Battery outgassing filter system and method to filter outgassing from a battery cell

1. A battery outgassing filter system, comprising:

a battery cell;

an external casing encapsulating the battery cell and including a casing vent; and

an outgassing filter disposed upon the casing vent and including a filter element including a first filter element portion operable to contain a first size of particulate matter and a second filter element portion operable to contain a second size of particulate matter relatively smaller than the first size of particulate matter; and

wherein the first filter element portion includes a wall flow filter element including a plurality of parallel filtration walls which is aligned to be parallel to a direction of a flow of gas through the battery outgassing filter system;

wherein the plurality of parallel filtration walls includes:

a first filtration wall including a first primary face; and

a second filtration wall adjacent to the first filtration wall and including a second primary face;

wherein the first primary face is parallel to the second primary face, and

wherein the flow of gas passes the first primary face and the second primary face in a direction perpendicular to the first primary face and the second primary face.

2. The battery outgassing filter system of claim 1 , wherein the first filter element portion includes a first filter mesh;

wherein the second filter element portion includes a second filter mesh; and

wherein the second filter mesh is finer than the first filter mesh.

3. The battery outgassing filter system of claim 1 , wherein the first filter element portion includes a foam-based porous filter element.

4. The battery outgassing filter system of claim 1 , wherein the first filter element portion includes a catalyzed filter element.

5. The battery outgassing filter system of claim 1 , wherein the outgassing filter includes a multi-layer filtration element.

6. The battery outgassing filter system of claim 1 , wherein the outgassing filter includes a multi-layer three-dimensional-polygon-shaped filtration element.

7. A battery outgassing filter system, comprising:

a battery cell;

an external casing encapsulating the battery cell and including a casing vent;

an outgassing filter disposed upon the casing vent and including a filter element including:

a first filter element portion including a first filter mesh operable to contain a first size of particulate matter, wherein the first filter element portion includes a wall flow filter element including a plurality of parallel filtration walls which is aligned to be parallel to a direction of a flow of gas through the battery outgassing filter system; and

a second filter element portion receiving a gas flow from the first filter element portion and including a second filter mesh operable to contain a second size of particulate matter relatively smaller than the first size of particulate matter; and

wherein the second filter mesh is finer than the first filter mesh;

wherein the plurality of parallel filtration walls includes:

a first filtration wall including a first primary face; and

a second filtration wall adjacent to the first filtration wall and including a second primary face;

wherein the first primary face is parallel to the second primary face, and

wherein the flow of gas passes the first primary face and the second primary face in a direction perpendicular to the first primary face and the second primary face.

8. The battery outgassing filter system of claim 7 , wherein the first filter element portion includes a foam-based porous filter element.

9. The battery outgassing filter system of claim 7 , wherein the first filter element portion includes a catalyzed filter element.

10. The battery outgassing filter system of claim 7 , wherein the outgassing filter includes a multi-layer filtration element.

11. The battery outgassing filter system of claim 7 , wherein the outgassing filter includes a multi-layer three-dimensional-polygon-shaped filtration element.

12. A method to filter outgassing from a battery cell, comprising:

containing the battery cell within an external casing, wherein gas generated by the battery cell may exit the external casing through a casing vent;

disposing an outgassing filter to the casing vent, wherein the gas generated by the battery cell and flowing through the casing vent passes through the outgassing filter, wherein the outgassing filter includes a first filter element portion operable to contain a first size of particulate matter and a second filter element portion operable to contain a second size of particulate matter relatively smaller than the first size of particulate matter; and

wherein the first filter element portion includes a wall flow filter element including a plurality of parallel filtration walls which is aligned to be parallel to a direction of a flow of gas through the battery outgassing filter system;

wherein the plurality of parallel filtration walls includes:

a first filtration wall including a first primary face; and

a second filtration wall adjacent to the first filtration wall and including a second primary face;

wherein the first primary face is parallel to the second primary face, and

wherein the flow of gas passes the first primary face and the second primary face in a direction perpendicular to the first primary face and the second primary face.

13. The method of claim 12 , further comprising permitting the gas generated by the battery cell to flow through the outgassing filter for some threshold period of time while particulate matter is contained within the outgassing filter.