Search

The coupling of material systems at different length scales enables new ways to take advantage of the unique properties of nano-/macroscale materials. Here, the self-organization of assembled metallacages generated ultralong nanowires, followed by the formation of nanowire-based soft films with diameters up to 6.5 cm. In contrast to previous reports that mainly focused on the preparation of metallacage assemblies with dimensions on the nano-/micrometer scale, the preparation of centimeter assemblies can serve as the bridge between nanostructures and the macroscopic world.

Hierarchical structures, with a high mass-loading of nanostructured lithium (Li) storage medium grafted upon large trunkframework, represent a novel approach towards high capacity and stable Li-ion batteries. We here report a new hierarchical structure of crystalline Si nanowires (c-Si NWs) grafted upon ultra-long tin dioxide (SnO2) NW trunks, where the latter frame up a large, conductive and stable architecture (i) to achieve a high mass-loading of c-Si NWs for Li-ion storage and (ii) to guarantee a good electric contact and fast charging process. The Si NWs branches are produced via a low-temperature vapor-liquid-solid (VLS) growth catalyzed by Sn droplets produced during a simple H2plasma treatment upon the SnO2trunks. Compared to other Si or SnO2NW-based anodes structures, the c-Si/SnO2NWs hierarchical structure demonstrates an outstanding performance with a high mass-load (~1.5mg/cm2) and a high areal capacity (~1.8mAh/cm2) after 100 cycles, without the use of any additional conductive polymer binder, highlighting the unique synergistic benefit of this hierarchical structure in boosting simultaneously the capacity and stability of Si-loaded Li-ion batteries.

Graphene nanosheets (GNS) anchored on Mn3O4 nanoparticles have been successfully synthesized through in situ thermal decomposition of Mn (NO3)2 without the use of any templates or surfactants. Mn3O4 particles were coordinately distributed on the GNS surface. This was achieved by forming 3D nanostructures to avoid detrimental graphene layer stacking, and was characterized using a scanning electron microscope. The Mn3O4/GNS nanocomposite delivers an initial capacity of 1450 mAh g-1 at a current density of 100 mA g-1. It also maintains a high reversible capacity of 930 mAh g-1 even after 60 charge-discharge cycles without showing any apparent decay.

Although possessing extremely high energy density, lithium-oxygen (Li-O2) battery suffered from large charge overpotential, low round-trip efficiency and poor cycling life, which limited the practical application of this smart system. Ru particles functionalized graphene aerogels (Ru-GAs) were designed and directly used as a free-standing cathode for Li-O2battery. The Ru-GAs showed hierarchical pores, which had the pore volumes of 2.8 and 14.1 cm3 g−1below and above critical pore diameter of 100 nm. The Ru-GA cathode in Li-O2battery delivered a high capacity of more than 12 000 mAh g−1and excellent cycling retention, which was mainly attributed to the three-dimensional porosity, abundant active sites with Ru particles and chemical stability arising from the character of binder-free cathode. Based on the results of in situ gas chromatography–mass spectrometry analysis, the reaction mechanism during charge process in aprotic electrolyte was proposed by the theory of three oxidation stages.