Research has been undertaken into the mixing of electroactive additives (EAA), for example, conducting polymers or particles, in five different cellulose structures and their further processing into electroactive papers and films. The cellulose structures considered included cellulose nanofibrils (CNF) hydrogels, CNG aerogels, CNF filaments, CNF films and cellulose papers. It has been demonstrated that the cellulose structure in combination with the electroactive polymer or particle, could be used to tailor numerous different properties. The cellulose could provide properties that support structural integrity, processability, ionic conductivity, shapeability and a large inner capacitive surface. The highly porous aerogel particles could be shaped using three-dimensional printed templates prior to freezing. The particles could be filled either with active material from the start before freeze-linking or filled with active material afterwards based on the layer by layer method. Electroactive paper could also be produced by adding the active component directly as a filler during papermaking, by adding CNF spun EA filaments cut into conveniently long staple fibres.