CN108767217B - Directional porous lithium iron phosphate-graphene composite material and preparation method thereof - Google Patents
Directional porous lithium iron phosphate-graphene composite material and preparation method thereof 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 relates to a directional porous lithium iron phosphate-graphene composite material and a preparation method thereof. The technical scheme is as follows: adding graphene oxide into 0.5-2 mol/L ferric salt aqueous solution according to the mass ratio of ferric salt to graphene oxide of 1: 0.2-2.6, and ultrasonically stirring to prepare solution I. Adding phosphoric acid into the solution I according to the mass ratio of ferric salt to phosphoric acid of 1: 1, and stirring to obtain a solution II. And adding the lithium salt aqueous solution into the solution II according to the mass ratio of the ferric salt to the lithium salt of 1: 1, and performing ultrasonic stirring to obtain a solution III. And (3) freezing the solution III in an oriented freezing device, drying in a vacuum freeze dryer, preserving heat under the protective atmosphere and at the temperature of 600-750 ℃, and cooling along with the furnace to obtain the oriented porous lithium iron phosphate-graphene composite material. The method has the advantages of simple process, convenient operation, short production period and controllable appearance; the prepared product is in a three-dimensional directional porous structure, the pore diameter and the pore wall thickness are uniform and controllable, and the electrochemical performance is excellent.
Description
Technical Field
The invention belongs to the technical field of lithium iron phosphate-graphene composite materials. In particular to a directional porous lithium iron phosphate-graphene composite material and a preparation method thereof.
Background
At present, energy conservation and environmental protection become the subjects of the times, clean renewable energy sources such as solar energy, wind energy, tidal energy and the like gradually replace traditional high-pollution non-renewable energy sources such as coal, petroleum, natural gas and the like, however, the defects of discontinuity and instability exist in the novel energy sources, so that the practical application of the novel energy sources is limited, and therefore, the energy conversion and the efficient storage of the renewable energy sources become more important. As an efficient energy conversion device, a Lithium Ion Battery (LIB) has been widely used in the fields of energy and power and 3C Electronic products (Computer, Communication and Consumer Electronic), and its performance and cost mainly depend on a positive electrode material. Among them, olivine-type lithium iron phosphate is unique among many positive electrode materials due to its advantages such as high theoretical specific capacity, low cost, excellent cycle stability and safety performance. However, the low ion diffusion rate and the low electronic conductivity hinder the performance of the lithium iron phosphate rate, greatly limit the use of the lithium iron phosphate material in the field of power batteries, and lead Chinese and foreign scholars to carry out much work aiming at the modification of the inherent defects of the lithium iron phosphate.
At present, the modification modes of lithium iron phosphate mainly comprise particle size nanocrystallization, porous morphology design, carbon coating, cation doping and the like, wherein the nanocrystallization of the lithium iron phosphate particles can obviously improve the specific discharge capacity of the material. However, the nanoparticles have high chemical activity, are easy to agglomerate, and are not beneficial to improving the cycling stability of the material. Compared with nano lithium iron phosphate, the lithium iron phosphate with the three-dimensional porous structure is expected to be widely applied to the field of power batteries due to the larger specific surface area, higher volume energy density and higher power density. At present, the preparation of porous lithium iron phosphate generally adopts a soft template method, a hard template method and a non-template method.
The non-template method has simple synthesis process and simple and convenient operation, but most of the formed holes are disordered; the soft template method has the advantages that the template agent is convenient to remove, the amorphous carbon generated after the template agent is pyrolyzed can improve the conductivity of the lithium iron phosphate, however, the crystallization temperature of the lithium iron phosphate is higher, and the soft template agent is decomposed at a lower temperature, so that a porous structure at a high temperature cannot be continuously supported, and the phenomenon of hole collapse is easy to occur.
The rigidity of the template used in the hard template method is high, the problem of hole collapse can be well avoided, and the preparation of the three-dimensional porous material is facilitated, but the template agent required by the hard template method needs to be prepared in advance, the process is complicated invisibly, the synthesis cost of the material is increased, the template agent is not completely removed, and byproducts are easy to introduce.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides a preparation method of an oriented porous lithium iron phosphate-graphene composite material, which has the advantages of simple process, convenient operation, short production period and controllable morphology; the directional porous lithium iron phosphate-graphene composite material prepared by the method is in a three-dimensional directional porous structure, the pore diameter and the pore wall thickness are uniform and controllable, and the electrochemical performance is excellent.
In order to achieve the purpose, the technical scheme adopted by the invention comprises the following specific steps:
(1) adding the graphene oxide into a ferric salt aqueous solution with the concentration of 0.5-2 mol/L according to the mass ratio of ferric salt to graphene oxide of 1: 0.2-2.6, and ultrasonically stirring for 0.5-1.5 h to obtain a solution I.
(2) And adding the phosphoric acid into the solution I according to the mass ratio of the ferric salt to the phosphoric acid of 1: 1, and stirring for 20-40 min to obtain a solution II.
(3) And adding a 4mol/L lithium salt aqueous solution into the solution II according to the mass ratio of the ferric salt to the lithium salt of 1: 1, and ultrasonically stirring for 30-40 min to obtain a solution III.
(4) And (3) placing the solution III in a directional freezing device, freezing for 20-40 min, and drying in a vacuum freeze dryer for 36-72 h to obtain the columnar xerogel.
(5) And (3) placing the columnar xerogel in a tubular atmosphere furnace, preserving heat for 8-10 h under the conditions of protective atmosphere and 600-750 ℃, and cooling along with the furnace to obtain the directional porous lithium iron phosphate-graphene composite material.
The directional porous lithium iron phosphate-graphene composite material is of a directional porous structure, holes are directionally arranged, the hole walls of the holes are formed by stacking lithium iron phosphate nanoparticles and graphene, and nanopores are distributed on the hole walls of the holes.
The ferric salt is one of ferric citrate, ferrous oxalate dihydrate and ferrous sulfate heptahydrate.
The lithium salt is one of lithium dihydrogen phosphate, lithium acetate dihydrate and lithium hydroxide monohydrate.
The directional freezing device comprises a low-temperature-resistant container, a copper column and a circular tube; a copper column is arranged at the central position of the bottom of the low-temperature resistant container, the copper column is an integral body formed by a large cylinder and a small cylinder which are coaxial, a round pipe is fixed on the cylindrical surface of the small cylinder, and a sealing ring is arranged between the annular surface of the copper column and the lower end surface of the round pipe; when in use, liquid nitrogen is filled in the low temperature resistant container, and the solution III is placed in the round tube.
The protective atmosphere is argon, or a mixed gas of nitrogen and hydrogen, or a mixed gas of argon and hydrogen.
Due to the adoption of the technical scheme, compared with the prior art for preparing the lithium iron phosphate material, the method has the following positive effects:
1. according to the invention, the pore diameter and the pore wall thickness of the prepared directional porous lithium iron phosphate-graphene composite material can be effectively regulated and controlled by changing the addition of the graphene oxide, the pore diameter of the prepared directional porous lithium iron phosphate-graphene composite material is 135-175 nm, and the pore wall thickness is 15-35 nm.
2. The three-dimensional directional porous structure of the directional porous lithium iron phosphate-graphene composite material prepared by the invention is a structure formed by directionally growing ice crystals along the direction of temperature gradient and then drying the ice crystals in vacuum. Liquid nitrogen in the low-temperature resistant plastic container transmits low temperature to the junction of the copper column and the solution III through the copper column, the solution III starts to crystallize at the interface to form small ice crystals and directionally grows to the surface of the solution III along the temperature gradient direction, and the round tube can avoid the influence of the external temperature around the solution III on the freezing process and ensure the consistency of the ice crystal growth in the directional freezing process.
The three-dimensional directional porous structure can effectively promote the infiltration of electrolyte to electrode materials, provides a directional channel for lithium ion transmission, and shortens an ion diffusion path. The two-dimensional graphene sheet is embedded in the porous pore wall sheet layer and serves as a bridge for electron transfer among the lithium iron phosphate nanoparticles, and the larger specific surface area can also provide more reactive sites for ions, so that the specific capacity and the rate capability of the material can be improved. Meanwhile, the nano holes in the hole wall sheet layer can effectively relieve the damage of the material structure caused by volume expansion in the charge and discharge process.
3. The directional porous lithium iron phosphate-graphene composite material can be prepared by utilizing a directional freezing device and combining subsequent drying and heat treatment processes. The template agent is not required to be prepared additionally, and meanwhile, the ice crystals with directional growth can be well removed through vacuum freeze drying, and the three-dimensional directional porous structure can be well maintained in the heat treatment process.
Therefore, the method has the advantages of simple process, convenient operation, short production period and controllable appearance; the prepared directional porous lithium iron phosphate-graphene composite material is in a three-dimensional directional porous structure, the pore diameter and the pore wall thickness are uniform and controllable, and the electrochemical performance is excellent.
Drawings
FIG. 1 is a schematic diagram of a directional freezer apparatus useful in the present invention;
FIG. 2 is a schematic view of the directional freezer shown in FIG. 1 in use;
FIG. 3 is an XRD pattern of a directional porous lithium iron phosphate-graphene composite material prepared by the present invention;
fig. 4 is a low-magnification SEM image of the directional porous lithium iron phosphate-graphene composite material shown in fig. 3;
fig. 5 is a high-magnification SEM image of the oriented porous lithium iron phosphate-graphene composite material shown in fig. 3.
Detailed Description
The invention is further described with reference to the following figures and detailed description, without limiting its scope.
Example 1
An oriented porous lithium iron phosphate-graphene composite material and a preparation method thereof. The preparation method comprises the following steps:
(1) adding the graphene oxide into a ferric salt aqueous solution with the concentration of 0.5-2 mol/L according to the mass ratio of ferric salt to graphene oxide of 1: 0.2-1.0, and ultrasonically stirring for 0.5-1.5 h to obtain a solution I.
(2) And adding the phosphoric acid into the solution I according to the mass ratio of the ferric salt to the phosphoric acid of 1: 1, and stirring for 20-40 min to obtain a solution II.
(3) And adding a 4mol/L lithium salt aqueous solution into the solution II according to the mass ratio of the ferric salt to the lithium salt of 1: 1, and ultrasonically stirring for 30-40 min to obtain a solution III.
(4) And (3) placing the solution III in a directional freezing device, freezing for 20-40 min, and drying in a vacuum freeze dryer for 36-48 h to obtain the columnar xerogel.
(5) And (3) placing the columnar xerogel in a tubular atmosphere furnace, preserving heat for 8-10 h under the conditions of protective atmosphere and 600-650 ℃, and cooling along with the furnace to obtain the directional porous lithium iron phosphate-graphene composite material.
The directional porous lithium iron phosphate-graphene composite material is of a directional porous structure, holes are directionally arranged, the hole walls of the holes are formed by stacking lithium iron phosphate nanoparticles and graphene, and nanopores are distributed on the hole walls of the holes.
As shown in figure 1, the directional freezing device comprises a low temperature resistant container (3), a copper column (2) and a circular tube (1). The copper column (2) is arranged at the central position of the bottom of the low temperature resistant container (3), the copper column (2) is a whole body formed by a large cylinder and a small cylinder which are coaxial, a round pipe (1) is fixed on the cylindrical surface of the small cylinder, and a sealing ring is arranged between the annular surface of the copper column (2) and the lower end surface of the round pipe (1). As shown in figure 2, when in use, the low temperature resistant container (3) is filled with liquid nitrogen (4), and the solution III (5) is placed in the round tube (1).
The ferric salt is ferric citrate; the lithium salt is lithium dihydrogen phosphate; the protective atmosphere is argon.
Fig. 3 is an XRD pattern of an oriented porous lithium iron phosphate-graphene composite material prepared in this example; FIG. 4 is a low-magnification SEM image of the article shown in FIG. 3; fig. 5 is a high-magnification SEM image of the article shown in fig. 3. As can be seen from fig. 3, the product is a pure-phase lithium iron phosphate material without any impurity peak. As can be seen from fig. 4 and 5, the prepared directional porous lithium iron phosphate-graphene composite material has uniform pore size distribution, the thickness of pore wall lamellae is about 18.8nm, and the pore size of nanopores is about 161.8 nm.
The directional porous lithium iron phosphate-graphene composite material prepared in the embodiment is a pure-phase lithium iron phosphate material, and the directional porous lithium iron phosphate-graphene composite material has uniform pore size distribution, the pore size is 155-175 nm, and the pore wall thickness is 15-25 nm.
Example 2
An oriented porous lithium iron phosphate-graphene composite material and a preparation method thereof. The preparation method comprises the following steps:
(1) adding the graphene oxide into a ferric salt aqueous solution with the concentration of 0.5-2 mol/L according to the mass ratio of ferric salt to graphene oxide of 1: 1.0-1.8, and ultrasonically stirring for 0.5-1.5 h to obtain a solution I.
(2) And adding the phosphoric acid into the solution I according to the mass ratio of the ferric salt to the phosphoric acid of 1: 1, and stirring for 20-40 min to obtain a solution II.
(3) And adding a 4mol/L lithium salt aqueous solution into the solution II according to the mass ratio of the ferric salt to the lithium salt of 1: 1, and ultrasonically stirring for 30-40 min to obtain a solution III.
(4) And (3) placing the solution III in a directional freezing device, freezing for 20-40 min, and drying in a vacuum freeze dryer for 48-60 h to obtain the columnar xerogel.
(5) And (3) placing the columnar xerogel in a tubular atmosphere furnace, preserving heat for 8-10 h under the conditions of protective atmosphere and 650-700 ℃, and cooling along with the furnace to obtain the directional porous lithium iron phosphate-graphene composite material.
The directional porous lithium iron phosphate-graphene composite material is of a directional porous structure, holes are directionally arranged, the hole walls of the holes are formed by stacking lithium iron phosphate nanoparticles and graphene, and nanopores are distributed on the hole walls of the holes.
The directional freezing apparatus and its use were the same as in example 1.
The ferric salt is ferrous oxalate dihydrate; the lithium salt is lithium acetate dihydrate; the protective atmosphere is a mixed gas of nitrogen and hydrogen.
The directional porous lithium iron phosphate-graphene composite material prepared by the embodiment is a pure-phase lithium iron phosphate material, the directional porous lithium iron phosphate-graphene composite material has uniform pore size distribution, the pore size is 145-165 nm, and the pore wall thickness is 20-30 nm.
Example 3
An oriented porous lithium iron phosphate-graphene composite material and a preparation method thereof. The preparation method comprises the following steps:
(1) adding the graphene oxide into a ferric salt aqueous solution with the concentration of 0.5-2 mol/L according to the mass ratio of ferric salt to graphene oxide of 1: 1.8-2.6, and ultrasonically stirring for 0.5-1.5 h to obtain a solution I.
(2) And adding the phosphoric acid into the solution I according to the mass ratio of the ferric salt to the phosphoric acid of 1: 1, and stirring for 20-40 min to obtain a solution II.
(3) And adding a 4mol/L lithium salt aqueous solution into the solution II according to the mass ratio of the ferric salt to the lithium salt of 1: 1, and ultrasonically stirring for 30-40 min to obtain a solution III.
(4) And (3) placing the solution III in a directional freezing device, freezing for 20-40 min, and drying in a vacuum freeze dryer for 60-72 h to obtain the columnar xerogel.
(5) And (3) placing the columnar xerogel in a tubular atmosphere furnace, preserving heat for 8-10 h under the conditions of protective atmosphere and 700-750 ℃, and cooling along with the furnace to obtain the directional porous lithium iron phosphate-graphene composite material.
The directional porous lithium iron phosphate-graphene composite material is of a directional porous structure, holes are directionally arranged, the hole walls of the holes are formed by stacking lithium iron phosphate nanoparticles and graphene, and nanopores are distributed on the hole walls of the holes.
The directional freezing apparatus and its use were the same as in example 1.
The iron salt is ferrous sulfate heptahydrate; the lithium salt is lithium hydroxide monohydrate; the protective atmosphere is a mixed gas of argon and hydrogen.
The directional porous lithium iron phosphate-graphene composite material prepared by the embodiment is a pure-phase lithium iron phosphate material, the directional porous lithium iron phosphate-graphene composite material has uniform pore size distribution, the pore size is 135-155 nm, and the pore wall thickness is 25-35 nm.
Compared with the prior art for preparing the lithium iron phosphate material, the specific embodiment has the following positive effects:
1. in the specific embodiment, the pore diameter and the pore wall thickness of the prepared directional porous lithium iron phosphate-graphene composite material can be effectively regulated and controlled by changing the addition of the graphene oxide, and the prepared product is pure-phase LiFePO4The material and the product are three-dimensional ordered porous structures, the holes are ordered in arrangement, and the pore diameters are uniform. The aperture is 135-175 nm, and the thickness of the hole wall is 15-35 nm.
2. The three-dimensional directional porous structure of the directional porous lithium iron phosphate-graphene composite material prepared by the embodiment is a structure formed by directionally growing ice crystals along the direction of temperature gradient and then drying the ice crystals in vacuum. Liquid nitrogen (4) filled in the low temperature resistant plastic container (3) transfers low temperature to the junction of the copper column (2) and the solution III (5) through the copper column (2), the solution III (5) starts to crystallize at the interface to form small ice crystals and directionally grow to the surface of the solution III (5) along the temperature gradient direction, and the round tube (1) can avoid the influence of the ambient temperature of the solution III (5) on the freezing process and ensure the consistency of the ice crystal growth in the directional freezing process.
The three-dimensional directional porous structure can effectively promote the infiltration of electrolyte to electrode materials, provides a directional channel for lithium ion transmission, and shortens an ion diffusion path. The two-dimensional graphene sheet is embedded in the porous pore wall sheet layer and serves as a bridge for electron transfer among the lithium iron phosphate nanoparticles, and the larger specific surface area can also provide more reactive sites for ions, so that the specific capacity and the rate capability of the material can be improved. Meanwhile, the nano-pores on the pore wall sheet layer can effectively relieve the damage of the material structure caused by volume expansion in the charge and discharge process.
3. The specific embodiment utilizes a directional freezing device and combines with subsequent drying and heat treatment processes to prepare the directional porous lithium iron phosphate-graphene composite material. The template agent is not required to be prepared additionally, and meanwhile, the ice crystals with directional growth can be well removed through vacuum freeze drying, and the three-dimensional directional porous structure can be well maintained in the heat treatment process.
Therefore, the specific implementation method has the advantages of simple process, convenience in operation, short production period and controllable appearance; the prepared directional porous lithium iron phosphate-graphene composite material is in a three-dimensional directional porous structure, the pore diameter and the pore wall thickness are uniform and controllable, and the electrochemical performance is excellent.
Claims (5)
1. A preparation method of a directional porous lithium iron phosphate-graphene composite material is characterized by comprising the following steps:
(1) adding graphene oxide into a ferric salt aqueous solution with the concentration of 0.5-2 mol/L according to the mass ratio of ferric salt to graphene oxide of 1: 0.2-2.6, and ultrasonically stirring for 0.5-1.5 h to obtain a solution I;
(2) adding the phosphoric acid into the solution I according to the mass ratio of the ferric salt to the phosphoric acid of 1: 1, and stirring for 20-40 min to obtain a solution II;
(3) adding a 4mol/L lithium salt aqueous solution into the solution II according to the mass ratio of the ferric salt to the lithium salt of 1: 1, and ultrasonically stirring for 30-40 min to obtain a solution III;
(4) placing the solution III in a directional freezing device, freezing for 20-40 min, and drying in a vacuum freeze dryer for 36-72 h to obtain columnar xerogel;
(5) placing the columnar xerogel in a tubular atmosphere furnace, preserving heat for 8-10 h under the conditions of protective atmosphere and 600-750 ℃, and cooling along with the furnace to obtain the directional porous lithium iron phosphate-graphene composite material;
the directional freezing device comprises a low-temperature resistant container (3), a copper column (2) and a circular tube (1); a copper column (2) is arranged at the central position of the bottom of the low-temperature resistant container (3), the copper column (2) is an integral body formed by a large cylinder and a small cylinder which are coaxial, a circular tube (1) is fixed on the cylindrical surface of the small cylinder, and a sealing ring is arranged between the annular surface of the copper column (2) and the lower end surface of the circular tube (1); when in use, the low temperature resistant container (3) is filled with liquid nitrogen (4), and the solution III (5) is arranged in the circular tube (1).
2. The method for preparing the directional porous lithium iron phosphate-graphene composite material according to claim 1, wherein the ferric salt is one of ferric citrate, ferrous oxalate dihydrate and ferrous sulfate heptahydrate.
3. The method for preparing an oriented porous lithium iron phosphate-graphene composite material according to claim 1, wherein the lithium salt is one of lithium dihydrogen phosphate, lithium acetate dihydrate and lithium hydroxide monohydrate.
4. The preparation method of the oriented porous lithium iron phosphate-graphene composite material according to claim 1, wherein the protective atmosphere is argon gas, or a mixed gas of nitrogen gas and hydrogen gas, or a mixed gas of argon gas and hydrogen gas.
5. An oriented porous lithium iron phosphate-graphene composite material, which is characterized in that the oriented porous lithium iron phosphate-graphene composite material is an oriented porous lithium iron phosphate-graphene composite material prepared by the preparation method of the oriented porous lithium iron phosphate-graphene composite material according to any one of claims 1 to 4;
the directional porous lithium iron phosphate-graphene composite material is of a directional porous structure, holes are directionally arranged, the hole walls of the holes are formed by stacking lithium iron phosphate nanoparticles and graphene, and nanopores are distributed on the hole walls of the holes.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101941693A (en) * | 2010-08-25 | 2011-01-12 | 北京理工大学 | Graphene aerogel and preparation method thereof |
| CN102941042A (en) * | 2012-10-25 | 2013-02-27 | 北京理工大学 | Graphene/metal oxide hybrid aerogel, preparation method and applications thereof |
| CN105895865A (en) * | 2014-12-12 | 2016-08-24 | 江南大学 | Graphene/lithium salt composite material |
| CN106920931A (en) * | 2017-03-02 | 2017-07-04 | 武汉科技大学 | Loaded mesoporous lithium iron phosphate nano piece composite of graphene aerogel and preparation method thereof |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101941693A (en) * | 2010-08-25 | 2011-01-12 | 北京理工大学 | Graphene aerogel and preparation method thereof |
| CN102941042A (en) * | 2012-10-25 | 2013-02-27 | 北京理工大学 | Graphene/metal oxide hybrid aerogel, preparation method and applications thereof |
| CN105895865A (en) * | 2014-12-12 | 2016-08-24 | 江南大学 | Graphene/lithium salt composite material |
| CN106920931A (en) * | 2017-03-02 | 2017-07-04 | 武汉科技大学 | Loaded mesoporous lithium iron phosphate nano piece composite of graphene aerogel and preparation method thereof |
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