Scalable assembly of polyaniline/Ti3C2Tx MXene modified cotton yarn flexible electrode for high-performance wearable energy storage

Developing miniaturization, adaptability and weavability fiber-shaped supercapacitors (F-SCs), presenting adequate active sites, interconnected electrolyte diffusion channels and good mechanical endurance, has been pivotal issues for controlled, reliable and stable power source in intelligent wearable system. Here, the flexible PANI/Ti3C2Tx modified cotton (PTC) yarn electrode was fabricated via coating method on a large scale. Ti3C2Tx flakes regard as a binder and anchor on the cotton yarn along with PANI nanoparticles to construct a conductive framework. Besides, embedding PANI nanoparticles obtaining favorable synergistic effect can not only provide large pseudo-capacitance, but also impede the self-restacking of Ti3C2Tx flakes, causing penetrative ions channels, abundant redox active sites and large surface area. What's more, the tough skeleton of cotton yarn endows remarkable mechanical endurance for electrode and device. As a result, the PTC yarn shows large mass capacitance (417.6F g- 1 at 1 A/g) and superior rate performance (225.7F g- 1 at 10 A/g) in three-electrode system. Moreover, the symmetric solid-state F-SCs deliver high capacitance of 175.6F g- 1 at 0.5 A/g, incredible energy density (6.1Wh kg- 1) and stable charge/discharge performance (98.5% capacitance retention after 2000 cycling). More importantly, the F-SCs exhibit impressive capacitance retention under deformation settings and ever integrated into the textile, which proves the bright future in the smart garment application.