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Flexible and micro-sized energy conversion/ storage components are extremely demanding in portable and multifunctional electronic devices, especially those small, flexible, roll-up and even wearable ones. Here in this paper, a two-step electrochemical deposition method has been developed to coat Ni fibers with reduced graphene oxide and MnO2subsequently, giving rise to Ni@reduced-graphene-oxide@MnO2sheath-core flexible electrode with a high areal specific capacitance of 119.4 mF cm−2at a current density of 0.5 mA cm−2in 1 mol L−1Na2SO4electrolyte. Using polyvinyl alcohol (PVA)- LiCl as a solid state electrolyte, two Ni@reduced-grapheneoxide@ MnO2flexible electrodes were assembled into a freestanding, lightweight, symmetrical fiber-shaped micro-supercapacitor device with a maximum areal capacitance of 26.9 mF cm−2. A high power density of 0.1W cm−3could be obtained when the energy density was as high as 0.27 mW h cm−3. Moreover, the resulting micro-supercapacitor device also demonstrated good flexibility and high cyclic stability. The present work provides a simple, facile and low-cost method for the fabrication of flexible, lightweight and wearable energy conversion/storage micro-devices with a high-performance. 便携式及多功能电子设备的不断进步要求为其提供动力能量的存储与转换器件向尺寸小、柔性、能够卷曲甚至可穿戴方向发展. 本文采用两步电化学沉积法依次将还原氧化石墨烯(rGO)和MnO2沉积到镍纤维上得到Ni@rGO@MnO2壳核结构的柔性电极. 该电极在 1 mol L−1Na2SO4电解液中电流密度为0.5 mA cm−2时面积比电容为119.4 mF cm−2. 以PVA-LiCl为固态电解液, 将两根Ni@rGO@MnO2电 极组装成自支撑、质轻、对称的纤维状微型超级电容器, 最大面积比电容为26.9 mF cm−2, 能量密度高达0.1 W cm−3(0.27 mW h cm−3). 此 外, 该微型超级电容器还展现了良好的柔性和循环性能. 这项研究工作主要提供了一种简单、易操作、低成本的制备柔性、质轻、可穿 戴的高性能能量存储设备的方法.