Wei Song1, Hanqing Zhao1, Jianqi Ye1, Mengmeng Kang1, Siyu Miao1, Zhong Li1. 1. Key Laboratory of Coal Science and Technology of Ministry of Education and Shanxi Province, Institute of Coal Chemical Engineering , Taiyuan University of Technology , Taiyuan 030024 , Shanxi , China.
Abstract
Ti-O-C channels for ultrafast sodium storage were constructed in N/S-co-doped TiO2-C nanofibers, which deliver a high rate performance of 181.9 mAh g-1 at 5 A g-1 after 3000 cycles. The existence of Ti-O-C bonds at the interface of TiO2-C phases was revealed by synchrotron radiation X-ray absorption spectra. Based on this, first-principles calculations further verified the low energy barrier for Na+ insertion/extraction in the Ti-O-C channels formed by the intimately integrated graphite layer with TiO2 near the surface. In addition, surface defects induced by heteroatoms accelerate the Na+ mass transfer through the pathway from the carbon surface to the Ti-O-C channel.
Ti-O-C channels for ultrafast n class="Chemical">sodium storage were constructed in N/S-co-doped TiO2-C nanofibers, which deliver a high rate performance of 181.9 mAh g-1 at 5 A g-1 after 3000 cycles. The existence of Ti-O-C bonds at the interface of TiO2-C phases was revealed by synchrotron radiation X-ray absorption spectra. Based on this, first-principles calculations further verified the low energy barrier for Na+ insertion/extraction in the Ti-O-C channels formed by the intimately integrated graphite layer with TiO2 near the surface. In addition, surface defects induced by heteroatoms accelerate the Na+ mass transfer through the pathway from the carbon surface to the Ti-O-C channel.