Mo-doped δ-MnO2 anode material synthesis and electrochemical performance for lithium-ion batteries

• Published in: Journal of applied electrochemistry 2020-07, Vol.50 (7), p.733-744
• Main Authors: Xia, Ao, Zhao, Chenpeng, Yu, Wanru, Han, Yuepeng, Yi, Jue, Tan, Guoqiang
• Format: Article
• Language: English
• Subjects: Anodes; Batteries; Charge transfer; Chemistry; Chemistry and Materials Science; Crystal lattices; Diffusion coefficient; Doping; Electrochemical analysis; Electrochemistry; Electrode materials; Electron microscopy; Electrons; Hydrothermal crystal growth; Industrial Chemistry/Chemical Engineering; Ion diffusion; Lithium-ion batteries; Manganese dioxide; Microscopy; Morphology; Photoelectrons; Physical Chemistry; Raman spectroscopy; Rechargeable batteries; Research Article; Spectrum analysis; X ray photoelectron spectroscopy; X-ray fluorescence
• ISSN: 0021-891X; 1572-8838
• DOI: 10.1007/s10800-020-01431-2

The present study synthesized Mo-doped δ-MnO 2 powders with different doping ratios by implementing hydrothermal method. Various analyses, namely X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), the Brunauer–Emmett–Teller (BET) method, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray fluorescence spectrometer (XRF), and electrochemical measurements, were applied to characterize the dependence of the δ-MnO 2 structure, morphology and electrochemical performance on Mo-doping. The experimental results indicated Mo 6+ ions entered into the δ-MnO 2 crystal lattice and occupied the Mn sites. Appropriate amount of Mo 6+ ions doping decreases the charge transfer resistance and increases the Li + ion diffusion coefficient, thus producing optimal electrochemical performance. The Mo 5% sample with Mo 6+ /Mn 2+ molar ratio of 5:100 in the original solution presented a specific charge capacity of 476.8 mAh g −1 after 100 cycles at 1000 mA g −1 as well as capacity retention ratio of 112.7%. Graphic abstract