CN111725516A - LiFePO4Preparation method of/CNTs composite positive electrode material - Google Patents
LiFePO4Preparation method of/CNTs composite positive electrode material Download PDFInfo
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- 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
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Abstract
The invention provides LiFePO4The preparation method of the/CNTs composite positive electrode material comprises the following steps: (1) preparing an iron-based catalyst/CNTs composite material by CVD; (2) mixing the catalyst/CNTs composite material with an acidic solution, and taking oxygen as an oxidant to obtain a precursor/CNTs composite material; (3) mixing a precursor/CNTs composite material, a phosphorus source and a lithium source according to a certain proportion; (4) sintering the mixed material at high temperature in a solid phase to obtain LiFePO4the/CNTs composite anode material. The invention utilizes the pressure oxidation method to dissolve the iron-based catalyst, accelerates the reaction, and effectively reduces the dosage of acid and alkali and the generation of reaction byproducts; the iron-based catalyst is utilized to prepare uniformly dispersed CNTs and LiFePO4the/CNTs composite positive electrode material inherits the characteristics; solves the problem of LiFePO4The poor conductivity of the anode material improves the materialElectrochemical performance.
Description
Technical Field
The invention relates to the technical field of lithium ion battery materials, in particular to LiFePO4A preparation method of a/CNTs composite anode material.
Background
With the continuous highlighting of environmental and energy problems, the traditional energy structure has been difficult to meet the requirements of modern society. The rapid development and popularization of new energy related industries are becoming increasingly urgent. As one of the most important energy storage devices at present, lithium ion batteries have been widely used in the fields of electric vehicles, 3C electronic products, energy storage, and the like. In particular, in recent years, the application of lithium ion batteries in the field of vehicle engineering has increased explosively, and the development of pure Electric Vehicles (EV) and Hybrid Electric Vehicles (HEV) has also profoundly influenced people's life style. Although the application of lithium ion batteries is quite extensive, the higher preparation cost and potential safety risk of the lithium ion batteries restrict the further development of the lithium ion batteries. The cost of the anode material, which is the most important component of the lithium ion battery, accounts for about 40% of the total cost of the lithium ion battery, and the performance of the anode material also determines the performance of the lithium ion battery. Currently, lithium ion battery positive electrode materials which have been commercially used mainly include ternary materials, lithium cobaltate, lithium manganate, lithium iron phosphate, and the like.
Lithium iron phosphate (LiFePO)4) Has a typical olivine structure and the theoretical specific discharge capacity of 170 mAh/g. The lithium iron phosphate anode material has good thermal stability, the safety of the lithium ion battery prepared by the lithium iron phosphate anode material is correspondingly good, and the thermal runaway risk in the actual use process is low. The lithium iron phosphate anode material belongs to the transformation of a two-phase structure in the charging and discharging processes, so that the structural stability is strong and the cycling stability is high. Meanwhile, the raw materials required for preparing the lithium iron phosphate anode material have wide sources and low price, and are environment-friendlyAnd the preparation cost of the lithium iron phosphate is relatively low compared with that of other lithium ion battery anode materials. For the reasons, the lithium iron phosphate material has wide application prospects in the fields of electric automobiles and large-scale energy storage. The lithium iron phosphate material is usually prepared by reacting a sulfate and a nitrate of iron as raw materials with phosphoric acid, adjusting the pH value of a solution by using an alkali solution to obtain iron phosphate, and mixing and sintering the iron phosphate with a lithium salt. In this process, a large amount of alkali is consumed, and a large amount of by-products are produced. Therefore, new synthetic methods are sought to solve these problems. In the disclosure of CN102983328A and CN110615418A, iron powder is used as a raw material to prepare lithium iron phosphate, and although the use of alkali and the generation of reaction by-products are avoided, the reaction time of iron powder and an acidic solution is long, and the usage amount of phosphoric acid is large, which is not beneficial to the practical production process of lithium iron phosphate.
The lithium iron phosphate anode material has poor electronic conductivity and ionic conductivity, so that the material has poor discharge performance under high rate. In order to realize further application of the lithium iron phosphate material, the material must be modified. The most important modification means of the lithium iron phosphate anode material is to compound the lithium iron phosphate anode material with a carbon-based material, so that the electronic conductivity of the lithium iron phosphate anode material is improved, and the electrochemical performance of the lithium iron phosphate anode material is further improved. Carbon Nanotubes (CNTs) have a one-dimensional structure, can construct a conductive network in a composite material, and are an important modified composite material. However, in the process of compounding lithium iron phosphate and carbon nanotubes, the composite material is uniformly prepared due to the problem of dispersion of the carbon nanotubes. Some researchers have proposed methods of growing carbon nanotubes in situ in lithium iron phosphate materials (CN102427130A, CN101533904A), but additional catalysts need to be introduced, and the catalysts may remain in the final composite material, affecting the electrochemical properties of the material. Therefore, a new process was developed to prepare LiFePO4the/CNTs composite anode material is particularly important.
Disclosure of Invention
The invention provides LiFePO4A preparation method of a/CNTs composite positive electrode material aims to solve the defects and shortcomings in the background technology.
In order to achieve the above object, embodiments of the present invention provide a LiFePO4The preparation method of the/CNTs composite positive electrode material comprises the following steps:
the method comprises the following steps: feeding a liquid-phase carbon source into a reaction furnace through spray feeding equipment in a protective atmosphere at a preset temperature by using an iron-based catalyst, and preparing a catalyst/CNTs composite material through CVD;
step two: mixing the catalyst/CNTs composite material with an acidic solution by taking oxygen as an oxidant, reacting at a preset temperature and pressure, filtering and washing for multiple times after the reaction is finished, and drying to obtain a precursor/CNTs composite material;
step three: mixing the precursor/CNTs composite material, an iron source, a phosphorus source and a lithium source according to a preset proportion, transferring the mixture into a ball mill, uniformly mixing for a preset time to obtain mixed slurry, and performing spray drying on the mixed slurry to obtain a mixed material;
step four: sintering the mixed material in a high-temperature solid phase in a protective atmosphere, and naturally cooling the mixed material to room temperature along with the furnace to obtain LiFePO4the/CNTs composite anode material.
In the first step, the content of iron in the iron-based catalyst is 50% -100%, and the particle size of the iron-based catalyst is 10nm < d <100000 nm.
In the first step, the protective atmosphere is argon or nitrogen, and the gas flow is 10sccm to 5000 sccm; the liquid-phase carbon source is one or more of ethanol, ethylene glycol, propanol, isopropanol, cyclohexane, polyethylene or polyvinyl alcohol; the atomization speed of the liquid phase carbon source is 5 ml/h-100 ml/h.
Wherein, in the first step, the CVD comprises a chemical vapor deposition method or a modified method; the reaction temperature for preparing the CNTs is 500-1200 ℃; the time for introducing the atomized liquid-phase carbon source is 10-300 min.
In the second step, the acidic solution is one or more of phosphoric acid, sulfuric acid, nitric acid and hydrochloric acid; the molar ratio of the iron-based catalyst to the acid is 1: 1-5; the liquid-solid ratio of the acidic solution to the iron-based catalyst/CNTs composite material is 5 ml/g-50 ml/g; the leaching temperature is 25-225 ℃; the oxygen partial pressure is 20KPa to 3000 KPa; the reaction time is 0.5-15 h.
Wherein the chemical formula of the precursor is (Fe)xM1-x)yO or (Fe)xM1-x)zPO4Wherein x is more than or equal to 0 and less than or equal to 0.5 and 0<y is less than or equal to 1.5, z is less than or equal to 1 and is less than or equal to 2/3, and M is one or more of Ni, Co, Mn, Cu, Zn, Mg, Al, Ti, Cr, Zr, W, Nb, Sn or Mo; the molar ratio of the precursor/CNTs composite material to the iron source to the phosphorus source to the lithium source is (Fe + M): p: li is 0.95-1.1: 0.95-1.1: 0.95 to 1.1.
In the third step, the iron source is one or more of sulfate, nitrate, phosphate, acetate or oxide of divalent or trivalent iron; the phosphorus source is one or more of phosphoric acid, ammonium monohydrogen phosphate, ammonium dihydrogen phosphate, ammonium phosphate or lithium dihydrogen phosphate; the lithium source is one or more of lithium hydroxide, lithium carbonate, lithium acetate, lithium oxalate or lithium dihydrogen phosphate.
In the third step, the time for ball milling and mixing is 0.5-20 h, and the ball milling rotating speed is 200-3000 r/min; the air inlet temperature of the spray drying is 120-220 ℃.
In the fourth step, the protective atmosphere is argon or nitrogen; the sintering temperature is 600-1000 ℃, and the sintering time is 5-20 h.
The scheme of the invention has the following beneficial effects:
the invention takes iron powder as a catalyst, and CNTs grow in situ on the catalyst through CVD, so that the catalyst/CNTs composite material is prepared. By controlling relevant parameters in the CVD process, the mass percentage of the iron-based catalyst and the CNTs can be controlled, and the CNTs in the composite material have good dispersibility and are used for subsequent LiFePO4The preparation of the cathode material provides an iron source and a carbon source.
The conversion of the catalyst/CNTs composite to the precursor/CNTs composite can be achieved by atmospheric or pressure oxidation leaching. In the process of atmospheric pressure oxidation leaching, the dissolution of iron powder is accelerated by forming an iron-carbon primary battery in an acid solution, so that the use amount of acid and the reaction time are reduced. During the pressure oxidation leaching, the following reactions mainly occur between Fe and the acidic solution in the catalyst/CNTs composite material:
Fe+2H++1/2O2＝Fe2++H2O
4Fe2++4H++O2＝4Fe3++2H2O
2Fe3++3H2O＝Fe2O3+6H+
by controlling the oxygen partial pressure during leaching, iron may be present in divalent and trivalent forms, respectively. According to whether phosphate is added or not and the reaction temperature is controlled, precursors in different forms can be prepared, for example, phosphate is added to prepare a phosphate precursor, and an oxide precursor can be obtained without adding phosphate. And (3) generating precipitates by taking the dispersed CNTs as nucleation sites, and filtering and washing to obtain the precursor/CNTs composite material. Then uniformly mixing the precursor with a phosphorus source, an iron source and a lithium source in a certain proportion, spray drying and granulating to obtain a precursor material, and carrying out high-temperature solid-phase reaction to obtain LiFePO4the/CNTs composite anode material.
The preparation method provided by the invention avoids the use of alkali, fully utilizes the catalyst iron source in the preparation process of the CNTs, shortens the preparation process of the CNTs, and obviously reduces the production cost. No by-product is produced in the reaction process, and the method is environment-friendly. Simultaneously, the prepared LiFePO4The CNTs in the/CNTs composite positive electrode material have good dispersibility, and no additional catalyst is introduced. Experiments prove that the LiFePO prepared by the method provided by the invention4The electrochemical performance of the/CNTs composite positive electrode material is excellent.
Drawings
FIG. 1 shows LiFePO of the present invention4A flow chart of a preparation method of the/CNTs composite anode material.
Detailed Description
In order to make the technical problems, technical solutions and advantages of the present invention more apparent, the following detailed description is given with reference to the accompanying drawings and specific embodiments.
The present invention is directed toThere is a problem in that a LiFePO is provided4A preparation method of a/CNTs composite anode material.
The first embodiment is as follows:
as shown in fig. 1, an embodiment of the present invention provides a LiFePO4The preparation method of the/CNTs composite positive electrode material comprises the following steps:
the method comprises the following steps: 50g of an iron-based catalyst having a median particle size of 15.43um (Fe content: 95%) was weighed, placed in a tube-type resistance furnace, the experimental apparatus was assembled and the airtightness of the apparatus was checked. Argon gas was introduced into the furnace to exhaust the air in the furnace, and the flow rate of argon gas was 500 sccm. The tubular resistance furnace was heated to 750 ℃ at a heating rate of 10 ℃/min. The furnace temperature was maintained, and the argon flow rate was adjusted to 100 sccm. Introducing cyclohexane at an atomization rate of 10ml/h, stopping introducing a carbon source after 60min, keeping the temperature for 30min, stopping heating, and naturally cooling to room temperature along with the furnace to obtain a catalyst/CNTs composite material; performing an inductively coupled plasma spectroscopy (ICP-OES) test on the material to obtain that the content of iron in the composite material is 85.41 wt%;
step two: 17.63g of phosphoric acid solution (with the concentration of 85%) is added into 200ml of deionized water, 10g of catalyst/carbon nanotube composite material is added after the mixture is fully stirred, and stirring is continued after oxygen is introduced. After reacting for 5 hours, filtering and washing to obtain mixed slurry;
step three: the mixed slurry was transferred to a ball mill, and 5.94g of lithium carbonate was added, and ball-milled at 300r/min for 3 hours to uniformly mix. Spray drying the mixed slurry at the air inlet temperature of 180 ℃ to obtain a mixed material;
step four: and (3) placing the mixed material in a tube furnace, heating to 700 ℃ at a speed of 5 ℃/min in an argon protective atmosphere, and preserving heat for 10 h. Cooling to room temperature along with the furnace to obtain LiFePO4the/CNTs composite anode material.
Grinding and uniformly mixing the lithium ion battery positive electrode material, the conductive carbon black and the polyvinylidene fluoride (PVDF) according to the mass ratio of 8:1:1, adding a proper amount of N-methyl pyrrolidone (NMP), mixing into slurry, coating the slurry on an aluminum foil, drying for 4 hours in a drying box at 120 ℃, and then cutting into pieces to prepare the lithium ion battery positive electrode piece. Takes a metal lithium sheet as a negative electrode and is fully protectedButton cells are assembled in a pneumatic glove box. And (3) testing the electrochemical performance of the battery by using a Newware battery testing system, activating at a multiplying power of 0.1C, and testing the cycle performance at a multiplying power of 1C. The LiFePO is found by tests4The first discharge specific capacity of the/CNTs composite anode material under the multiplying power of 1C is 155.6mAh g-1And the capacity circulation retention rate after 100 circles reaches 95.76%.
Example two:
the method comprises the following steps: 50g of an iron-based catalyst having a median particle size of 25.23um (98% Fe) was weighed, placed in a tube-type resistance furnace, the experimental apparatus was assembled and the airtightness of the apparatus was checked. And introducing argon to discharge the air in the furnace, wherein the flow of the argon is 1000 sccm. The tubular resistance furnace was heated to 950 ℃ at a rate of 15 ℃/min. The furnace temperature was maintained, and the argon flow rate was adjusted to 200 sccm. Introducing ethanol at an atomization rate of 20ml/h, stopping introducing a carbon source after 30min, keeping the temperature for 60min, stopping heating, and naturally cooling to room temperature along with the furnace to obtain a catalyst/CNTs composite material; performing an inductively coupled plasma spectroscopy (ICP-OES) test on the material to obtain that the content of iron in the composite material is 87.38 wt%;
step two: 48.40g of 95 wt% sulfuric acid is weighed, and the volume is adjusted to 400ml by deionized water, and then the mixture is added into a high-pressure reaction kettle. Weighing 20g of Fe/CNTs composite material, adding the Fe/CNTs composite material into a high-pressure reaction kettle, carrying out primary reaction for 10min, and then sealing the high-pressure reaction kettle. Oxygen was slowly introduced into the autoclave, the oxygen partial pressure was controlled at 1000Kpa, and the heating power was turned on to heat the autoclave to 170 ℃ and start stirring. As the reaction proceeds, oxygen is continuously consumed, and the oxygen pressure is kept stable by pressurizing according to the indication of the oxygen pressure meter. After reacting for 2h, stopping heating and stirring, lifting the autoclave out of the furnace body for placing, naturally cooling, and opening a deflation valve. Removing the slurry in the autoclave, filtering and washing for multiple times, and drying the filter cake to obtain Fe2O3a/CNTs composite; the ICP-OES test is carried out to obtain Fe2O3The Fe content in the/CNTs composite material is 62.47 wt%;
step three: weighing Fe2O310g of/CNTs composite material, 12.89g of phosphoric acid (85 wt%), 2.67g of lithium hydroxide and 300ml of deionized water. Adding into a ball millIn a pot, ball milling is carried out for 2 hours at 500r/min for uniform mixing. Spray drying the mixed slurry at the air inlet temperature of 150 ℃ to obtain a mixed material;
step four: and (3) placing the mixed material in a tube furnace, heating to 750 ℃ at the speed of 5 ℃/min in the argon protective atmosphere, and preserving heat for 6 h. Cooling to room temperature along with the furnace to obtain LiFePO4the/CNTs composite anode material.
Grinding and uniformly mixing the lithium ion battery positive electrode material, the conductive carbon black and the polyvinylidene fluoride (PVDF) according to the mass ratio of 8:1:1, adding a proper amount of N-methyl pyrrolidone (NMP), mixing into slurry, coating the slurry on an aluminum foil, drying for 4 hours in a drying box at 120 ℃, and then cutting into pieces to prepare the lithium ion battery positive electrode piece. And (3) assembling the button cell in a glove box filled with protective gas by taking a metal lithium sheet as a negative electrode. And (3) testing the electrochemical performance of the battery by using a Newware battery testing system, activating at a multiplying power of 0.1C, and testing the cycle performance at a multiplying power of 1C. The LiFePO is found by tests4The first discharge specific capacity of the/CNTs composite anode material under the multiplying power of 1C is 156.7mAh g-1And the capacity circulation retention rate after 100 circles reaches 97.38%.
Example three:
the method comprises the following steps: 50g of iron powder with a median particle size of 0.83um was weighed, the catalyst was placed in a tube-type resistance furnace, the experimental setup was assembled and the air tightness of the setup was checked. Argon gas was introduced into the furnace to exhaust the air in the furnace, and the flow rate of argon gas was 200 sccm. The tubular resistance furnace was heated to 750 ℃ at a heating rate of 10 ℃/min. The furnace temperature was maintained, and the argon flow rate was adjusted to 50 sccm. Introducing polyethylene at an atomization rate of 30ml/h, stopping introducing a carbon source after 30min, keeping the temperature for 60min, stopping heating, naturally cooling to room temperature along with the furnace, and taking out deposits on the alumina sheets to obtain the Fe/CNTs composite material; performing inductively coupled plasma spectroscopy (ICP-OES) test on the material to obtain that the content of iron in the composite material is 84.37 wt%;
step two: adding sulfuric acid-phosphoric acid mixed acid, using deionized water to make the volume constant to 300ml, adding the above-mentioned material into high-pressure reaction still. Weighing 20g of Fe/CNTs composite material, adding the Fe/CNTs composite material into a high-pressure reaction kettle, carrying out primary reaction for 10min, and then sealing the high-pressure reaction kettle. Nitrogen is slowly introduced into the high-pressure kettle,controlling the oxygen partial pressure to be 1500Kpa, simultaneously turning on a heating power supply, and starting stirring when the temperature is heated to 200 ℃. As the reaction proceeds, oxygen is continuously consumed, and the oxygen pressure is kept stable by pressurizing according to the indication of the oxygen pressure meter. After reacting for 1h, stopping heating and stirring, lifting the autoclave out of the furnace body for placing, naturally cooling, and opening a deflation valve. Removing the slurry in the autoclave, filtering and washing for multiple times, and drying the filter cake to obtain Fe3(PO4)2a/CNTs composite;
step three: weighing Fe3(PO4)2CNTs composite material, lithium oxalate and 300ml of deionized water. Adding the mixture into a ball milling tank, and carrying out ball milling for 3 hours at the speed of 300r/min to uniformly mix the materials. Spray drying the mixed slurry at the air inlet temperature of 200 ℃ to obtain a mixed material;
step four: and (3) placing the mixed material in a tube furnace, heating to 700 ℃ at a speed of 10 ℃/min in an argon protective atmosphere, and preserving heat for 8h for roasting. Cooling to room temperature along with the furnace to obtain LiFePO4the/CNTs composite anode material.
Grinding and uniformly mixing the lithium ion battery positive electrode material, the conductive carbon black and the polyvinylidene fluoride (PVDF) according to the mass ratio of 8:1:1, adding a proper amount of N-methyl pyrrolidone (NMP), mixing into slurry, coating the slurry on an aluminum foil, drying for 4 hours in a drying box at 120 ℃, and then cutting into pieces to prepare the lithium ion battery positive electrode piece. And (3) assembling the button cell in a glove box filled with protective gas by taking a metal lithium sheet as a negative electrode. And (3) testing the electrochemical performance of the battery by using a Newware battery testing system, activating at a multiplying power of 0.1C, and testing the cycle performance at a multiplying power of 1C. The LiFePO is found by tests4The first discharge specific capacity of the/CNTs composite anode material under the multiplying power of 1C is 153.4mAh g-1And the capacity circulation retention rate after 100 circles reaches 96.26%.
While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.
Claims (9)
1. LiFePO4The preparation method of the/CNTs composite positive electrode material is characterized by comprising the following steps of:
the method comprises the following steps: feeding a liquid-phase carbon source into a reaction furnace through spray feeding equipment in a protective atmosphere at a preset temperature by using an iron-based catalyst, and preparing a catalyst/CNTs composite material through CVD;
step two: mixing the catalyst/CNTs composite material with an acidic solution by taking oxygen as an oxidant, reacting at a preset temperature and pressure, filtering and washing for multiple times after the reaction is finished, and drying to obtain a precursor/CNTs composite material;
step three: mixing the precursor/CNTs composite material, an iron source, a phosphorus source and a lithium source according to a preset proportion, transferring the mixture into a ball mill, uniformly mixing for a preset time to obtain mixed slurry, and performing spray drying on the mixed slurry to obtain a mixed material;
step four: sintering the mixed material in a high-temperature solid phase in a protective atmosphere, and naturally cooling the mixed material to room temperature along with the furnace to obtain LiFePO4the/CNTs composite anode material.
2. The LiFePO according to claim 14The preparation method of the/CNTs composite anode material is characterized in that in the step one, the content of iron in the iron-based catalyst is 50% -100%, and the particle size of the iron-based catalyst is 10nm<d<100000nm。
3. The LiFePO according to claim 14The preparation method of the/CNTs composite anode material is characterized in that in the step one, the protective atmosphere is argon or nitrogen, and the gas flow is 10 sccm-5000 sccm; the liquid-phase carbon source is one or more of ethanol, ethylene glycol, propanol, isopropanol, cyclohexane, polyethylene or polyvinyl alcohol; the atomization speed of the liquid phase carbon source is 5 ml/h-100 ml/h.
4. The LiFePO according to claim 14The preparation method of the/CNTs composite anode material is characterized in that in the step one, the CVD comprises a chemical vapor deposition method or an improved methodA method; the reaction temperature for preparing the CNTs is 500-1200 ℃; the time for introducing the atomized liquid-phase carbon source is 10-300 min.
5. The LiFePO according to claim 14The preparation method of the/CNTs composite positive electrode material is characterized in that in the second step, the acidic solution is one or more of phosphoric acid, sulfuric acid, nitric acid or hydrochloric acid; the molar ratio of the iron-based catalyst to the acid is 1: 1-5; the liquid-solid ratio of the acidic solution to the iron-based catalyst/CNTs composite material is 5 ml/g-50 ml/g; the leaching temperature is 25-225 ℃; the oxygen partial pressure is 20KPa to 3000 KPa; the reaction time is 0.5-15 h.
6. The LiFePO according to claim 14The preparation method of the/CNTs composite anode material is characterized in that the chemical formula of the precursor is (Fe)xM1-x)yO or (Fe)xM1-x)zPO4Wherein x is more than or equal to 0 and less than or equal to 0.5 and 0<y is less than or equal to 1.5, z is less than or equal to 1 and is less than or equal to 2/3, and M is one or more of Ni, Co, Mn, Cu, Zn, Mg, Al, Ti, Cr, Zr, W, Nb, Sn or Mo; the molar ratio of the precursor/CNTs composite material to the iron source, the phosphorus source and the lithium source is (Fe + M): p: li is 0.95-1.1: 0.95-1.1: 0.95 to 1.1.
7. The LiFePO according to claim 14The preparation method of the/CNTs composite anode material is characterized in that in the third step, the iron source is one or more of sulfate, nitrate, phosphate, acetate or oxide of bivalent or trivalent iron; the phosphorus source is one or more of phosphoric acid, ammonium monohydrogen phosphate, ammonium dihydrogen phosphate, ammonium phosphate or lithium dihydrogen phosphate; the lithium source is one or more of lithium hydroxide, lithium carbonate, lithium acetate, lithium oxalate or lithium dihydrogen phosphate.
8. The LiFePO according to claim 14The preparation method of the/CNTs composite positive electrode material is characterized in that in the third step, the time for ball milling and mixing is 0.5h ∞The ball milling speed is 200r/min to 3000r/min for 20 h; the air inlet temperature of the spray drying is 120-220 ℃.
9. The LiFePO according to claim 14The preparation method of the/CNTs composite anode material is characterized in that in the fourth step, the protective atmosphere is argon or nitrogen; the sintering temperature is 600-1000 ℃, and the sintering time is 5-20 h.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN102427130A (en) * | 2011-03-23 | 2012-04-25 | 上海中兴派能能源科技有限公司 | Lithium iron phosphate-carbon nanotube composite material, preparation method, and application thereof |
| CN102544499A (en) * | 2012-03-14 | 2012-07-04 | 天津大学 | Method for preparing lithium ferrous phosphate (LiFePO4) and carbon nano tube composite cathode material for lithium battery |
| CN107093732A (en) * | 2017-05-10 | 2017-08-25 | 彭枭雄 | It is a kind of for lithium iron phosphate/carbon nano-tube nano composite of anode material of lithium battery and preparation method thereof |
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| CN102427130A (en) * | 2011-03-23 | 2012-04-25 | 上海中兴派能能源科技有限公司 | Lithium iron phosphate-carbon nanotube composite material, preparation method, and application thereof |
| CN102544499A (en) * | 2012-03-14 | 2012-07-04 | 天津大学 | Method for preparing lithium ferrous phosphate (LiFePO4) and carbon nano tube composite cathode material for lithium battery |
| CN107093732A (en) * | 2017-05-10 | 2017-08-25 | 彭枭雄 | It is a kind of for lithium iron phosphate/carbon nano-tube nano composite of anode material of lithium battery and preparation method thereof |
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| CN114188508A (en) * | 2021-10-28 | 2022-03-15 | 厦门理工学院 | Lithium iron phosphate cathode material, preparation method and application |
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