Advanced BaLi₂Ti₆O₁₄ Anode Fabricated via Lithium Site Substitution by Magnesium

Abstract

Advanced Na- and Mg-doped BaLi2Ti6O14 anodes in the form of BaLi1.9M0.1Ti6O14 (M = Na, Mg) are successfully fabricated and evaluated as lithium storage materials for rechargeable lithium-ion batteries. The effects of Na- and Mg-dopings on the crystal structure, surface morphology and electrochemical behavior are investigated for BaLi2Ti6O14. The results show that both Na and Mg elements are successfully introduced into the Li site, and they do not alter the basic structure of BaLi2Ti6O14. The resulting BaLi1.9M0.1Ti6O14 (M = Na, Mg) exhibit significant improvements on the electrochemical performance in terms of the rate capability and cycle performance. Especially for BaLi1.9Mg0.1Ti6O14, it can deliver an initial charge capacity of 111.7 mAh g–1 at 5C. After 200 cycles, it still can maintain a reversible capacity of 90.1 mAh g–1 with the capacity retention of 80.7%. The enhanced electrochemical properties can be attributed to the reduced particle size, decreased charge transfer resistance and enhanced ionic/electronic conductivity induced by Mg doping. Besides, in situ X-ray diffraction also reveals that BaLi1.9Mg0.1Ti6O14 has high structural stability and reversibility during charge/discharge process.

Hollow and hierarchical Na2Li2Ti6O14 microspheres with high electrochemical performance as anode material for lithium-ion battery

“…Spinel lithium titanium oxide (Li4Ti5O12) with a flat plateau at about 1.55 V (vs. Li/Li + ) is one of the most popular anode materials for Li-ion batteries [6], and it can be discharged down to 0 V (vs. Li/Li + ) without causing any structural degradations (zero-strain insertion material) [7]. Similarly, mixed alkali titanium oxides, MxLi2Ti6O14 (M = Ba, Sr, Na2), were also proposed recently [8][9][10]. By introducing alkali derivatives into titanium dioxides, the potential of the anode materials can be lowered [11].…”

H0.92K0.08TiNbO5 Nanowires Enabling High-Performance Lithium-Ion Uptake

“…According to the calculation results, the D Li for anodic peak is 1.97 × 10 –11 cm 2 s –1 and for the cathodic peak it is 1.15 × 10 –11 cm 2 s –1 . As shown in Figure d, the lithium-ion diffusion coefficient of H 0.92 K 0.08 TiNbO 5 nanowires is higher than some widely reported electrode materials, such as Li 4 Ti 5 O 12 , TiNb 6 O 17 , BaLi 2 Ti 6 O 14 , and LiV 3 O 8 . It suggests the better kinetics of H 0.92 K 0.08 TiNbO 5 nanowires.…”

LiCrTiO4 Nanowires as High-Performance Cathodes for Magnesium–Lithium Hybrid Batteries

“…To further investigate the ions storage mechanism, XPS tests were carried out to track the probable element valence changes of the pristine LCT-W and its lithiated/delithiated samples (Figure ). As shown in Figure a, the featured peaks of Cr 3+ are maintained at 576.2 and 586.3 eV during the whole discharge–charge process, which means that Cr 3+ does not participate in the redox reaction . In contrast, XPS spectra of Ti exhibit a continuous change during the Li + insertion and extraction, indicating that the capacity of LiCrTiO 4 is totally associated with the redox of Ti 3+ /Ti 4+ .…”

“…As shown in Figure 5a, the featured peaks of Cr 3+ are maintained at 576.2 and 586.3 eV during the whole discharge−charge process, which means that Cr 3+ does not participate in the redox reaction. 33 In contrast, XPS spectra of Ti exhibit a continuous change during the Li + insertion and extraction, indicating that the capacity of LiCrTiO 4 is totally associated with the redox of Ti 3+ /Ti 4+ . 34 As shown in Figure 5b, the Ti 2p spectrum of the fresh electrode shows two peaks at 458.6 and 464.4 eV, which are assigned to the doublet Ti 2p 3/2 and Ti 2p 1/2 of Ti 4+ in the pristine LiCrTiO 4 nanowires.…”