TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Components: The particulate electroactive material is a silicon-comprising material. The particulate electroactive material comprises particles having a particle core and electroactive pillars extending from the particle core. The pillars of the silicon-comprising particles are silicon pillars. The core of the silicon-comprising particles comprises silicon. Silicon-comprising particles consist essentially of n- or p-doped silicon and where the pillars are integral with the core. The first and second carbon elongate nanostructure materials are each independently selected from carbon nanotubes and carbon nanofibers. The first carbon elongate nanostructure material is a nanofiber and the second elongate carbon nanostructure material is a nanotube. One or more of the elongate carbon nanostructure materials has a functionalized surface, optionally a surface functionalized with a nitrogen-containing group or an oxygen containing group. The composition further comprises graphite. It comprises at least two elongate carbon nanostructure materials. Preferred Parameters: The first elongate nanostructure has a mean average diameter of at least 100 nm. The second elongate carbon nanostructure material has a mean average diameter of no more than 90 nm, optionally a mean average diameter in the range of 40-90 nm. The crystallite length (Lc) of the graphite is optionally at least 50 nm, optionally at least 100 nm. Preferred Composition: The first elongate nanostructure : second elongate nanostructure weight ratio is in the range of 2.5:1 to 20:1. At least first and second elongate carbon nanostructures independently have an aspect ratio of at least 50. At least first and second elongate carbon nanostructure materials are provided in a total amount in the range of 0.1-15 wt.% of the composition. The graphite is provided in the composition in an amount of 1-30 wt.%, optionally 1-20 wt.%. The carbon black is provided in an amount of at least 0.5 wt.% of the composition, and optionally less than 10 wt.% of the composition, optionally less than 4 wt.% of the composition.