A high-performance, all-textile and spirally wound asymmetric supercapacitors based on core–sheath structured MnO2 nanoribbons and cotton-derived carbon cloth

Abstract An increasing emphasis on green chemistry and high-efficient utilization of natural resources has raised more demands for more facile, rapid and cost-effective approaches for preparation of energy-storage equipment. Herein, we demonstrate a simple, fast and cheap approach to create a core–sheath structured textile electrode based on cotton-derived carbon cloth (CDCC, core) and MnO2 nanoribbons (sheath). A good interface bonding between the in-situ grown MnO2 and carbon fibers of CDCC aided electron transfer. The abundant MnO2 nanostructures increased electrochemically active areas accessed by electrolyte ions and the porous CDCC acted as an electrolyte reservoir to shorten ion-diffusion path and facilitate efficient infiltration of electrolyte ions. Because of these advantages, the MnO2/CDCC electrode exhibits a high areal specific capacitance of 202 mF cm−2. In addition, the flexible electrode was assembled into an all-textile and spirally wound asymmetric supercapacitor with an outstanding electrochemical activity, like a high areal energy density of 30.1 μW h cm−2 at 0.15 mW cm−2 and an excellent capacitance retention of 87.7% after 5000 cycles. Another meritorious contribution is the synthetic strategy realizing a more direct, eco-friendly and efficient utilization way of cellulose resource, which avoided pollutions from cellulose purification or pretreatment.