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Highlights The open hollow structure enhances the accessibility of atomically dispersed Ru sites and improves the diffusion efficiency of catalytic molecules The abundant atomically dispersed Ru sites on the surface of catalyst provide a large number of oxygen adsorption and Li2O2 nucleation sites The lithium–oxygen battery assembled with h-RuNC could catalyze the production of Li2O2 with better dispersion and improve the cycling stability.

Lithium sulfide (Li2S) is an attractive cathode material with a high theoretical specific capacity (1166 mAh g-1). However, the poor cycle life and rate capability have remained significant challenges, preventing its practical application. Here, Li2S spheres with size control have been synthesized for the first time, and a CVD method for converting them into stable carbon-coated Li2S core-shell (Li2S@C) particles has been successfully employed. These Li2S@C particles with protective and conductive carbon shells show promising specific capacities and cycling performance with a high initial discharge capacity of 972 mAh g-1 Li2S (1394 mAh g-1 S) at the 0.2C rate. Even with no added carbon, a very high Li2S content (88 wt % Li2S) electrode composed of 98 wt % 1 μm Li2S@C spheres and 2 wt % binder shows rather stable cycling performance, and little morphology change after 400 cycles at the 0.5C rate. [ABSTRACT FROM AUTHOR]

Shape control of nanocrystals has become an indispensable part in material research, such as developing new battery raw materials and synthesizing high activity catalysts. In this work, one-dimensional LiV3O8 nanorods have been fabricated by high temperature solid-state reaction using V2O5 nanowires as precursors obtained via a hydrothermal method. The as-prepared LiV3O8 nanorods were characterized by x-ray diffraction, transmission electron microscopy, scanning electron microscopy, and galvanostatic tests, compared with LiV3O8 samples synthesized by the traditional one-step solid-state method. The results show that LiV3O8 nanorods exhibited better electrochemical performance than those synthesized by the traditional method, indicating that a different shape will lead to huge distinctions in electrochemical properties. This work demonstrates that Li-insertion/deintercalation dynamics might be crystal morphology-sensitive. [ABSTRACT FROM AUTHOR]

We report a facile process for the controllable synthesis of the Mn3O4nanocrystals with different sizes and shapes, which includes dots, rods, and wires in the presence of the surfactants dodecanol and oleylamine. It is notable that the uniform-sized nanocrystals were achieved under mild experimental conditions and the common inorganic salt, such as manganese(II) nitrate, was adopted as the precursor. Furthermore, the as-prepared monodisperse nanocrystals, as ideal building blocks, can be rationally assembled into three-dimensional (3D) Mn3O4colloidal spheres, using a facile ultrasonication strategy. In particular, the 3D colloidal spheres can be successfully converted to LiMn2O4nanocrystals, which show distinct electrochemical performance, mainly depending on their crystallinity and size. [ABSTRACT FROM AUTHOR]

Large over-potentials during battery operation remain a big obstacle for aprotic Li–O2 batteries. Herein, a nanocomposite of about 4 nm cobalt monoxide nanocrystals grown in situ on reduced graphene oxide substrates (CoO/RGO) has been synthesized via a thermal decomposition method. The CoO/RGO cathode delivers a high initial capacity of 14 450 mAh g−1 at a current density of 200 mA g−1. Simultaneously it displays little capacity fading after 32 cycles with a capacity restriction of 1000 mAh g−1. Additionally, compared with Ketjenblack and general CoO nanoparticles, ultrathin CoO nanoparticle-decorated RGO electrode materials with a delaminated structure display an observable reduction of over-potential in Li–O2 batteries. These results demonstrate that the introduction of RGO improves the performance of CoO, which is a promising strategy for optimizing the design of electrocatalysts for aprotic rechargeable Li–O2 batteries. [ABSTRACT FROM AUTHOR]