Oxidation resistant separator for a battery
A method for preventing oxidation of a polyolefin separator in a lithium ion secondary battery includes the steps of: providing a lithium ion secondary battery having a positive electrode and a polyolefin separator film; and positioning an antioxidative barrier coating between the positive electrode and the polyolefin separator film, the antioxidative barrier coating being made of a polymer having a resistance to oxidation greater than polyethylene.
1. A method for preventing oxidation on a polyolefin separator in a lithium ion secondary battery comprising the steps of:
providing a lithium ion secondary battery having a positive electrode and a polyolefin separator film; and
positioning an antioxidative barrier coating between the positive electrode and the polyolefin separator film,
the antioxidative barrier coating comprises polyvinylidene fluoride and polypropylene;
wherein the antioxidative barrier coating has a weight of <0.15 mg/cm 2 .
2. The method of claim 1 wherein the antioxidative barrier coating is a discrete polymer coating formed onto the polyolefin separator film and/or the positive electrode by a coating method selected from the group consisting of brushing, spraying, applying via roller, and applying by immersion.
3. The method of claim 1 wherein the antioxidative barrier coating is formed on the polyolefin separator film.
4. The method of claim 1 wherein the antioxidative barrier coating is formed on the positive electrode.
5. The method of claim 1
wherein at least one of polyvinylidene fluoride and polypropylene is included in the polyolefin separator film.
6. The method of claim 1 wherein the polyolefin separator film is made of polyethylene, copolymers thereof and mixtures thereof.
7. The method of claim 6 wherein the polyolefin separator film is a single layered film.
8. The method of claim 6 wherein the polyolefin separator film is a multi-layered film.
9. A method for preventing oxidation on a polyolefin separator in a lithium ion secondary battery comprising the steps of:
providing a lithium ion secondary battery having a positive electrode and a polyolefin separator film;
adding an antioxidative barrier between the positive electrode and the separator film,
the antioxidative barrier including a polymer having a resistance to oxidation greater than polyethylene,
the polymer comprises polyvinylidene fluoride and polypropylene; and
positioning the antioxidative barrier toward the positive electrode;
wherein the antioxidative barrier has a weight of <0.15 mg/cm 2 .
10. The method of claim 9 wherein the antioxidative barrier is a discrete polymer coating formed on the polyolefin separator film.
11. A method for preventing oxidation on a polyolefin separator in a lithium ion secondary battery comprising the steps of:
providing a lithium ion secondary battery having a positive electrode and a polyolefin separator film;
positioning an antioxidative barrier coating between the positive electrode and the polyolefin separator film,
the antioxidative barrier coating is a discrete polymer coating formed on the polyolefin separator film and/or on the positive electrode,
the antioxidative barrier coating includes a polymer having a resistance to oxidation greater than polyethylene, and
the polymer comprises polyvinylidene fluoride and polypropylene; and
wherein the antioxidative barrier coating has a weight of <0.15 mg/cm 2 .