Creating new architectures with a combined superiority of diverse materials achieving for more fantastic performances are attracting great attention recently. Herein, we introduce a novel dual metal (oxide) microsphere reinforced by vertically aligned carbon nanotubes (CNTs) and covered with a titanium oxide metal ion transfer diffusion layer. The CNTs penetrate the oxide particles and buffer structural volume change, while enhancing electrical conductivity. Meanwhile, the external TiO2-C shell serves as a transport pathway for mobile metal ions (e.g., Li+) and acts as a protective layer for the inner oxides by reducing the electrolyte/metal oxide interfacial area and minimizing side reactions. The proposed design is shown to significantly improve the stability and Coulombic efficiency (CE) of metal (oxide) anodes. For example, the as-prepared MnO-CNTs@TiO2-C microsphere demonstrates an extremely high capacity of 967 mAh g-1 after 200 cycles, where a CE as high as 99% is maintained. Even at a harsh rate of 5 A g-1 (ca. 5C), a capacity of 389 mAh g-1 can be maintained for thousands of cycles. The proposed oxide anode design was combined with nickel-rich cathode to make a full-cell battery that works at high voltage and exhibits impressive stability and life span.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: This work is supported by the National Natural Science Foundation of China 21978281, 21703285, 21975250) and the National Key R&D Program of China SQ2017YFE9128100). The authors also thank the Independent Research Project of the State Key Laboratory of Rare Earth Resources Utilization (110005R086), Changchun Institute of Applied Chemistry, and the Chinese Academy of Sciences. The research was partially supported by King Abdullah University of Science and Technology (KAUST).