A battery on a conductive metal wire and components of a battery on a conductive metal wire of circular cross section diameter of 5-500 micrometers and methods of making the battery and battery components are disclosed. In one embodiment, the battery features a porous anode or cathode layer which assist with ion exchange in batteries. Methods of forming the porous anode or cathode layer include deposition of an inert gas or hydrogen enriched carbon or silicon layer on a heated metal wire followed by annealing of the inert gas or hydrogen enriched carbon silicon layer. Energy storage devices having bundles of batteries on wires are also disclosed as are other energy storage devices.

Flexible electrical devices are provided that include a coated inner carbon nanotube electrode that has an exterior surface, an outer carbon nanotube electrode disposed on the exterior surface of the coated inner carbon nanotube electrode, and an overlap region in which the coated inner carbon nanotube electrode and the outer carbon nanotube electrode overlap one another, in which the device has a fiber-like geometry and first and second electrode ends. Methods are provided for fabricating an electrical component that includes a flexible electrical component having a fiber-like geometry and includes carbon nanotube electrodes.

A negative electrode active material for a non-aqueous electrolyte secondary battery according to one example of an embodiment comprises composite particles (30) that include a lithium aluminate phase (31) and a silicon phase (32) dispersed in the lithium aluminate phase (31). The composite particles (30) have an internal porosity of 25% or less before being charged and discharged for the first time.

A negative electrode includes a negative electrode active material layer, wherein the negative electrode active material layer includes a negative electrode active material and a conductive agent, wherein the negative electrode active material includes a silicon-based active material, the silicon-based active material includes SiO.sub.x (0x<2), the conductive agent includes a carbon nanotube structure in which 2 to 5,000 single-walled carbon nanotube units are bonded side by side, and the carbon nanotube structure is included in an amount of 0.01 wt % to 1.0 wt % in the negative electrode active material layer. A secondary battery including the negative electrode, and a method of preparing same are also provided.