Advanced separators based on aromatic polymer for high energy density lithium batteries
A process includes casting a solution including poly(phenylene oxide), inorganic nanoparticles, a solvent, and a non-solvent on a substrate; and removing the solvent to form a porous film; wherein: the porous film is configured for use as a porous separator for a lithium ion battery.
1. A process for forming a porous film separator on the surface of an electrode, the process comprising:
casting a solution comprising poly(phenylene oxide), inorganic nanoparticles, a solvent, and a non-solvent on the electrode, wherein the electrode comprises an electroactive material and a current collector; and
removing the solvent to form the porous film separator on the surface of the electrode;
wherein:
the inorganic nanoparticles have an average particle size of from about 1 nm to about 100 nm;
the solvent is selected from the group consisting of a halogenated solvent, benzene, xylene, toluene, and a mixture of any two or more thereof; and
the non-solvent is selected from the group consisting of an alcohol, acetone, N,N-dimethylformamide, N-Methyl-2-pyrrolidone, N,N-dimethylacetamide, and a mixture of any two or more thereof.
2. The process of claim 1 , wherein a volume ratio of non-solvent to solvent is from about 0.001 to about 0.30.
3. The process of claim 1 , wherein a volume ratio of non-solvent to solvent is from about 0.1 to about 0.2.
4. The process of claim 1 , wherein the solvent comprises a halogenated solvent selected from the group consisting of chloroform, methylene chloride, carbon tetrachloride, chlorobenzene, dichlorobenzene, or a mixture of any two or more thereof.
5. The process of claim 1 , wherein the non-solvent comprises an alcohol and the alcohol is selected from the group consisting of n-propanol, n-butanol, n-pentanol, n-hexanol, n-heptanol, n-octanol, isomers thereof, or a mixture of any two or more alcohols or isomers thereof.
6. The process of claim 1 , wherein the inorganic nanoparticles are silica nanoparticles, alumina nanoparticles, or a combination thereof.
7. The process of claim 1 further comprising drying the porous film separator.
8. The process of claim 1 , wherein the inorganic nanoparticles are present from about 1 wt % to about 50 wt % with regard to the poly(phenylene oxide).
9. The process of claim 1 , wherein the inorganic nanoparticles are present from about 5 wt % to about 20 wt % with regard to the poly(phenylene oxide).
10. The process of claim 1 , wherein the inorganic nanoparticles are present from about 10 wt % to about 20 wt % with regard to the poly(phenylene oxide).
11. The process of claim 1 further comprising forming a second porous film on the porous film, the forming comprising casting a second solution comprising poly(phenylene oxide), inorganic nanoparticles, a solvent, and a non-solvent on the porous film separator; and removing the solvent to form a two-layer porous film.
12. The process of claim 1 , wherein the poly(phenylene oxide) is poly(2,6-dimethyl-1,4-phenylene oxide).