Anatase TiO2 Nanoparticles Supported By Cu/Ni Micro-Channeled Current Collector as a Novel Electrode for Lithium-Ion Batteries

Abstract

Transition metal oxides (TMOs), a typical materials family for electrodes of lithium-ion batteries (LIBs), have unstable capacity performance and lack of durability after combining with a flat current collector. Novel designs of both active materials and current collectors are necessary to eliminate those issues. In this work, a hierarchical micro-electrode for LIBs is successfully designed and fabricated. Anatase TiO2 nanoparticles (diameter ~100 nm) are synthesized as the active materials. A porous Cu/Ni current collector with vertically-aligned Ni micro-channels supports TiO2 active materials. Electrochemical characterizations illustrates that such electrode has enhanced capacity, stable rate performance, and durable lifespan. The maximum insertion coefficient for the Li ion intercalation reaction is as high as ~0.85, which is one of the greatest results for anatase LIB anodes. Furthermore, cross-sectional electron microscopic imaging along with X-ray energy dispersive spectroscopic elemental analysis confirmed the uniform spatial distribution of TiO2 nanoparticles inside the Ni micro-channels. This distribution is maintained after numbers of cycles. A synergistic effect between nano-TiO2 active material and porous Cu/Ni current collector is the main reason. The favorable properties of the Cu/Ni/TiO2 anode are improved electrochemical reactivity, reduced lithium ion diffusion pathways, great specific surface area, effective buffering of volume changes of TiO2 nanoparticles, and the optimal paths for chargers transport.