title: Core-double-shell, carbon nanotube@polypyrrole@MnO₂ sponge as freestanding, compressible supercapacitor electrode.
abstract: Design and fabrication of structurally optimized electrode materials are important for many energy applications such as supercapacitors and batteries. Here, we report a three-component, hierarchical, bulk electrode with tailored microstructure and electrochemical properties. Our supercapacitor electrode consists of a three-dimensional carbon nanotube (CNT) network (also called sponge) as a flexible and conductive skeleton, an intermediate polymer layer (polypyrrole, PPy) with good interface, and a metal oxide layer outside providing more surface area. These three components form a well-defined core-double-shell configuration that is distinct from simple core-shell or hybrid structures, and the synergistic effect leads to enhanced supercapacitor performance including high specific capacitance (even under severe compression) and excellent cycling stability. The mechanism study reveals that the shell sequence is a key factor; in our system, the CNT-PPy-MnO2 structure shows higher capacitance than the CNT-MnO2-PPy sequence. Our porous core-double-shell sponges can serve as freestanding, compressible electrodes for various energy devices.
authors.affiliation: Department of Mechanical Engineering, Tsinghua University , Beijing 100084, P. R. China.
authors.forename: Peixu
authors.initials: P
authors.lastname: Li
authors.forename: Yanbing
authors.initials: Y
authors.lastname: Yang
authors.forename: Enzheng
authors.initials: E
authors.lastname: Shi
authors.forename: Qicang
authors.initials: Q
authors.lastname: Shen
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Shang
authors.forename: Shiting
authors.initials: S
authors.lastname: Wu
authors.forename: Jinquan
authors.initials: J
authors.lastname: Wei
authors.forename: Kunlin
authors.initials: K
authors.lastname: Wang
authors.forename: Hongwei
authors.initials: H
authors.lastname: Zhu
authors.forename: Quan
authors.initials: Q
authors.lastname: Yuan
authors.forename: Anyuan
authors.initials: A
authors.lastname: Cao
authors.forename: Dehai
authors.initials: D
authors.lastname: Wu