Flexible membranes and coated electrodes for lithium based batteries
An example of a flexible membrane includes a porous membrane and a solid electrolyte coating formed on at least a portion of a surface of the porous membrane, in pores of the porous membrane, or both on the surface and in the pores. The solid electrolyte coating includes i) a polymer chain or ii) an inorganic ionically conductive material. The polymer chain or the inorganic material includes a group to interact or react with a polysulfide through covalent bonding or supramolecular interaction.
1. A flexible membrane, comprising:
a porous membrane; and
a solid electrolyte coating formed on at least a portion of a surface of the porous membrane, in pores of the porous membrane, or both on the surface and in the pores, the solid electrolyte coating including a polymer chain selected from the group consisting of polydopamine, polythiophene, polypyrrole, polyaniline, polyacetylene, polyphenylacetylene, polydiacetylene, and derivatives thereof, the polymer chain being saturated with oxygen anions or sulfur anions to enable diffusion of lithium cations, and to suppress diffusion of polysulfide anions.
2. The flexible membrane as defined in claim 1 wherein the porous membrane is selected from the group consisting of a porous polymer membrane or a porous inorganic membrane.
3. The flexible membrane as defined in claim 2 wherein the porous polymer membrane is a surfactant treated porous polypropylene membrane or a surfactant treated porous polyethylene membrane.
4. The flexible membrane as defined in claim 2 wherein the porous inorganic membrane is selected from the group consisting of a porous ceramic membrane, a porous oxide membrane, a porous nitride membrane, a porous silicate membrane, and a porous carbide membrane.
5. The flexible membrane as defined in claim 1 wherein a thickness of the solid electrolyte coating ranges from about 10 nm to about 2 μm.
6. A method for coating a lithium battery component, the method comprising:
providing the lithium battery component, the lithium battery component being a porous membrane;
exposing the lithium battery component to a solvent including a solid electrolyte precursor;
exposing the solid electrolyte precursor to a treatment process that forms a solid electrolyte coating precursor on the lithium battery component; and
reacting or interacting the solid electrolyte coating precursor with polysulfide anions to form a solid electrolyte coating including a polymer chain saturated with oxygen anions or sulfur anions to enable diffusion of lithium cations and to suppress diffusion of polysulfide anions, wherein the polymer chain is selected from the group consisting of polydopamine, polythiophene, polypyrrole, polyaniline, polyacetylene, polyphenylacetylene, polydiacetylene, and derivatives thereof.
7. The method as defined, in claim 6 wherein the exposing of the lithium battery component to the solvent including the solid electrolyte precursor includes immersing the lithium battery component in the solvent including the solid electrolyte precursor or depositing the solvent including the solid electrolyte precursor on a surface of the lithium battery component.
8. The method as defined in claim 6 wherein the solid electrolyte precursor is a monomer and wherein the treatment process is polymerization.
9. A lithium sulfur battery, comprising:
a sulfur based positive electrode;
a negative electrode; and
a flexible membrane positioned between the sulfur based positive electrode and the negative electrode, the flexible membrane including:
a porous membrane; and
a solid electrolyte coating formed on at least a portion of a surface of the porous membrane, in pores of the porous membrane, or both on the surface and in the pores, the solid electrolyte coating including a polymer chain selected from the group consisting of polydopamine, polythiophene, polypyrrole, polyaniline, polyacetylene, polyphenylacetylene, polydiacetylene, and derivatives thereof, the polymer chain being saturated with oxygen anions or sulfur anions to enable diffusion of lithium cations, and to suppress diffusion of polysulfide anions.