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US 10,593,932 B2Granted
Process for metal-sulfur battery cathode containing humic acid-derived conductive foam
AssigneeGlobal Graphene Group, Inc.
InventorsAruna Zhamu, Bor Z. Jang
Life of this patent
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Abstract
Provided is a process for producing a sulfur cathode for a metal-sulfur battery. The process comprises: (a) Preparing a humic acid-derived foam or combined humic acid/graphene-derived foam composed of multiple pores and pore walls, wherein the pore walls contain one or a plurality of hexagonal carbon atomic planes; and (b) Impregnating the foam with sulfur or sulfide in a form of thin particles or coating, having a diameter or thickness less than 500 nm, which are lodged in the pores or deposited on the pore walls of the foam.
Claims17
A process for producing sulfur cathode for a metal-sulfur battery, said process comprising:
- (a) preparing a humic acid dispersion having multiple humic acid molecules and optional graphene sheets dispersed in a liquid medium, wherein said humic acid is selected from the group consisting of oxidized humic acid, reduced humic acid, fluorinated humic acid, chlorinated humic acid, brominated humic acid, iodized humic acid, hydrogenated humic acid, nitrogenated humic acid, doped humic acid, chemically functionalized humic acid, and a combinations thereof and wherein said dispersion contains a blowing agent having a blowing agent-to-humic acid weight ratio from 0/1.0 to 1.0/1.0;
- (b) dispensing and depositing said humic acid dispersion onto a surface of a supporting substrate to form a wet layer of humic acid and partially or completely removing said liquid medium from the wet layer of humic acid to form a dried layer of humic acid;
- (c) heat treating the dried layer of humic acid at a first heat treatment temperature from 80° C. to 3,200° C. at a desired heating rate sufficient to induce volatile gas molecules from non-carbon elements or to activate said blowing agent for producing a humic acid-derived foam, wherein a porosity is substantially open cell and said pore walls contain single-layer or few-layer humic acid-derived hexagonal carbon atomic planes, said few-layer hexagonal carbon atomic planes have 2-10 layers of stacked hexagonal carbon atomic planes having an inter-plane spacing d002 from 0.3354 nm to 0.60 nm as measured by X-ray diffraction, and said single-layer or few-layer hexagonal carbon atomic planes contain 0.01% to 25% by weight of non-carbon elements;
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- (d) impregnating said foam with sulfur or sulfide in a form of thin particles or a coating, having a diameter or thickness less than 500 nm, which are lodged in said pores or deposited on said pore walls.
2 more elements
A process for producing sulfur cathode for a metal-sulfur battery, said process comprising:
- (a) preparing a humic acid dispersion having multiple humic acid molecules and optional graphene sheets dispersed in a liquid medium, wherein said humic acid is selected from the group consisting of oxidized humic acid, reduced humic acid, fluorinated humic acid, chlorinated humic acid, brominated humic acid, iodized humic acid, hydrogenated humic acid, nitrogenated humic acid, doped humic acid, chemically functionalized humic acid, and a combinations thereof;
- (b) dispensing said humic acid dispersion onto a surface of a supporting substrate to form a wet layer of humic acid and partially or completely removing said liquid medium from the wet layer of humic acid to form a dried layer of humic acid, wherein said dispensing optionally includes an orientation-inducing stress;
- (c) heat treating the dried layer of humic acid at a first heat treatment temperature from 80° C. to 3,200° C. at a desired heating rate sufficient to induce volatile gas molecules from non-carbon elements for producing a humic acid-derived foam, wherein pore walls of said humic acid-derived foam contain single-layer or few-layer humic acid-derived hexagonal carbon atomic planes, said few-layer hexagonal carbon atomic planes have 2-10 layers of stacked hexagonal carbon atomic planes having an inter-plane spacing d002 from 0.3354 nm to 0.60 nm as measured by X-ray diffraction, and said single-layer or few-layer hexagonal carbon atomic planes contain 0.01% to 25% by weight of non-carbon elements;
- (d) optionally heat-treating the humic acid-derived foam at a second heat treatment temperature higher than said first heat treatment temperature for a length of time sufficient for obtaining a graphitic foam wherein said pore walls contain stacked hexagonal carbon atomic planes having an inter-planar spacing d002 from 0.3354 nm to 0.36 nm and a content of non-carbon elements less than 2% by weight;
- (e) optionally comprising a compression step during or after a heat treatment step to reduce a thickness, a pore size, or a porosity level of said humic acid-derived foam;
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- (f) impregnating said foam with sulfur or sulfide in a form of thin particles or coating, having a diameter or thickness less than 500 nm, which are lodged in said pores or deposited on said pore walls.
4 more elements
Dependencies are inferred from the claim text.