Wire-shaped supercapacitors（SCs） possessing light-weight, good flexibility and weavability have caught much attention, but it is still a challenge to extend the lifespan of the devices with gradual aging due to the ...Wire-shaped supercapacitors（SCs） possessing light-weight, good flexibility and weavability have caught much attention, but it is still a challenge to extend the lifespan of the devices with gradual aging due to the rough usage or external factors. Herein, we report a new stretchable and selfhealable wire-shaped SC. In the typical process, two polyvinyl alcohol/potassium hydroxide（PVA/KOH） hydrogel wrapped with urchin-like NiCo2O4 nanomaterials were twisted together to form a complete SC devices. It is noted that the as-prepared PVA hydrogel can be easily stretched up to 300% with small tensile stress of 12.51 kPa, superior to nearly 350 kPa at 300%strain of the polyurethane. Moreover, the wire-like SCs exhibit excellent electrochemical performance with areal capacitance of 3.88 mF cm^-2 at the current density of 0.053 mA cm^-2, good cycling stability maintaining 88.23% after 1000 charge/discharge cycles, and 82.19% capacitance retention even after four damaging/healing cycles. These results indicate that wireshaped SCs with two twisted NiCo2O4 coated polyvinyl alcohol hydrogel fibers is a promising structure for achieving the goal of high stability and long-life time. This work may provide a new solution for new generation of self-healable and wearable electronic devices.展开更多
基金supported by the National Natural Science Foundation of China (61625404 and 61504136)Beijing Natural Science Foundation (4162062)the Key Research Program of Frontiers Sciences,CAS(QYZDY-SSW-JSC004)
文摘Wire-shaped supercapacitors（SCs） possessing light-weight, good flexibility and weavability have caught much attention, but it is still a challenge to extend the lifespan of the devices with gradual aging due to the rough usage or external factors. Herein, we report a new stretchable and selfhealable wire-shaped SC. In the typical process, two polyvinyl alcohol/potassium hydroxide（PVA/KOH） hydrogel wrapped with urchin-like NiCo2O4 nanomaterials were twisted together to form a complete SC devices. It is noted that the as-prepared PVA hydrogel can be easily stretched up to 300% with small tensile stress of 12.51 kPa, superior to nearly 350 kPa at 300%strain of the polyurethane. Moreover, the wire-like SCs exhibit excellent electrochemical performance with areal capacitance of 3.88 mF cm^-2 at the current density of 0.053 mA cm^-2, good cycling stability maintaining 88.23% after 1000 charge/discharge cycles, and 82.19% capacitance retention even after four damaging/healing cycles. These results indicate that wireshaped SCs with two twisted NiCo2O4 coated polyvinyl alcohol hydrogel fibers is a promising structure for achieving the goal of high stability and long-life time. This work may provide a new solution for new generation of self-healable and wearable electronic devices.
