title: Flexible Overoxidized Polypyrrole Films with Orderly Structure as High-Performance Anodes for Li- and Na-Ion Batteries.
abstract: Flexible polypyrrole (PPy) films with highly ordered structures were fabricated by a novel vapor phase polymerization (VPP) process and used as the anode material in lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). The PPy films demonstrate excellent rate performance and cycling stability. At a charge/discharge rate of 1 C, the reversible capacities of the PPy film anode reach 284.9 and 177.4 mAh g-1in LIBs and SIBs, respectively. Even at a charge/discharge rate of 20 C, the reversible capacity of the PPy film anode retains 54.0% and 52.9% of the capacity of 1 C in LIBs and SIBs, respectively. After 1000 electrochemical cycles at a rate of 10 C, there is no obvious capacity fading. The molecular structure and electrochemical behaviors of Li- and Na-ion doping and dedoping in the PPy films are investigated by XPS and ex situ XRD. It is believed that the PPy film electrodes in the overoxidized state can be reversibly charged and discharged through the doping and dedoping of lithium or sodium ions. Because of the self-adaptation of the doped ions, the ordered pyrrolic chain structure can realize a fast charge/discharge process. This result may substantially contribute to the progress of research into flexible polymer electrodes in various types of batteries.
authors.affiliation: Material Science & Engineering School, University of Shanghai for Science and Technology , Shanghai 200093, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Yuan
authors.affiliation: Material Science & Engineering School, University of Shanghai for Science and Technology , Shanghai 200093, China.
authors.forename: Jiafeng
authors.initials: J
authors.lastname: Ruan
authors.affiliation: Shanghai Electrochemical Energy Devices Research Center, Department of Chemical Engineering, Shanghai Jiao Tong University , Shanghai 200240, China.|Sinopoly Battery Research Centre , Shanghai 200241, China.
authors.forename: Weimin
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Material Science & Engineering School, University of Shanghai for Science and Technology , Shanghai 200093, China.
authors.forename: Zhuopeng
authors.initials: Z
authors.lastname: Tan
authors.affiliation: Material Science & Engineering School, University of Shanghai for Science and Technology , Shanghai 200093, China.
authors.forename: Junhe
authors.initials: J
authors.lastname: Yang
authors.affiliation: Shanghai Electrochemical Energy Devices Research Center, Department of Chemical Engineering, Shanghai Jiao Tong University , Shanghai 200240, China.|Sinopoly Battery Research Centre , Shanghai 200241, China.
authors.forename: Zi-Feng
authors.initials: ZF
authors.lastname: Ma
authors.affiliation: Material Science & Engineering School, University of Shanghai for Science and Technology , Shanghai 200093, China.
authors.forename: Shiyou
authors.identifier: http://orcid.org/0000-0002-6614-9567
authors.initials: S
authors.lastname: Zheng
keywords: Li-ion battery; Na-ion battery; flexible; free-standing anode; orderly structure; overoxidized; polypyrrole film; vapor phase polymerization