“…In recent years, increased scientific interest has turned toward the use of cellulose fiber (CF)—an abundant, renewable, recyclable, and biodegradable material—as a substrate for the preparation of freestanding electrodes [15,16,17,18,19]. An additional attraction of CF is that its large number of surface functional groups enables the fibers to bind with electrochemically active materials, e.g., carbon nanotubes (CNTs) [20,21], graphene/graphite [5,13,22,23,24], conducting polymers [16,17,20,22,25,26], and metal ions and oxides [18,27,28] to form freestanding electrodes.…”