阅读说明：本技术 一种纳米材料修饰的氟化碳电极材料的制备方法 (Preparation method of nanomaterial-modified carbon fluoride electrode material ) 是由 张红梅 王振 陈铤 王建勇 陈晓涛 王庆杰 王华国 于 2019-11-18 设计创作，主要内容包括：本发明公开了一种纳米材料修饰的氟化碳电极材料的制备方法,将介质和氟化碳混合,加入镍铁合金混合,再加入纳米材料反应后,经晾干、真空干燥、研磨后,在氩气气氛下煅烧,冷却至室温,再经研磨、过100～200目筛后,制得所述纳米材料修饰的氟化碳电极材料；所述纳米材料和氟化碳按照质量比＝(0.5～5):100组成,本申请采用纳米材料对氟化碳材料进行修饰改性,纳米材料均匀地分布在氟化碳材料表面,增加了氟化碳材料的导电性,有效改善了氟化碳材料的电压滞后以及低温性能的问题,提高了锂氟化碳电池的倍率性能。(The invention discloses a preparation method of a carbon fluoride electrode material modified by a nano material, which comprises the steps of mixing a medium and carbon fluoride, adding a nickel-iron alloy, mixing, adding the nano material, reacting, drying in the air, drying in vacuum, grinding, calcining in an argon atmosphere, cooling to room temperature, grinding, and sieving with a 100-200-mesh sieve to obtain the carbon fluoride electrode material modified by the nano material; the lithium fluorocarbon battery comprises the nano material and carbon fluoride according to the mass ratio of (0.5-5): 100, the carbon fluoride material is modified by the nano material, and the nano material is uniformly distributed on the surface of the carbon fluoride material, so that the conductivity of the carbon fluoride material is increased, the problems of voltage lag and low-temperature performance of the carbon fluoride material are effectively solved, and the rate capability of the lithium fluorocarbon battery is improved.)

1. A preparation method of a nanomaterial-modified fluorocarbon electrode material is a dispersion-calcination method and is characterized by comprising the following steps:

step 1: adding a medium and carbon fluoride into a high-speed centrifugal dispersion tank according to the mass ratio of (2-3): 1, dispersing the material in the high-speed centrifugal dispersion tank at a rotating speed of 2000-3000 r/min for 10-30 min, then adding a nickel-iron alloy with the mass of 5-10% of the carbon fluoride, and dispersing in the high-speed centrifugal dispersion tank at a rotating speed of 2000-3000 r/min for 5-15 min;

step 2: adding a silver nano material into a high-speed centrifugal dispersion tank, dispersing the material in the high-speed centrifugal dispersion tank at a rotating speed of 3000-3500 r/min for 1-2 h, and then placing the material in an ultrasonic dispersion instrument for ultrasonic dispersion for 5-10min to obtain slurry;

and step 3: drying the slurry obtained in the step 2 at room temperature, placing the dried slurry in a microwave reactor, heating the slurry under the action of 200-500W, keeping the temperature for 1-3 min when the temperature of the slurry is raised to 70-80 ℃, and then carrying out vacuum drying for 8-12 h in a vacuum environment at 30-40 ℃ to obtain a mixture;

and 4, step 4: grinding the mixture obtained in the step 3 until the mixture is sieved by a sieve of 100-200 meshes to obtain mixture powder;

and 5: calcining the mixture powder obtained in the step 4 for 1-12 hours in an argon atmosphere, wherein the temperature rise speed is 5-10 ℃/min, and the calcining temperature is 300-450 ℃;

step 6: and (5) cooling the calcined material in the step (5) to room temperature at the speed of 10-20 ℃/min, grinding, and sieving with a 100-200-mesh sieve to obtain the carbon fluoride electrode material modified by the nano material.

2. The method for preparing the nanomaterial-modified fluorocarbon electrode material according to claim 1, wherein: in the step 1, the medium is composed of ethanol and acetone according to a mass ratio of (7-10) to 1.

3. The method for preparing the nanomaterial-modified fluorocarbon electrode material according to claim 1, wherein: in the step 2, the silver nano material is prepared into a nano material with the diameter of 10-100 nm by modifying silver powder with cyclodextrin, and the specific method comprises the following steps: 1) putting cyclodextrin into distilled water at the temperature of 40-50 ℃, uniformly mixing to prepare a solution with the mass concentration of 20-30%, adding silver powder with the mass (0.8-1.3) times of that of the cyclodextrin into the solution, stirring and reacting for 45-60 min at the constant temperature of 40-50 ℃, standing for 3-5 h at low temperature, filtering, washing, drying, and grinding to the diameter of 10-100 nm.

4. The method for preparing the nanomaterial-modified fluorocarbon electrode material according to claim 1, wherein: in step 2, the mass ratio of the nano material to the carbon fluoride material is (0.5-5): 100.

5. The method for preparing the nanomaterial-modified fluorocarbon electrode material according to claim 1, wherein: in step 3, the vacuum degree of the vacuum drying is-0.08 kPa to-0.09 kPa.

6. A preparation method of a nanomaterial-modified fluorocarbon electrode is characterized by comprising the following steps:

(1) and (3) mixing slurry: weighing superconducting carbon, graphene, ketjen black, CMC, SBR, a solvent and a carbon fluoride electrode material modified by a nano material according to a mass ratio, mixing all the raw materials, and uniformly stirring to prepare a mixed slurry;

(2) coating: uniformly coating the obtained mixed slurry on two sides of an aluminum foil, and drying in an oven at 70-90 ℃ for 30-60 min to obtain a carbon fluoride pole piece modified by the nano material;

(3) hot rolling: and (3) carrying out hot rolling on the carbon fluoride pole piece modified by the nano material to obtain the carbon fluoride electrode modified by the nano material.

7. The method of claim 6, wherein the nanomaterial-modified fluorocarbon electrode is prepared by: the mass ratio of the superconducting carbon to the graphene to the Ketjen black to the CMC to the SBR to the solvent to the nanomaterial-modified fluorocarbon electrode material is (0.02-0.03): (0.01-0.02): (0.02-0.03): (0.03-0.04): 1.8-2.2): 0.85-0.90).

8. The method of claim 6, wherein the nanomaterial-modified fluorocarbon electrode is prepared by: in the step (1), the stirring speed is 300-500 r/min, and the time is 65-100 min.

9. The method of claim 6, wherein the nanomaterial-modified fluorocarbon electrode is prepared by: in the step (2), the density of the mixed slurry coated on the aluminum foil is 2.0-3.3 g/100cm ²。

10. The method of claim 6, wherein the nanomaterial-modified fluorocarbon electrode is prepared by: in the step (3), the temperature of the hot rolling is 35-50 ℃, and the thickness is 0.15-0.19 mm.

Technical Field

The invention belongs to the technical field of production and processing of lithium primary batteries, and particularly relates to a preparation method of a carbon fluoride electrode material modified by a nano material.

Background

A primary lithium battery (primary lithium battery), which is a high-energy chemical primary battery and is commonly called a lithium battery. The lithium metal is used as a negative electrode, solid salt or salt dissolved in an organic solvent is used as an electrolyte, and metal oxide or other solid and liquid oxidants are used as positive electrode active substances. Universal round lithium manganese dioxide (Li/MnO) ₂) The cell and the lithium fluorocarbon [ Li/(CFx) n ] cell are designated by the letters CR and BR, respectively, and the numbers following them indicate the cell type. Lithium primary batteries are a generic term for this family of chemical sources of electrical energy that use metallic lithium as the negative electrode material.

The lithium fluorocarbon battery is a high-energy-density primary battery, the practical specific energy can reach 250-700 Wh/kg, and is multiple times of that of a dry battery, and the battery is easy to miniaturize and lighten. The carbon fluoride material is very stable, so that the capacity retention rate of the lithium-carbon fluoride battery at high temperature is high, and the lithium-carbon fluoride battery basically cannot decay. Carbon fluoride is a compound formed by the reaction of carbon in various forms with fluorine gas, and although the compound has electrochemical activity, the compound has high chemical stability in an organic electrolyte, and cannot be thermally decomposed at a temperature of up to 500 ℃, so that the compound has long storage life and good high-temperature performance. In addition, the positive electrode material for the system battery is fluorinatedCarbon also has the following advantages: 1) the point placing platform is stable, and the working temperature range is wide (the use requirement of minus 40-135 ℃ can be met); 2) high potential and low self-discharge (less than or equal to 1%/year); 3) the theoretical specific capacity is high, and when the fluorocarbon ratio x is 1, the theoretical specific capacity is up to 865mAh g ^-1About 170 mAh.g.specific capacity of lithium iron phosphate in positive electrode material of lithium secondary battery ^-1) Specific capacity (-280 mAh.g) of ternary material ^-1) 3-5 times of the total weight of the composition; 4) the safety is good, and the environment is protected; the lithium fluorocarbon cell is easy to realize miniaturization and light weight, and has high safety and long storage life (>10 years), can meet the requirements of high-level civil and military power supplies, and is widely applied to various civil and military fields such as cardiac pacemakers, special machine tools, electronic radio frequency identification systems, missile ignition systems, airplanes, small satellites or space weapons and the like, maneuvering orbital transfer launching, kinetic energy interception missiles, space stations and the like. However, the fluorocarbon positive electrode material also has some insurmountable defects, which are as follows: 1) the specific capacity of the carbon fluoride anode material is determined by fluorine content, the higher the fluorine content is, the higher the theoretical specific capacity of the material is, but the fluorine content can restrict the electronic conductivity of the anode material; for example, when the fluorocarbon ratio is close to 1, the fluorocarbon acts as an electronic insulator, so that the specific capacity and rate performance of the lithium fluorocarbon battery are usually mutually restricted, and the two are difficult to achieve the optimal conditions at the same time. 2) The low electronic conductivity and slow electrode reaction kinetics of the carbon fluoride anode material cause battery voltage hysteresis and poor low-temperature performance; 3) the lithium/carbon fluoride battery generates heat obviously in the discharging process, and the design, use and safety of the battery pack and the design of a power supply system are directly influenced; 4) low capacity performance and large capacity loss under low current density.

Patent application CN104577107A, discloses a surface modification method of carbon fluoride material; the preparation method comprises the following steps: mixing nano copper and carbon fluoride, adding a solvent, and performing ball milling to form mixed slurry; drying the mixed slurry to form a mixture; sieving the mixture to obtain mixture powder; sieving the mixture to obtain mixture powder; placing the mixture powder into an atmosphere furnace for calcining; and taking out the calcined mixture powder, cooling to room temperature, and sieving to obtain the carbon fluoride material modified by the nano-copper. According to the method, after the carbon fluoride and the nano-copper with good conductivity are mixed, and the nano-copper is calcined at high temperature in an inert atmosphere, the nano-copper reacts on the surface of the carbon fluoride, so that the voltage hysteresis phenomenon of the carbon fluoride is obviously improved, and the high rate performance and the low temperature performance are improved. Although the patent improves the voltage hysteresis of the carbon fluoride, the 0.1C multiplying power of the prepared battery only improves the initial discharge voltage of the carbon fluoride material from 2.35V to 2.49V, and the plateau voltage from 2.49V to 2.52V, so the improvement effect is not obvious.

With the rapid development of the technologies in the fields of portable electronic equipment, precision medical treatment, aerostat, aerospace and the like, a lithium primary chemical power supply with high power, high specific energy and high safety is urgently needed. The current lithium fluorocarbon battery has the technical problem of serious voltage hysteresis. Because the conductive polymer has good stability and conductivity, students at home and abroad increasingly adopt conductive polypyrrole, polyaniline, polythiophene and the like to modify the carbon fluoride material, but the effect is not satisfactory.

Disclosure of Invention

The invention provides a preparation method of a carbon fluoride electrode material modified by a nano material to solve the technical problems. According to the method, the carbon fluoride material is modified by adopting the nano material, and the nano material is uniformly coated on the surface of the carbon fluoride material by utilizing a dispersion-calcination method, so that the conductivity of the carbon fluoride material is increased, the problems of voltage lag, low-temperature performance and large capacity loss of the carbon fluoride material are effectively solved, and the rate capability of the lithium-carbon fluoride battery is improved; compared with the method for coating the modified carbon fluoride material by the conductive polymers such as polyaniline, polythiophene and the like, the technical scheme of the invention does not adopt toxic and harmful substances, and belongs to an environment-friendly material.

In order to achieve the above purpose, the invention adopts the following technical scheme:

a preparation method of a nanomaterial-modified fluorocarbon electrode material is a dispersion-calcination method and comprises the following steps:

step 1: adding a medium and carbon fluoride into a high-speed centrifugal dispersion tank according to the mass ratio of (2-3): 1, dispersing the material in the high-speed centrifugal dispersion tank at a rotating speed of 2000-3000 r/min for 10-30 min, then adding a nickel-iron alloy with the mass of 5-10% of the carbon fluoride, and dispersing in the high-speed centrifugal dispersion tank at a rotating speed of 2000-3000 r/min for 5-15 min;

step 2: adding a silver nano material into a high-speed centrifugal dispersion tank, dispersing the material in the high-speed centrifugal dispersion tank at a rotating speed of 3000-3500 r/min for 1-2 h, and then placing the material in an ultrasonic dispersion instrument for ultrasonic dispersion for 5-10min to obtain slurry;

and step 3: drying the slurry obtained in the step 2 at room temperature, placing the dried slurry in a microwave reactor, heating the slurry under the action of 200-500W, keeping the temperature for 1-3 min when the temperature of the slurry is raised to 70-80 ℃, and then carrying out vacuum drying for 8-12 h in a vacuum environment at 30-40 ℃ to obtain a mixture;

and 4, step 4: grinding the mixture obtained in the step 3 until the mixture is sieved by a sieve of 100-200 meshes to obtain mixture powder;

and 5: calcining the mixture powder obtained in the step 4 for 1-12 hours in an argon atmosphere, wherein the temperature rise speed is 5-10 ℃/min, and the calcining temperature is 300-450 ℃;

step 6: and (5) cooling the calcined material in the step (5) to room temperature at the speed of 10-20 ℃/min, grinding, and sieving with a 100-200-mesh sieve to obtain the carbon fluoride electrode material modified by the nano material.

Further, in the step 1, the medium is composed of ethanol and acetone according to a mass ratio of (7-10) to 1.

Further, in step 2, the working conditions of the ultrasonic dispersion are: the frequency is 55-65 kHz, and the power is 200-300W.

Further, in step 1, the particle size of the nickel-iron alloy is in the nanometer level.

Further, in the step 2, the silver nano material is prepared into a nano material with the diameter of 10-100 nm by modifying silver powder with cyclodextrin, and the specific method comprises the following steps: 1) putting cyclodextrin into distilled water at the temperature of 40-50 ℃, uniformly mixing to prepare a solution with the mass concentration of 20-30%, adding silver powder with the mass (0.8-1.3) times of that of the cyclodextrin into the solution, stirring and reacting for 45-60 min at the constant temperature of 40-50 ℃, standing for 3-5 h at low temperature, filtering, washing, drying, and grinding to the diameter of 10-100 nm.

Further, the low-temperature standing temperature is 0-4 ℃.

In step 2, the mass ratio of the silver nanomaterial to the carbon fluoride material is (0.5-5): 100.

Further, in step 3, the vacuum degree of the vacuum drying is-0.08 kPa to-0.09 kPa.

Further, the preparation method of the nanomaterial-modified carbon fluoride electrode comprises the following steps:

(1) and (3) mixing slurry: weighing superconducting carbon, graphene, ketjen black, CMC, SBR, a solvent and a carbon fluoride electrode material modified by a nano material according to a mass ratio, mixing all the raw materials, and uniformly stirring to prepare a mixed slurry;

(2) coating: uniformly coating the obtained mixed slurry on two sides of an aluminum foil, and drying in an oven at 70-90 ℃ for 30-60 min to obtain a carbon fluoride pole piece modified by the nano material;

(3) hot rolling: and (3) carrying out hot rolling on the carbon fluoride pole piece modified by the nano material to obtain the carbon fluoride electrode modified by the nano material.

Furthermore, the mass ratio of the superconducting carbon, the graphene, the ketjen black, the CMC, the SBR, the solvent and the carbon fluoride electrode material modified by the nano material is (0.02-0.03): (0.01-0.02): (0.02-0.03): (0.03-0.04): (1.8-2.2): 0.85-0.90).

Further, in the step (1), the stirring speed is 300-500 r/min, and the time is 65-100 min.

Further, in the step (2), the density of the mixed slurry coated on the aluminum foil is 2.0-3.3 g/100cm ²。

Further, in the step (3), the temperature of hot rolling is 35-50 ℃, and the thickness is 0.15-0.19 mm.

Furthermore, the mass ratio of the superconducting carbon to the graphene to the Ketjen black to the CMC to the SBR to the solvent to the nanomaterial-modified fluorocarbon electrode material is 0.03:0.01:0.02:0.02:0.03 (1.9-2.1) to (0.86-0.89).

Further, the mass ratio of the superconducting carbon to the graphene to the ketjen black to the CMC to the SBR to the solvent to the nanomaterial-modified fluorocarbon electrode material is 0.02:0.02:0.03:0.03:0.04:2.0: 0.87.

Due to the adoption of the technical scheme, the invention has the following beneficial effects:

(1) according to the method, the carbon fluoride material is modified by the nano material with good conductivity, and the nano material is uniformly distributed on the surface of the carbon fluoride material, so that the conductivity of the carbon fluoride material is increased, the voltage hysteresis problem of the carbon fluoride material is effectively improved, and the rate performance of the carbon fluoride material is improved.

(2) The carbon fluoride electrode material modified by the nano material is different from the common carbon fluoride electrode material modified by manganese dioxide and silver metavanadate in that the mode of improving the conductivity of the carbon fluoride electrode modified by manganese dioxide and silver metavanadate is equivalent to the synergistic reaction of a composite electrode, and the conductivity of the carbon fluoride electrode material is increased by coating a small amount of nano material on the surface of the carbon fluoride electrode material, so that the problem of voltage hysteresis of the carbon fluoride electrode is solved.

(3) The carbon fluoride electrode material modified by the nano material is applied to the lithium carbon fluoride battery, so that the voltage lag of the carbon fluoride electrode is effectively improved, the platform voltage of the electrode is improved, and the effect is obvious. The low-wave voltage of the carbon fluoride electrode is increased from 2.35V to 2.5V, which is increased by 6%; the platform voltage is increased from 2.5V to more than 2.8V, and is increased by 12%. Compared with the carbon fluoride electrode in the prior art, the voltage lag and the plateau voltage are greatly improved, and the discharge performance of the carbon fluoride material is greatly improved.

(4) After carbon fluoride is dispersed, firstly adding a nickel-iron alloy for redispersion, utilizing the reaction force of mechanical force and solution to enable the distance between the carbon fluoride and the nickel-iron alloy to be extremely close, then adding a silver nano material for dispersion, enabling the silver nano material to be capable of coating the nickel-iron alloy and simultaneously to be attached to the carbon fluoride, then conducting ultrasonic dispersion, utilizing an electromagnetic wave absorption material and ultrasonic cavitation to enable an insulating fluoride layer on the surface of the carbon fluoride to be damaged to a certain extent, further enabling silver powder to be capable of being embedded, then utilizing the unique thermal effect and non-thermal effect of microwaves to enable a cyclodextrin structure and the nickel-iron alloy to be uniformly distributed on the surface of the carbon fluoride, utilizing the wave absorbing capacity of the nickel-iron alloy and the cyclodextrin, further improving the electromagnetic shielding efficiency, and further effectively solving the problem of capacity wave absorption loss; simultaneously, this application is through the parameter control to ultrasonic dispersion and microwave treatment for silver powder can imbed the carbon fluoride surface uniformly, firmly, has still prevented the serious destruction to the carbon fluoride, makes the electric conductivity of carbon fluoride not influenced.

(5) The carbon fluoride electrode surface has connected ferronickel through the cyclodextrin structure in this application, and ferronickel's dielectric constant is higher relatively, has improved the rate of induction, has helped solving the problem that the voltage lags behind, utilizes ferronickel's characteristic simultaneously, has still improved the low temperature performance of electrode.

Drawings

In order to illustrate the embodiments of the present invention or the technical solutions in the prior art more clearly, the drawings needed in the description of the embodiments or the prior art will be briefly introduced below, it is obvious that the drawings in the following description are only some examples of the present invention, and for a person skilled in the art, without inventive step, other drawings can be obtained according to these drawings:

FIG. 1 is a discharge curve of the nanomaterial-modified fluorocarbon electrode material obtained in example 1 of the present application at 25 ℃ in comparison with that of comparative example 1;

Detailed Description

The following is a detailed description of the embodiments of the present invention, but the present invention is not limited to these embodiments, and any modifications or substitutions in the basic spirit of the embodiments are included in the scope of the present invention as claimed in the claims.