Lithium-sulfur battery diaphragm, preparation method thereof and lithium-sulfur battery

Abstract

The invention provides a lithium-sulfur battery diaphragm, a preparation method thereof and a lithium-sulfur battery. The lithium-sulfur battery diaphragm comprises a diaphragm substrate and a diaphragm coating arranged on the surface of the diaphragm substrate, and the diaphragm coating comprises a Fe3O4 / carbon nanotube / carbon fiber compound. The lithium-sulfur battery diaphragm is prepared through a one-pot method and heat treatment, the preparation method is simple and low in cost, and the prepared lithium-sulfur battery diaphragm has good conductivity, can effectively adsorb lithium polysulfide, provides a large number of active sites, efficiently catalyzes conversion between lithium polysulfide and improves the cycling stability of a lithium-sulfur battery.

Description

technical field

[0001] The invention belongs to the technical field of lithium batteries, and relates to a lithium-sulfur battery diaphragm, a preparation method thereof and a lithium-sulfur battery. Background technique

[0002] At present, with the continuous development and progress of society, people's lives are increasingly dependent on energy storage devices such as portable electronic devices and electric vehicles. Although lithium-ion battery technology has been very popular and applied today, due to its specific capacity The lower level can no longer meet people's needs. Lithium-sulfur batteries have a high theoretical energy density (2567Wh kg -1 ), high theoretical specific capacity (1675mAh g -1 ), lower cost, and environmental friendliness are considered to be one of the most promising energy storage systems. However, with the deepening of research, the slow redox kinetics of the intermediate product polysulfides in the charging and discharging process of the...

Examples

Embodiment 1

[0062] This embodiment provides a lithium-sulfur battery separator, the front SEM image of which is as follows figure 1 As shown, the cross-sectional SEM image is shown in figure 2 As shown, the lithium-sulfur battery diaphragm includes a diaphragm substrate and a diaphragm coating disposed on the surface of the diaphragm substrate, and the diaphragm coating includes Fe 3 o 4 / carbon nanotube / carbon fiber composite, PVDF and conductive carbon black, with the Fe 3 o 4 / The mass of carbon nanotubes / carbon fiber composites is 100%, the Fe 3 o 4 The content of carbon nanotubes is 60%, the content of carbon nanotubes is 35%, the content of carbon fibers is 5%, and the separator matrix is ​​polypropylene separator (celgard 2500).

[0063] The preparation method of the lithium-sulfur battery separator described in this embodiment comprises the following steps:

[0064] (1) Dissolve ferric chloride and sodium oleate at a molar ratio of 1:2.9 in a mixed solvent of ethanol, d...

Embodiment 2

[0070] This embodiment provides a lithium-sulfur battery diaphragm, the lithium-sulfur battery diaphragm includes a diaphragm substrate and a diaphragm coating disposed on the surface of the diaphragm substrate, and the diaphragm coating includes Fe 3 o 4 / carbon nanotube / carbon fiber composite, PVDF and conductive carbon black, with the Fe 3 o 4 / The mass of carbon nanotubes / carbon fiber composites is 100%, the Fe 3 o 4 The content of carbon nanotubes is 70%, the content of carbon nanotubes is 25%, the content of carbon fibers is 5%, and the separator matrix is ​​polypropylene separator (celgard 2500).

[0071] The preparation method of the lithium-sulfur battery separator described in this embodiment comprises the following steps:

[0072](1) Dissolve ferric chloride and sodium oleate at a molar ratio of 1:2.5 in a mixed solvent of ethanol, distilled water and n-hexane with a volume ratio of 4:3:7, put it into a magnetic rotor, and heat at 60°C And reflux for 6h, th...

Embodiment 3

[0077] This embodiment provides a lithium-sulfur battery diaphragm, the lithium-sulfur battery diaphragm includes a diaphragm substrate and a diaphragm coating disposed on the surface of the diaphragm substrate, and the diaphragm coating includes Fe 3 o 4 / carbon nanotube / carbon fiber composite, PVDF and conductive carbon black, with the Fe 3 o 4 / The mass of carbon nanotubes / carbon fiber composites is 100%, the Fe 3 o 4 The content of carbon nanotubes is 40%, the content of carbon nanotubes is 50%, the content of carbon fibers is 10%, and the separator matrix is ​​polypropylene separator (celgard 2500).

[0078] The preparation method of the lithium-sulfur battery separator described in this embodiment comprises the following steps:

[0079] (1) Dissolve ferric chloride and sodium oleate in a molar ratio of 1:3 in a mixed solvent of ethanol, distilled water and n-hexane with a volume ratio of 4:3:7, put it into a magnetic rotor, and heat at 70°C And reflux for 3h, th...

technical field

[0001] The invention belongs to the technical field of lithium batteries, and relates to a lithium-sulfur battery diaphragm, a preparation method thereof and a lithium-sulfur battery. Background technique

[0002] At present, with the continuous development and progress of society, people's lives are increasingly dependent on energy storage devices such as portable electronic devices and electric vehicles. Although lithium-ion battery technology has been very popular and applied today, due to its specific capacity The lower level can no longer meet people's needs. Lithium-sulfur batteries have a high theoretical energy density (2567Wh kg -1 ), high theoretical specific capacity (1675mAh g -1 ), lower cost, and environmental friendliness are considered to be one of the most promising energy storage systems. However, with the deepening of research, the slow redox kinetics of the intermediate product polysulfides in the charging and discharging process of the...

Examples

Embodiment 1

[0062] This embodiment provides a lithium-sulfur battery separator, the front SEM image of which is as follows figure 1 As shown, the cross-sectional SEM image is shown in figure 2 As shown, the lithium-sulfur battery diaphragm includes a diaphragm substrate and a diaphragm coating disposed on the surface of the diaphragm substrate, and the diaphragm coating includes Fe 3 o 4 / carbon nanotube / carbon fiber composite, PVDF and conductive carbon black, with the Fe 3 o 4 / The mass of carbon nanotubes / carbon fiber composites is 100%, the Fe 3 o 4 The content of carbon nanotubes is 60%, the content of carbon nanotubes is 35%, the content of carbon fibers is 5%, and the separator matrix is ​​polypropylene separator (celgard 2500).

[0063] The preparation method of the lithium-sulfur battery separator described in this embodiment comprises the following steps:

[0064] (1) Dissolve ferric chloride and sodium oleate at a molar ratio of 1:2.9 in a mixed solvent of ethanol, d...

Embodiment 2

[0070] This embodiment provides a lithium-sulfur battery diaphragm, the lithium-sulfur battery diaphragm includes a diaphragm substrate and a diaphragm coating disposed on the surface of the diaphragm substrate, and the diaphragm coating includes Fe 3 o 4 / carbon nanotube / carbon fiber composite, PVDF and conductive carbon black, with the Fe 3 o 4 / The mass of carbon nanotubes / carbon fiber composites is 100%, the Fe 3 o 4 The content of carbon nanotubes is 70%, the content of carbon nanotubes is 25%, the content of carbon fibers is 5%, and the separator matrix is ​​polypropylene separator (celgard 2500).

[0071] The preparation method of the lithium-sulfur battery separator described in this embodiment comprises the following steps:

[0072](1) Dissolve ferric chloride and sodium oleate at a molar ratio of 1:2.5 in a mixed solvent of ethanol, distilled water and n-hexane with a volume ratio of 4:3:7, put it into a magnetic rotor, and heat at 60°C And reflux for 6h, th...

Embodiment 3

[0077] This embodiment provides a lithium-sulfur battery diaphragm, the lithium-sulfur battery diaphragm includes a diaphragm substrate and a diaphragm coating disposed on the surface of the diaphragm substrate, and the diaphragm coating includes Fe 3 o 4 / carbon nanotube / carbon fiber composite, PVDF and conductive carbon black, with the Fe 3 o 4 / The mass of carbon nanotubes / carbon fiber composites is 100%, the Fe 3 o 4 The content of carbon nanotubes is 40%, the content of carbon nanotubes is 50%, the content of carbon fibers is 10%, and the separator matrix is ​​polypropylene separator (celgard 2500).

[0078] The preparation method of the lithium-sulfur battery separator described in this embodiment comprises the following steps:

[0079] (1) Dissolve ferric chloride and sodium oleate in a molar ratio of 1:3 in a mixed solvent of ethanol, distilled water and n-hexane with a volume ratio of 4:3:7, put it into a magnetic rotor, and heat at 70°C And reflux for 3h, th...

Images