Sulfur based active material for a positive electrode
AssigneeGM Global Technology Operations LLC
InventorsWeidong Zhou, Xingcheng Xiao, Mei Cai
Life of this patent
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Abstract
A sulfur based active material has a core-shell structure including a hollow core and a porous carbon shell surrounding the hollow core. Sulfur is present in a portion of the hollow core. A polymer shell coating is formed on the porous carbon shell. The polymer shell coating includes nitrogen atoms that bond to carbon atoms of the porous carbon shell so that the porous carbon shell is a nitrogen-confused porous carbon shell.
Claims19
A sulfur based active material, comprising:
- a core-shell structure, including:
- a hollow core;
- and
- a porous carbon shell surrounding the hollow core;
- sulfur present in a portion of the hollow core;
- and
- a polymer shell coating formed on the porous carbon shell, the polymer shell coating including nitrogen atoms that bond to carbon atoms of the porous carbon shell so that the porous carbon shell is a nitrogen-confused porous carbon shell.
A positive electrode, comprising:
- a sulfur based active material, including:
- a core-shell structure with a hollow core and a porous carbon shell surrounding the hollow core;
- sulfur present in a portion of the hollow core;
- and
- a polymer shell coating formed on the porous carbon shell, the polymer shell coating including nitrogen atoms that bond to carbon atoms of the porous carbon shell so that the porous carbon shell is a nitrogen-confused porous carbon shell;
- a conductive carbon material;
- and
- a binder.
A method for making a sulfur based active material, the method comprising:
- forming a porous carbon shell having a hollow core;
- incorporating sulfur into the hollow core, thereby forming a hollow carbon-sulfur composite;
- dispersing the hollow carbon-sulfur composite in an aqueous solution including a nitrogen-containing monomer and having an alkaline pH, thereby forming a dispersion;
- and
- stirring the dispersion at a reaction temperature for a time sufficient to polymerize the nitrogen-containing monomer and to form a polymer shell coating on the porous carbon shell of the hollow carbon-sulfur composite, whereby at least some of the nitrogen atoms of the polymer shell coating bond to carbon atoms of the porous carbon shell to form a nitrogen-confused porous carbon shell.
A lithium-sulfur battery, comprising:
- a positive electrode, including:
- a sulfur based active material, including:
- a core-shell structure with a hollow core and a porous carbon shell surrounding the hollow core;
- sulfur present in a portion of the hollow core;
- and
- a polymer shell coating formed on the porous carbon shell, the polymer shell coating including nitrogen atoms that bond to carbon atoms of the porous carbon shell so that the porous carbon shell is a nitrogen-confused porous carbon shell;
- a conductive carbon material;
- and
- a binder;
- a negative electrode;
- a porous membrane positioned between the positive electrode and the negative electrode;
- and
- an electrolyte in contact with at least the porous membrane.
Dependencies are inferred from the claim text.