Spinel LiMn2O4 Nanorods via Template–Engaged Method and as Cathode Materials for Li-Ion Batteries

Spinel LiMn2O4 nanorods were prepared by a hydrothermal method followed by solid-state lithiation. The produce β-MnO2 nanowire as template, and LiOH·H2O was used as lithium source. The spinel LiMn2O4 nanorods samples were characterized by SEM, XRD, (HR)TEM, and galvanostatic charge/discharge profile measurement. Compared with the LiMn2O4 nanoparticles, the LiMn2O4 nanorods showed superior cycling stability, better rate capability, good high temperature performance, and delivered a discharge capacity of 122 mAh/g (at 1 C, 100 cycles).

An efficient Lithium-metal Battery Based on Graphene Oxide-Modified Heat Resistant Gel Polymer Electrolyte with Superior Cycling Stability and Excellent Rate Capability

Lithium-metal battery has revived increasing attention and research on account of the growing demands for high-energy electrical energy storage, but the unsatisfied cycling stability and service safety have greatly limited...

Effect of additives on wettability, thermal stability and electrochemical properties of γ-Al2O3-coating separator for lithium-ion batteries

Physical properties of separator, as important parameters in affecting electrochemical performance and safety of lithium ion batteries, should be paid more attention. In this study, three kinds of surfactants and dispersants were adopted to investigate their effects on thermal stability, wettability and electrochemical properties of γ-Al2O3 coating polyethylene-based separator. The experimental results showed that with the synergistic helpfulness of PEG-2000 as surfactant and D-067 as dispersant, γ-Al2O3 coating polyethylene separator demonstrates superior thermal stability (no significant thermal shrinkage after heating at 120°C), electrolyte uptake ability and improved wettability (contact angle of 27.9°). Based on further testing results in Li//MCMB coin cells, the cell with γ-Al2O3 coating polyethylene separator exhibits higher capacity and superior cycling stability than other two bare counterparts separators at room temperature after 200 cycles. These results demonstrate that the as-prepared separator is highly promising for lithium ion battery application with the help of suitable surfactant and dispersant.

Morphology and Structure Induced Co3O4 Nanowires High-Performance Supercapacitor Electrode Material

The electrochemical performance of the material depends heavily on the morphologies and structural characteristics of the material. Co3O4 samples show the remarkable electrochemical performance owing to the high porosity, appropriate pore size distribution and novel architecture and the effect of NH4F for morphology. Co3O4 nanowires grown on Ni foam have been synthesized through a facile hydrothermal approach, revealing large capacitance of 2178.4 mF cm−2 at the current density of 2 mA cm−2 and superior cycling stability.

Realizing high-power and high-capacity zinc/sodium metal anodes through interfacial chemistry regulation

Stable plating/stripping of metal electrodes under high power and high capacity remains a great challenge. Tailoring the deposition behavior on the substrate could partly resolve dendrites’ formation, but it usually works only under low current densities and limited capacities. Here we turn to regulate the separator’s interfacial chemistry through tin coating with decent conductivity and excellent zincophilicity. The former homogenizes the electric field distribution for smooth zinc metal on the substrate, while the latter enables the concurrent zinc deposition on the separator with a face-to-face growth. Consequently, dendrite-free zinc morphologies and superior cycling stability are achieved at simultaneous high current densities and large cycling capacities (1000 h at 5 mA/cm2 for 5 mAh/cm2 and 500 h at 10 mA/cm2 for 10 mAh/cm2). Furthermore, the concept could be readily extended to sodium metal anodes, demonstrating the interfacial chemistry regulation of separator is a promising route to circumvent the metal anode challenges.

How 10 at% Al Addition in the Ti-V-Zr-Nb High-Entropy Alloy Changes Hydrogen Sorption Properties

Al0.10Ti0.30V0.25Zr0.10Nb0.25 was prepared to evaluate the effect of 10% aluminum into the previously reported quaternary alloy, Ti0.325V0.275Zr0.125Nb0.275. The as-cast quinary alloy formed a single-phase body centered cubic solid solution and transformed into a body centered tetragonal after hydrogenation. The alloy had a storage capacity of 1.6 H/M (2.6 wt.%) with fast absorption kinetics at room temperature, reaching full capacity within the first 10 min. The major improvements of Al addition (10%) were related to the desorption and cycling properties of the material. The temperature for hydrogen release was significantly decreased by around 100 °C, and the quinary alloy showed superior cycling stability and higher reversible storage capacity than its quaternary counterpart, 94% and 85% of their respective initial capacity, after 20 hydrogenation cycles without phase decomposition.