Abstract: A novel hybrid lithium-ion anode material based on coaxially coated Si shells on vertically aligned carbon nanofiber (CNF) arrays. The unique cup-stacking graphitic microstructure makes the bare vertically aligned CNF array an effective Li+ intercalation medium. Highly reversible Li+ intercalation and extraction were observed at high power rates. More importantly, the highly conductive and mechanically stable CNF core optionally supports a coaxially coated amorphous Si shell which has much higher theoretical specific capacity by forming fully lithiated alloy. Addition of surface effect dominant sites in close proximity to the intercalation medium results in a hybrid device that includes advantages of both batteries and capacitors.

Abstract: A novel hybrid lithium-ion anode material based on coaxially coated Si shells on vertically aligned carbon nanofiber (CNF) arrays. The unique cup-stacking graphitic microstructure makes the bare vertically aligned CNF array an effective Li+ intercalation medium. Highly reversible Li+ intercalation and extraction were observed at high power rates. More importantly, the highly conductive and mechanically stable CNF core optionally supports a coaxially coated amorphous Si shell which has much higher theoretical specific capacity by forming fully lithiated alloy. Addition of surface effect dominant sites in close proximity to the intercalation medium results in a hybrid device that includes advantages of both batteries and capacitors.

Abstract: A novel hybrid lithium-ion anode material based on coaxially coated Si shells on vertically aligned carbon nanofiber (CNF) arrays. The unique cup-stacking graphitic microstructure makes the bare vertically aligned CNF array an effective Li+ intercalation medium. Highly reversible Li+ intercalation and extraction were observed at high power rates. More importantly, the highly conductive and mechanically stable CNF core optionally supports a coaxially coated amorphous Si shell which has much higher theoretical specific capacity by forming fully lithiated alloy. Addition of surface effect dominant sites in close proximity to the intercalation medium results in a hybrid device that includes advantages of both batteries and capacitors.

Abstract: A high capacity electrode includes a conducting substrate on which a plurality of support filaments are disposed. Each of the support filaments have a length substantially greater than their width and may include, for example, a carbon nano-tube (CNT), a carbon nano-fiber (CNF), and/or a nano-wire (NW). The support filaments are coated with a material, such as silicon, having a greater ion absorbing capacity greater than the neat support filaments. A trunk region of the support filaments proximate to the substrate is optionally kept free of ion absorbing material. This trunk region allows for the expansion of the ion absorbing material without detaching the support filaments form the substrate.

Abstract: A high capacity electrode includes a conducting substrate on which a plurality of support filaments are disposed. Each of the support filaments have a length substantially greater than their width and may include, for example, a carbon nano-tube (CNT), a carbon nano-fiber (CNF), and/or a nano-wire (NW). The support filaments are coated with a material, such as silicon, having a greater ion absorbing capacity greater than the neat support filaments. A trunk region of the support filaments proximate to the substrate is optionally kept free of ion absorbing material. This trunk region allows for the expansion of the ion absorbing material without detaching the support filaments form the substrate.

Abstract: An electrode including structures configured to prevent an intercalation layer from detaching from the electrode and/or a structure configured to create a region on the electrode having a lower concentration of intercalation material. The electrode includes a support filament on which the intercalation layer is disposed. The support filament optionally has nano-scale dimensions.