Method for uniformly doping, modifying, regenerating and repairing failed layered metal oxide electrode material

Abstract

The invention belongs to the field of electrochemical energy conversion and energy storage materials, and particularly relates to a method for uniformly doping, modifying, regenerating and repairing a failed layered metal oxide electrode material, which comprises the following steps of: respectively mixing a metal compound, a layered metal oxide electrode material, a lithium-containing compound and an organic matter additive, heating while stirring until a solvent is evaporated to dryness, and calcining to obtain the lithium-doped layered metal oxide electrode material. And the uniformly doped and modified layered metal oxide electrode material is obtained. The energy and power density of the positive electrode material are improved, the problem of decommissioning battery treatment can be solved to a great extent, and the positive electrode material has a good application prospect.

Description

Technical Field

[0001] The present invention belongs to the field of electrochemical energy conversion and energy storage materials, and particularly relates to a method for uniformly doping and modifying a regenerated and repaired failed layered metal oxide electrode material. Background Art

[0002] Lithium-ion batteries have become the key to contemporary variable energy storage solutions. However, the limited lifespan of lithium-ion batteries poses an increasingly severe challenge to the disposal of waste batteries, which requires progress in recycling technologies to mitigate environmental impacts and recover valuable materials. Traditional pyrometallurgical and hydrometallurgical recycling methods aim to extract elements and highly rely on high temperatures and toxic chemicals, which can cause environmental damage. In contrast, direct recycling is expected to be a more environmentally friendly, cost-effective approach. By directly recycling failed cathode materials through a "repair"-centered method, extensive and destructive processing stages are avoided, and the original structure and inherent properties of the cathode materials are retained.

[0003] A cathode material uniformly coated with high-entropy oxide and its preparation method (application number: 2024112485755) disclose coating a failed layered metal oxide electrode material with a high-entropy oxide having lattice phase matching to restore the performance of the electrode material, and an obvious coating layer can be seen in the disclosed photos. Different from surface coating, in order to ensure the mechanical integrity of the cathode material and obtain optimal electrochemical performance, uniform bulk doping modification can be carried out. Therefore, seeking a recycling and modification method that can uniformly repair failed layered metal oxide cathode materials is an urgent problem to be solved. Summary of the Invention

[0004] The present invention mainly provides a method for uniformly repairing the structure of a failed layered metal oxide and uniformly doping a failed layered metal oxide to solve the problem that existing layered metal oxide electrode materials are not easily recycled:

[0005] A method for uniformly doping and modifying a regenerated and repaired failed layered metal oxide electrode material, in which one or several metal compounds containing metal elements, a layered metal oxide electrode material, a lithium-containing compound, and an organic matter auxiliary are respectively mixed, then heated with stirring until the solvent is evaporated to dryness, and then calcined to obtain a uniformly doped and modified layered metal oxide electrode material.

[0006] Furthermore, the mass ratio of the auxiliary to the layered metal oxide electrode material is 1:10 - 100.

[0007] Further, when there is one type of the metal compound, the metal compound includes a metal compound with a doping site in the lithium layer or a metal compound with a doping site in the transition metal layer; when there are several types of the metal compounds, the metal compounds include one or several metal compounds with a doping site in the lithium layer and one or several metal compounds with a doping site in the transition metal layer.

[0008] Further, when there is one type of the metal compound, the metal compound includes one of water-soluble and / or alcohol-soluble sodium-containing compounds, potassium-containing compounds, rubidium-containing compounds, magnesium-containing compounds, calcium-containing compounds, copper-containing compounds, zinc-containing compounds, strontium-containing compounds, cadmium-containing compounds, barium-containing compounds, scandium-containing compounds, yttrium-containing compounds, indium-containing compounds, antimony-containing compounds, lanthanum-containing compounds, cerium-containing compounds, praseodymium-containing compounds, neodymium-containing compounds, promethium-containing compounds, samarium-containing compounds, europium-containing compounds, gadolinium-containing compounds, terbium-containing compounds, dysprosium-containing compounds, holmium-containing compounds, erbium-containing compounds, thulium-containing compounds, ytterbium-containing compounds, lutetium-containing compounds, bismuth-containing compounds, zirconium-containing compounds, tin-containing compounds, hafnium-containing compounds or lead-containing compounds with a doping site in the lithium layer, or one of water-soluble and / or alcohol-soluble aluminum-containing compounds, chromium-containing compounds, iron-containing compounds, gallium-containing compounds, titanium-containing compounds, germanium-containing compounds, vanadium-containing compounds, niobium-containing compounds, tantalum-containing compounds, molybdenum-containing compounds or tungsten-containing compounds with a doping site in the transition metal layer.

[0009] Further, the metal compound includes monovalent doping elements: one or several of sodium-containing compounds, potassium-containing compounds or rubidium-containing compounds; divalent doping elements: one or several of magnesium-containing compounds, calcium-containing compounds, copper-containing compounds, zinc-containing compounds, strontium-containing compounds, cadmium-containing compounds or barium-containing compounds; trivalent doping elements: one or several of aluminum-containing compounds, scandium-containing compounds, chromium-containing compounds, iron-containing compounds, gallium-containing compounds, yttrium-containing compounds, indium-containing compounds, antimony-containing compounds, lanthanum-containing compounds, cerium-containing compounds, praseodymium-containing compounds, neodymium-containing compounds, promethium-containing compounds, samarium-containing compounds, europium-containing compounds, gadolinium-containing compounds, terbium-containing compounds, dysprosium-containing compounds, holmium-containing compounds, erbium-containing compounds, thulium-containing compounds, ytterbium-containing compounds, lutetium-containing compounds or bismuth-containing compounds; tetravalent doping elements: one or several of titanium-containing compounds, germanium-containing compounds, zirconium-containing compounds, tin-containing compounds, hafnium-containing compounds or lead-containing compounds; pentavalent doping elements: one or several of vanadium-containing compounds, niobium-containing compounds or tantalum-containing compounds; hexavalent doping elements: one or several of molybdenum-containing compounds or tungsten-containing compounds.

[0010] Further, the sodium-containing compound includes one or more of sodium nitrate, sodium acetate, sodium hydroxide, sodium carbonate, sodium chloride, sodium citrate or sodium sulfate; the potassium-containing compound includes one or more of potassium nitrate, potassium acetate, potassium hydroxide, potassium carbonate, potassium chloride, potassium citrate or potassium sulfate; the rubidium-containing compound includes one or more of rubidium nitrate, rubidium acetate, rubidium hydroxide, rubidium carbonate, rubidium chloride or rubidium sulfate; the magnesium-containing compound includes one or more of magnesium nitrate, magnesium acetate, magnesium chloride or magnesium sulfate; the calcium-containing compound includes one or more of calcium nitrate, calcium acetate or calcium chloride; the copper-containing compound includes one or more of copper nitrate, copper acetate, copper chloride or copper sulfate; the zinc-containing compound includes one or more of zinc nitrate, zinc acetate, zinc chloride, zinc citrate or zinc sulfate; the strontium-containing compound includes one or more of strontium nitrate, strontium acetate, strontium chloride, strontium citrate or strontium hydroxide; the cadmium-containing compound includes one or more of cadmium nitrate, cadmium acetate, cadmium chloride or cadmium sulfate; the barium-containing compound includes one or more of barium nitrate, barium acetate, barium chloride or barium hydroxide; the aluminum-containing compound includes one or more of aluminum nitrate, aluminum chloride or aluminum sulfate; the scandium-containing compound includes one or more of scandium nitrate, scandium acetate, scandium chloride or scandium sulfate; the chromium-containing compound includes one or more of chromium nitrate, chromium acetate, chromium chloride or chromium citrate; the iron-containing compound includes one or more of iron nitrate, iron acetate, iron chloride, iron citrate or iron sulfate; the gallium-containing compound includes one or more of gallium nitrate, gallium acetate, gallium chloride, gallium citrate or gallium sulfate; the yttrium-containing compound includes one or more of yttrium nitrate, yttrium acetate, yttrium chloride or yttrium sulfate; the indium-containing compound includes one or more of indium nitrate, indium acetate, indium chloride or indium sulfate; the antimony-containing compound includes one or more of antimony acetate or antimony chloride; the lanthanum-containing compound includes one or more of lanthanum nitrate, lanthanum acetate, lanthanum chloride or lanthanum sulfate; the cerium-containing compound includes one or more of cerium nitrate, cerium acetate, cerium chloride or cerium sulfate; the praseodymium-containing compound includes one or more of praseodymium nitrate, praseodymium acetate, praseodymium chloride or praseodymium sulfate; the neodymium-containing compound includes one or more of neodymium nitrate, neodymium acetate, neodymium chloride or neodymium sulfate; the promethium-containing compound includes one or more of promethium nitrate, promethium acetate or promethium chloride; the samarium-containing compound includes one or more of samarium nitrate, samarium acetate, samarium chloride, samarium hydroxide or samarium sulfate; the europium-containing compound includes one or more of europium nitrate, europium acetate, europium chloride or europium sulfate; the gadolinium-containing compound includes one or more of gadolinium nitrate, gadolinium acetate, gadolinium chloride or gadolinium sulfate; the terbium-containing compound includes one or more of terbium nitrate, terbium acetate, terbium chloride or terbium sulfate; the dysprosium-containing compound includes one or more of dysprosium nitrate, dysprosium acetate, dysprosium chloride or dysprosium sulfate; the holmium-containing compound includes one or more of holmium nitrate, holmium acetate, holmium chloride or holmium sulfate;The erbium-containing compound includes one or more of erbium nitrate, erbium acetate, erbium chloride or erbium sulfate; the thulium-containing compound includes one or more of thulium nitrate, thulium acetate, thulium chloride or thulium sulfate; the ytterbium-containing compound includes one or more of ytterbium nitrate, ytterbium acetate, ytterbium chloride or ytterbium sulfate; the lutetium-containing compound includes one or more of lutetium nitrate, lutetium acetate, lutetium chloride or lutetium sulfate; the bismuth-containing compound includes one or more of bismuth nitrate or dysprosium chloride; the titanium-containing compound includes one or more of titanium chloride or titanium citrate; the germanium-containing compound includes one or more of germanium nitrate or germanium chloride; the zirconium-containing compound includes one or more of zirconium nitrate, zirconium acetate, zirconium chloride, zirconium citrate or zirconium sulfate; the tin-containing compound includes one or more of tin nitrate, tin acetate, tin chloride, tin citrate or tin sulfate; the hafnium-containing compound includes one or more of hafnium nitrate, hafnium acetate or hafnium chloride; the lead-containing compound includes one or more of lead nitrate or lead acetate; the vanadium-containing compound includes one or more of vanadium nitrate, vanadium acetate, vanadium chloride or vanadium sulfate; the niobium-containing compound includes one or more of niobium sulfate or niobium oxalate; the tantalum-containing compound includes ammonium tantalate; the molybdenum-containing compound includes one or more of molybdenum nitrate or ammonium molybdate; the tungsten-containing compound includes one or more of tungsten acetate or ammonium tungstate.

[0011] Further, the auxiliary agent includes one or more of polyvinylpyrrolidone, dopamine, glucose, sucrose, guar gum, carboxymethyl cellulose, polyacrylic acid or polyacrylonitrile.

[0012] Further, the lithium-containing compound includes one or more of lithium nitrate, lithium hydroxide, lithium chloride, lithium citrate, lithium carbonate or lithium acetate.

[0013] Further, the atomic ratio of the metal element of the failed layered metal oxide electrode material to the metal compound is 100:0.1 to 10; the molar ratio of the layered metal oxide electrode material to the lithium-containing compound is 100:5 to 85.

[0014] Further, the layered metal oxide electrode material is a failed layered metal oxide electrode material of 0 to 80%.

[0015] Further, it includes the following steps:

[0016] (1) Add the metal compound and the lithium-containing compound to a solvent and mix evenly.

[0017] (2) Add the auxiliary agent to the system and mix evenly to obtain a mixed solution.

[0018] (3) While stirring, add the layered metal oxide electrode material to the mixed solution and mix evenly to obtain a precursor solution.

[0019] (4) Stir and heat the precursor solution until it is completely evaporated, and obtain the precursor after sufficient drying.

[0020] (5) Calcinate the obtained precursor in a combustion-supporting atmosphere to obtain a uniformly doped and modified layered metal oxide electrode material.

[0021] Further, the temperature of the calcination in step (5) is 800 - 900 °C, the heating rate is 3 - 10 °C / min, and the heat preservation time is 4 - 14 h.

[0022] By adopting the above scheme, the method of the present invention has the following advantages:

[0023] 1. The layered metal oxide cathode material selected in the present invention will have a loss of components and form vacancies after failure, which is conducive to the doping of elements.

[0024] 2. Some elements tend to be doped in the lithium layer, and some elements tend to be doped in the transition metal layer. Due to the different degrees of preference of different metals for doping sites, when two doping metals coexist, different metals will spontaneously occupy the doping sites in the lithium layer and the transition metal layer according to the priority of preference. The present invention conducts dual-element doping on the elements doped in the lithium layer and the transition metal layer. After cycling 200 times at a high voltage, it can still have a specific capacity close to 90%. The performance obtained by the dual-element doping is more excellent than that of single-element doping, achieving the effect of 1 + 1 > 2.

[0025] 3. After the metal elements of the present invention are doped into the bulk phase of the layered metal oxide cathode material, they can act as "pillars" to prevent the layered structure from collapsing due to expansion and contraction, enhancing the structural stability of the cathode material.

[0026] 4. The morphology of the layered metal oxide cathode material before and after doping by the method of the present invention does not change significantly, indicating that doping by the method of the present invention is beneficial to restoring the morphology of the cathode material.

[0027] 5. The method of the present invention forms stronger M - O bonds (M is the doping atom) between the rare earth atoms doped on the layered metal oxide cathode material and the material itself, which can effectively inhibit the loss of lattice oxygen.

[0028] 6. The doping elements in the method of the present invention weaken the cation mixing, and the layered structure is transformed into a rock salt phase and a spinel phase, achieving the purpose of inhibiting the phase transition.

[0029] 7. The present invention can not only restore the structure and performance of the failed layered metal oxide material, but also enhance the stability of the layered metal oxide at high voltage through doping, further improving its energy density and meeting the ever-changing performance requirements of lithium-ion batteries. Description of the Drawings

[0030] Figure 1 It is the SEM image of the repaired NCM523 cathode material doped with 1% Cr in Example 1.

[0031] Figure 2 It is the TEM image of the repaired NCM523 cathode material doped with 1% Cr in Example 1.

[0032] Figure 3 It is the SEM image of the repaired NCM523 cathode material doped with 1% Ce in Example 3.

[0033] Figure 4 It is the TEM image of the repaired NCM523 cathode material doped with 1% Ce in Example 3.

[0034] Figure 5 It is the SEM image of the repaired NCM523 cathode material co-doped with Cr and Ce in Example 5.

[0035] Figure 6 It is the TEM image of the repaired NCM523 cathode material co-doped with Cr and Ce in Example 5.

[0036] Figure 7 It is the cycling performance graph of the repaired NCM523 cathode material doped with 1% Cr in Example 1.

[0037] Figure 8 It is the cycling performance graph of the repaired NCM523 cathode material doped with 2% Ce in Example 2.

[0038] Figure 9 It is the cycling performance graph of the repaired NCM523 cathode material doped with 1% Ce in Example 3.

[0039] Figure 10 It is the cycling performance graph of the repaired NCM523 cathode material doped with 2% Ce in Example 4.

[0040] Figure 11 It is the cycling performance graph of the repaired NCM523 cathode material co-doped with Cr and Ce in Example 5.

[0041] Figure 12 It is the cycling performance graph of the repaired undoped NCM523 cathode material in the comparative example. Detailed Description of the Invention

[0042] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0043] Example 1:

[0044] (1) Weigh 1.154 g of LiNO 3 and 0.197 g of Cr(NO 3 ) 3 ·9H 2 O, dissolve it in 30 mL of water, and stir well until completely dissolved to obtain a mixed solution A.

[0045] (2) Weigh 0.4 g of polyvinylpyrrolidone (PVP) and add it to the mixed solution A, stir well for 3 h to obtain a mixed solution B.

[0046] (3) Weigh 4.649 g of 30%-deactivated NCM523 and add it to the solution B, stir well for 3 h to obtain a precursor solution C.

[0047] (4) Heat and stir the solution C at 80 °C until the water evaporates completely, and then place it in a vacuum drying oven and dry it for 12 h to obtain a uniformly repaired and doped NCM523 precursor D.

[0048] (5) Put the precursor D into a box furnace and sinter it at 800 °C for 10 h to obtain a uniformly repaired and doped NCM523 cathode material E.

[0049] Figure 1 It can be seen that after doping by the method of the present invention, the morphology of the cathode material does not change significantly.

[0050] Figure 2 It can be seen that after doping by the method of the present invention, clear lattice fringes can be seen on the surface of the sample, indicating that the doped sample has good crystallization and the atoms are tightly and uniformly bonded.

[0051] Example 2:

[0052] The difference from Example 1 is that the doping amount of Cr(NO 3 ) 3 ·9H 2 O is twice that of Example 1.

[0053] Example 3:

[0054] (1) Weigh 1.151 g of LiNO 3 and 0.213 g of Ce(NO 3 )3 ·6H 2 Dissolve 3 in 30 mL of water, and stir well until completely dissolved to obtain a mixed solution A.

[0055] (2) Weigh 0.4 g of polyvinylpyrrolidone (PVP) and add it to the mixed solution A, and stir well for 3 h to obtain a mixed solution B.

[0056] (3) Weigh 4.636 g of 30% inactivated NCM523 and add it to the solution B, and stir well for 3 h to obtain a precursor solution C.

[0057] (4) Heat and stir the solution C at 80 °C until the water evaporates completely, and then place it in a vacuum drying oven and dry it for 12 h to obtain a uniformly repaired and doped NCM523 precursor D.

[0058] (5) Put the precursor D into a box furnace and sinter it at 850 °C for 10 h to obtain a uniformly repaired and doped NCM523 cathode material E.

[0059] Figure 3 It can be seen that after doping by the method of the present invention, the morphology of the cathode material has no obvious change, the particle surface is smooth, and no obvious unincorporated impurities are seen.

[0060] Figure 4 It can be seen that after doping by the method of the present invention, clear lattice fringes can be seen on the surface of the sample, indicating that the doped sample has good crystallization and the atoms are tightly and uniformly bonded.

[0061] Example 4:

[0062] The difference from Example 3 is that the doping amount of Ce(NO 3 ) 3 ·6H 2 O is twice that of Example 3.

[0063] Example 5:

[0064] (1) Weigh 1.114 g of LiNO 3 , 0.190 g of Cr(NO 3 ) 3 ·9H 2 O and 0.206 g of Ce(NO 3 ) 3 ·6H 2 Dissolve in 30 mL of water, and stir well until completely dissolved to obtain a mixed solution A.

[0065] (2) Weigh 0.4 g of polyvinylpyrrolidone (PVP) and add it to the mixed solution A, and stir well for 3 h to obtain a mixed solution B.

[0066] (3) Weigh 4.489 g of NCM523 with 30% inactivation and add it to Solution B. Stir well for 3 h to obtain precursor solution C.

[0067] (4) Heat and stir solution C at 80 °C until the water evaporates completely, then place it in a vacuum drying oven and dry for 12 h to obtain uniformly repaired and doped NCM523 precursor D.

[0068] (5) Put precursor D into a box furnace and sinter at 850 °C for 10 h to obtain uniformly repaired and doped NCM523 cathode material E.

[0069] Figure 3 It can be seen that after doping by the method of the present invention, the morphology of the cathode material has not changed significantly, the particle surface is smooth, and no obvious unincorporated impurities are seen.

[0070] Figure 4 It can be seen that after doping by the method of the present invention, clear lattice fringes can be seen on the sample surface, indicating that the sample after dual-element doping has good crystallization, and the atoms are closely and uniformly combined.

[0071] Example 6:

[0072] (1) Weigh 1.151 g of LiNO 3 and 0.213 g of La(NO 3 ) 3 ·6H 2 O and dissolve it in 30 mL of water. After stirring well until completely dissolved, obtain mixed solution A.

[0073] (2) Weigh 0.4 g of polyvinylpyrrolidone (PVP) and add it to mixed solution A. Stir well for 3 h to obtain mixed solution B.

[0074] (3) Weigh 4.636 g of NCM523 with 30% inactivation and add it to solution B. Stir well for 3 h to obtain precursor solution C.

[0075] (4) Heat and stir solution C at 80 °C until the water evaporates completely, then place it in a vacuum drying oven and dry for 12 h to obtain uniformly repaired and doped NCM523 precursor D.

[0076] (5) Put precursor D into a box furnace and sinter at 800 °C for 10 h to obtain uniformly repaired and doped NCM523 cathode material E.

[0077] Example 7:

[0078] (1) Weigh 1.144 g of LiNO 3 and 0.211 g of Ce(NO 3 ) 3 ·6H2 O is dissolved in 30 mL of water and stirred thoroughly until completely dissolved to obtain a mixed solution A.

[0079] (2) Weigh 0.06 g of polyvinylpyrrolidone (PVP) and add it to the mixed solution A, and stir thoroughly for 3 h to obtain a mixed solution B.

[0080] (3) Weigh 4.645 g of 30%-deactivated NCM811 and add it to the solution B, and stir thoroughly for 3 h to obtain a precursor solution C.

[0081] (4) Heat and stir the solution C at 80 °C until the water evaporates completely, and then place it in a vacuum drying oven and dry it for 12 h to obtain a uniformly repaired and doped NCM811 precursor D.

[0082] (5) Put the precursor D into a box furnace and sinter it at 850 °C for 10 h to obtain a uniformly repaired and doped NCM811 cathode material E.

[0083] Comparative example:

[0084] (1) Weigh 1.25 g of LiNO 3 and dissolve it in 30 mL of water. After stirring thoroughly until completely dissolved, a mixed solution A is obtained.

[0085] (2) Weigh 0.4 g of polyvinylpyrrolidone (PVP) and add it to the mixed solution A, and stir thoroughly for 3 h to obtain a mixed solution B.

[0086] (3) Weigh 4.75 g of 30%-deactivated NCM523 and add it to the solution B, and stir thoroughly for 3 h to obtain a precursor solution C.

[0087] (4) Heat and stir the solution C at 80 °C until the water evaporates completely, and then place it in a vacuum drying oven and dry it for 12 h to obtain a uniformly repaired NCM523 precursor D.

[0088] (5) Put the precursor D into a box furnace and sinter it at 800 °C for 10 h to obtain a uniformly repaired NCM523 cathode material.

[0089] Electrochemical performance test:

[0090] Using lithium as the negative electrode, the button batteries are made from Examples 1-5 and the comparative example respectively, and a 200-cycle long-term cycling test is carried out under a voltage window of 2.7-4.5 V. The results are as Figures 7 to 12 shown. At high voltage, after 200 cycles, the specific capacities of the examples with metal doping are all above 80%, while the specific capacity of the comparative example repaired only with lithium is only 76.7%. Compare Figure 10 with Figure 7 and 9、11 Comparison shows that by using the method of the present invention, a very small amount of metal doping can greatly improve the cycling stability of the repaired electrode at high voltages, and a huge improvement in performance can be achieved with a minimal increase in cost.

[0091] On this basis, Example 5 simultaneously uses chromium in the transition metal layer and cerium in the lithium layer as doping sites for co-doping. Comparing Figure 7 、 Figure 8 and Figure 11 , as well as Figure 9 、 Figure 10 and Figure 11 It can be seen that the relationship between the doping amount of a single doping element and the cycling efficiency is not entirely a positive influence. Continuing to increase the doping amount may cause the cycling performance to decline. However, in Example 5, co-doping with multiple elements can fully occupy the doping sites. As an electrode, it can maintain a specific capacity of nearly 87% after 200 cycles at high voltages, achieving a huge improvement in cycling performance. There are no obvious unincorporated impurities on the surface of the obtained sample. Moreover, it shows that designing multi-element doping for doping sites can further improve the structural stability and strength of the electrode material, and can greatly improve the structural integrity of the electrode material during charge and discharge. The method of the present invention has strong practicability and has made great progress.

[0092] For those skilled in the art, various corresponding changes and deformations can be made according to the technical solutions and concepts described above, and all these changes and deformations should fall within the protection scope of the claims of the present invention.

Claims

1. A method for uniformly doping, modifying, regenerating and repairing failed layered metal oxide electrode materials, characterized in that: One or more metal compounds containing metal elements, layered metal oxide electrode materials, lithium-containing compounds and organic additives are mixed separately, then heated while stirring until the solvent evaporates, and then calcined to obtain a uniformly doped and modified layered metal oxide electrode material.

2. The method for uniformly doping, modifying, regenerating and repairing failed layered metal oxide electrode materials according to claim 1, characterized in that: The mass ratio of the auxiliary agent to the layered metal oxide electrode material is 1:10-100.

3. The method for uniformly doping, modifying, regenerating and repairing failed layered metal oxide electrode materials according to claim 1, characterized in that: When the metal compound is one, the metal compound includes a metal compound with a doping site in a lithium layer or a metal compound with a doping site in a transition metal layer; When there are several kinds of metal compounds, the metal compounds include one or several metal compounds with doping sites in the lithium layer, and one or several metal compounds with doping sites in the transition metal layer.

4. The method for uniformly doping, modifying, regenerating and repairing failed layered metal oxide electrode materials according to claim 1 or 3, characterized in that: The metal compound is one, and the metal compound includes a water-soluble and / or alcohol-soluble sodium-containing compound, a potassium-containing compound, a rubidium-containing compound, a magnesium-containing compound, a calcium-containing compound, a copper-containing compound, a zinc-containing compound, a strontium-containing compound, a cadmium-containing compound or a barium-containing compound, a scandium-containing compound, a yttrium-containing compound, an indium-containing compound, an antimony-containing compound, a lanthanum-containing compound, a cerium-containing compound, a praseodymium-containing compound, a neodymium-containing compound, a promethium-containing compound, a samarium-containing compound, a europium-containing compound, and a gadolinium-containing compound. , one of the terbium-containing compounds, dysprosium-containing compounds, holmium-containing compounds, erbium-containing compounds, thulium-containing compounds, ytterbium-containing compounds, lutetium-containing compounds, bismuth-containing compounds, zirconium-containing compounds, tin-containing compounds, hafnium-containing compounds or lead-containing compounds, or one of the water-soluble and / or alcohol-soluble aluminum-containing compounds, chromium-containing compounds, iron-containing compounds, gallium-containing compounds, titanium-containing compounds, germanium-containing compounds, vanadium-containing compounds, niobium-containing compounds, tantalum-containing compounds, molybdenum-containing compounds or tungsten-containing compounds whose doping sites are in the transition metal layer.

5. The method for uniformly doping, modifying, regenerating and repairing failed layered metal oxide electrode materials according to claim 1, characterized in that: The auxiliary agent includes one or more of polyvinyl pyrrolidone, dopamine, glucose, sucrose, guar gum, carboxymethyl cellulose, polyacrylic acid or polyacrylonitrile.

6. The method for uniformly doping, modifying, regenerating and repairing failed layered metal oxide electrode materials according to claim 1, characterized in that: The lithium-containing compound includes one or more of lithium nitrate, lithium hydroxide, lithium chloride, lithium citrate, lithium carbonate or lithium acetate.

7. The method for uniformly doping, modifying, regenerating and repairing failed layered metal oxide electrode materials according to claim 1, characterized in that: The atomic ratio of the failed layered metal oxide electrode material to the metal element of the metal compound is 100:0.1-10; the molar ratio of the layered metal oxide electrode material to the lithium-containing compound is 100:5-85.

8. The method for uniformly doping, modifying, regenerating and repairing failed layered metal oxide electrode materials according to claim 1, characterized in that: The layered metal oxide electrode material is a layered metal oxide electrode material with a failure rate of 0 to 80%.

9. The method for uniformly doping, modifying, regenerating and repairing failed layered metal oxide electrode materials according to claim 1, characterized in that: The following steps are involved: (1) adding a metal compound and a lithium-containing compound to a solvent and uniformly mixing them; (2) adding an auxiliary agent to the system and mixing uniformly to obtain a mixed solution; (3) adding a layered metal oxide electrode material to the mixed solution while stirring, and mixing evenly to obtain a precursor solution; (4) heating the precursor liquid while stirring until it is evaporated to dryness, and obtaining the precursor after being fully dried; (5) calcining the obtained precursor in a combustion-supporting atmosphere to obtain a uniformly doped and modified layered metal oxide electrode material.

10. The method for uniformly doping, modifying, regenerating and repairing failed layered metal oxide electrode materials according to claim 9, characterized in that: The calcination temperature in step (5) is 800-900° C., the heating rate is 3-10° C. / min, and the insulation time is 4-14 h.

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