Self-Assembly Growth of 3D WO3 Framework with Interpenetrated Nanosheets as Binder-Free Anode for Lithium Ion Batteries

A novel three-dimensional (3D) tungsten trioxide (WO3) framework is self-assembly grown from tungsten (W) foil by an anodization process. The as-prepared framework is constructed by interpenetrated WO3 nanosheets with the thickness of 30 nm, which exhibits a larger specific area and can be directly used as binder-free anode for lithium ion battery. This unique structure could benefit to relieve the stress caused by the volume change during the electrochemical reaction. Besides, the direct contact between the WO3 nanosheets and the metallic substrate could also contribute to the better adhesion and higher electronic conductivity. Furthermore, electronic conductive silver (Ag) nanoparticles (NPs) are anchored uniformly on the WO3 nanosheets, which greatly enhance the electronic conductivity of 3D WO3 framework and the stability of 'solid-electrolyte interphase' (SEI) film. With the optimal decorated amount of Ag NPs, the electrode not only delivers the highest capacity of 681 mAh g(-1) after 150 cycles, but also manifests an excellent reversible capacity as high as 370 mAh g(-1) at a high rate of 1 mA cm(-2). (C) 2017 The Electrochemical Society. All rights reserved.