Effect of Mg+2 and Bi+3 co-doping on structural and electrochemical properties of lithium titanium oxide for use as anode material in lithium-ion battery

• Published in: Journal of electroanalytical chemistry (Lausanne, Switzerland) Switzerland), 2020-11, Vol.876, p.114515, Article 114515
• Main Authors: Firdous, Naila, Arshad, Nasima, Muzaffar, Nazan, Norby, Poul
• Format: Article
• Language: English
• Subjects: Anode effect; Ball milling; Bismuth; Charge transfer; Commercialization; Coulombic efficiency; Cyclic stability; Diffusion coefficient; Diffusion rate; Doping; Electrochemical analysis; Electrode materials; Enhanced electronic conductivity; Excellent specific capacity; Lattice parameters; Li+ ion battery anode; Li4-x/2 MgxTi5-x/2BixO12; Lithium; Lithium-ion batteries; Magnesium; Phase composition; Rechargeable batteries; Structural analysis; Titanium oxides
• ISSN: 1572-6657; 1873-2569
• DOI: 10.1016/j.jelechem.2020.114515

This study describes the effect of magnesium and bismuth co-doping on the structure and electrochemical properties of Li4Ti5O12 as potential negative electrode materials for lithium-ion batteries. The substituted spinel cubic Li4-x/2 MgxTi5-x/2BixO12 (X = 0, 0.05, 0.1) (LTO-MB) materials were prepared through facile ball milling assisted solid-state method. Structural analysis revealed that LTO-MB materials have space group Fd3m. Basic structure and phase composition of Li4Ti5O12 does not changed by Mg-Bi co-doping, lattice parameters are slightly increased. No remarkable change in the morphology was observed in the co-doped materials under the magnification of 2 μm. Significant improvement in the rate capability of LTO-MB materials can be observed upon Mg-Bi co-doping. Both co-doped compositions (LTO-MB-05, LTO-MB-1) have shown greater electrochemical performance as compared to pristine LTO-MB-0. The improvement in the electrochemical performance can be attributed to the mechanism by which co-doping increased conductivity and lithium diffusion coefficient. LTO-MB-05 exhibited specific capacity of ~200 mAhg−1 at 0.1C which is greater than LTO-MB-1(180 mAhg−1) and pristine LTO-MB-0 (165 mAhg−1) at same C-rate. Similarly, the higher value of Li+ diffusion constant (4.77 × 10−12 cm2 s−1) and lower charge transfer resistance (18.77 Ω) together with enhanced discharge capacity are proving LTO-MB-05 a good anode candidate for commercialization. [Display omitted] •Facile solid-state synthesis of Mg and Bi co-doped Li4-x/2 MgxTi5-x/2BixO12.•Higher electronic conductivity and Lithium-ion diffusion coefficient.•Higher current density and least polarization.•LTO-MB-05 exhibits high coulombic efficiency, good cyclic stability and rate performance.