Preparation and characterization of SrLi2Ti6O14@C/Ag as lithium storage anode material for rechargeable batteries

Abstract

In this work, silver and carbon co-coated SrLi2Ti6O14 is synthesized by using a solid-state assisted solution method, with glucose as carbon source and silver nitrate as Ag source. The structural and morphological properties of as-prepared samples are characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), which confirm that C/Ag composite layer is uniformly coated on the surface of SrLi2Ti6O14. Electrochemical measurements like galvanostatic charge/discharge tests, rate performance, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) analysis are also undertaken to evaluate and compare the lithium storage capability of SrLi2Ti6O14 before and after coating. According to the results, SrLi2Ti6O14@C/Ag presents enhanced electrochemical capability compared with bare material. It can be found that bare SrLi2Ti6O14 only delivers the reversible capacity of 140.32mAhg−1 with capacity retention of 90.7% at 100mAg−1 after 200 cycles. In contrast, SrLi2Ti6O14@C/Ag presents the reversible capacity of 151.20mAhg−1 with only 6.7% capacity loss after 200 cycles. The improvement is owing to the increase of electronic conductivity and the decrease in the redox polarization after coating. In order to further investigate the structural stability of SrLi2Ti6O14@C/Ag, in-situ XRD was performed as well. All the results prove that the C/Ag co-coating has positive effect on the electrochemical performance of SrLi2Ti6O14.