neutral, and after drying, the acid-treated Li 1.05 Mn 0.85 Ti 0.1 O2 material is obtained.

[0182] The acid-treated Li 1.05 Mn 0.85 Ti 0.1 O2 material is treated in a high-temperature furnace at any temperature ranging from 150 to 600°C in an air atmosphere for 0.5 to 10 hours, to obtain Li 1.05 Mn 0.85 Ti 0.1 O2-based composite cathode material. Depending on the length of the annealing treatment, the number of ions in the composite cathode material obtained is different, which is not exemplified here, and the specific test can be set according to the requirement.

[0183] Figure 16 The XRD pattern of the composite cathode material obtained by proton exchange treatment with tetrafluoroboric acid (HBF4) is shown; in combination with Figure 16 The XRD pattern shown, it can be seen that the composite material is composed of disordered rock salt phase and spinel phase.

[0184] Example Five:

[0185] Prepare the material, and the material includes: lithium nitrate, manganese acetate tetrahydrate, and isopropyl titanate.

[0186] The lithium nitrate, manganese acetate tetrahydrate, and isopropyl titanate are dissolved and stirred in ethanol according to the molar ratio 0.525:0.425:0.1 to obtain a precursor liquid, and the precursor gel is obtained by aging at room temperature.

[0187] The obtained precursor gel is pre-calcined at any temperature in the range of 300-600°C, and then isothermal treated at any temperature in the range of 900-1200°C for any time in the range of 5 min-20 h to obtain Li 1.05 Mn 0.85 Ti 0.1 O2 material.

[0188] The obtained Li 1.05 Mn 0.85 Ti 0.1 O2 material is soaked in nitric acid with mass fraction of 0.02%-20% and heated and stirred for 0.5 h-10 h, and then the suspension is repeatedly washed and centrifuged with deionized water and ethanol in sequence until the supernatant is neutral, and after drying, the acid-treated Li 1.05 Mn 0.85 Ti 0.1 O2 material is obtained.

[0189] The acid-treated Li 1.05 Mn 0.85 Ti 0.1 O2 material is isothermal treated at any temperature in the range of 150-600°C for 0.5 h-10 h in a high-temperature furnace under air atmosphere to obtain Li 1.05 Mn 0.85 Ti 0.1 O2-based composite cathode material.

[0190] Figure 17 The XRD pattern of the composite cathode material obtained based on nitric acid treatment is shown, which is composed of disordered rock salt phase and spinel phase.

[0191] Further, the composite cathode material Li 1.05 Mn 0.85 Ti 0.1 O2-based composite cathode material obtained in the above example is prepared into a composite cathode electrode by dry method, and the electrode is assembled with lithium sheet into a button cell for electrochemical performance test. It is shown in combination with Figure 18 The first cycle charge-discharge curve of the Li 1.05 Mn 0.85 Ti 0.1 O2-based composite cathode material obtained based on nitric acid treatment is shown. Through comparison by experiment, it can be seen that the Li 1.05 Mn 0.85 Ti 0.1 O2-based composite cathode material has a discharge specific capacity of 281 mAh·g - 1 and an energy density of 753 Wh·kg -1 at a charge-discharge current density of 50 mA·g -1 1, which is superior to Li 1.05 Mn0.85 Ti 0.1 64mAh·g of O2 cathode material -1 The discharge capacity and 174Wh·kg -1 The energy density and LiMn 1.80 Ti 0.2 262mAh·g of O4-spinel cathode material -1 The discharge capacity and 805Wh·kg -1 energy density.

[0192] Optionally, the prepared materials also include fluorides to obtain fluorinated disordered rock salt cathode materials. Fluorides include lithium fluoride, manganese fluoride, titanium manganese, and ammonium fluoride. Fluorinated disordered rock salt lithium-rich oxides have good anion oxygen redox reversibility (less oxygen release) during charge and discharge.

[0193] The following is a comparative example of a method for preparing electrode materials in related art, specifically as follows:

[0194] Comparative Example 1

[0195] Lithium nitrate, manganese acetate tetrahydrate and isopropyl titanate were dissolved and stirred in ethanol at a molar ratio of 0.525:0.425:0.1 by a sol-gel method to obtain a precursor liquid, which was then aged at room temperature to obtain a precursor gel.

[0196] The precursor gel was pre-calcined in air at 300°C to 600°C, and then kept at 900°C to 1200°C in a high temperature furnace for 5 minutes to 20 hours to obtain Li 1.05 Mn 0.85 Ti 0.1 O2 material. Combined Figure 19 Shows Li 1.05 Mn 0.85 Ti 0.1 XRD spectrum of O2 positive electrode material, which is a disordered rock salt phase.

[0197] Li 1.05 Mn 0.85 Ti 0.1 O2 positive electrode material is made into electrodes and assembled with lithium sheets into button batteries. Figure 20 Shows Li 1.05 Mn 0.85 Ti 0.1 The first cycle charge and discharge curve of O2 cathode material, Li 1.05 Mn 0.85 Ti 0.1 O2 cathode material at 50 mA g -1 The charge and discharge current density is only 64mAh·g -1 The specific capacity and 174Wh·kg-1 The experiment shows that it is impossible to reduce the diffusion barrier of lithium ions in the bulk phase of disordered rock salt materials without relying on high-energy ball milling or chemical treatment, making it difficult to achieve the interconnection of the percolation network and the migration of lithium ions.

[0198] Comparative Example 2

[0199] Lithium carbonate, manganese trioxide, manganese dioxide and titanium dioxide oxide are added to mixing balls of stainless steel or zirconium oxide of different sizes in a molar ratio of 0.5:0.5:0.8:0.2 by a solid phase method and planetary ball milling is performed at a speed between 150 rpm and 2000 rpm to mix them uniformly to obtain an oxide mixed precursor.

[0200] The obtained oxide mixed precursor is heated at 700°C to 900°C in a high temperature furnace for 0.5h to 20h to obtain LiMn 1.80 Ti 0.2 O4 material. Combined Figure 21 As shown, LiMn 1.80 Ti 0.2 XRD pattern of O4 material, which is spinel phase.

[0201] LiMn 1.80 Ti 0.2 O4-spinel positive electrode material is made into electrodes and assembled with lithium sheets into button batteries. Figure 22 As shown, LiMn 1.80 Ti 0.2 The first cycle charge and discharge curve of O4-spinel cathode material, LiMn 1.80 Ti 0.2 O4-spinel cathode material at 50mA·g -1 The charge and discharge current density is 262mAh·g -1 The specific capacity and 805Wh·kg -1 However, its cycling stability is poor, with a capacity retention rate of only 72% after 10 cycles.

[0202] The test data of Examples 1 to 5 above, as well as the test data of Comparative Examples 1 and 2, are summarized in Table 1.

[0203] Table 1

[0204]

[0205]

[0206] Compared with the test data of Comparative Example 1 and Comparative Example 2, it can be found from the test data of Example 1 to Example 5 in combination with Table 1 that the initial specific discharge capacity and capacity retention of Example 1 to Example 5 are higher than those of Comparative Example 1, which indicates that the proton exchange and annealing treatment can improve the initial disordered rock salt material (Li 1+a TM 1-a O 2-b F b The local ordered unit is established in (a>0, b≥0) to form a long-range disordered and locally ordered composite structure electrode material Li x TM y O 4-z F z (2.5≤x+y≤4, 0.25≤x≤2.75, 1≤y≤2.5, 0≤z≤1).

[0207] The local ordered unit significantly improves the electrochemical performance of the Li x TM y O 4-z F z electrode material, is conducive to controlling the lithium ion transmission and improving the capacity and rate capability of the Li x TM y O 4-z F z positive electrode material. At the same time, under the condition of not relying on high-energy ball milling, the introduction of the local ordered unit can also realize the reduction of the lithium ion migration barrier, thereby effectively connecting the percolation network of the lithium ion migration from the octahedral-tetrahedral-octahedral, and improving the lithium ion migration rate to achieve a performance effect comparable to high-energy ball milling.

[0208] On the other hand, for the traditional structure ordered spinel material (Li x TM 3-x O4 (1≤x≤2)) with excellent rate performance, i.e., high energy density, the introduction of local disorder can effectively inhibit the harmful phase transition from cubic symmetry to tetragonal symmetry of the traditional ordered spinel material due to the John-Teller effect of manganese ions during long-term cycling, resulting in poor capacity retention. By adopting the design of double / multiple structure composite to enhance the electrochemical performance of a single structure system, the spinel component with high rate performance is introduced into the disordered rock salt material matrix structure, which effectively hinders the undesirable phase transition of the spinel positive electrode material and improves the rate performance of the Li x TM y O 4-z F z positive electrode material.

[0209] The above description and drawings suffice to fully enable one skilled in the art to practice the embodiments of the present disclosure. Other embodiments can include structural and other changes. The embodiments are merely representative of possible variations. Individual components and functions are optional unless explicitly required, and the order of operations can be varied. Portions and features of some embodiments can be included in, or substituted for, portions and features of other embodiments. The embodiments of the present disclosure are not limited to the structures described above and shown in the drawings, and can be varied in a variety of ways. The scope of the present disclosure is limited only by the claims that follow.

Claims

1. An electrode material, characterized in that The electrode material has the following chemical formula: Li x TM y O 4-z F z ; wherein 2.5≤x+y≤4, 0≤z≤1, and TM comprises one or more redox-active transition metals; The interior of a single particle of electrode material is a composite phase structure; The composite phase structure includes two or three of the disordered rock salt phase structure, spinel phase structure and layered phase structure.

2. The electrode material according to claim 1, characterized in that Redox-active transition metals include: Mn, Ni, Fe, Co, Cr, Mo, V, Ru or Rh.

3. The electrode material according to claim 1, characterized in that TM also includes: One or more non-redox active transition metals.

4. The electrode material according to claim 3, characterized in that Non-redox active transition metals include: Ti, Nb, Zr, Ta, Sn, Sb, W, Te, Hf, Na, K, Ca, Mg, Zn, Ga or Al.

5. The electrode material according to any one of claims 1 to 4, characterized in that 0.25≤x≤2.75, 1≤y≤2.

5.

6. A positive electrode material for a lithium battery, characterized in that: include: The electrode material according to any one of claims 1 to 5.

7. A lithium battery, characterized in that: include: The electrode material according to any one of claims 1 to 5; or The positive electrode material for a lithium battery as claimed in claim 6.

8. An electrical device, characterized in that: include: The lithium battery according to claim 7.

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