†Department of Physics and Materials Science, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong 999077, China.
‡Institute of Textiles and Clothing, The Hong Kong Polytechnic University, 11 Hong Chong Road, Hung Hom, Hong Kong 999077, China.
ACS Nano. 2015 Jun 23;9(6):6242-51. doi: 10.1021/acsnano.5b01602. Epub 2015 Jun 4.
Yarn-based supercapacitors have received considerable attention recently, offering unprecedented opportunities for future wearable electronic devices (e.g., smart clothes). However, the reliability and lifespan of yarn-based supercapacitors can be seriously limited by accidental mechanical damage during practical applications. Therefore, a supercapacitor endowed with mechanically and electrically self-healing properties is a brilliant solution to the challenge. Compared with the conventional planar-like or large wire-like structure, the reconnection of the broken yarn electrode composed of multiple tiny fibers (diameter <20 μm) is much more difficult and challenging, which directly affects the restoration of electrical conductivity after damage. Herein, a self-healable yarn-based supercapacitor that ensures the reconnection of broken electrodes has been successfully developed by wrapping magnetic electrodes around a self-healing polymer shell. The strong force from magnetic attraction between the broken yarn electrodes benefits reconnection of fibers in the yarn electrodes during self-healing and thus offers an effective strategy for the restoration of electric conductivity, whereas the polymer shell recovers the configuration integrity and mechanical strength. With the design, the specific capacitance of our prototype can be restored up to 71.8% even after four breaking/healing cycles with great maintenance of the whole device's mechanical properties. This work may inspire the design and fabrication of other distinctive self-healable and wearable electronic devices.
基于纱线的超级电容器最近受到了广泛关注，为未来的可穿戴电子设备（例如智能服装）提供了前所未有的机会。然而，在实际应用中，意外的机械损伤可能会严重限制基于纱线的超级电容器的可靠性和寿命。因此，具有机械和电气自修复性能的超级电容器是解决这一挑战的绝佳方案。与传统的平面状或大线状结构相比，由多个直径<20 μm的微小纤维组成的断裂纱线电极的重新连接更加困难和具有挑战性，这直接影响到损坏后的电导率恢复。在此，通过在自愈聚合物壳周围包裹磁性电极，成功开发了一种可确保断裂电极重新连接的自修复纱线基超级电容器。在自修复过程中，断裂纱线电极之间的磁性吸引力产生的强大作用力有利于纤维的重新连接，从而为电导率的恢复提供了有效的策略，而聚合物壳则恢复了结构完整性和机械强度。通过这种设计，即使在经过四次断裂/修复循环后，我们的原型器件的比电容仍可恢复至 71.8%，同时整个器件的机械性能也得到了很好的保持。这项工作可能会启发其他独特的自修复和可穿戴电子设备的设计和制造。
