The extreme instability and strong chemical activity of carbyne, the infinite sp 1 hybridized carbon chain, are responsible for its low possibility to survive at ambient conditions. Therefore, much less has been possible to explore about carbyne as compared to other novel carbon allotropes like fullerenes, nanotubes and graphene. Although end-capping groups can be used to stabilize a carbon chain, length limitation is still a barrier for its actual production, and even more for applications. Here, we report on a novel route for bulk production of record long acethylenic linear carbon chains protected by thin double-walled carbon nanotubes. A corresponding extremely high Raman band is the first proof of a truly bulk yield formation of very long arrangements, which is unambiguously confirmed by transmission electron microscopy. Our production establishes a way to exceptionally long stable carbon chains, and an elegant forerunner towards the final goal of a bulk production of essentially infinite carbyne.Different kinds of allotropes can be formed from elemental carbon due to its sp n hybridization 1 . 1 arXiv:1507.04896v2 [cond-mat.mtrl-sci]

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Silicon-based materials are considered as strong candidates to next-generation lithium ion battery anodes because of their ultrahigh specific capacities. However, the pulverization and delamination of electrochemical active materials originated from the huge volume expansion (>300%) of silicon during the lithiation process results in rapid capacity fade, especially in high mass loading electrodes. Here we demonstrate that direct chemical vapor deposition (CVD) growth of vertical graphene nanosheets on commercial SiO microparticles can provide a stable conducting network via interconnected vertical graphene encapsulation during lithiation, thus remarkably improving the cycling stability in high mass loading SiO anodes. The vertical graphene encapsulated SiO (d-SiO@vG) anode exhibits a high capacity of 1600 mA h/g and a retention up to 93% after 100 cycles at a high areal mass loading of 1.5 mg/cm. Furthermore, 5 wt % d-SiO@vG as additives increased the energy density of traditional graphite/NCA 18650 cell by ∼15%. We believe that the results strongly imply the important role of CVD-grown vertical graphene encapsulation in promoting the commercial application of silicon-based anodes.