Carbon electrode structures for batteries
In certain embodiments, an electrode includes a body of material formed in substantial part of carbon, the body having an exterior surface and an interior located within the exterior surface, and a plurality cavities located in the interior of the body. Each of the cavities is in communication with the exterior of the body and has an interior surface. The cavities can each be sized to accommodate a battery separator located therein and substantially covering the interior surface of the cavity.
1. A method of forming an electrode for a battery, the method comprising:
providing a stack of sheets, wherein
each sheet comprises a first precursor,
the first precursor comprises silicon,
the stack of sheets includes an attachment substance between neighboring sheets of the stack of sheets; and
the attachment substance comprises a second precursor;
pulling apart neighboring sheets of the stack of sheets in areas not attached by the attachment substance such that a plurality of pores is formed between the neighboring sheets; and
pyrolysing the stack of sheets to convert the first precursor and the second precursor into carbon.
2. The method of claim 1 , wherein the first precursor further comprises one or more of: a polyimide, a phenolic resin, or an epoxy resin.
3. The method of claim 1 , comprising placing, prior to the pyrolysing of the stack of sheets, pins between the neighboring sheets to retain the plurality of pores formed between the neighboring sheets.
4. The method of claim 1 , wherein providing the stack of sheets comprises:
applying first lines of the attachment substance to a first surface of a first sheet of the stack of sheets; and
stacking a second sheet of the stack of sheets on the first sheet such that the first lines of the attachment substance directly attach the first sheet of the electrode to the second sheet of the electrode.
5. The method of claim 4 , wherein the first lines of the attachment substance are substantially parallel.
6. The method of claim 5 , wherein providing the stack of sheets comprises:
applying second lines of the attachment substance on a second surface of the second sheet such that the second lines are laterally offset from the first lines and substantially parallel to the first lines; and
stacking a third sheet of the stack of sheets on the second sheet such that the second lines of the attachment substance directly attach the third sheet of the electrode to the second sheet of the electrode.
7. The method of claim 4 , wherein the first lines have a thickness that is about one-third of a distance between adjacent first lines of the attachment substance.
8. The method of claim 1 , wherein the plurality of pores are substantially regularly spaced.
9. The method of claim 1 , wherein the electrode comprises a volume and the plurality of pores comprise at least 50 percent of the volume.
10. The method of claim 1 , wherein the pyrolysing the stack of sheets comprises pyrolysing the stack of sheets after pulling apart the neighboring sheets to form the plurality of pores.
11. The method of claim 1 , comprising the pyrolysing the stack of sheets comprises pyrolysing the stack of sheets while pulling apart the neighboring sheets to form the plurality of pores.
12. The method of claim 1 , further comprises applying the attachment substance as a liquid to one or more sheets of the stack of sheets.
13. A method of forming a battery cell, the method comprising:
forming a first electrode of the battery cell, wherein the forming comprises:
providing a stack of sheets, wherein
each sheet comprises a first precursor mixture,
the first precursor mixture comprises a first precursor and silicon,
the stack of sheets includes an attachment substance between neighboring sheets of the stack of sheets, and
the attachment substance comprises a second precursor;
pulling pull apart neighboring sheets of the stack of sheets in areas not attached by the attachment substance such that a plurality of pores is formed between the neighboring sheets; and
pyrolysing the stack of sheets to convert the first precursor and the second precursor into carbon; and
after forming the first electrode,
coating a pore of the plurality of pores with a separator; and
inserting a second electrode of the battery cell into the pore such that the separator isolates the first electrode from the second electrode.
14. The method of claim 13 , wherein the first precursor comprises one or more of: a polyimide, a phenolic resin, or an epoxy resin.
15. The method of claim 13 , comprising placing, prior to the pyrolysing of the stack of sheets, pins between the neighboring sheets to retain the plurality of pores formed between the neighboring sheets.
16. The method of claim 13 , wherein providing the stack of sheets comprises:
applying first lines of the attachment substance to a first surface of a first sheet of the stack of sheets; and
stacking a second sheet of the stack of sheets on the first sheet.
17. The method of claim 16 , wherein the first lines of the attachment substance are substantially parallel.
18. The method of claim 16 , wherein the first lines have a thickness that is about one-third of a distance between adjacent first lines of the attachment substance.
19. The method of claim 18 , wherein providing the stack of sheets comprises:
applying second lines of the attachment substance on a second surface of the second sheet such that the second lines are laterally offset from the first lines and substantially parallel to the first lines; and
stacking a third sheet of the stack of sheets on the second sheet.
20. The method of claim 13 , wherein the plurality of pores are substantially regularly spaced.
21. The method of claim 13 , wherein the first electrode comprises a volume and the plurality of pores comprise at least 50 percent of the volume.
22. The method of claim 13 , wherein the pyrolysing the stack of sheets comprises pyrolysing the stack of sheets after pulling apart the neighboring sheets to form the plurality of pores.
23. The method of claim 13 , comprising the pyrolysing the stack of sheets comprises pyrolysing the stack of sheets while pulling apart the neighboring sheets to form the plurality of pores.
24. The method of claim 13 , further comprises applying the attachment substance as a liquid to one or more sheets of the stack of sheets.