Abstract: Provided herein are nanostructures for lithium ion battery electrodes and methods of fabrication. In some embodiments, a nanostructure template coated with a silicon-based coating is provided. The silicon coating may include a non-conformal, more porous silicon-rich SiEx layer and a conformal, denser SiEx layer on the non-conformal, more porous layer. In some embodiments, two different deposition processes are used: a PECVD layer to deposit the non-conformal, silicon-rich SiEx layer and a thermal CVD process to deposit the conformal layer. The silicon-rich SiEx material prevents silicon crystalline domain growth, limits macroscopic swelling, increases lithium diffusion rate and enhances significantly battery life during lithium ion battery cycle of charge and discharge.

Abstract: Provided are examples of electrochemically active electrode materials, electrodes using such materials, and methods of manufacturing such electrodes. Electrochemically active electrode materials may include a high surface area template containing a metal silicide and a layer of high capacity active material deposited over the template. The template may serve as a mechanical support for the active material and/or an electrical conductor between the active material and, for example, a substrate. Due to the high surface area of the template, even a thin layer of the active material can provide sufficient active material loading and corresponding battery capacity. As such, a thickness of the layer may be maintained below the fracture threshold of the active material used and preserve its structural integrity during battery cycling.

Abstract: Provided herein are nanostructures for lithium ion battery electrodes and methods of fabrication. In some embodiments, a nanostructure template coated with a silicon coating is provided. The silicon coating may include a non-conformal, more porous layer and a conformal, denser layer on the non-conformal, more porous layer. In some embodiments, two different deposition processes, e.g., a PECVD layer to deposit the non-conformal layer and a thermal CVD process to deposit the conformal layer, are used. Anodes including the nanostructures have longer cycle lifetimes than anodes made using either a PECVD or thermal CVD method alone.

Abstract: Although silicon-oxide based particles have stable capacity and high cycling efficiency as anode active material, they are known to suffer significant capacity loss during the first battery cycles. The addition of lithium silicate may help to mitigate the initial capacity loss, but it has been difficult to produce such anodes. During battery manufacture cell components are exposed to water, and lithium silicate is water soluble. As lithium silicate dissolves, the pH of the water increases, which can etch silicon, degrading the anode active material. Such degradation can be mitigated by doping lithium silicate with multivalent elements or by converting some silicon to metal silicide before water processing. Doping of lithium silicate makes it less soluble in water. And metal silicide is not as easily etched as silicon.

Abstract: Apparatuses and methods for depositing materials on both sides of a web while it passes a substantially vertical direction are provided. In particular embodiments, a web does not contact any hardware components during the deposition. A web may be supported before and after the deposition chamber but not inside the deposition chamber. At such support points, the web may be exposed to different conditions (e.g., temperature) than during the deposition. Also provided are substrates having materials deposited on both sides that may be fabricated by the methods and apparatuses.