Jin Wang1, Guiyu Liu1, Kaili Fan1, Dan Zhao1, Beibei Liu1, Jianbo Jiang2, Dong Qian3, Chunming Yang4, Junhua Li5. 1. Hunan Provincial Key Laboratory of Chemical Power Resources, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, PR China. 2. College of Chemistry and Chemical Engineering, Jishou University, Jishou 416000, PR China. 3. Hunan Provincial Key Laboratory of Chemical Power Resources, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, PR China. Electronic address: qiandong6@vip.sina.com. 4. College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, PR China. 5. Key Laboratory of Functional Metal-Organic Compounds of Hunan Province, College of Chemistry and Material Science, Hengyang Normal University, Hengyang 421008, PR China. Electronic address: junhua325@126.com.
Abstract
N-doped carbon coated TiO2 nanoparticles (TiO2@NC) were synthesized through a simple two-step route, in which dopamine was simultaneously utilized as both nitrogen and carbon sources. With TiO2@NC applied in the Na-ion battery (SIB) anodes, the continuous and uniform N-doped carbon layer can not only enhance the electrical conductivity of TiO2 and facilitate the surface pseudocapacitive process, but also serve as a buffer layer to accommodate the volume expansion during the sodiation-desodiation processes. The as-prepared TiO2@NC exhibits excellent electrochemical performance when utilized as the SIB anodes, which delivers a remarkably high reversible capacity of 250.2 mAh g-1 at a rate of 0.25C (84 mA g-1) after 200 cycles and still retains 122.1 mAh g-1 at 10C (3.35 A g-1) even after 3000 cycles accompanied with a 95.3% retention of the maximum capacity, outperforming most of the reported TiO2/C-based composites as SIB anodes. To our best knowledge, the preparation of TiO2@NC with dopamine as both nitrogen and carbon sources and its application in the SIB anodes are reported for the first time.
N-doped carbon coated n class="Chemical">TiO2 nanoparticles (TiO2@NC) were synthesized through a simple two-step route, in which dopamine was simultaneously utilized as both nitrogen and carbon sources. With TiO2@NC applied in the Na-ion battery (SIB) anodes, the continuous and uniform N-doped carbon layer can not only enhance the electrical conductivity of TiO2 and facilitate the surface pseudocapacitive process, but also serve as a buffer layer to accommodate the volume expansion during the sodiation-desodiation processes. The as-prepared TiO2@NC exhibits excellent electrochemical performance when utilized as the SIB anodes, which delivers a remarkably high reversible capacity of 250.2 mAh g-1 at a rate of 0.25C (84 mA g-1) after 200 cycles and still retains 122.1 mAh g-1 at 10C (3.35 A g-1) even after 3000 cycles accompanied with a 95.3% retention of the maximum capacity, outperforming most of the reported TiO2/C-based composites as SIB anodes. To our best knowledge, the preparation of TiO2@NC with dopamine as both nitrogen and carbon sources and its application in the SIB anodes are reported for the first time.