Aqueous Li-ion cells with superior cycling performance using multi-channeled polyaniline/Fe2O3 nanotube anodes

Abstract

We developed a Fe₂O₃-decorated polyaniline (PANI/Fe₂O₃) multi-channeled nanotube structure as aqueous rechargeable lithium-ion battery (ARLIB) anode using polymerized aniline–Mo₃O₁₀ (ANI–Mo₃O₁₀) nanowires as the template. The removal of MoO_x from the intercalated layered MoO_x/PANI structures results in a multi-channeled nanotube structure, and the subsequent hydrothermal growth of Fe₂O₃ nanoparticles on PANI surface can simultaneously re-dope PANI into a highly conductive form. The multi-channeled nanotube structure allows for sufficient electrolyte impregnation and efficient one-dimensional electron transport, and the decorated Fe₂O₃ surface layer offers a much extended voltage window of the electrode and improves chemical and electrochemical stability. As a proof-of-concept, the initial discharge and charge capacities of the PANI/Fe₂O₃ multi-channeled nanotube anode are 60.5 and 54.2 mA h g⁻¹ at a current rate of 150 mA g⁻¹, respectively. When fabricated as an ARLIB full cell with the PANI/Fe₂O₃ multi-channeled nanotube anode and a LiMn₂O₄ cathode, an initial discharge capacity of 50.5 mA h g⁻¹ is obtained at the current rate of 150 mA g⁻¹, with superior capacity retention of 73.3% after over 1000 charge/discharge cycles.