Industrially weavable metal/cotton yarn air electrodes for highly flexible and stable wire-shaped Li-O₂ batteries

Li-O₂ batteries feature extremely high energy density, making their wire-shaped devices a promising candidate for wearable energy-storage application. However, it is a major challenge to explore industrially feasible electrodes for this type of linear batteries. Herein, for the first time, we have demonstrated an effective strategy to fabricate a feasible electrode on a large scale by dyeing industrially weavable and highly conductive metal/cotton yarns with the active material ink, RuO₂-coated nitrogen-doped carbon nanotube (CNT). The obtained wire-shaped Li-O₂ battery exhibits a high discharge capacity of 1981 mA h g_carbon⁻¹ at a current density of 320 mA g_carbon⁻¹ and could stably work beyond 100 cycles (more than 600 hours) without obvious degradation, even under bending conditions. The new freestanding type electrode will represent a critical step towards the production and practical application of flexible Li-O₂ batteries.