Hierarchically porous wearable composites for high-performance stretchable supercapacitors

Abstract

With the rapid development of wearable electronic devices, the demand for flexible, durable, and high-performance energy storage systems has increased significantly. Nevertheless, maintaining stable electrochemical performance during stretching while ensuring high stretchability and mechanical stability remains a challenge. Herein, this study proposes a novel type of stretchable supercapacitors made from carbon nanotube (CNT) and styrene-butadiene-styrene (SBS) composite scaffolds prepared on pre-stretched carbon fabrics using the breath figure method. Hydrothermal treatment is then performed to grow NiCo-LDH at the treated carbon fabrics. This method induces the formation of a hierarchically porous structure under high humidity conditions, controls the hydrothermal growth of NiCo-LDH in the CNT/SBS composite scaffold, and significantly enhances the electrochemical performance and mechanical stability. The supercapacitor demonstrates remarkable retention of 94% capacitance under 80% tensile strain and sustains a small 8% degradation over 20 000 charge–discharge cycles, achieving a specific capacitance of 4948 mF cm⁻2 at 2 mA cm⁻2. The device has an energy density of 801.6 µWh cm⁻2 (400.6 Wh kg⁻¹) and exhibits excellent performance at a power density of 3.5 mW cm⁻2 (1749.5 W kg⁻¹). These properties make the supercapacitors a potential for next-generation smart wearables and wearable electronics. Graphical abstract: [Figure not available: see fulltext.]