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

Highlights: • A facile and fast method was created to develop a core–sheath structured electrode. • MnO₂ nanoribbons (sheath) were in-situ grown on the surface of carbon fibers (core). • The flexible electrode was assembled into an all-textile and spirally wound ASC. • An outstanding electrochemical activity was achieved for the CDCC//MnO₂/CDCC ASC. • The ASC is eco-friendly and biodegradable due to the all-cotton-derived components. 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.