TiO2 Nanotube Arrays Grafted with MnO2 Nanosheets as High-Performance Anode for Lithium Ion Battery

•It is the first time to design and fabricate 3D architecture of TiO2 nanotube arrays grafted with MnO2 nanosheets.•MnO2 nanosheet thickness has a major impact on capacity, cycle performance and conductivity.•A new possible mechanism is proposed to explain “late rise of capacity” phenomenon.•The composite combines the advantages both from MnO2 with high capacity and TNAs with excellent cycle stability.

Unique TiO2 nanotube arrays (TNAs) grafted with MnO2 nanosheets is synthesized for the first time as an anode for Li battery. The character of the special structure is MnO2 nanosheets grown on the outer, inner surface and tip of the TNAs. The composite combines the advantages both from MnO2 with high capacity (1230 mA h g−1) and TNAs with excellent cycle stability and superior electrical conductivity. Besides, the MnO2 nanosheet layer with different thickness on the surface of TNAs is fabricated through controlling hydrothermal reaction time and it is found that the thickness has a significant impact on capacity, cycle performance and conductivity. Additionally, a very abnormal phenomenon that we call “late rise of capacity” is discovered in the capacity test after several hundreds of cycle times, for which a possible mechanism is proposed according to material characterization.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide