Highly flexible TiO2-coated stainless steel fabric electrode prepared by liquid-phase deposition

Abstract

Abstract In order to construct flexible lithium-ion batteries, stainless steel (SUS) fabric is used as a current collector for the negative electrode of lithium-ion batteries. TiO 2 is coated onto the SUS fabric by liquid-phase deposition to construct an electrode consisting of an SUS wire core and a TiO 2 shell. A folding test is then conducted to assess the robustness of TiO 2 -coated SUS fabric, during which no detachment of TiO 2 particles from the SUS current collector is observed; the negative electrode shows a consistent electrochemical cycle performance even under severe physical duress. The TiO 2 -SUS fabric integration shows excellent flexibility without loss of electrochemical efficacy under mechanical stress, which occurs owing to three main factors. First, the mechanical stress imposed by folding is effectively dissipated by the 3-dimensional structure of the SUS fabric. Secondly, the TiO 2 electrode itself is free from mechanical stress owing to negligible volume change during electrochemical cycling. Thirdly, the high interfacial adhesion strength between TiO 2 and SUS fabric due to covalent bond formation during liquid-phase deposition prevents the loss of active material from the negative electrode during the folding tests.