阅读说明：本技术 一种纤维材料及其制备方法和应用 (fiber materials, and preparation method and application thereof ) 是由 何海勇 王德宇 潘林海 于 2018-07-18 设计创作，主要内容包括：本申请公开了一种纤维材料及其制备方法和应用,所述材料由海藻酸钠基复合纤维膜通过烧结制备得到。所述材料可用作锂金属二次电池负极集流体；纤维之间的多孔结构能够有效的缓解锂嵌入与脱出过程中的体积变化。此外,材料自身较大的比表面积能够减少局部电流密度,有利于锂的均匀沉积。该材料用作锂金属二次电池负极集流体能够明显抑制锂枝晶的形成,有效提高锂金属电池的使用寿命。同时,本发明所提供的制备工艺简单易行,生产成本低廉,在实际生产中具有很大的应用前景。(The application discloses fiber materials and a preparation method and application thereof, wherein the materials are prepared by sintering a sodium alginate-based composite fiber membrane, the materials can be used as a negative electrode current collector of a lithium metal secondary battery, and a porous structure among fibers can effectively relieve the volume change in the process of lithium intercalation and deintercalation.)

1, kinds of fiber material, characterized by that, the said material is prepared from sodium alginate based composite fiber membrane through sintering.

2. The material according to claim 1, wherein the material has a porous structure among fibers, and the specific surface area of the material is 0.3-0.36 m²/g；

The diameter of the fiber is 100 nm-1000 nm.

3. The material according to claim 1, wherein the sodium alginate-based composite fiber membrane comprises an additive therein;

preferably, the additive comprises at least of polyethylene oxide, gelatin, chitosan, chitin and polyvinyl alcohol.

4. The material of , wherein the thickness of the film is 10-300 μm and the diameter of the fiber is 100-1000 nm.

5. A method of making a fibrous material according to any of claims 1 to 4 and , comprising:

and (3) carrying out electrostatic spinning on the solution containing the sodium alginate, and sintering to obtain the fiber material.

6. The method as claimed in claim 5, wherein the solution containing sodium alginate comprises additives;

the mass fraction of the additive in the solution containing sodium alginate is 0.1-50%;

preferably, the mass fraction of the sodium alginate in the solution containing the sodium alginate is 0.1-10%;

preferably, the solvent in the solution containing sodium alginate is selected from water or a mixed solvent of water;

preferably, the mixed solvent further comprises at least of methanol, ethanol, glycerol, formic acid and acetic acid.

7. The method according to claim 5, characterized in that the electrospinning conditions are: the inner diameter of a spinning needle head is 0.16-2.20 mm, the voltage is 8-15 KV, the distance between the needle head and a receiving device is 8-20 cm, the spinning temperature is 25-60 ℃, the spinning flow is 0.5-3 mL/h, and the rotating speed of a receiving roller is 15-35 m/h;

preferably, the sintering conditions are: preserving heat for 2-4 h at 650-850 ℃ in an inactive atmosphere;

preferably, the temperature rise rate in the sintering process is 3-5 ℃/min;

preferably, the temperature rise rate of the sintering process is 2 deg.C/min.

8. The method of claim 5, wherein the method comprises:

(1) preparing sodium alginate, an additive and a solvent into a polymer solution and removing bubbles in the polymer solution;

(2) performing electrostatic spinning on the polymer solution prepared in the step (1) to obtain a sodium alginate-based composite nanofiber membrane;

(3) and (3) sintering the sodium alginate-based composite nanofiber membrane obtained in the step (2), and obtaining the nanofiber material after the sintering treatment is finished.

9, lithium metal secondary battery negative electrode current collectors, characterized by comprising at least of the fibrous materials of claims 1-4- , prepared according to the method of claims 5-8- .

10. The negative electrode current collector of a lithium metal secondary battery according to claim 9 is applied to a lithium air battery and/or a lithium sulfur battery.

Technical Field

The application relates to fiber materials and a preparation method and application thereof, belonging to the field of material preparation.

Background

The lithium metal negative electrode has very high theoretical specific capacity (3860mA h g)^-1) And a lower reduction potential (-3.04V, relative to standard hydrogen electrodes), are the most promising negative electrode materials for high energy density lithium secondary battery systems. However, the charging and discharging processThe growth of the lithium dendrites can cause repeated fracture and regeneration of SEI, and potential safety hazards are brought; unstable deposition and dissolution of lithium metal in the circulation process are easy to form 'dead lithium', and the coulombic efficiency of the battery is reduced. These problems hinder practical application of lithium metal negative electrodes.

Sodium alginate (figure 1 is a sodium alginate structure diagram) is derived from algae plants such as brown algae in the sea and is renewable resources, the sodium alginate is easily dissolved in water to form viscous liquid, and the sodium alginate is natural polysaccharide carbohydrates, has carboxyl, has the characteristics of excellent biocompatibility, no toxic or side effect, controllable biodegradability, no antibiotics and the like, and can be used as food additives, thickening agents, stabilizing agents, textile dyeing assistants, hemostatic agents, medical stent materials and other fields due to the excellent performances.

Disclosure of Invention

According to aspects of the application, fiber materials are provided, the fiber materials can be used as a negative current collector of a lithium metal secondary battery, and the porous structure among fibers can effectively relieve the volume change in the process of lithium intercalation and deintercalation.

The fiber material is characterized in that the material is prepared by sintering a sodium alginate-based composite fiber membrane.

Optionally, the sodium alginate-based composite fiber membrane is a sodium alginate-based composite nanofiber membrane.

Optionally, the material has a porous structure among fibers, and the specific surface area of the material is 0.3-0.36 m²(ii)/g; the fiber diameter is 100nm &1000nm。

Optionally, an additive is included in the sodium alginate-based composite fiber membrane.

Optionally, the additive comprises at least of polyethylene oxide, gelatin, chitosan, chitin, polyvinyl alcohol.

Optionally, the thickness of the sodium alginate-based composite nanofiber membrane is 10-300 μm, and the fiber diameter is 100-1000 nm.

In another aspect of the present application, there is provided a method for preparing the fiber material of any , comprising:

and (3) carrying out electrostatic spinning on the solution containing the sodium alginate, and sintering to obtain the fiber material.

Optionally, the solution containing sodium alginate is subjected to electrostatic spinning after air bubbles are removed.

Optionally, the solution containing sodium alginate further comprises an additive;

the mass fraction of the additive in the solution containing sodium alginate is 0.1-50%.

Optionally, the mass fraction of sodium alginate in the solution containing sodium alginate is 0.1-10%.

Optionally, the upper limit of the mass fraction of the additive in the sodium alginate containing solution is selected from 0.2%, 0.5%, 1%, 1.5%, 2%, 2.8%, 5%, 5.3%, 6.5%, 7.6%, 10%, 15%, 20%, 21%, 28%, 31%, 32%, 35%, 40%, 45% or 50%; the lower limit is selected from 0.1%, 0.2%, 0.5%, 1%, 1.5%, 2%, 2.8%, 5%, 5.3%, 6.5%, 7.6%, 10%, 15%, 20%, 21%, 28%, 31%, 32%, 35%, 40% or 45%.

Optionally, the upper limit of the mass fraction of sodium alginate in the sodium alginate containing solution is selected from 0.2%, 0.5%, 0.9%, 1%, 1.4%, 2%, 2.5%, 2.8%, 3%, 3.2%, 3.5%, 4%, 4.5%, 5%, 5.3%, 6.25%, 7%, 7.6%, 8%, 9% or 10%; the lower limit is selected from 0.1%, 0.2%, 0.5%, 0.9%, 1%, 1.4%, 2%, 2.5%, 2.8%, 3%, 3.2%, 3.5%, 4%, 4.5%, 5%, 5.3%, 6.25%, 7%, 7.6%, 8%, or 9%.

Optionally, the solvent in the solution containing sodium alginate is selected from water or a mixed solvent of water.

Optionally, the mixed solvent further comprises at least of methanol, ethanol, glycerol, formic acid and acetic acid.

Optionally, the ratio of the solvent to the water in the mixed solvent of water is 0.1% to 99%.

Optionally, the sodium alginate-containing solution is obtained in a manner comprising: adding sodium alginate and additive into solvent, stirring to obtain the solution containing sodium alginate.

Optionally, the stirring time is 6-24 h.

Optionally, the stirring is magnetic stirring.

Optionally, the electrospinning conditions are: the inner diameter of the spinning needle is 0.16-2.20 mm, the voltage is 8-15 KV, the distance between the needle and the receiving device is 8-20 cm, the spinning temperature is 25-60 ℃, the spinning flow is 0.5-3 mL/h, and the rotating speed of the receiving roller is 15-35 m/h.

Optionally, the electrospinning conditions are: the inner diameter of the spinning needle is 0.6mm, the voltage is 15KV, the distance between the needle and the receiving device is 10cm, the spinning temperature is 25-60 ℃, the spinning flow is 0.5-3 mL/h, and the rotating speed of the receiving roller is 15-35 m/h.

Optionally, the receiving means is an aluminum foil.

Optionally, the sintering is performed under an inert atmosphere.

Optionally, the sintering conditions are: and (3) preserving the heat for 2-4 hours at 650-850 ℃ in an inert atmosphere.

Optionally, the inert atmosphere comprises at least of nitrogen and inert gas.

Optionally, the inert atmosphere is selected from N₂Atmosphere or Ar atmosphere.

Optionally, the upper temperature limit of the sintering is selected from 700 ℃, 750 ℃, 800 ℃ or 850 ℃; the lower limit is selected from 650 deg.C, 700 deg.C, 750 deg.C or 800 deg.C.

Optionally, the upper time limit of the sintering is selected from 2.5h, 3h, 3.5h or 4 h; the lower limit is selected from 2.5h, 3h or 3.5 h.

Optionally, the temperature rise rate in the sintering process is 3-5 ℃/min.

Optionally, the temperature rise rate of the sintering process is 2 ℃/min.

Optionally, the method comprises:

(1) preparing sodium alginate, an additive and a solvent into a polymer solution and removing bubbles in the polymer solution;

(2) performing electrostatic spinning on the polymer solution prepared in the step (1) to obtain a sodium alginate-based composite nanofiber membrane;

(3) and (3) sintering the sodium alginate-based composite nanofiber membrane obtained in the step (2), and obtaining the nanofiber material after the sintering treatment is finished.

Optionally, the thickness of the sodium alginate-based composite nanofiber membrane in the step (2) is 10-300 μm, and the fiber diameter is 100-1000 nm.

The fibrous current collector has a large specific surface area, and can reduce the local current density in the lithium deposition process, which is beneficial to uniform deposition of lithium. In addition, the porous structure formed between the fibers can effectively relieve the volume change in the lithium intercalation and deintercalation process. The material used as the negative current collector of the lithium metal secondary battery can obviously inhibit the formation of lithium dendrites and effectively prolong the service life of the lithium metal secondary battery.

In yet another aspect of the present application, there are provided lithium metal secondary battery negative electrode current collectors, comprising at least of the fibrous material of any above, prepared according to any above.

Optionally, the lithium metal secondary battery negative electrode current collector is the fiber material.

Optionally, the negative electrode current collector of the lithium metal secondary battery is applied to a lithium air battery and/or a lithium sulfur battery.

The application discloses a preparation method of lithium metal secondary battery negative electrode current collectors, which comprises the following steps:

step 1, preparing sodium alginate, an additive and a solvent into polymer solution with constant concentration and removing bubbles in the polymer solution;

step 2, performing electrostatic spinning on the polymer solution prepared in the step 1 to obtain a sodium alginate composite nanofiber membrane;

and 3, sintering the sodium alginate composite nanofiber membrane obtained in the step 2, wherein the material obtained after sintering can be used as a negative current collector of the lithium metal secondary battery.

The beneficial effects that this application can produce include:

the sodium alginate composite nanofiber material in the application is used as a current collector material of a negative electrode of a lithium metal secondary battery, and the porous structure between fibers can effectively relieve the volume change of lithium insertion and separation processes. In addition, the larger specific surface area of the material can reduce local current density, and is beneficial to uniform deposition of lithium. The material used as a lithium metal negative electrode current collector can obviously inhibit the formation of lithium dendrites and effectively prolong the service life of the lithium metal secondary battery. Meanwhile, the preparation process provided by the invention is simple and easy to implement, has low production cost, and has a great application prospect in actual production.

Drawings

FIG. 1 is a diagram showing the structure of sodium alginate;

fig. 2 is an SEM image of negative electrode current collector 1# of the lithium metal secondary battery prepared in example 1;

fig. 3 is a time-voltage diagram of a half-cell assembled with a lithium sheet and a negative electrode current collector 1# of the lithium metal secondary battery prepared in example 1.

Fig. 4 is a cycle performance test chart of a half cell assembled with a lithium sheet and a negative electrode current collector 1# of the lithium metal secondary battery prepared in example 1.

Detailed Description

The present application will be described in detail with reference to examples, but the present application is not limited to these examples.

Unless otherwise specified, the raw materials such as sodium alginate, chitosan, polyvinyl alcohol, gelatin, polyethylene oxide, etc. in the examples of the present application are purchased from alatin reagent (shanghai) co.

The sodium alginate is purchased from chemical reagents of national drug group, ltd.

The chitosan was purchased from national drug group chemical agents, ltd.

The polyvinyl alcohol is purchased from national pharmaceutical group chemical agents, ltd.

The gelatin was purchased from alatin reagent (shanghai) ltd.

The polyethylene oxide was purchased from national pharmaceutical group chemical agents, ltd.

The analysis method in the examples of the present application is as follows:

SEM analysis was performed using a field emission scanning electron microscope thermal field from Sirion200, FEI, USA.

Electrochemical performance analysis was performed using the wuhan blue electricity company CT2001A blue cell test system.

Specific surface area test analysis was performed using a Coulter Ommishop 100CX specific surface and porosity Analyzer (BET) instrument.