TW201922884A - Preparation method for a composite comprising sulfur-containing conductive polymer - Google Patents

Abstract

A preparation method for a composite comprising conductive sulfur-containing polymer, comprising steps of: A. uniformly mixing sulfur, polymer, and graphene into a mixture; B. heating the mixture to 80 DEG C to 120 DEG C in an inert gas enclosure for drying and dehydrogenating the mixture to form a conductive polymer; and C. keeping the mixture of step B at constant temperature for 0.5 to 3 hours at a temperature of 150 DEG C to 300 DEG C and a pressure of 14.5 Psi to 725 Psi until the mixture is dehydrogenated and the sulfur is melted, so as to form a sulfur-containing conductive polymer, and the sulfur-containing conductive polymer further combining with the graphene to form a composite comprising sulfur-containing conductive polymer.

Description

Preparation method of composite material containing sulfur conductive polymer

The present invention relates to a method for preparing a composite material containing a sulfur-containing conductive polymer, and more particularly to a composite material for a sulfur-containing conductive polymer used on an electrode of a secondary battery.

The application range of mobile devices has become increasingly widespread and has become inseparable from the lives of modern people. With this development, the requirements for the capacity and life of secondary batteries are also increasing. Lithium batteries are currently the most popular mobile device power supply because of their high working voltage and high energy density. In order to pursue higher capacitance and better battery performance, lithium batteries of various chemical compositions have been developed, among which lithium-sulfur batteries are attracting attention because of their higher capacitance than general lithium metal oxide batteries.

However, when sulfur is heated during charging and discharging, it becomes liquid polysulfide and flows around the electrolyte or anode of the battery, reducing the amount of recyclable sulfur active material, resulting in a decrease in the charging capacity and life of the battery, making it difficult to use pure sulfur. It is applied to secondary lithium batteries. Therefore, improving the form of sulfur in lithium-sulfur batteries is an important issue in the application of lithium-sulfur batteries.

In view of the above, in order to provide a structure different from the conventional technology and to improve the above disadvantages, the inventors have accumulated many years of experience and continuous development and improvement, and the present invention has been produced.

An object of the present invention is to provide a method for preparing a sulfur-containing conductive polymer, which can Improve the form of sulfur in lithium-sulfur batteries, so that sulfur active substances can be effectively recycled to maintain the battery's charging capacity and improve battery life.

In order to achieve the above object, the present invention provides a method for preparing a sulfur-containing conductive polymer, which comprises the steps of: A. uniformly mixing sulfur, a polymer and graphene into a mixture; B. in an inert gas The mixture is heated to 80 to 120 ° C in an environment, dried and dehydrogenated to form a conductive polymer; and C. The mixture of step B is at a temperature ranging from 150 ° C to 300 ° C and 14.5 Psi to The pressure of 725Psi is maintained at a constant temperature of 0.5 to 3 hours to dehydrogenation to initiate a sulfur melting reaction to form a sulfur-conductive polymer and form a composite of a sulfur-containing conductive polymer with graphene.

When implemented, the material ratio in the mixture in step A is 10-95% by weight of sulfur, 4.9-89% by weight of polymer, and 0.1-85% by weight of graphene.

When implemented, the purity of sulfur is from 99.50% to 99.99%.

When implemented, the graphene is a single crystal graphene having a particle diameter of 0.2 to 5 nm, and the number of layers is a single layer, a double layer or a multilayered layer.

When implemented, the polymer is selected from one of the group consisting of polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), polyacrylonitrile (PAN), polystyrene (PS), and polyethylene oxide (PEO). ).

When implemented, the inert gas is argon or nitrogen.

When implemented, the composite of the sulfur-containing conductive polymer formed in step C is in the form of a powder, a granule, a block or a fiber.

In order to further understand the present invention, the specific embodiments of the present invention and the effects achieved thereby are described in detail below with reference to the drawings and drawings.

A-C‧‧ steps

10‧‧‧sulfur conductive polymer

20‧‧‧Layered graphene

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a flow chart showing an embodiment of a method for preparing a composite material of a sulfur-containing conductive polymer of the present invention.

Fig. 2 is a schematic view showing the structure of one embodiment of the composite material of the sulfur-containing conductive polymer of the present invention.

Figure 3 is a graph of charge and discharge of one embodiment of a battery using the composite of the present invention.

Figure 4 is a graph showing the charge and discharge cycle of one embodiment of a battery using the composite of the present invention.

Please refer to FIG. 1 , which is a flow chart of a preferred embodiment of a method for preparing a composite material of a sulfur-containing conductive polymer, which comprises the following steps: A. sulfur, polymer and graphene Mixing uniformly into a mixture; B. heating the mixture to 80 to 120 ° C in an inert gas atmosphere, drying and dehydrogenating to form a conductive polymer; and C. the mixture of step B is Maintaining a constant temperature of 0.5 to 3 hours at a temperature ranging from 150 ° C to 300 ° C and a pressure range of 14.5 Psi to 725 Psi to a dehydrogenation sulfur-smelting reaction to form a sulfur-conductive polymer and forming a sulfur-containing conductive polymer with graphene Composite material.

In a preferred embodiment, the material ratio in the mixture in the foregoing step A is 10-95 wt% of sulfur, 4.9-89 wt% of polymer, 0.1-85 wt% of graphene; purity of sulfur is 99.50% to 99.99%; graphite The olefin is a large-area single crystal graphene having a particle diameter of 0.2 to 5 nm, and the number of layers is a single layer, a double layer or a plurality of layers; the polymer is selected from one of the group consisting of polyvinylidene fluoride (PVDF). ), polyvinyl fluoride (PVF), polyacrylonitrile (PAN), polystyrene (PS), polyethylene oxide (PEO).

In a preferred embodiment, the inert gas in the foregoing step B is argon (Ar) or nitrogen (N ₂ ).

In a preferred embodiment, the composite material of the sulfur-containing conductive polymer formed in the foregoing step C has a sulfur content of 50-90% by weight, and graphene can increase the conductivity of the composite material, and the sulfur-containing conductive polymer The shape of the composite material can be powder, granule, block or fiber, and can be normally charged and discharged at room temperature. For the structure of the composite material of the sulfur-containing conductive polymer of the present invention, refer to the embodiment shown in FIG. 2, which comprises the stacked layered graphene 20, and the sulfur-containing conductive polymer 10 sandwiched in the layered graphene 20. .

The composite material produced by the method for producing a composite material of a sulfur-containing conductive polymer of the present invention is mainly applied to an electrode of a secondary battery such as a lithium battery. In one example, a lithium-sulfur battery cell includes a positive electrode, a negative electrode, a separator, and an electrolyte, wherein the positive electrode structure is: a composite material of a sulfur-containing conductive polymer/solvent/adhesive/conductive agent/coagulant/aluminum foil, and a negative electrode structure. It is: metal lithium/copper foil, the diaphragm is a wet diaphragm, and the electrolyte is a liquid or colloidal electrolyte. Fig. 3 is a graph showing the charge and discharge curves of the battery in the present example. The charge and discharge curve in the figure shows that the composite material of the present invention is used in the positive electrode of the lithium-sulfur battery, and the charge and discharge rate of the battery can reach 100%. Fig. 4 is a graph showing the charge and discharge cycle of the battery in the present example. The graph shows that the charge rate of the battery is less than 3% after charging and discharging cycles of 1 C (battery capacity) for 500 times, showing good stability.

Therefore, the present invention has the following advantages:

1. The present invention can effectively recycle the active substance of sulfur, thereby improving the charging rate of battery cycle charging.

2. The invention can prevent the sulfur from flowing into the liquid during the charging and discharging process and flows in the battery, because This can increase the number of cycles of battery charging, improve battery stability and extend battery life.

In summary, according to the above disclosure, the present invention can achieve the intended purpose, and provides a preparation method of a sulfur-containing conductive polymer capable of improving the charging capacity and life of the battery, which is highly valuable for industrial use.提出 Submit an invention patent application in accordance with the law.

Claims (7)

A method for preparing a composite material containing a sulfur-containing conductive polymer, the preparation method comprising the steps of: A. uniformly mixing sulfur, a polymer and graphene into a mixture; B. heating the mixture to 80 under an inert gas atmosphere To 120 ° C, dry and dehydrogenate to form a conductive polymer; and C. maintain the mixture of step B at a temperature range of 150 ° C to 300 ° C and a pressure range of 14.5 Psi to 725 Psi 0.5 The desulfurization and sulfurization reaction is carried out until 3 hours to form a sulfur-conductive polymer and form a composite of a sulfur-containing conductive polymer with graphene. The preparation method according to claim 1, wherein the material ratio in the mixture in the step A is 10-95% by weight of sulfur, 4.9-89% by weight of the polymer, and 0.1-85% by weight of graphene. The preparation method of claim 1, wherein the sulfur has a purity of from 99.50% to 99.99%. The preparation method according to claim 1, wherein the graphene is a single crystal graphene having a particle diameter of 0.2 to 5 nm, and the number of layers is a single layer, a double layer or a plurality of layers. The preparation method of claim 1, wherein the polymer is selected from the group consisting of polyvinylidene fluoride, polyvinyl fluoride, polyacrylonitrile, polystyrene, and polyethylene oxide. The preparation method of claim 1, wherein the inert gas is argon or nitrogen. The preparation method of claim 1, wherein the sulfur-containing conductive polymer composite formed in the step C is in the form of a powder, a granule, a block or a fiber.