Current AB_(5)-type hydrogen storage alloys employed in nickel-metal hydride(NiMH)batteries exhibit exceptional low-temperature discharge performance but suffer from limited cycle life and insufficient high-temperatur...Current AB_(5)-type hydrogen storage alloys employed in nickel-metal hydride(NiMH)batteries exhibit exceptional low-temperature discharge performance but suffer from limited cycle life and insufficient high-temperature stability.To overcome these challenges,we introduce a hydrothermal synthesized LaF_(3)coating layer on the surface of the AB_(5)anode material.This LaF_(3)coating layer adds a protective barrier for the active material,significantly improving the battery's cycle life and high-temperature stability.Our findings indicate that(1)the LaF_(3)coated anode demonstrates an extended cycle life with increased specific capacity and a capacity retention of 88%after 40 cycles of abusive overcharging and rapid discharging at room temperature.(2)The synthesized anode exhibits a 97%recovery of its specific capacity of 292.7 mAh/g following 144 h of high-temperature storage.(3)The low-temperature discharge capacity of the synthesized anode remains on par with the pristine AB_(5)alloy at 230.4 mAh/g in a-40℃environment.This research presents a significant advancement in hydrogen storage alloy coatings and offers valuable insights for designing electrodes in NiMH batteries.展开更多
Nano sized La0.4F3：Ce0.45,Tb0.15（core）, La0.4F3：Ce0.45,Tb0.15（Ti O2）（core） shell, La0.55F：Ce0.45, and La0.85F3：Tb0.15 particles were synthesized by adopting co-precipitation technique in acidic environment a...Nano sized La0.4F3：Ce0.45,Tb0.15（core）, La0.4F3：Ce0.45,Tb0.15（Ti O2）（core） shell, La0.55F：Ce0.45, and La0.85F3：Tb0.15 particles were synthesized by adopting co-precipitation technique in acidic environment and coated with Ti O2 to form a core-shell structure by adopting a mechanical dispersion method at room temperature. The synthesized materials were characterized using X-ray diffraction（XRD）, transmission electron microscopy（TEM）, Fourier transform infrared spectroscopy（FTIR）, ultraviolet-visible spectroscopy（UV-Vis） absorption, photoluminescence and lifetime spectroscopy. The crystal structure of La0.4F3：Ce0.45,Tb0.15 remained the same as La F3 after being doped with Ce and Tb ions but with a slight decrease in the lattice parameter. TEM image confirmed the formation of a core-shell structure. The La0.4F3：Ce0.45,Tb0.15/Ti O2 exhibited Tb3＋ fluorescence enhancement by a factor of 1.76. Scintillation from the synthesized materials was also observed under X-ray excitation.展开更多
基金supported by the National Science Foundation(No.ECCS-2025462)financially supported by Enterprise Support Scheme(ESS),which is one of the funding programs of Innovation and Technology Fund by Hong Kong government and aims to provide funding support for local companies to conduct in-house research and development(R&D)work with a view to encouraging the private sector to invest in R&D.
文摘Current AB_(5)-type hydrogen storage alloys employed in nickel-metal hydride(NiMH)batteries exhibit exceptional low-temperature discharge performance but suffer from limited cycle life and insufficient high-temperature stability.To overcome these challenges,we introduce a hydrothermal synthesized LaF_(3)coating layer on the surface of the AB_(5)anode material.This LaF_(3)coating layer adds a protective barrier for the active material,significantly improving the battery's cycle life and high-temperature stability.Our findings indicate that(1)the LaF_(3)coated anode demonstrates an extended cycle life with increased specific capacity and a capacity retention of 88%after 40 cycles of abusive overcharging and rapid discharging at room temperature.(2)The synthesized anode exhibits a 97%recovery of its specific capacity of 292.7 mAh/g following 144 h of high-temperature storage.(3)The low-temperature discharge capacity of the synthesized anode remains on par with the pristine AB_(5)alloy at 230.4 mAh/g in a-40℃environment.This research presents a significant advancement in hydrogen storage alloy coatings and offers valuable insights for designing electrodes in NiMH batteries.
文摘Nano sized La0.4F3：Ce0.45,Tb0.15（core）, La0.4F3：Ce0.45,Tb0.15（Ti O2）（core） shell, La0.55F：Ce0.45, and La0.85F3：Tb0.15 particles were synthesized by adopting co-precipitation technique in acidic environment and coated with Ti O2 to form a core-shell structure by adopting a mechanical dispersion method at room temperature. The synthesized materials were characterized using X-ray diffraction（XRD）, transmission electron microscopy（TEM）, Fourier transform infrared spectroscopy（FTIR）, ultraviolet-visible spectroscopy（UV-Vis） absorption, photoluminescence and lifetime spectroscopy. The crystal structure of La0.4F3：Ce0.45,Tb0.15 remained the same as La F3 after being doped with Ce and Tb ions but with a slight decrease in the lattice parameter. TEM image confirmed the formation of a core-shell structure. The La0.4F3：Ce0.45,Tb0.15/Ti O2 exhibited Tb3＋ fluorescence enhancement by a factor of 1.76. Scintillation from the synthesized materials was also observed under X-ray excitation.
