Surface Modification of Li_1.2Ni_0.13Mn_0.54Co_0.13O₂ by Hydrazine Vapor as Cathode Material for Lithium-Ion Batteries

An artificial interface is successfully prepared on the surface of the layered lithium-rich cathode material Li_1.2Ni_0.13Mn_0.54Co_0.12O₂ via treating it with hydrazine vapor, followed by an annealing process. The inductively coupled plasma-atomic emission spectrometry (ICP) results indicate that lithium ions are leached out from the surface of Li_1.2Ni_0.13Mn_0.54Co_0.12O₂ by the hydrazine vapor. A lithium-deficiency-driven transformation from layered to spinel at the particle surface happens in the annealing process, which is proved by the results of X-ray diffraction (XRD) and high-resolution transmission electron microscope (HRTEM). It is also found that the content of the spinel phase increases at higher annealing temperature, and an internal structural evolution from Li_1–<i>x</i>M₂O₄-type spinel to M₃O₄-type spinel takes place simultaneously. Compared to the pristine Li_1.2Ni_0.13Mn_0.54Co_0.12O₂, the surface-modified sample annealed at 300 °C delivers a larger initial discharge capacity of 295.6 mA h g^–1 with a Coulombic efficiency of 89.5% and a better rate performance (191.7 mA h g^–1 at 400 mA g^–1)

The Florida nurse : off. bulletin of the Florida Nurses' Association

Mg²⁺/Li⁺ hybrid batteries have recently been constructed combining a Mg anode, a Li⁺-intercalation electrode, and an electrolyte containing both Mg²⁺ and Li⁺. These batteries have been reported to outperform all the previously reported magnesium batteries in terms of specific capacity, cycling stability, and rate capability. Herein, we report the outstanding electrochemical performance of Mg²⁺/Li⁺ hybrid batteries consisting of a one-dimensional mesoporous TiO₂(B) cathode, a Mg anode, and an electrolyte consisting of 0.5 mol L^–1 Mg­(BH₄)₂ + 1.5 mol L^–1 LiBH₄ in tetraglyme. A highly synergetic interaction between Li⁺ and Mg²⁺ ions toward the pseudo-capacitive reaction is proposed. The hybrid batteries show superior rate performance with 130 mAh g^–1 at 1 C and 115 mAh g^–1 at 2 C, together with excellent cyclability up to 6000 cycles