Insights into the Li+ storage mechanism of TiC@C-TiO2 core-shell nanostructures as high performance anodes. (August 2018)

• Record Type: Journal Article
• Authors: Cao, Songjie; Xue, Zhe; Yang, Chengwu; Qin, Jiaqian; Zhang, Long; Yu, Pengfei; Wang, Shanmin; Zhao, Yusheng; Zhang, Xinyu; Liu, Riping
• Is Part Of: Nano energy. Volume 50(2018)
• Page Start: 25
• Page End: 34
• Publication Date: 2018-08
• Subjects: Lithium-ion battery anode -- Core-shell nanostructure -- Titanium dioxide -- Titanium carbide -- First-principle calculation; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2018.05.022
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: Titanium carbide @ carbon-doped titanium dioxide (TiC@C-TiO2 ) core-shell nanostructures are designed, prepared and demonstrated for the application in lithium ion battery anode. Synthesis of these specific core-shell nanostructures is achieved via a facile, novel, and one-pot approach using oxidative growth of C-TiO2 onto TiC nanoparticles, which has a higher electrochemical activity than those of pure P25 and TiC nanoparticles. The core-shell nanostructured anodes exhibit a high lithium storage capacity (352.8 mAh g −1 at 100 mA g −1 ), good rate capability (253.6 mAh g −1 at 1 A g −1, 158.1 mAh g −1 at 10 A g −1 ), and outstanding cycle stability in lithium ion batteries (LIBs) (~ 150 mAh g −1 at 10 A g −1 after 400 cycles), which is about 48 times and 7 times higher than that of TiO2 electrode (~ 3.3 mAh g −1 at 10 A g −1 ) and TiC (~ 25 mAh g −1 at 10 A g −1 ). According to the first-principle calculation, the ultrahigh capacity and cycle stability of the as-prepared anode is ascribed to the enhancement of Li + absorption and diffusion ability through formation of C-TiO2 porous layer onto the conductive TiC particles. Moreover, the increase of electron density around the Fermi level is found to be mainly caused by the core-shell nanostructures. The results demonstrate that the presence of TiC plays an important role in providing high conductivity and the novel core-shell nanostructure can buffer the huge volume expansion and contraction during prolonged cycling, resulting in great potential applications in LIBs. Graphical abstract: fx1 Highlights: TiC@C-TiO2 core-shell nanostructures are prepared and demonstrated for anode materials. TiC@C-TiO2 is achieved using oxidative growth of C-TiO2 onto TiC nanoparticles. TiC@C-TiO2 exhibits a high capacity, good rate capability, and outstanding cycle stability. First-principle calculation was performed to understand the Li + storage mechanism.