WO2022205831A1 - 一种离子通道稳定性高的掺杂改性正极材料 - Google Patents

一种离子通道稳定性高的掺杂改性正极材料 Download PDF

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WO2022205831A1
WO2022205831A1 PCT/CN2021/123465 CN2021123465W WO2022205831A1 WO 2022205831 A1 WO2022205831 A1 WO 2022205831A1 CN 2021123465 W CN2021123465 W CN 2021123465W WO 2022205831 A1 WO2022205831 A1 WO 2022205831A1
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positive electrode
electrode material
carrier structure
doped modified
ion channel
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French (fr)
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汉海霞
陈瑶
许梦清
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万向一二三股份公司
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/362—Composites
    • H01M4/364—Composites as mixtures
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/60—Heating or cooling; Temperature control
    • H01M10/61—Types of temperature control
    • H01M10/613—Cooling or keeping cold
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/60—Heating or cooling; Temperature control
    • H01M10/65—Means for temperature control structurally associated with the cells
    • H01M10/653—Means for temperature control structurally associated with the cells characterised by electrically insulating or thermally conductive materials
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/60—Heating or cooling; Temperature control
    • H01M10/65—Means for temperature control structurally associated with the cells
    • H01M10/654—Means for temperature control structurally associated with the cells located inside the innermost case of the cells, e.g. mandrels, electrodes or electrolytes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
    • H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
    • H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/5825—Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M2004/021—Physical characteristics, e.g. porosity, surface area
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
    • H01M2004/028—Positive electrodes
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the invention relates to the field of positive electrode materials for lithium batteries, in particular to a doped modified positive electrode material with high ion channel stability.
  • a lithium-ion battery is a secondary battery (rechargeable battery) that mainly relies on the movement of lithium ions between the positive and negative electrodes to work.
  • Li ions intercalate and deintercalate back and forth between the two electrodes: during charging, Li ions are deintercalated from the positive electrode, intercalated into the negative electrode through the electrolyte, and the negative electrode is in a lithium-rich state; during discharge, the opposite is true.
  • there are many ways to improve the cycle performance of lithium-ion batteries Select stable materials, including positive and negative electrodes and electrolyte materials, and then combine them in the most reasonable ratio to form a high-performance lithium-ion battery.
  • the cathode material such as doping and coating improvement of the lithium ion ternary material (NCM) cathode material to slow down the deterioration of the crystal structure of the cathode material during cycling.
  • NCM lithium ion ternary material
  • the positive electrode material and the negative electrode material are required to have strong physical and chemical stability. Physical stability: The positive electrode material and the negative electrode material are required to have structural stability during the conduction process and the charge-discharge process.
  • Patent number CN2013106975871 patent name: LiV 3 O 8 and LiNi 0.4 Co 0.2 Mn 0.4 O 2 blended and modified lithium battery cathode material preparation method
  • the invention relates to the manufacture of lithium battery cathode material, in particular a LiV 3 O 8
  • a preparation method of a lithium battery cathode material blended with LiNi 0.4 Co 0.2 Mn 0.4 O 2 is modified.
  • the method of the invention includes the following steps: a. preparation of positive electrode material LiV 3 O 8 ; b. preparation of ternary positive electrode LiNi 0.4 Co 0.2 Mn 0.4 O 2 ; c .
  • a positive electrode material with high compaction density can be obtained through the blending modification of the ternary material and LiV 3 O 8 , and the capacity performance can be effectively improved after testing.
  • the present invention is to overcome the problem of poor cycle performance of the positive electrode material in the prior art lithium battery, and to provide a doped modified positive electrode material with high ion channel stability.
  • the positive electrode material with stable pores and good integrity makes the prepared lithium battery positive electrode material have strong cycle performance and long service life, which can effectively realize the material selection and process optimization of lithium ion battery.
  • a doped modified positive electrode with high ion channel stability is: supported nickel cobalt lithium manganate mixed with lithium manganese iron phosphate material.
  • the mass ratio of the loaded nickel-cobalt lithium manganate to the lithium manganese iron phosphate material is 1:0.25-0.4.
  • the loaded nickel-cobalt lithium manganate itself has a stable and orderly ion channel arrangement structure, and there are many hydroxyl groups and positively charged metal active sites on the loaded nickel-cobalt lithium manganate.
  • Lithium iron manganese phosphate material with an olivine-like crystal structure is doped into it.
  • the lithium iron manganese phosphate material inherits the stable structure of lithium iron phosphate olivine crystal, and its structural stability is better than the layered structure of ternary materials.
  • lithium iron manganese phosphate material itself has relatively stable lithium ion channels, the lithium ion channel is composed of coordination structure Mn 2+ O 6 , and the structure active site on lithium manganese iron phosphate (Mn 2+ , O 2- and PO 4 3- , etc.) can attract and coordinate with many hydroxyl groups and positively charged metal active sites on the supported nickel-cobalt lithium manganate to form an effective and unified whole, and lithium manganese iron phosphate can also Further complex and diversified lithium ion pore structure on NiCoMnO2 was prepared, and the lithium ion pore channels with scattered, orderly arrangement, strong integration and high stability were prepared.
  • Grafting active group add the supported carrier structure, glycidyl neodecanoate and ⁇ -cyclodextrin into N,N-dimethylformamide in a mass ratio, and stir to react at 65-75°C for 18- 22h, filtered and washed to obtain a grafted support structure;
  • step (1) Mn 2+ is used as the skeleton core, and terephthalic acid, vinyl acetate, vinyl terephthalic acid and dimethylacetamide are used as coordination
  • the polymer is polymerized, and then diethylenetriamine is added for cross-linking to form an ordered three-dimensional arrangement frame, in which polyvinyl acetate, terephthalate and vinyl terephthalate are used as substitution compounds.
  • the body is embedded in the structure of the three-dimensional arrangement framework; after adding styrene monomer and initiator peroxyketal in step (2), polystyrene, terephthalic acid and terephthalic acid can be formed in the three-dimensional arrangement framework arranged along the pore direction
  • the ester can connect Zn 2+ and polystyrene in the channel at the same time, bridge the polymer chains of adjacent channels together, and form a framework structure with high stability; in step (3), add trisodium aminotriacetate, aminotriacetate As a complex, trisodium acetate can selectively dissolve part of the organic framework near the polystyrene arrangement in the preliminary support structure.
  • the pore diameter in the three-dimensional arrangement framework is larger and the specific surface area is larger. larger, the adsorption capacity of nickel cobalt lithium manganate is stronger, which is convenient for subsequent adsorption and connection of nickel cobalt lithium manganate; in step (4), ⁇ -cyclodextrin is used to activate and modify the supported carrier structure, because ⁇ -The cyclodextrin has a larger ring and more hydroxyl groups, which can be stably connected to the load carrier structure, and while increasing the active site of hydroxyl groups, it also promotes the structural stability of the load carrier structure; in step (5) , more hydroxyl sites are formed on the surface of the activated load carrier structure, the metal ion groups on the nickel cobalt lithium manganate and the active groups on the binder PVDF 761 can be smoothly adsorbed and connected to the hydroxyl groups, and the hydroxyl sites It also has a strong adsorption effect on organic binders with strong polarity
  • the sequence of preparing the loaded carrier structure and then loading the lithium nickel cobalt manganate can be combined, which can protect the raw material activity of the nickel cobalt lithium manganate to a greater extent and avoid the polymerization of the embedded lithium nickel cobalt manganate during the preparation process. Lithium ion channels are destroyed or blocked by the action of compounds or ligands.
  • the preparation method of the present invention enables the nickel-cobalt lithium manganate to be arranged in an orderly manner along the frame structure of the loaded carrier structure, and the loaded support structure can also provide a better support for the nickel-cobalt lithium manganate, whether it is for the nickel-cobalt lithium manganate
  • Both the orderly arrangement of the lithium ion channels and the prevention of the collapse of the lithium ion channels have significant positive effects.
  • Mn in the load carrier structure can effectively connect the nickel cobalt lithium manganate in each channel in the load carrier structure frame to form numerous densely connected veins, which greatly improves the conductivity and the internal conductivity of the positive electrode material.
  • the heat dissipation capability enables the positive electrode material to have a longer life cycle.
  • the ratio of MnSO 4 ⁇ 4H 2 O to ethanol is 1.2-1.4 g: 80 mL; the mass ratio of terephthalic acid, vinyl acetate, vinyl terephthalic acid and dimethylacetamide is is 1:1.05-1.3:1.1-1.3:1.5-1.6.
  • the volume ratio of the Mn 2+ solution, the mixed solution and the diethylenetriamine solution is 1:2.8-3.6:0.6-0.8.
  • the ratio of manganese has a great influence on the cycle performance of the cathode doped modified materials. It is very important to choose the appropriate ratio of ferromanganese elements: on the one hand, the plateau voltage of manganese is about 4.1V, which increases The content of manganese can increase the median voltage of the positive electrode doping modified material, but if the content of manganese is too much, there is a risk of precipitation of manganese, which has a great impact on capacity and safety. Therefore, the selection of suitable manganese is the most critical.
  • the present invention further improves the stability of the manganese element from the Mn 2+ coordination of the supported carrier.
  • step (1) heating and stirring conditions: 96-100° C., stirring for 0.8-1.2 h.
  • the mass ratio of the three-dimensionally arranged framework, styrene propylene and peroxyketal is 3:2-2.5:0.5-0.8.
  • the mass ratio of the first carrier structure to trisodium aminotriacetate is 2-2.5:0.7-1.0.
  • the mass ratio of the loaded carrier structure, glycidyl neodecanoate to ⁇ -cyclodextrin and N,N-dimethylformamide is 1:0.6-0.8:1.5-2:0.4 -0.6.
  • step (5) the ratio of the grafted support structure, nickel cobalt lithium manganate and PVDF 761 is 1:2-3:0.15-0.4.
  • the present invention has the following beneficial effects:
  • the supported nickel-cobalt lithium manganate of the present invention is doped into a lithium manganese iron phosphate material with an olivine-like crystal structure to form an effective and unified whole, and the lithium manganese iron phosphate can also be further complex and diversified to support nickel, cobalt, and manganese.
  • the preparation method of the present invention enables the nickel-cobalt lithium manganate to be arranged in an orderly manner along the frame structure of the loaded carrier structure, and the loaded support structure can also provide better support for the nickel-cobalt lithium manganate, whether it is for nickel-cobalt lithium manganate.
  • the orderly arrangement of the lithium ion channels in lithium manganate or the prevention of the collapse of the lithium ion channels has a significant positive effect;
  • the metal ion (Mn) connection function of the load carrier supporting nickel cobalt lithium manganate itself further strengthens the conductive effect of metal ions between the added components, and at the same time improves the heat dissipation performance of the positive electrode material, so that the final The prepared lithium battery is more durable.
  • the doped modified positive electrode material is: a material of lithium manganese iron phosphate mixed with nickel cobalt lithium manganate in a mass ratio of 1:0.25-0.4.
  • the preparation process of the loaded nickel cobalt lithium manganate is:
  • Grafting active group add the supported carrier structure, glycidyl neodecanoate and ⁇ -cyclodextrin into N,N-dimethylformamide in a mass ratio, and stir to react at 65-75°C for 18- 22h, filter and wash to obtain the grafted support structure; the mass ratio of the loaded support structure, glycidyl neodecanoate to ⁇ -cyclodextrin and N,N-dimethylformamide is 1:0.6-0.8:1.5- 2: 0.4-0.6;
  • a doped modified positive electrode with high ion channel stability is: supported nickel cobalt lithium manganate mixed with lithium manganese iron phosphate material at a mass ratio of 1:0.32.
  • the preparation process of the loaded nickel-cobalt lithium manganate is:
  • Grafting active group add the supported carrier structure, glycidyl neodecanoate and ⁇ -cyclodextrin into N,N-dimethylformamide in a mass ratio, stir and react at 70°C for 20h, filter and remove Washing to obtain a grafted carrier structure; the mass ratio of the loaded carrier structure, glycidyl neodecanoate to ⁇ -cyclodextrin and N,N-dimethylformamide is 1:0.7:1.8:0.5;
  • a doped modified positive electrode with high ion channel stability is: supported nickel cobalt lithium manganate mixed with lithium manganese iron phosphate material at a mass ratio of 1:0.35.
  • the preparation process of the loaded nickel-cobalt lithium manganate is:
  • a doped modified positive electrode with high ion channel stability is: supported nickel cobalt lithium manganate mixed with lithium manganese iron phosphate material at a mass ratio of 1:0.3.
  • the preparation process of the loaded nickel-cobalt lithium manganate is:
  • Grafting active group add the supported carrier structure, glycidyl neodecanoate and ⁇ -cyclodextrin into N,N-dimethylformamide in a mass ratio, stir and react at 72°C for 21.5h, filter and washing to obtain a grafted carrier structure; the mass ratio of the loaded carrier structure, glycidyl neodecanoate, ⁇ -cyclodextrin and N,N-dimethylformamide is 1:0.75:1.85:0.55;
  • a doped modified positive electrode with high ion channel stability is: supported nickel cobalt lithium manganate mixed with lithium manganese iron phosphate material at a mass ratio of 1:0.25.
  • the preparation process of the loaded nickel-cobalt lithium manganate is:
  • Grafting active group add the supported carrier structure, glycidyl neodecanoate and ⁇ -cyclodextrin into N,N-dimethylformamide in a mass ratio, stir and react at 65°C for 18h, filter and remove Washing to obtain a grafted carrier structure; the mass ratio of the loaded carrier structure, glycidyl neodecanoate to ⁇ -cyclodextrin and N,N-dimethylformamide is 1:0.6:2:0.4;
  • a doped modified positive electrode with high ion channel stability is: supported nickel cobalt lithium manganate mixed with lithium manganese iron phosphate material at a mass ratio of 1:0.4.
  • the preparation process of the loaded nickel cobalt lithium manganate is:
  • Grafting active group add the supported carrier structure, glycidyl neodecanoate and ⁇ -cyclodextrin into N,N-dimethylformamide in a mass ratio, stir and react at 75°C for 18h, filter and remove Washing to obtain a grafted carrier structure; the mass ratio of the loaded carrier structure, glycidyl neodecanoate to ⁇ -cyclodextrin and N,N-dimethylformamide is 1:0.8:1.5:0.6;
  • Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that the content of the lithium iron manganese phosphate material is too much, the mass ratio of the loaded nickel cobalt lithium manganate to the lithium iron manganese phosphate material is 1:0.6, and the rest of the steps are the same as in Example 1.
  • Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that the nickel cobalt lithium manganate material is not supported, and the rest of the steps are the same as those of Example 1.
  • Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that Zn(NO 3 ) 2 .6H 2 O is used to replace MnSO 4 .4H 2 O in step (1) in the preparation process of the supported nickel-cobalt lithium manganate, and the remaining steps are the same as those of the embodiment. 1 is the same.
  • Comparative Example 4 The difference between Comparative Example 4 and Example 1 is that the step (3) selective dissolution is omitted in the preparation process of the supported nickel-cobalt lithium manganate, and the remaining steps are the same as those of Example 1.
  • Comparative Example 5 The difference between Comparative Example 5 and Example 1 is that in the preparation process of the supported nickel-cobalt lithium manganate, step (4) grafting active groups is omitted, and the remaining steps are the same as those of Example 1.
  • the doped modified positive electrode materials prepared in the above examples and comparative examples were used to prepare corresponding batteries, and the relevant performance tests of the batteries were carried out.
  • Positive electrode positive electrode material, Super P, VGCF, PVDF, its mass ratio is 92:2:2:3;
  • Negative electrode lithium metal sheet
  • Test voltage 2.8 ⁇ 4.3V
  • Capacity test conditions 0.1C room temperature constant current charge and discharge test.
  • Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that the content of lithium iron manganese phosphate material is too much, and the mass ratio of loaded nickel cobalt lithium manganate to lithium iron manganese phosphate material is 1:0.6; If the content of manganese is too high, manganese will be precipitated, which has a great impact on capacity and safety. At the same time, the content of loaded nickel cobalt lithium manganate can be reduced first, and then the stability and order of ion channels in the doping modified cathode material can be reduced. The performance of the battery will be reduced, and the performance of the final battery will be reduced.
  • the difference between Comparative Example 2 and Example 1 is that the nickel-cobalt lithium manganate material is not loaded; the preparation method of the present invention enables the nickel-cobalt lithium manganate to be arranged in an orderly manner along the frame structure of the loaded carrier structure, and the loaded support structure is also It can provide a good support for nickel cobalt lithium manganate, whether it is the orderly arrangement of lithium ion channels in nickel cobalt lithium manganate or the prevention of the collapse of lithium ion channels, which has a significant positive effect. Affects the conductivity and cycle performance of the final material.
  • Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that Zn(NO 3 ) 2 ⁇ 6H 2 O is used to replace MnSO 4 ⁇ 4H 2 O in step (1) in the preparation process of the supported nickel cobalt lithium manganate; It can effectively connect the nickel cobalt lithium manganate in each channel in the load carrier structure frame to form countless densely connected veins, which greatly improves the median voltage and electrical performance inside the positive electrode material, making the positive electrode material It has a long service period; the Mn 2+ of the load carrier is coordinated to further improve the stability of manganese element and reduce the precipitation of manganese element in the positive electrode material, and the above effect cannot be achieved after replacement.
  • Comparative Example 4 The difference between Comparative Example 4 and Example 1 is that the selective dissolution of step (3) is omitted in the preparation process of loaded nickel-cobalt lithium manganate; the selective dissolution of step (3) is omitted in the preparation of loaded nickel-cobalt lithium manganate; Not adding trisodium aminotriacetate selectively dissolves part of the organic framework in the preliminary support structure, which will reduce the porosity and specific surface area in the final loaded support structure, thereby reducing the loading capacity of the loaded support structure, and finally make nickel cobalt lithium manganate The effective load is greatly reduced, and the inner diameter of the pores is small, which cannot fully accommodate the nickel-cobalt lithium manganate, and cannot effectively protect and support the nickel-cobalt lithium manganate, so the related electrochemical performance will be greatly reduced.
  • Comparative Example 5 The difference between Comparative Example 5 and Example 1 is that the grafting active group in step (4) is omitted in the preparation process of the supported nickel cobalt lithium manganate; the ⁇ -cyclodextrin in step (4) is omitted in the preparation of the supported carrier structure. Grafting activation; the lack of surface activation and grafting on the preparation of the loaded support structure will reduce the number of active sites on the surface of the prepared loaded support structure, and the nickel cobalt lithium manganate cannot be smoothly or stably connected to the loaded support structure.
  • the raw materials and equipment used in the present invention are the common raw materials and equipment in the art; the methods used in the present invention, unless otherwise specified, are the conventional methods in the art.

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Abstract

本发明涉及锂电池正极材料领域，针对现有锂电池中正极材料循环性能差的问题，公开了一种离子通道稳定性高的掺杂改性正极材料，所述掺杂改性正极材料为：混掺有磷酸锰铁锂材料的负载镍钴锰酸锂，负载镍钴锰酸锂与磷酸锰铁锂材料质量比为1：0.25-0.4。所述负载镍钴锰酸锂的制备过程为：（1）制成三维排列框架；（2）制成第一载体结构；（3）选择性溶解；（4）接枝活性基团；（5）负载。本发明能够制备出具有良好导热性、导电性、高稳定性孔道及整体性性能好的正极材料，使得制备出来的锂电池正极材料具有较强的循环性能与较长的使用寿命，可以有效实现锂离子电池的材料优选和工艺优化。

Description

一种离子通道稳定性高的掺杂改性正极材料 技术领域
本发明涉及锂电池正极材料领域，尤其是涉及一种离子通道稳定性高的掺杂改性正极材料。
背景技术
锂离子电池是一种二次电池(充电电池)，它主要依靠锂离子在正极和负极之间移动来工作。在充放电过程中，Li离子在两个电极之间往返嵌入和脱嵌：充电时，Li离子从正极脱嵌，经过电解质嵌入负极，负极处于富锂状态；放电时则相反。目前锂离子电池中提高循环性能的方法较多，选用稳定的材料，包括正极负极和电解液材料，然后以一种最合理的配比方式组合起来，形成一种高性能的锂离子电池。多数情况下，提高电芯的循环性能从正极材料着手，比如对锂离子三元材料(NCM)正极材料进行掺杂和包覆改进以减缓正极材料在循环过程中晶体结构的恶化。在电池使用的过程中，由于电池中Li离子电池的不断嵌入和脱嵌，这就要求正极材料与负极材料具有较强的物理稳定性与化学稳定性。物理稳定性：要求正极材料与负极材料在导电过程与充放电过程中具有结构稳定，既要具有保证Li离子的顺利迁移的离子通道，又要具备Li离子脱嵌防止空穴塌陷的能力，尤其是当电池持续充放电后产热高温的情况下。化学稳定性：当随着电池内温度与湿度的变化，电极材料的各组分依然保持有较好的形状，而不会影响到Li离子嵌入、脱嵌和运输。因此，制备出具有物理稳定性与化学稳定性高的锂电池正极材料具有重要的意义。
专利号CN2013106975871，专利名称：LiV 3O 8和LiNi 0.4Co 0.2Mn 0.4O 2共混改性锂电池正极材料的制备方法，本发明涉及锂电池正极材料的制造，具体是一种LiV 3O 8和LiNi 0.4Co 0.2Mn 0.4O 2共混改性锂电池正极材料的制备方法。本发明的方法包括以下步骤：a.正极材料LiV 3O 8的制备；b.三元正极LiNi 0.4Co 0.2Mn 0.4O 2的制备；c.将正极材料LiV 3O 8和LiNi 0.4Co 0.2Mn 0.4O 2按照3：7的质量比在三维锥混机内混合；在马弗炉内烧结，在480-500℃预烧2h；650-675℃烧结4h；在800-825℃烧结6h，并在此温度保温8h；后随炉自然冷却，破碎，最后制得共混材料(LiV 3O 8和LiNi 0.4Co 0.2Mn 0.4O 2)。本发明通过三元材料与LiV 3O 8的共混改性，能够获得高压实密度的正极材料，经检测，可以有效提高容量性能。
上述专利不足之处在于，仅采用简单的物理混合，且混合后需要进行高温烧结，一方面会易破坏三元材料基体结构，另一方面混合组分间无化学键产生不利于锂离子通道的构建。
发明内容
本发明是为了克服现有技术的锂电池中正极材料循环性能差的问题，提供一种离子通 道稳定性高的掺杂改性正极材料，本发明能够制备出具有良好导热性、导电性、高稳定性孔道及整体性性能好的正极材料，使得制备出来的锂电池正极材料具有较强的循环性能与较长的使用寿命，可以有效实现锂离子电池的材料优选和工艺优化。
为了实现上述目的，本发明采用以下技术方案：
一种离子通道稳定性高的掺杂改性正极，所述掺杂改性正极材料为：混掺有磷酸锰铁锂材料的负载镍钴锰酸锂。
作为优选，负载镍钴锰酸锂与磷酸锰铁锂材料质量比为1：0.25-0.4。
本发明的负载镍钴锰酸锂本身就具有稳定有序的离子通道排列结构，且负载镍钴锰酸锂上存在许多羟基及带正电金属活性位点，通过在负载镍钴锰酸锂材料中掺杂入具有橄榄石状的晶体结构的磷酸锰铁锂材料，磷酸锰铁锂材料继承了磷酸铁锂橄榄石晶体的稳定结构，其结构稳定性优于三元材料的层状结构，在循环性能方面独特的优势；磷酸锰铁锂材料自身存在较稳定的锂离子通道，锂离子通道周围由配位结构Mn 2+O 6组成，磷酸锰铁锂上的结构活性位点(Mn 2+、O 2-及PO 4 3-等)能够与负载镍钴锰酸锂上的许多羟基及带正电金属活性位点发生吸引配位作用，形成一个有效统一的整体，磷酸锰铁锂也能够进一步复杂多元化负载镍钴锰酸锂上的锂离子孔道结构，制备得到错落有致、排列有序及一体性强稳定性高的阡陌交通的锂离子孔道。能够有效进一步提升锂电池的有效循环性能及电化学性能，极大延长锂电池的使用寿。另外，由于负载镍钴锰酸锂的负载载体本身的金属离子连通作用，进一步加强了各添加组分之间的金属离子体的导电作用，同时提升了正极材料的散热性能，使得最终制备得到的锂电池更加耐用。
作为优选，所述负载镍钴锰酸锂的制备过程为：
(1)制成三维排列框架：将MnSO 4·4H 2O分散在乙醇中，超声处理20-30min得到Mn 2+溶液，将对苯二甲酸、乙酸乙烯、乙烯基对苯二甲酸及二甲基乙酰胺混合均匀得到混合溶液，然后将混合溶液倒入Mn 2+溶液中，加热搅拌得到配位体溶液，再加入二乙烯三胺溶液，升温至115-120℃下搅拌1.8-2h，降至室温形成三维排列框架；
(2)制成第一载体结构：将三维排列框架加入苯丙烯与过氧缩酮的混合溶液中，升温至85-90℃，保温16-18h，得到第一载体结构；
(3)选择性溶解：往第一载体结构中加入氨基三乙酸三钠，常温下搅拌70-80min，静置0.3-0.5h后离心收集产物，乙醇洗涤次后45-50℃干燥，得到负载载体结构；
(4)接枝活性基团：将负载载体结构、新癸酸缩水甘油酯与γ-环糊精按质量比加入N,N-二甲基甲酰胺中，在65-75℃搅拌反应18-22h，过滤并洗涤，得到接枝载体结构；
(5)负载：将接枝载体结构加入到镍钴锰酸锂中混合均匀，继续加入PVDF 761，搅拌3-4h，过滤得到负载镍钴锰酸锂。
本发明中制备负载镍钴锰酸锂的过程中：步骤(1)中以Mn 2+作为骨架核心，对苯二甲酸、乙酸乙烯、乙烯基对苯二甲酸及二甲基乙酰胺作为配位体进行聚合，再加入二乙烯三胺进行交联，形成有序排列的三维排列框架，三维排列框架中聚乙酸乙烯酯、对苯二甲酸酯和乙烯基对苯二甲酸酯作为取代配体嵌入到三维排列框架的结构中；步骤(2)中加入苯乙烯单体与引发剂过氧缩酮后，能够在三维排列框架中形成沿孔隙方向排列的聚苯乙烯，对苯二甲酸酯能够同时连接上Zn 2+和孔道中的聚苯乙烯，将相邻孔道的聚合物链桥接在一起，形成稳定性高的框架结构；步骤(3)中加入氨基三乙酸三钠，氨基三乙酸三钠作为络合物，能够选择性溶解掉初步载体结构中的靠近聚苯乙烯排列的部分有机框架，在保证结构稳定性的前提下，使得三维排列框架中的孔隙直径更大，比表面积更大，对镍钴锰酸锂的吸附能力更强，便于后续镍钴锰酸锂的吸附及连接；步骤(4)中采用γ-环糊精来对负载载体结构进行活化改性，因为γ-环糊精上具有较大的环状与较多的羟基，能够稳定的连接到负载载体结构上，在增加羟基活性位点的同时，也促进负载载体结构的结构稳定；步骤(5)中，在活化负载载体结构表面形成较多的羟基位点，镍钴锰酸锂上的金属离子基团及粘结剂PVDF 761上的活性基团能够顺利的吸附并连接到羟基上，羟基位点对极性较强的有机物粘结剂也具有较强的吸附作用，有利于有机物粘结剂的均匀分散，形成有效稳定的一体化结构。
本发明中，采用先制备负载载体结构再负载镍钴锰酸锂的顺序来进行组合，能够较大程度保护镍钴锰酸锂的原材料活性，避免包埋式镍钴锰酸锂在制备过程聚合物或配位体的作用而破坏或者堵塞锂离子通道。本发明的制备方法使得镍钴锰酸锂能够沿着负载载体结构的框架结构有序排列，负载载体结构也能够为镍钴锰酸锂提供较好的支撑作用，无论是对镍钴锰酸锂中锂离子孔道的有序排列还是防止其中锂离子孔道的坍塌都具有显著的积极作用。另外，负载载体结构中的Mn能够将负载载体结构框架内的各通道中的镍钴锰酸锂进行有效连通，形成无数密集连通的脉络，这较大程度的提升了正极材料内部的导电能力与散热能力，使得该正极材料具有较长的使用周期。
作为优选，步骤(1)中，MnSO 4·4H 2O和乙醇的比例为1.2-1.4g：80mL；对苯二甲酸、乙酸乙烯、乙烯基对苯二甲酸及二甲基乙酰胺的质量比为1：1.05-1.3：1.1-1.3：1.5-1.6。
作为优选，步骤(1)中，Mn 2+溶液、混合溶液及二乙烯三胺溶液的体积比为1：2.8-3.6：0.6-0.8。
正极掺杂改性材料中，锰的比例对正极掺杂改性材料的循环性能影响较大，选择合适 的锰铁元素比例是至关重要的：一方面锰的平台电压在4.1V左右，提高锰的含量就能提高正极掺杂改性材料的中值电压，但是锰元素含量过多则会有锰元素析出的风险，对容量和安全影响较大，所以选择合适锰元素是最为关键的，本发明从负载载体的Mn 2+配位上来进一步提升锰元素的稳定性。
作为优选，步骤(1)中，加热搅拌条件：96-100℃，搅拌0.8-1.2h。
作为优选，步骤(2)中，三维排列框架、苯丙烯与过氧缩酮的质量比为3：2-2.5：0.5-0.8。
作为优选，步骤(3)中，第一载体结构与氨基三乙酸三钠的质量比为2-2.5：0.7-1.0。
作为优选，步骤(4)中，负载载体结构、新癸酸缩水甘油酯与γ-环糊精及N,N-二甲基甲酰胺的质量比为1：0.6-0.8：1.5-2：0.4-0.6。
作为优选，步骤(5)中，接枝载体结构、镍钴锰酸锂及PVDF 761的比例为1：2-3：0.15-0.4。
因此，本发明具有如下有益效果：
(1)本发明的负载镍钴锰酸锂掺杂入具有橄榄石状的晶体结构的磷酸锰铁锂材料，形成一个有效统一的整体，磷酸锰铁锂也能够进一步复杂多元化负载镍钴锰酸锂上的锂离子孔道结构，制备得到错落有致、排列有序及一体性强稳定性高的阡陌交通的锂离子孔道；
(2)本发明的制备方法使得镍钴锰酸锂能够沿着负载载体结构的框架结构有序排列，负载载体结构也能够为镍钴锰酸锂提供较好的支撑作用，无论是对镍钴锰酸锂中锂离子孔道的有序排列还是防止其中锂离子孔道的坍塌都具有显著的积极作用；
(3)负载镍钴锰酸锂的负载载体本身的金属离子(Mn)连通作用，进一步加强了各添加组分之间的金属离子体的导电作用，同时提升了正极材料的散热性能，使得最终制备得到的锂电池更加耐用。
具体实施方式
下面结合具体实施方式对本发明做进一步的描述。
总实施例
一种离子通道稳定性高的掺杂改性正极，所述掺杂改性正极材料为：负载镍钴锰酸锂中按质量比1：0.25-0.4混掺磷酸锰铁锂材料。
所述负载镍钴锰酸锂的制备过程为：
(1)制成三维排列框架：将MnSO 4·4H 2O分散在乙醇中，超声处理20-30min得到Mn 2+溶液，将对苯二甲酸、乙酸乙烯、乙烯基对苯二甲酸及二甲基乙酰胺按照质量比混合均匀得到混合溶液，然后将混合溶液倒入Mn 2+溶液中，96-100℃搅拌0.8-1.2h得到配位体溶液，再 加入二乙烯三胺溶液，升温至115-120℃下搅拌1.8-2h，降至室温形成三维排列框架；MnSO 4·4H 2O和乙醇的比例为1.2-1.4g：80mL；对苯二甲酸、乙酸乙烯、乙烯基对苯二甲酸及二甲基乙酰胺的质量比为1：1.05-1.3：1.1-1.3：1.5-1.6；Mn 2+溶液、混合溶液及二乙烯三胺溶液的体积比为1：2.8-3.6：0.6-0.8；
(2)制成第一载体结构：将三维排列框架加入苯丙烯与过氧缩酮的混合溶液中，升温至85-90℃，保温16-18h，得到第一载体结构；三维排列框架、苯丙烯与过氧缩酮的质量比为3：2-2.5：0.5-0.8；
(3)选择性溶解：往第一载体结构中加入氨基三乙酸三钠，常温下搅拌70-80min，静置0.3-0.5h后离心收集产物，乙醇洗涤三次后在45-50℃烘箱中过夜干燥，得到负载载体结构；第一载体结构与氨基三乙酸三钠的质量比2-2.5：0.7-1.0；
(4)接枝活性基团：将负载载体结构、新癸酸缩水甘油酯与γ-环糊精按质量比加入N,N-二甲基甲酰胺中，在65-75℃搅拌反应18-22h，过滤并洗涤，得到接枝载体结构；负载载体结构、新癸酸缩水甘油酯与γ-环糊精及N,N-二甲基甲酰胺的质量比为1：0.6-0.8：1.5-2：0.4-0.6；
(5)负载：将接枝载体结构加入到镍钴锰酸锂中混合均匀，继续加入PVDF 761，搅拌3-4h，过滤得到负载镍钴锰酸锂；接枝载体结构、镍钴锰酸锂及PVDF 761的比例为1：2-3：0.15-0.4。
实施例1
一种离子通道稳定性高的掺杂改性正极，所述掺杂改性正极材料为：负载镍钴锰酸锂中按质量比1：0.32混掺磷酸锰铁锂材料。
所述负载镍钴锰酸锂的制备过程为：
(1)制成三维排列框架：将MnSO 4·4H 2O分散在乙醇中，超声处理25min得到Mn 2+溶液，将对苯二甲酸、乙酸乙烯、乙烯基对苯二甲酸及二甲基乙酰胺按照质量比混合均匀得到混合溶液，然后将混合溶液倒入Mn 2+溶液中，98℃搅拌1.0h得到配位体溶液，再加入二乙烯三胺溶液，升温至118℃下搅拌1.9h，降至室温形成三维排列框架；MnSO 4·4H 2O和乙醇的比例为1.3g：80mL；对苯二甲酸、乙酸乙烯、乙烯基对苯二甲酸及二甲基乙酰胺的质量比为1：1.2：1.2：1.55；Mn 2+溶液、混合溶液及二乙烯三胺溶液的体积比为1：3.2：0.7；
(2)制成第一载体结构：将三维排列框架加入苯丙烯与过氧缩酮的混合溶液中，升温至88℃，保温17h，得到第一载体结构；三维排列框架、苯丙烯与过氧缩酮的质量比为3：2.3：0.65；
(3)选择性溶解：往第一载体结构中加入氨基三乙酸三钠，常温下搅拌75min，静置0.4h后离心收集产物，乙醇洗涤三次后在48℃烘箱中过夜干燥，得到负载载体结构；第一载体结构与氨基三乙酸三钠的质量比2.3：0.85；
(4)接枝活性基团：将负载载体结构、新癸酸缩水甘油酯与γ-环糊精按质量比加入N,N-二甲基甲酰胺中，在70℃搅拌反应20h，过滤并洗涤，得到接枝载体结构；负载载体结构、新癸酸缩水甘油酯与γ-环糊精及N,N-二甲基甲酰胺的质量比为1：0.7：1.8：0.5；
(5)负载：将接枝载体结构加入到镍钴锰酸锂中混合均匀，继续加入PVDF 761，搅拌3.5h，过滤得到负载镍钴锰酸锂；接枝载体结构、镍钴锰酸锂及PVDF 761的比例为1g：2.5g：0.32g。
实施例2
一种离子通道稳定性高的掺杂改性正极，所述掺杂改性正极材料为：负载镍钴锰酸锂中按质量比1：0.35混掺磷酸锰铁锂材料。
所述负载镍钴锰酸锂的制备过程为：
(1)制成三维排列框架：将MnSO 4·4H 2O分散在乙醇中，超声处理28min得到Mn 2+溶液，将对苯二甲酸、乙酸乙烯、乙烯基对苯二甲酸及二甲基乙酰胺按照质量比混合均匀得到混合溶液，然后将混合溶液倒入Mn 2+溶液中，97℃搅拌1.1h得到配位体溶液，再加入二乙烯三胺溶液，升温至116℃下搅拌1.95h，降至室温形成三维排列框架；MnSO 4·4H 2O和乙醇的比例为1.25g：80mL；对苯二甲酸、乙酸乙烯、乙烯基对苯二甲酸及二甲基乙酰胺的质量比为1：1.08：1.15：1.52；Mn 2+溶液、混合溶液及二乙烯三胺溶液的体积比为1：2.9：0.65；
(2)制成第一载体结构：将三维排列框架加入苯丙烯与过氧缩酮的混合溶液中，升温至86℃，保温16.5h，得到第一载体结构；三维排列框架、苯丙烯与过氧缩酮的质量比为3：2.1：0.55；
(3)选择性溶解：往第一载体结构中加入氨基三乙酸三钠，常温下搅拌78min，静置0.35h后离心收集产物，乙醇洗涤三次后在46℃烘箱中过夜干燥，得到负载载体结构；第一载体结构与氨基三乙酸三钠的质量比2.4：0.8；
(4)接枝活性基团：将负载载体结构、新癸酸缩水甘油酯与γ-环糊精按质量比加入N,N-二甲基甲酰胺中，在68℃搅拌反应18.5h，过滤并洗涤，得到接枝载体结构；负载载体结构、新癸酸缩水甘油酯与γ-环糊精及N,N-二甲基甲酰胺的质量比为1：0.65：1.9：0.48；
(5)负载：将接枝载体结构加入到镍钴锰酸锂中混合均匀，继续加入PVDF 761，搅拌3.8h，过滤得到负载镍钴锰酸锂；接枝载体结构、镍钴锰酸锂及PVDF 761的比例为1g：2.2g：0.2g。
实施例3
一种离子通道稳定性高的掺杂改性正极，所述掺杂改性正极材料为：负载镍钴锰酸锂中按质量比1：0.3混掺磷酸锰铁锂材料。
所述负载镍钴锰酸锂的制备过程为：
(1)制成三维排列框架：将MnSO 4·4H 2O分散在乙醇中，超声处理22min得到Mn 2+溶液， 将对苯二甲酸、乙酸乙烯、乙烯基对苯二甲酸及二甲基乙酰胺按照质量比混合均匀得到混合溶液，然后将混合溶液倒入Mn 2+溶液中，99℃搅拌0.9h得到配位体溶液，再加入二乙烯三胺溶液，升温至119℃下搅拌1.85h，降至室温形成三维排列框架；MnSO 4·4H 2O和乙醇的比例为1.25g：80mL；对苯二甲酸、乙酸乙烯、乙烯基对苯二甲酸及二甲基乙酰胺的质量比为1：1.25：1.28：1.58；Mn 2+溶液、混合溶液及二乙烯三胺溶液的体积比为1：3.4：0.75；
(2)制成第一载体结构：将三维排列框架加入苯丙烯与过氧缩酮的混合溶液中，升温至89℃，保温16.5h，得到第一载体结构；三维排列框架、苯丙烯与过氧缩酮的质量比为3：2.4：0.58；
(3)选择性溶解：往第一载体结构中加入氨基三乙酸三钠，常温下搅拌78min，静置0.45h后离心收集产物，乙醇洗涤三次后在58℃烘箱中过夜干燥，得到负载载体结构；第一载体结构与氨基三乙酸三钠的质量比2.4：0.95；
(4)接枝活性基团：将负载载体结构、新癸酸缩水甘油酯与γ-环糊精按质量比加入N,N-二甲基甲酰胺中，在72℃搅拌反应21.5h，过滤并洗涤，得到接枝载体结构；负载载体结构、新癸酸缩水甘油酯与γ-环糊精及N,N-二甲基甲酰胺的质量比为1：0.75：1.85：0.55；
(5)负载：将接枝载体结构加入到镍钴锰酸锂中混合均匀，继续加入PVDF 761，搅拌3.8h，过滤得到负载镍钴锰酸锂；接枝载体结构、镍钴锰酸锂及PVDF 761的比例为1g：2.8g：0.38g。
实施例4
一种离子通道稳定性高的掺杂改性正极，所述掺杂改性正极材料为：负载镍钴锰酸锂中按质量比1：0.25混掺磷酸锰铁锂材料。
所述负载镍钴锰酸锂的制备过程为：
(1)制成三维排列框架：将MnSO 4·4H 2O分散在乙醇中，超声处理30min得到Mn 2+溶液，将对苯二甲酸、乙酸乙烯、乙烯基对苯二甲酸及二甲基乙酰胺按照质量比混合均匀得到混合溶液，然后将混合溶液倒入Mn 2+溶液中，96℃搅拌1.2h得到配位体溶液，再加入二乙烯三胺溶液，升温至115℃下搅拌2h，降至室温形成三维排列框架；MnSO 4·4H 2O和乙醇的比例为1.2g：80mL；对苯二甲酸、乙酸乙烯、乙烯基对苯二甲酸及二甲基乙酰胺的质量比为1：1.05：1.3：1.5；Mn 2+溶液、混合溶液及二乙烯三胺溶液的体积比为1：2.8：0.6；
(2)制成第一载体结构：将三维排列框架加入苯丙烯与过氧缩酮的混合溶液中，升温至85℃，保温18h，得到第一载体结构；三维排列框架、苯丙烯与过氧缩酮的质量比为3：2：0.8；
(3)选择性溶解：往第一载体结构中加入氨基三乙酸三钠，常温下搅拌70min，静置0.5h后离心收集产物，乙醇洗涤三次后在45℃烘箱中过夜干燥，得到负载载体结构；第一载体结构与氨基三乙酸三钠的质量比2：1.0；
(4)接枝活性基团：将负载载体结构、新癸酸缩水甘油酯与γ-环糊精按质量比加入N,N-二甲基甲酰胺中，在65℃搅拌反应18h，过滤并洗涤，得到接枝载体结构；负载载体结构、新癸酸缩水甘油酯与γ-环糊精及N,N-二甲基甲酰胺的质量比为1：0.6：2：0.4；
(5)负载：将接枝载体结构加入到镍钴锰酸锂中混合均匀，继续加入PVDF 761，搅拌3h，过滤得到负载镍钴锰酸锂；接枝载体结构、镍钴锰酸锂及PVDF 761的比例为1g：2g：0.4g。
实施例5
一种离子通道稳定性高的掺杂改性正极，所述掺杂改性正极材料为：负载镍钴锰酸锂中按质量比1：0.4混掺磷酸锰铁锂材料。
所述负载镍钴锰酸锂的制备过程为：
(1)制成三维排列框架：将MnSO 4·4H 2O分散在乙醇中，超声处理30min得到Mn 2+溶液，将对苯二甲酸、乙酸乙烯、乙烯基对苯二甲酸及二甲基乙酰胺按照质量比混合均匀得到混合溶液，然后将混合溶液倒入Mn 2+溶液中，100℃搅拌0.8h得到配位体溶液，再加入二乙烯三胺溶液，升温至120℃下搅拌1.8h，降至室温形成三维排列框架；MnSO 4·4H 2O和乙醇的比例为1.4g：80mL；对苯二甲酸、乙酸乙烯、乙烯基对苯二甲酸及二甲基乙酰胺的质量比为1：1.3：1.1：1.6；Mn 2+溶液、混合溶液及二乙烯三胺溶液的体积比为1：3.6：0.6；
(2)制成第一载体结构：将三维排列框架加入苯丙烯与过氧缩酮的混合溶液中，升温至90℃，保温16h，得到第一载体结构；三维排列框架、苯丙烯与过氧缩酮的质量比为3：2.5：0.5；
(3)选择性溶解：往第一载体结构中加入氨基三乙酸三钠，常温下搅拌80min，静置0.3h后离心收集产物，乙醇洗涤三次后在50℃烘箱中过夜干燥，得到负载载体结构；第一载体结构与氨基三乙酸三钠的质量比2.5：0.7；
(4)接枝活性基团：将负载载体结构、新癸酸缩水甘油酯与γ-环糊精按质量比加入N,N-二甲基甲酰胺中，在75℃搅拌反应18h，过滤并洗涤，得到接枝载体结构；负载载体结构、新癸酸缩水甘油酯与γ-环糊精及N,N-二甲基甲酰胺的质量比为1：0.8：1.5：0.6；
(5)负载：将接枝载体结构加入到镍钴锰酸锂中混合均匀，继续加入PVDF 761，搅拌4h，过滤得到负载镍钴锰酸锂；接枝载体结构、镍钴锰酸锂及PVDF 761的比例为1g：3g：0.15g。
对比例1与实施例1的区别在于，磷酸锰铁锂材料的含量过多，负载镍钴锰酸锂与磷酸锰铁锂材料质量比为1：0.6，其余步骤都与实施例1相同。
对比例2与实施例1的区别在于，未对镍钴锰酸锂材料进行负载，其余步骤都与实施例1相同。
对比例3与实施例1的区别在于，负载镍钴锰酸锂制备过程中步骤(1)中采用 Zn(NO 3) 2·6H 2O替代MnSO 4·4H 2O，其余步骤都与实施例1相同。
对比例4与实施例1的区别在于，负载镍钴锰酸锂制备过程中省略了步骤(3)选择性溶解，其余步骤都与实施例1相同。
对比例5与实施例1的区别在于，负载镍钴锰酸锂制备过程中省略了步骤(4)接枝活性基团，其余步骤都与实施例1相同。
将上述实施例与对比例所制备得到的掺杂改性正极材料用来制备成相应电池，并对电池进行相关性能测试。
2032扣式电池测试：
正极：正极材料，Super P，VGCF，PVDF，其质量比为92:2:2:3；
负极：金属锂片；
电解液：1mol/L的LiPF6溶解于碳酸乙烯酯(EC)、碳酸甲乙酯(EMC)和碳酸二甲酯(DMC)(EC:EMC:DMC＝1:1:1wt％)；
测试电压：2.8～4.3V；
容量测试条件：0.1C室温恒流充放电测试。
表1 各项目与掺杂改性正极材料所制备的电池的相关性能评价指标
材料 可逆容量(mAh/g) 首次效率(％) 100周循环保持率(％)
实施例1 177 92 99
实施例2 175 90 98
实施例3 172 91 95
实施例4 169 90 94
实施例5 168 90 97
对比例1 165 88 88
对比例2 147 75 75
对比例3 160 91 86
对比例4 158 90 87
对比例5 162 89 84
结论分析：由上述表格可以看出，实施例1-5在本发明保护范围内的添加组分及相关性能参数能够欧制备得到的稳定性高的掺杂改性正极材料，才能够制备出具有良好导热性、导电性、高稳定性孔道及整体性性能好的正极材料，使得制备出来的锂电池正极材料具有较强的循环性能与较长的使用寿命。
对比例1与实施例1的区别在于，磷酸锰铁锂材料的含量过多，负载镍钴锰酸锂与磷酸锰铁锂材料质量比为1：0.6；由于磷酸锰铁锂的含量过多，锰元素含量过多则会有锰元素析出，对容量和安全影响较大，同时负载镍钴锰酸锂的含量先能够对减少后，掺杂改性正极材料中离子孔道的稳定性及有序性会降低，进而造成最终所制得电池的性能下降。
对比例2与实施例1的区别在于，未对镍钴锰酸锂材料进行负载；本发明的制备方法 使得镍钴锰酸锂能够沿着负载载体结构的框架结构有序排列，负载载体结构也能够为镍钴锰酸锂提供较好的支撑作用，无论是对镍钴锰酸锂中锂离子孔道的有序排列还是防止其中锂离子孔道的坍塌都具有显著的积极作用，未进行负载将直接影响到最终材料的导电率与循环性能。
对比例3与实施例1的区别在于，负载镍钴锰酸锂制备过程中步骤(1)中采用Zn(NO 3) 2·6H 2O替代MnSO 4·4H 2O；负载载体结构中的Mn能够将负载载体结构框架内的各通道中的镍钴锰酸锂进行有效连通，形成无数密集连通的脉络，这较大程度的提升了正极材料内部的中值电压及电性能，使得该正极材料具有较长的使用周期；负载载体的Mn 2+配位上来进一步提升锰元素的稳定性，降低正极材料中的锰元素析出，替换后无法达到上述效果。
对比例4与实施例1的区别在于，负载镍钴锰酸锂制备过程中省略了步骤(3)选择性溶解；制备负载镍钴锰酸锂过程中省略了步骤(3)的选择性溶解；未加入氨基三乙酸三钠对初步载体结构中的部分有机框架选择性溶解，会降低最终负载载体结构中的孔隙率及比表面积，进而降低负载载体结构的负载能力，最终使得镍钴锰酸锂有效负载量大大减少，并且孔隙内径较小，无法充分容纳镍钴锰酸锂，不能使镍钴锰酸锂得到有效的保护与支撑，因而相关的电化学性能会大打折扣。
对比例5与实施例1的区别在于，负载镍钴锰酸锂制备过程中省略了步骤(4)接枝活性基团；制备负载载体结构过程中省略了步骤(4)的γ-环糊精接枝活化；未对制备负载载体结构进行表面的活化接枝，会使得制备负载载体结构表面的活性位点数量减少，镍钴锰酸锂亦不能顺利或稳定的连接到负载载体结构上，也会使得固定化镍钴锰酸锂在使用过程中有大量的镍钴锰酸锂脱出分散，进而降低固定化镍钴锰酸锂的导电效率与锂离子通道稳定性。
由实施例1～5以及对比例1～5的数据可知，只有在本发明权利要求范围内的方案，才能够在各方面均能满足上述要求。而对于配比的改动、原料的替换/加减、加料顺序的改变，或者工艺参数的修改或者变动，均会带来相应的负面影响。
本发明中所用原料、设备，若无特别说明，均为本领域的常用原料、设备；本发明中所用方法，若无特别说明，均为本领域的常规方法。
以上所述，仅是本发明的较佳实施例，并非对本发明作任何限制，凡是根据本发明技术实质对以上实施例所作的任何简单修改、变更以及等效变换，均仍属于本发明技术方案的保护范围。

Claims (10)

  1. 一种离子通道稳定性高的掺杂改性正极材料，其特征是，所述掺杂改性正极材料为：混掺有磷酸锰铁锂材料的负载镍钴锰酸锂。
  2. 根据权利要求1所述的一种离子通道稳定性高的掺杂改性正极材料，其特征是，所述负载镍钴锰酸锂与磷酸锰铁锂材料质量比为1:0.25-0.4。
  3. 根据权利要求1或2所述的一种离子通道稳定性高的掺杂改性正极材料，其特征是，所述负载镍钴锰酸锂的制备过程为：
    (1)制成三维排列框架：将MnSO 4·4H 2O分散在乙醇中，超声处理得到Mn 2+溶液，将对苯二甲酸、乙酸乙烯、乙烯基对苯二甲酸及二甲基乙酰胺混合均匀得到混合溶液，然后将混合溶液倒入Mn 2+溶液中，加热搅拌得到配位体溶液，再加入二乙烯三胺溶液，升温至115-120℃下搅拌，降至室温形成三维排列框架；
    (2)制成第一载体结构：将三维排列框架加入苯丙烯与过氧缩酮的混合溶液中，升温反应，保温，得到第一载体结构；
    (3)选择性溶解：往第一载体结构中加入氨基三乙酸三钠，常温下搅拌，静置后离心收集产物，乙醇洗涤后干燥，得到负载载体结构；
    (4)接枝活性基团：将负载载体结构、新癸酸缩水甘油酯与γ-环糊精按质量比加入N,N-二甲基甲酰胺中，加热搅拌反应，过滤并洗涤，得到接枝载体结构；
    (5)负载：将接枝载体结构加入到镍钴锰酸锂中混合均匀，继续加入PVDF，搅拌，过滤得到负载镍钴锰酸锂。
  4. 根据权利要求3所述的一种离子通道稳定性高的掺杂改性正极材料，其特征是，步骤(1)中，MnSO 4·4H 2O和乙醇的比例为1.2-1.4g：80mL；对苯二甲酸、乙酸乙烯、乙烯基对苯二甲酸及二甲基乙酰胺的质量比为1：1.05-1.3：1.1-1.3：1.5-1.6。
  5. 根据权利要求3所述的一种离子通道稳定性高的掺杂改性正极材料，其特征是，步骤(1)中，Mn 2+溶液、混合溶液及二乙烯三胺溶液的体积比为1：2.8-3.6：0.6-0.8。
  6. 根据权利要求3所述的一种离子通道稳定性高的掺杂改性正极材料，其特征是，步骤(1)中，加热搅拌条件为96-100℃，搅拌0.8-1.2h。
  7. 根据权利要求3所述的一种离子通道稳定性高的掺杂改性正极材料，其特征是，步骤(2)中，三维排列框架、苯丙烯与过氧缩酮的质量比为3：2-2.5：0.5-0.8。
  8. 根据权利要求3所述的一种离子通道稳定性高的掺杂改性正极材料，其特征是，步骤(3)中，第一载体结构与氨基三乙酸三钠的质量比2-2.5：0.7-1.0。
  9. 根据权利要求3所述的一种离子通道稳定性高的掺杂改性正极材料，其特征是，步骤(4) 中，负载载体结构、新癸酸缩水甘油酯与γ-环糊精及N,N-二甲基甲酰胺的质量比为1：0.6-0.8：1.5-2：0.4-0.6。
  10. 根据权利要求3所述的一种离子通道稳定性高的掺杂改性正极材料，其特征是，步骤(5)中，接枝载体结构、镍钴锰酸锂及PVDF的比例为1：2-3：0.15-0.4。
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