title: Constructed uninterrupted charge-transfer pathways in three-dimensional micro/nanointerconnected carbon-based electrodes for high energy-density ultralight flexible supercapacitors.
abstract: A type of freestanding three-dimensional (3D) micro/nanointerconnected structure, with a conjunction of microsized 3D graphene networks, nanosized 3D carbon nanofiber (CNF) forests, and consequently loaded MnO2 nanosheets, has been designed as the electrodes of an ultralight flexible supercapacitor. The resulting 3D graphene/CNFs/MnO2 composite networks exhibit remarkable flexibility and highly mechanical properties due to good and intimate contacts among them, without current collectors and binders. Simultaneously, this designed 3D micro/nanointerconnected structure can provide an uninterrupted double charges freeway network for both electron and electrolyte ion to minimize electron accumulation and ion-diffusing resistance, leading to an excellent electrochemical performance. The ultrahigh specific capacitance of 946 F/g from cyclic voltammetry (CV) (or 920 F/g from galvanostatic charging/discharging (GCD)) were obtained, which is superior to that of the present electrode materials based on 3D graphene/MnO2 hybrid structure (482 F/g). Furthermore, we have also investigated the superior electrochemical performances of an asymmetric supercapacitor device (weight of less than 12 mg/cm(2) and thickness of ~0.8 mm), showing a total capacitance of 0.33 F/cm(2) at a window voltage of 1.8 V and a maximum energy density of 53.4 W h/kg for driving a digital clock for 42 min. These inspiring performances would make our designed supercapacitors become one of the most promising candidates for the future flexible and lightweight energy storage systems.
authors: School of Physical Science and Technology and §College of Chemistry and Chemical Engineering, Lanzhou University , Lanzhou 730000, Gansu, P.R. China.
authors: Yongmin
authors: Y
authors: He
authors: Wanjun
authors: W
authors: Chen
authors: Jinyuan
authors: J
authors: Zhou
authors: Xiaodong
authors: X
authors: Li
authors: Pengyi
authors: P
authors: Tang
authors: Zhenxing
authors: Z
authors: Zhang
authors: Jiecai
authors: J
authors: Fu
authors: Erqing
authors: E
authors: Xie