Granular molybdenum dioxide precipitated on N-doped carbon nanorods with multistage architecture for ultralong-life sodium-ion batteries. (1st December 2019)

• Record Type: Journal Article
• Authors: Zeng, Fanyan; Yang, Leyan; Pan, Yang; Xu, Meng; Liu, Hongyan; Yu, Maohui; Guo, Manman; Yuan, Cailei
• Is Part Of: Electrochimica acta. Volume 325(2019)
• Publication Date: 2019-12-01
• Subjects: N-doped carbon nanorods -- Precipitates -- In-situ phase transformation -- Ultra-long cycling stability -- Sodium-ion batteries; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2019.134903
• Languages: English
• ISSNs: 0013-4686

Abstract

Abstract: Developing high-performance anode materials is a crucial research target of sodium-ion batteries (SIBs). Transition metal oxides (TMOs) have attracted great interest as potential anodes, but their applications are still hindered by slow reaction kinetics and large volume changes. Herein, Mo-aniline nanorods (Mo-ANRs) are prepared as precursors by a simple self-polymerized method in acid condition. After the in-situ phase transformation during annealing, multistage composites (N-CNRs@g-MoO2 ) are formed, with N-doped carbon nanorods (N-CNRs) converted from polymeric aniline ligands, on which granular molybdenum dioxide (g-MoO2 ) are uniformly precipitated and residual MoO2 nanodots are remained. As anode materials for SIBs, N-CNRs@g-MoO2 electrode is benefited from the shortened ion/electron diffusion length caused by steady g-MoO2 and residual nanodots, and the enhanced electrical conductivity and relieved volume changes introduced by N-CNRs and unique architecture. Thus, N-CNRs@g-MoO2 electrode delivers high discharge capacity (497.5 mAh g −1 at 0.05 A g −1 ), excellent rate performance and ultra-long cycling stability (165.6 mAh g −1 at 10.0 A g −1 after 12000 cycles), and 122% capacity retention is obtained at 1.0 A g −1 over 500 cycles even after the rate test. The significant enhancements in sodium-ion storage are mainly attributed to the multistage architecture and synergistic advantages among MoO2 nanodots, N-CNRs and g-MoO2 . These results indicate that the in-situ phase transformation route has great potential in constructing novel composites with unique architecture for high-performance SIBs. Graphical abstract: A Mo-aniline-derived N-CNRs@g-MoO2 composites with multistage architecture are constructed by in-situ phase transformation route. The composites exhibit excellent sodium-ion storage performance due to the synergistic effects among MoO2 nanodots, N-CNRs and g-MoO2 . Importantly, the ultra-long cyclic stability is acquired at high current rates (218.2 mAh g −1 at 5.0 A g −1 after 5000 cycles and 165.6 mAh g −1 at 10.0 A g −1 after 12000 cycles).Image 1 Highlights: Mo-ANRs are self-polymerized from MoO4 2+ anions and aniline under acid solution. Multistage architectures of N-CNRs@g-MoO2 is constructed by in-situ phase transformation route. g-MoO2 are precipitated on N-CNRs and residual MoO2 nanodots are embedded in N-CNRs. N-CNRs@g-MoO2 deliver extraordinary rate capability and ultra-long cyclic stability (12000 cycles).