Hollow carbon-sulfur positive electrode composite material coated with flaky manganese dioxide and preparation and application thereof

A technology of manganese dioxide and composite materials, applied in battery electrodes, electrical components, non-aqueous electrolyte storage batteries, etc., can solve problems such as poor capacity retention, complex reaction, low Coulombic efficiency, etc., and achieve uniform carbon sphere shape, Simple preparation process and controllable carbon layer thickness

Inactive Publication Date: 2019-06-04
DALIAN INST OF CHEM PHYSICS CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

In addition, sulfur reacts complexly with lithium ions during the discharge process, undergoing a process from long-chain polysulfides (Li 2 S x ,4

Method used

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  • Hollow carbon-sulfur positive electrode composite material coated with flaky manganese dioxide and preparation and application thereof
  • Hollow carbon-sulfur positive electrode composite material coated with flaky manganese dioxide and preparation and application thereof
  • Hollow carbon-sulfur positive electrode composite material coated with flaky manganese dioxide and preparation and application thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] The steps of preparing the hollow carbon-sulfur composite material are the same as those of the comparative example. Take 0.1g of the carbon-sulfur composite material, sonicate it for 1 hour, disperse it in 80ml of deionized water, and add 20ml of 0.03mol / L KMnO 4 The solution was reacted in a water bath at 70° C. for 2 hours, centrifuged, washed, and dried to obtain a flaky manganese dioxide-coated hollow carbon-sulfur material. The coating of the subsequent pole piece and the assembly test of the battery are the same as the comparative example. The XRD powder diffraction pattern of the carbon composite material coated with manganese dioxide; image 3 Shown; transmission electron microscope picture is shown in Figure 4 shown.

[0032] Depend on figure 1 It can be seen that the particle size is 200+20nm, from which it can be seen that there are abundant microporous and mesopore structures distributed on the surface of hollow carbon spheres. The carbon layer and the...

Embodiment 2

[0036] The procedure for preparing the hollow carbon-sulfur composite material is the same as that of the comparative example. Take 0.1g of the carbon-sulfur composite material, sonicate it for 1 hour, disperse it in 80ml of deionized water, and add 20ml of 0.01mol / L KMnO 4 The solution was reacted in a water bath at 70° C. for 2 hours, centrifuged, washed, and dried to obtain a flaky manganese dioxide-coated hollow carbon-sulfur material. The coating of the subsequent pole piece and the assembly test of the battery are the same as the comparative example. XRD powder diffraction pattern of manganese dioxide-coated carbon composite materials; scanning electron microscope, transmission electron microscope test, battery specific capacity test, the results show that KMnO 4 Concentration decreases although the reduction of MnO in composites 2 content, but it also provides enough pathways for the migration of lithium ions, and the capacity performance of the battery is slightly low...

Embodiment 3

[0038] The procedure for preparing the hollow carbon-sulfur composite material is the same as that of the comparative example. Take 0.1g of the carbon-sulfur composite material, sonicate it for 1 hour, disperse it in 80ml of deionized water, and add 20ml of 0.1mol / L KMnO 4 The solution was reacted in a water bath at 70° C. for 2 hours, centrifuged, washed, and dried to obtain a flaky manganese dioxide-coated hollow carbon-sulfur material. The coating of the subsequent pole piece and the assembly test of the battery are the same as the comparative example. XRD powder diffraction pattern of manganese dioxide-coated carbon composite materials; scanning electron microscope, transmission electron microscope test, battery specific capacity test, the results show that KMnO 4 Concentration increase increases the MnO 2 Although the content of the pole piece is reduced, the capacity retention rate of the battery is improved.

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Abstract

The invention provides a hollow carbon-sulfur positive electrode composite material coated with flaky manganese dioxide and preparation and application thereof. The carbon and sulfur composite material coated with the manganese dioxide has a carbon content of 10% to 30% and a manganese dioxide content of 10% to 30%, a sulfur content of 40% to 80%, wherein the manganese dioxide is a sheet-like structure and is tightly wrapped on the outer surface of the hollow carbon-sulfur composite material, and the sulfur is mainly distributed in hollow carbon ball cavities and carbon layer mesopores. Hollowcarbon balls with mesoporous structures are prepared with a one-step method with tetraethyl orthosilicate as a silicon source and resorcinol and formaldehyde as carbon sources, the method is simple,the process is controllable, and the carbon balls are uniform in particle size. The manganese dioxide of the sheet-like structure is subjected to thermal processing and is coated, the hollow carbon balls provide sufficient space for carrying the sulfur, the rich point-to-point contact between the carbon balls can ensure rapid electron transfer, sheet-like manganese dioxide coating layers at the surfaces of the carbon balls have strong chemical adsorption on polysulfides, the 'shuttle effect' is effectively alleviated, and the cycle stability and rate performance of the battery are improved.

Description

technical field [0001] The invention belongs to the technical field of new energy, and in particular relates to a hollow carbon-sulfur cathode composite material coated with sheet-like manganese dioxide, as well as its preparation and application. Background technique [0002] With the continuous advancement of new energy development and utilization technology, secondary batteries are playing an increasingly important role as an important energy carrier. Among them, lithium-ion batteries have been widely used in energy storage fields such as small mobile power supplies and power batteries due to their good safety, cycle stability, and low cost. However, due to its lower theoretical specific capacity (<300mAhg -1 ) can no longer meet people's needs for high specific energy batteries, and it is of great significance to develop a new type of secondary battery with high specific energy, long cycle life, low cost and environmental friendliness. Among them, lithium-sulfur bat...

Claims

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Application Information

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IPC IPC(8): H01M4/36H01M10/052
CPCY02E60/10
Inventor 陈剑邵钦君
Owner DALIAN INST OF CHEM PHYSICS CHINESE ACAD OF SCI
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