Tuning Superhydrophobic Materials with Negative Surface Energy Domains.

Hydrophobic/superhydrophobic materials with intrinsic water repellence are highly desirable in engineering fields including anti-icing in aerocrafts, antidrag and anticorrosion in ships, and antifog and self-cleaning in optical lenses, screen, mirrors, and windows. However, superhydrophobic material should have small surface energy (SE) and a micro/nanosurface structure which can reduce solid-liquid contact significantly. The low SE is generally found in organic materials with inferior mechanical properties that is undesirable in engineering.

Enhancing the High-Voltage Cycling Performance of LiNi(0.5)Mn(0.3)Co(0.2)O2 by Retarding Its Interfacial Reaction with an Electrolyte by Atomic-Layer-Deposited Al2O3.

High-voltage (>4.3 V) operation of LiNi(x)Mn(y)Co(z)O2 (NMC; 0 ≤ x, y, z < 1) for high capacity has become a new challenge for next-generation lithium-ion batteries because of the rapid capacity degradation over cycling. In this work, we investigate the performance of LiNi(0.

Kinetics Tuning of Li-Ion Diffusion in Layered Li(NixMnyCoz)O2.

Using ab initio calculations combined with experiments, we clarified how the kinetics of Li-ion diffusion can be tuned in LiNixMnyCozO2 (NMC, x + y + z = 1) materials. It is found that Li-ions tend to choose oxygen dumbbell hopping (ODH) at the early stage of charging (delithiation), and tetrahedral site hopping (TSH) begins to dominate when more than 1/3 Li-ions are extracted. In both ODH and TSH, the Li-ions surrounded by nickel (especially with low valence state) are more likely to diffuse with low activation energy and form an advantageous path.

A core-shell nanohollow-γ-Fe2O3@graphene hybrid prepared through the Kirkendall process as a high performance anode material for lithium ion batteries.

We synthesized a core-shell structure with graphene as the shell and nano-hollow γ-Fe2O3 as the core through a Kirkendall process at room temperature. When this hybrid is used as an anode material for lithium-ion batteries, it exhibits a remarkable electrochemical performance: a high reversible capacity of 1095, 833, and 551 mA h g(-1) at the current rates of 0.1 C, 1 C, and 2 C, respectively.