- Previous Article
- Next Article
- Table of Contents
Journal of Applied Electrochemistry, Vol.47, No.8, 855-864, 2017
Carbon-wrapped four-component Na-Ni-Ti-Co oxides via sol-gel process for NIB anode material with superior cycling stability
An easy sol-gel method was devised to synthesize the carbon-wrapped Na0.67Ni0.17Ti0.67Co0.17O2 nanoparticles (NNTC/C), which served as anode material in the new type of sodium-ion batteries. Functioned as the sodium storage medium, the NNTC/C exhibited initial discharge/charge capacities of 122/110 mA h g(-1) at the rate of 0.2 C in the voltage range of 0.2-2.5 V with capacity retention of almost 82% of its initial capacity after 500 cycles. It is indicated that among the component metals, redox association only exists between the Ti4+/Ti3+ couple and the Na+ insertion and extraction during the charge/discharge process. In addition, ex situ X-ray diffraction analysis illustrated a small fluctuation of cell volume in the cycling, suggesting a high level of reversible structural changeability and stability of the NNTC/C. The characterization results demonstrate that the NNTC/C is an ideal candidate as anode material for high-performance sodium-ion batteries.
Keywords:Four-component oxide;Anode material;Sol-gel method;Cycle performance;Redox couple Ti4+/Ti3+