Freestanding Three-Dimensional CuO/NiO Core-Shell Nanowire Arrays as High-Performance Lithium-Ion Battery Anode

The Realization of ZnO Nanowires Interconnection through Femtosecond Laser Irradiation of Ag Nanoparticles Solder

Nanowire interconnection is the basis for the construction and integration of micro-nano functional devices. But so far, it is still difficult to achieve a reliable interconnection of metal oxide nanowires. This letter proposes an approach for soldering ZnO nanowires through femtosecond laser irradiation of Ag nanoparticles solder. In this paper, the effect of femtosecond laser fluence and irradiation time on the morphology of Ag solders and the interconnection state of ZnO nanowires are studied, respectively. The I-V electrical characterization of nanowire interconnection before and after soldering is completed. The results demonstrate that ZnO nanowires achieve better interconnection. The UV light response of the ZnO-Ag-ZnO interconnection structure after soldering is investigated. The approach confirms the effectiveness of a femtosecond irradiated metal nanoparticles solder to achieve metal oxide interconnection, offering the prospect of more metal oxide nanowires interconnection and device development.

Hierarchical Stratiform of a Fluorine-Doped NiO Prism as an Enhanced Anode for Lithium-Ion Storage

Doping is regarded as a prominent strategy to optimize the crystal structure and composition of battery materials to withstand the anisotropic expansion induced by the repeated insertion and extraction of guest ions. The well-known knowledge and experience obtained from doping engineering predominate in cathode materials but have not been fully explored for anodes yet. Here, we propose the practical doping of fluorine ions into the host lattice of nickel oxide to unveil the correlation between the crystal structure and electrochemical properties. Multiple ion transmission pathways are created by the orderly two-dimensional nanosheets, and thus the stress/strain can be significantly relieved with trace fluorine doping, ensuring the mechanical integrity of the active particle and superior electrochemical properties. Density functional theory calculations manifest that the F doping in NiO could improve crystal structural stability, modulate the charge distribution, and enhance the conductivity, which promotes the performance of lithium-ion storage.

In Situ Precipitation-Induced Growth of Leaf-like CuO Nanostructures on Cu-Ni Alloys for Binder-Free Anodes in Li-Ion Batteries

CuC₂ O₄ ⋅x H₂ O was facilely prepared on a Cu-Ni alloy substrate by in situ precipitation-induced growth by using a mixture of sodium persulfate, hydrogen peroxide, and oxalic acid. Thermal annealing allowed the conversion of CuC₂ O₄ ⋅x H₂ O to leaf-like CuO nanostructures with a thickness of a few tens of micrometers of sub-sized nanoparticles, which were applied for fabricating binder-free anodes for lithium-ion batteries. Ni was a nucleation site for CuC₂ O₄ ⋅x H₂ O, which was uniformly formed on the entire substrate. The concentration of each component in the mixture solution caused significant morphological changes because of the different elution of copper ions. CuO nanostructures annealed at 550 °C showed large areal and gravimetric capacity with excellent capacity retention of 95.5 % after 200 cycles at a high current density because of their appropriate structural morphology, which not only allowed the formation of a stable solid electrolyte interphase layer but also enabled a reversible reaction during the charge/discharge process.