阅读说明：本技术 一种多孔碳微球原位复合纳米TiO2的制备方法和应用 (Porous carbon microsphere in-situ composite nano TiO2Preparation method and application of ) 是由 程承 于 2020-12-30 设计创作，主要内容包括：本发明涉及锂离子电池技术领域,且公开了一种多孔碳微球原位复合纳米TiO-2,TiO-2纳米管具有更高的比表面积和锂离子脱嵌位点,TiO-2纳米管均匀分散在聚丙烯腈微球中,进一步通过预氧化脱氢-环化过程和高温碳化过程,聚丙烯腈微球碳化生成氮掺杂多孔碳球,而TiO-2纳米管高度分散在氮掺杂多孔碳球基团中,氮掺杂有利于提高多孔碳球的电化学性质和导电性,产生丰富的锂离子脱嵌位点,进一步加速电子和锂离子的扩散,同时氮掺杂多孔碳球的修饰有利于减少TiO-2纳米管体积膨胀的现象,起到稳定TiO-2的纳米管状结构形貌,有利于提高负极材料的结构稳定性和电化学循环稳定性。(The invention relates to the technical field of lithium ion batteries, and discloses a porous carbon microsphere in-situ composite nano TiO 2 ，TiO 2 The nano-tube has higher specific surface area and lithium ion de-intercalation sites, TiO 2 The nano-tubes are uniformly dispersed in the polyacrylonitrile microspheres, and the polyacrylonitrile microspheres are carbonized to generate nitrogen-doped porous carbon spheres through a pre-oxidation dehydrogenation-cyclization process and a high-temperature carbonization process, while the TiO microspheres 2 The nanotubes are highly dispersed in the nitrogen-doped porous carbon sphere group, nitrogen doping is beneficial to improving the electrochemical property and the conductivity of the porous carbon sphere, rich lithium ion de-intercalation sites are generated, the diffusion of electrons and lithium ions is further accelerated, and meanwhile modification of the nitrogen-doped porous carbon sphere is beneficial to reducing TiO 2 The volume expansion phenomenon of the nano tube plays a role in stabilizing TiO 2 The shape of the nano-tube structure is beneficial to improving the structural stability and the electrochemical cycling stability of the cathode material.)

1. Porous carbon microsphere in-situ composite nano TiO₂The method is characterized in that: the porous carbon microsphere in-situ composite nano TiO₂The preparation method comprises the following steps:

(1) adding distilled water, sodium hydroxide and nano TiO into a reaction bottle₂Performing ultrasonic treatment to uniformly disperse the solution, pouring the solution into a reaction kettle, heating the solution to 140 ℃, and reacting for 20-30h to obtain TiO₂A nanotube.

(2) Adding TiO into mixed solvent of ethanol and diluted ammonia water in a reaction bottle₂The nano tube and the silane coupling agent are subjected to ultrasonic treatment to be uniformly dispersed, heated to 40-60 ℃ and reacted for 5-10h to obtain modified TiO₂A nanotube.

(3) Adding a mixed solvent of distilled water and ethanol into a reaction bottle in a nitrogen atmosphere, and adding modified TiO₂Performing ultrasonic treatment on the nanotube until the nanotube is uniformly dispersed, heating the nanotube to 60-70 ℃, adding acrylonitrile, slowly dropwise adding a potassium persulfate solution, and reacting for 3-6h to obtain polyacrylonitrile microsphere modified TiO₂A nanotube.

(4) Modifying polyacrylonitrile microsphere with TiO₂Placing the nano tube in an atmosphere tube furnace, and performing a pre-oxidation process to obtain the dehydrogenation-cyclization polyacrylonitrile microsphere modified TiO₂A nanotube.

(5) Modifying TiO with dehydrogenation-cyclization polyacrylonitrile microspheres with the mass ratio of 10:25-40₂Grinding and mixing the nanotube and potassium hydroxide, placing the mixture in an atmosphere tube furnace, and carrying out carbonization to prepare the porous carbon microsphere precursorComposite nano TiO₂The material is applied to the negative electrode material of the lithium ion battery.

2. The porous carbon microsphere in-situ composite nano TiO according to claim 1₂The method is characterized in that: the sodium hydroxide and the nano TiO in the step (1)₂The mass ratio of (A) to (B) is 20-30: 1.

3. The porous carbon microsphere in-situ composite nano TiO according to claim 1₂The method is characterized in that: the silane coupling agent in the step (2) is vinyltrimethoxysilane or vinyltriethoxysilane and TiO₂The mass ratio of the nanotubes is 20-40: 100.

4. The porous carbon microsphere in-situ composite nano TiO according to claim 1₂The method is characterized in that: TiO in the step (3)₂The mass ratio of the nanotube, the acrylonitrile and the potassium persulfate is 100:60-120: 0.5-3.

5. The porous carbon microsphere in-situ composite nano TiO according to claim 1₂The method is characterized in that: the pre-oxidation process in the step (4) is pre-oxidation for 1-2h at the temperature of 300 ℃ in an air atmosphere.

6. The porous carbon microsphere in-situ composite nano TiO according to claim 1₂The method is characterized in that: the carbonization process in the step (5) is in an argon atmosphere, and the carbonization is carried out for 2-3h at the temperature of 750-.

Technical Field

The invention relates to the technical field of lithium ion batteries, in particular to porous carbon microsphere in-situ composite nanoTiO₂The preparation method and the application thereof.

Background

In recent years, the over-development and use of fossil energy by human beings lead to the gradual decrease of fossil fuel reserves and bring serious pollution to the environment, and new energy storage systems, such as lithium ion charging, fuel cells, super capacitors and the like, are vigorously developed by various countries, while lithium ion batteries have the advantages of high energy density, long cycle life, environmental friendliness and the like, have wide application in portable electronic products such as notebook computers, mobile phones and the like, and show wide development prospects in the fields of new energy resources such as new energy electric automobiles, aerospace and large-scale energy storage and the like.

The negative electrode material of the current commercial lithium ion battery is a graphite negative electrode material, but the actual specific capacity of the graphite negative electrode material is lower, so that the specific capacity needs to be developed. The novel negative electrode material with good cycling stability, such as an active carbon negative electrode material, an alloy negative electrode material and a metal oxide negative electrode material, wherein the working process of the titanium dioxide negative electrode material is a lithium removal-lithium insertion process, and the titanium dioxide negative electrode material is non-toxic, environment-friendly and stable in chemical property, and has wide research in the lithium ion battery negative electrode material, but the electronic conductivity and the ionic conductivity of the titanium dioxide are low, so that the diffusion and the migration of electrons and lithium ions are not facilitated, the rate capability and the specific capacity of the negative electrode material are low, and the development of the titanium dioxide negative electrode material is limited.

Technical problem to be solved

Aiming at the defects of the prior art, the invention provides a porous carbon microsphere in-situ composite nano TiO₂The preparation method and the application solve the problem that the rate capability and the specific capacity of the titanium dioxide cathode material are lower.

(II) technical scheme

In order to achieve the purpose, the invention provides the following technical scheme: porous carbon microsphere in-situ composite nano TiO₂The porous carbon microsphere is compounded with nano TiO in situ₂The preparation method comprises the following steps:

(1) adding distilled water, sodium hydroxide and nano TiO into a reaction bottle₂Ultrasonic treatment toUniformly dispersing, pouring the solution into a reaction kettle, heating to 140 ℃ for reaction for 20-30h, and washing with dilute hydrochloric acid and distilled water to obtain TiO₂A nanotube.

(2) Adding TiO into mixed solvent of ethanol and diluted ammonia water in a reaction bottle₂The nano tube and the silane coupling agent are subjected to ultrasonic treatment to be uniformly dispersed, heated to 40-60 ℃, stirred at a constant speed for reaction for 5-10 hours, centrifugally separated, washed by distilled water and ethanol to obtain modified TiO₂A nanotube.

(3) Adding a mixed solvent of distilled water and ethanol into a reaction bottle in a nitrogen atmosphere, and adding modified TiO₂Performing ultrasonic treatment on the nanotube until the nanotube is uniformly dispersed, heating the nanotube to 60-70 ℃, adding acrylonitrile, then slowly dropwise adding a potassium persulfate solution, stirring the solution at a constant speed for reaction for 3-6h, removing the solvent by freeze drying, and washing the solution by using distilled water to obtain the polyacrylonitrile microsphere modified TiO₂A nanotube.

(4) Modifying polyacrylonitrile microsphere with TiO₂Placing the nano tube in an atmosphere tube furnace, and performing a pre-oxidation process to obtain the dehydrogenation-cyclization polyacrylonitrile microsphere modified TiO₂A nanotube.

(5) Modifying TiO with dehydrogenation-cyclization polyacrylonitrile microspheres with the mass ratio of 10:25-40₂Grinding and mixing the nanotube and potassium hydroxide, placing the mixture in an atmosphere tube furnace, and carrying out a carbonization process to prepare the porous carbon microsphere in-situ composite nano TiO₂The material is applied to the negative electrode material of the lithium ion battery.

Preferably, the sodium hydroxide and the nano TiO in the step (1)₂The mass ratio of (A) to (B) is 20-30: 1.

Preferably, the silane coupling agent in step (2) is vinyltrimethoxysilane or vinyltriethoxysilane, and TiO₂The mass ratio of the nanotubes is 20-40: 100.

Preferably, TiO in the step (3)₂The mass ratio of the nanotube, the acrylonitrile and the potassium persulfate is 100:60-120: 0.5-3.

Preferably, the pre-oxidation process in the step (4) is pre-oxidation at 250-300 ℃ for 1-2h in an air atmosphere.

Preferably, the carbonization process in the step (5) is an argon atmosphere, and the carbonization is performed at 750-850 ℃ for 2-3 h.

(III) advantageous technical effects

Compared with the prior art, the invention has the following beneficial technical effects:

the porous carbon microsphere in-situ composite nano TiO₂Nano TiO2₂In the sodium hydroxide strong alkali system, partial sodium titanate and other by-products are generated to ensure that the nano TiO₂The lattice structure is stripped, recombined and curled, and then curled into the nano-tube TiO₂Compared with the traditional nano TiO₂，TiO₂The nano tube has higher specific surface area and lithium ion de-intercalation sites, thereby improving the diffusion coefficient of lithium ions, promoting the de-intercalation and intercalation processes of the lithium ions and improving the specific capacity of the cathode material.

The porous carbon microsphere in-situ composite nano TiO₂TiO treated with strong alkali sodium hydroxide₂The nanotube surface contains a large amount of hydroxyl which is easy to react with the vinyl silane coupling agent, thereby obtaining the modified TiO with rich surface alkenyl content₂Nanotubes of acrylonitrile with modified TiO during soap-free emulsion polymerization₂The alkenyl on the surface of the nano tube is copolymerized to obtain the polyacrylonitrile microsphere modified TiO₂Nanotube of TiO₂The nano-tubes are uniformly dispersed in the polyacrylonitrile microspheres, and the polyacrylonitrile microspheres are carbonized to generate nitrogen-doped porous carbon spheres through a pre-oxidation dehydrogenation-cyclization process and a high-temperature carbonization process, while the TiO microspheres₂The nanotubes are highly dispersed in the nitrogen-doped porous carbon sphere group, nitrogen doping is beneficial to improving the electrochemical property and the conductivity of the porous carbon sphere, rich lithium ion de-intercalation sites are generated, the diffusion of electrons and lithium ions is further accelerated, and meanwhile modification of the nitrogen-doped porous carbon sphere is beneficial to reducing TiO₂The volume expansion phenomenon of the nano tube plays a role in stabilizing TiO₂The shape of the nano-tube structure is beneficial to improving the structural stability and the electrochemical cycling stability of the cathode material.

Detailed Description

To achieve the above object, the present invention provides the following embodiments and examples: porous carbon microsphere in-situ composite nanoTiO rice₂The preparation method comprises the following steps:

(1) adding distilled water, sodium hydroxide and nano TiO with the mass ratio of 20-30:1 into a reaction bottle₂Performing ultrasonic treatment to uniformly disperse, pouring the solution into a reaction kettle, heating to 140 ℃ for reaction for 20-30h, and performing acid washing with dilute hydrochloric acid and washing with distilled water to obtain TiO₂A nanotube.

(2) Adding TiO with the mass ratio of 20-40:100 into a mixed solvent of ethanol and diluted ammonia water in a reaction bottle₂The nanotube and silane coupling agent are vinyl trimethoxy silane or vinyl triethoxy silane, the mixture is subjected to ultrasonic treatment to be uniformly dispersed, the mixture is heated to 40-60 ℃, stirred at a constant speed to react for 5-10h, and the modified TiO2 nanotube is obtained through centrifugal separation, washing with distilled water and ethanol.

(3) Adding a mixed solvent of distilled water and ethanol into a reaction bottle in a nitrogen atmosphere, and adding modified TiO₂Nano tube, ultrasonic treating to disperse uniformly, heating to 60-70 deg.C, adding acrylonitrile, and slowly dropping potassium persulfate solution, in which TiO is₂The mass ratio of the nanotube, acrylonitrile and potassium persulfate is 100:60-120:0.5-3, the mixture is stirred at a constant speed for reaction for 3-6h, and then the mixture is frozen, dried and washed by distilled water to obtain polyacrylonitrile microsphere modified TiO₂A nanotube.

(4) Modifying polyacrylonitrile microsphere with TiO₂Placing the nano-tube in an atmosphere tube furnace, pre-oxidizing for 1-2h at the temperature of 250-300 ℃ in the air atmosphere to obtain the dehydrogenation-cyclization polyacrylonitrile microsphere modified TiO₂A nanotube.

(5) Modifying TiO with dehydrogenation-cyclization polyacrylonitrile microspheres with the mass ratio of 10:25-40₂Grinding and mixing the nanotube and potassium hydroxide, placing the mixture in an atmosphere tube furnace, carbonizing the mixture for 2 to 3 hours at the temperature of 750 ℃ and 850 ℃ in the argon atmosphere to prepare the porous carbon microsphere in-situ composite nano TiO₂The material is applied to the negative electrode material of the lithium ion battery.

Example 1

(1) Adding distilled water, sodium hydroxide and nano TiO with the mass ratio of 20:1 into a reaction bottle₂Ultrasonic treating to disperse uniformly, pouring the solution into a reaction kettle, heating to 120 ℃, reacting for 20h, washing with dilute hydrochloric acid and distilled waterTo obtain TiO₂A nanotube.

(2) Adding TiO with the mass ratio of 20:100 into a mixed solvent of ethanol and diluted ammonia water in a reaction bottle₂The nano tube and the silane coupling agent are vinyl trimethoxy silane or vinyl triethoxy silane, the mixture is subjected to ultrasonic treatment to be uniformly dispersed, the mixture is heated to 40 ℃, stirred at a constant speed to react for 5 hours, and the mixture is subjected to centrifugal separation, distilled water and ethanol washing to obtain the modified TiO2 nano tube.

(3) Adding a mixed solvent of distilled water and ethanol into a reaction bottle in a nitrogen atmosphere, and adding modified TiO₂Nano tube, ultrasonic treating to disperse uniformly, heating to 60 deg.C, adding acrylonitrile, and slowly dropping potassium persulfate solution, in which TiO is₂The mass ratio of the nanotube, acrylonitrile and potassium persulfate is 100:60:0.5, the mixture is stirred at a constant speed for reaction for 3 hours, and the mixture is freeze-dried to remove the solvent and washed by distilled water to obtain the polyacrylonitrile microsphere modified TiO₂A nanotube.

(4) Modifying polyacrylonitrile microsphere with TiO₂Placing the nano tube in an atmosphere tube furnace, and pre-oxidizing for 1h at 250 ℃ in the air atmosphere to obtain the dehydrogenation-cyclization polyacrylonitrile microsphere modified TiO₂A nanotube.

(5) Modifying TiO with dehydrogenation-cyclization polyacrylonitrile microspheres with the mass ratio of 10:25₂Grinding and mixing the nanotube and potassium hydroxide, placing the mixture in an atmosphere tube furnace, carbonizing the mixture for 2 hours at 750 ℃ in an argon atmosphere, and preparing the porous carbon microsphere in-situ composite nano TiO₂。

Example 2

(1) Adding distilled water, sodium hydroxide and nano TiO with the mass ratio of 25:1 into a reaction bottle₂Ultrasonically treating until the solution is uniformly dispersed, pouring the solution into a reaction kettle, heating to 130 ℃, reacting for 24 hours, and pickling with dilute hydrochloric acid and washing with distilled water to obtain TiO₂A nanotube.

(2) Adding TiO with the mass ratio of 30:100 into a mixed solvent of ethanol and diluted ammonia water in a reaction bottle₂The nanotube and silane coupling agent are vinyl trimethoxy silane or vinyl triethoxy silane, the mixture is subjected to ultrasonic treatment to be uniformly dispersed, the mixture is heated to 50 ℃, stirred at a constant speed to react for 8 hours, and the mixture is subjected to centrifugal separation, distilled water and ethanol washing to obtain the modified TiO2 nanotube.

(3) Adding a mixed solvent of distilled water and ethanol into a reaction bottle in a nitrogen atmosphere, and adding modified TiO₂Nano tube, ultrasonic treating to disperse uniformly, heating to 65 deg.C, adding acrylonitrile, slowly dropping potassium persulfate solution, in which TiO is₂The mass ratio of the nanotube, acrylonitrile and potassium persulfate is 100:90:1.5, the mixture is stirred at a constant speed for reaction for 4 hours, and the mixture is freeze-dried to remove the solvent and washed by distilled water to obtain the polyacrylonitrile microsphere modified TiO₂A nanotube.

(4) Modifying polyacrylonitrile microsphere with TiO₂Placing the nano tube in an atmosphere tube furnace, pre-oxidizing for 1.5h at 280 ℃ in the air atmosphere to obtain the dehydrogenation-cyclization polyacrylonitrile microsphere modified TiO₂A nanotube.

(5) Modifying TiO with dehydrogenation-cyclization polyacrylonitrile microspheres with the mass ratio of 10:35₂Grinding and mixing the nanotube and potassium hydroxide, placing the mixture in an atmosphere tube furnace, carbonizing the mixture for 2.5 hours at 800 ℃ in an argon atmosphere, and preparing the porous carbon microsphere in-situ composite nano TiO₂。

Example 3

(1) Adding distilled water, sodium hydroxide and nano TiO with the mass ratio of 30:1 into a reaction bottle₂Ultrasonically treating until the solution is uniformly dispersed, pouring the solution into a reaction kettle, heating to 140 ℃, reacting for 30 hours, and pickling with dilute hydrochloric acid and washing with distilled water to obtain TiO₂A nanotube.

(2) Adding TiO with the mass ratio of 40:100 into a mixed solvent of ethanol and diluted ammonia water in a reaction bottle₂The nanotube and silane coupling agent are vinyl trimethoxy silane or vinyl triethoxy silane, the mixture is subjected to ultrasonic treatment to be uniformly dispersed, the mixture is heated to 60 ℃, stirred at a constant speed for reaction for 10 hours, and then subjected to centrifugal separation, distilled water and ethanol washing to obtain the modified TiO2 nanotube.

(3) Adding a mixed solvent of distilled water and ethanol into a reaction bottle in a nitrogen atmosphere, and adding modified TiO₂The nanotube is ultrasonically treated to be evenly dispersed, the mixture is heated to 70 ℃, acrylonitrile is added, and then potassium persulfate solution, wherein TiO is added in dropwise₂The mass ratio of the nanotube, the acrylonitrile and the potassium persulfate is 100:120:3, the mixture is stirred at a constant speed for reaction for 6 hours, the solvent is removed by freeze drying,washing with distilled water to obtain polyacrylonitrile microsphere modified TiO₂A nanotube.

(4) Modifying polyacrylonitrile microsphere with TiO₂Placing the nano tube in an atmosphere tube furnace, and pre-oxidizing for 2h at 300 ℃ in the air atmosphere to obtain the dehydrogenation-cyclization polyacrylonitrile microsphere modified TiO₂A nanotube.

(5) Modifying TiO with dehydrogenation-cyclization polyacrylonitrile microspheres with the mass ratio of 10:40₂Grinding and mixing the nanotube and potassium hydroxide, placing the mixture in an atmosphere tube furnace, carbonizing the mixture for 3 hours at 850 ℃ in an argon atmosphere, and preparing the porous carbon microsphere in-situ composite nano TiO₂。

Comparative example 1

(1) Adding distilled water, sodium hydroxide and nano TiO in a mass ratio of 15:1 into a reaction bottle₂Ultrasonically treating until the solution is uniformly dispersed, pouring the solution into a reaction kettle, heating to 140 ℃, reacting for 20 hours, and pickling with dilute hydrochloric acid and washing with distilled water to obtain TiO₂A nanotube.

(2) Adding TiO with the mass ratio of 10:100 into a mixed solvent of ethanol and diluted ammonia water in a reaction bottle₂The nanotube and silane coupling agent are vinyl trimethoxy silane or vinyl triethoxy silane, the mixture is subjected to ultrasonic treatment to be uniformly dispersed, the mixture is heated to 60 ℃, stirred at a constant speed to react for 8 hours, and the mixture is subjected to centrifugal separation, distilled water and ethanol washing to obtain the modified TiO2 nanotube.

(3) Adding a mixed solvent of distilled water and ethanol into a reaction bottle in a nitrogen atmosphere, and adding modified TiO₂Nano tube, ultrasonic treating to disperse uniformly, heating to 60 deg.C, adding acrylonitrile, and slowly dropping potassium persulfate solution, in which TiO is₂The mass ratio of the nanotube, acrylonitrile and potassium persulfate is 100:40:0.2, the mixture is stirred at a constant speed for reaction for 6 hours, and the mixture is freeze-dried to remove the solvent and washed by distilled water to obtain the polyacrylonitrile microsphere modified TiO₂A nanotube.

(4) Modifying polyacrylonitrile microsphere with TiO₂Placing the nano tube in an atmosphere tube furnace, pre-oxidizing for 1.5h at 280 ℃ in the air atmosphere to obtain the dehydrogenation-cyclization polyacrylonitrile microsphere modified TiO₂A nanotube.

(5) Dehydrocyclization at a mass ratio of 1:1Polyacrylonitrile microsphere modified TiO₂Grinding and mixing the nanotube and potassium hydroxide, placing the mixture in an atmosphere tube furnace, carbonizing the mixture for 3 hours at 850 ℃ in an argon atmosphere, and preparing the porous carbon microsphere in-situ composite nano TiO₂。

Comparative example 2

(1) Adding distilled water, sodium hydroxide and nano TiO with the mass ratio of 35:1 into a reaction bottle₂Ultrasonically treating until the solution is uniformly dispersed, pouring the solution into a reaction kettle, heating to 130 ℃, reacting for 24 hours, and pickling with dilute hydrochloric acid and washing with distilled water to obtain TiO₂A nanotube.

(2) Adding TiO with the mass ratio of 50:100 into a mixed solvent of ethanol and diluted ammonia water in a reaction bottle₂The nano tube and the silane coupling agent are vinyl trimethoxy silane or vinyl triethoxy silane, the mixture is subjected to ultrasonic treatment to be uniformly dispersed, the mixture is heated to 40 ℃, stirred at a constant speed for reaction for 10 hours, and the mixture is subjected to centrifugal separation, distilled water and ethanol washing to obtain the modified TiO2 nano tube.

(3) Adding a mixed solvent of distilled water and ethanol into a reaction bottle in a nitrogen atmosphere, and adding modified TiO₂The nanotube is ultrasonically treated to be evenly dispersed, the mixture is heated to 70 ℃, acrylonitrile is added, and then potassium persulfate solution, wherein TiO is added in dropwise₂The mass ratio of the nanotube, acrylonitrile and potassium persulfate is 100:150:4, the mixture is stirred at a constant speed for reaction for 3 hours, and then the mixture is frozen, dried and washed by distilled water to obtain polyacrylonitrile microsphere modified TiO₂A nanotube.

(4) Modifying polyacrylonitrile microsphere with TiO₂Placing the nano tube in an atmosphere tube furnace, and pre-oxidizing for 2h at 250 ℃ in the air atmosphere to obtain the dehydrogenation-cyclization polyacrylonitrile microsphere modified TiO₂A nanotube.

(5) Modifying TiO with dehydrogenation-cyclization polyacrylonitrile microspheres with the mass ratio of 10:50₂Grinding and mixing the nanotube and potassium hydroxide, placing the mixture in an atmosphere tube furnace, carbonizing the mixture for 2.5 hours at 800 ℃ in an argon atmosphere, and preparing the porous carbon microsphere in-situ composite nano TiO₂。

In-situ compounding of porous carbon microsphere with nano TiO₂Mixing with N-methyl pyrrolidone solvent, acetylene black as conductive agent and polyvinylidene fluoride as adhesiveCoating the slurry on the surface of a copper foil, drying, cutting and punching a layer electrode plate to prepare a working electrode of a negative electrode of a lithium ion battery, taking a lithium sheet as a working positive electrode of a positive electrode, taking a 1mol/L lithium hexafluorophosphate solution as an electrolyte, taking a polypropylene porous membrane as a diaphragm, assembling the lithium ion battery into a button battery in an argon glove box, and carrying out an electrochemical performance test in a CT2001A battery test system with the test standard of GB/T36276 + 2018.