SI-CONTAINING COMPOSITE ANODE FOR ENERGY STORAGE DEVICES

1 . A composition comprising:

a shell that is substantially carbon encapsulating a volume that contains a nanoform of silicon and a void space.

2 . A method of fabricating a composition comprising:

combining a nanoform of silicon with a carbon precursor and sintering the combination with a laser.

3 . An electrode for an energy storage device comprising:

an encapsulated form of silicon dispersed in a binder-free carbon network and disposed on a current collector.

4 . An energy storage device comprising an electrode comprising an encapsulated form of silicon dispersed in a binder-free carbon network and disposed on a current collector.

5 . A method of making an electrode for use in an energy storage device comprising:

providing an active material layer comprising silicon and a polymer binder; and

sintering the active material layer to carbonize at least a portion of the polymer binder.

6 . The method of claim 5 , wherein sintering the active material layer comprises:

applying a laser beam to the active material layer to heat a localized region of the active material layer to carbonize at least a portion of the polymer binder.

7 . The method of claim 6 , further comprising scanning the laser beam to successive positions on the active material layer.

8 . The method of claim 6 , wherein applying a laser beam to the active material layer comprises applying a sheet shaped beam, and wherein the localized region comprises a strip across a major surface of the active material layer.

9 . The method of claim 8 , further comprising advancing the active material layer in a direction transverse to the sheet shaped beam to expose successive regions of the active material layer to the beam.

10 . The method of claim 9 , wherein advancing the active material layer comprises a continuous roll to role process.

11 . The method of claim 6 , wherein applying a laser beam to the active material layer to heat a localized region of the active material layer to carbonize at least a portion of the polymer binder comprises controlling the beam to maintain the temperature of in the localized region above the carbonization temperature of the polymer binder, but below a temperature at which the active material or an underlying substrate would be damaged.

12 . The method of claim 5 , wherein the active material layer contains silicon oxide, and at least one form of nanoscopic carbon.

13 . The method of claim 5 , wherein providing the active material layer comprises forming a slurry, applying the slurry to form a coating on a substrate.

14 . An electrode formed by the process of claim 5 .

15 . The electrode of claim 14 , wherein the active material layer is substantially free of polymer binders.