A Bamboo-Inspired Nanostructure Design for Flexible, Foldable, and Twistable Energy Storage Devices

• DOI: 10.1021/acs.nanolett.5b00738
• Publication Date: 2015-05-26T13:32:36Z
• Authors: Yongming Sun; Ryan B. Sills; Xianluo Hu; Zhi Wei Seh; Xu Xiao; Henghui Xu; Wei Luo; Huanyu Jin; Ying Xin; Tianqi Li; Zhaoliang Zhang; Jun Zhou; Wei Cai; Yunhui Huang; Yi Cui
• Keywords: 02 engineering and technology; Pliability; Poaceae; 0210 nano-technology; Porosity; 7. Clean energy; 620; Nanostructures

Flexible energy storage devices are critical components for emerging flexible electronics. Electrode design is key in the development of all-solid-state supercapacitors with superior electrochemical performances and mechanical durability. Herein, we propose a bamboo-like graphitic carbon nanofiber with a well-balanced macro-, meso-, and microporosity, enabling excellent mechanical flexibility, foldability, and electrochemical performances. Our design is inspired by the structure of bamboos, where a periodic distribution of interior holes along the length and graded pore structure at the cross section not only enhance their stability under different mechanical deformation conditions but also provide a high surface area accessible to the electrolyte and low ion-transport resistance. The prepared nanofiber network electrode recovers its initial state easily after 3-folded manipulation. The mechanically robust membrane is explored as a free-standing electrode for a flexible all-solid-state supercapacitor. Without the need for extra support, the volumetric energy and power densities based on the whole device are greatly improved compared to the state-of-the-art devices. Even under continuous dynamic operations of forceful bending (90°) and twisting (180°), the as-designed device still exhibits stable electrochemical performances with 100% capacitance retention. Such a unique supercapacitor holds great promise for high-performance flexible electronics.