A novel bismuth–carbon composite, in which bismuth nanoparticles were anchored in a nitrogen-doped carbon matrix (Bi@NC), is proposed as anode for high volumetric energy density lithium ion batteries (LIBs). Bi@NC composite was synthesized via carbonization of Zn-containing zeolitic imidazolate (ZIF-8) and replacement of Zn with Bi, resulting in the N-doped carbon that was hierarchically porous and anchored with Bi nanoparticles. The matrix provides a highly electronic conductive network that facilitates the lithiation/delithiation of Bi. Additionally, it restrains aggregation of Bi nanoparticles and serves as a buffer layer to alleviate the mechanical strain of Bi nanoparticles upon Li insertion/extraction. With these contributions, Bi@NC exhibits excellent cycling stability and rate capacity compared to bare Bi nanoparticles or their simple composites with carbon. This study provides a new approach for fabricating high volumetric energy density LIBs.Electronic supplementary materialThe online version of this article (10.1007/s40820-018-0209-1) contains supplementary material, which is available to authorized users.

All‐solid‐state zinc–air batteries are characterized as low cost and have high energy density, providing wearable devices with an ideal power source. However, the sluggish oxygen reduction and evolution reactions in air cathodes are obstacles to its flexible and rechargeable application. Herein, a strategy called MOF‐on‐MOF (MOF, metal‐organic framework) is presented for the structural design of air cathodes, which creatively develops an efficient oxygen catalyst comprising hierarchical Co 3 O 4 nanoparticles anchored in nitrogen‐doped carbon nano‐micro arrays on flexible carbon cloth (Co 3 O 4 @N‐CNMAs/CC). This hierarchical and free‐standing structure design guarantees high catalyst loading on air cathodes with multiple electrocatalytic activity sites, undoubtedly boosting reaction kinetics, and energy density of an all‐solid‐state zinc–air battery. The integrated Co 3 O 4 @N‐CNMAs/CC cathode in an all‐solid‐state zinc–air battery exhibits a high open circuit potential of 1.461 V, a high capacity of 815 mAh g −1 Zn at 1 mA cm −2 , a high energy density of 1010 Wh kg −1 Zn, excellent cycling stability as well as outstanding mechanical flexibility, significantly outperforming the Pt/C‐based cathode. This work opens a new door for the practical applications of rechargeable zinc–air batteries in wearable electronic devices.

Impacts of submesoscale processes on transport are investigated numerically in an energetic mesoscale flow with an ocean model run at two horizontal resolutions, 1 and 5 km. The focus is the northwestern Gulf of Mexico, where the Loop Current eddies are surrounded by smaller vortices. By increasing the horizontal resolution, the number and strength of submesoscale eddies and vorticity filaments within the mixed layer increase dramatically and with them the vertical velocities. Inside the coherent eddies and at their peripheries, increased vertical velocities for increasing resolution are associated to near‐inertial motions and they are not limited to the mixed layer, but are found at all depths. Horizontal velocities, on the contrary, are similar. Lagrangian isobaric tracers are deployed close to the surface and at 100 m, and three‐dimensional, neutrally buoyant particles are released close to the surface, at the base of the mixed layer and at 100 m. The modeled horizontal dispersion curves for each deployment depth are independent of the kind of particles and of horizontal resolution. Close to the ocean surface, however, convergence zones, generated by submesoscale ageostrophic motions and resolved at 1 km resolution, influence the details of the tracer distributions. Vertical dispersion increases by several folds for increasing resolution at all depths explored, with the largest differences found close to the surface. Therefore, submesoscales processes play a fundamental role in driving vertical transport in eddy‐dominated flows, both within and below the mixed layer, for times comparable to the Eulerian time scale.

A silane molecule with an unsaturated functionality effectively scavenges harmful hydrogen fluoride from the electrolyte and forms a complex, which experiences preferential oxidation and eventually delivers the fluorine species to the interphase that protects cathodes of high energy density batteries.

Oceanic mesoscale eddies with typical sizes of 30–200 km contain more than half of the kinetic energy of the ocean. With an average lifespan of several months, they are major contributors to the transport of heat, nutrients, plankton, dissolved oxygen and carbon in the ocean. Mesoscale eddies have been observed and studied over the past 50 years, nonetheless our understanding of the details of their structure remains incomplete due to lack of systematic high-resolution measurements. To bridge this gap, a survey of a mesoscale anticyclone was conducted in early 2014 in the South China Sea capturing its structure at submesoscale resolution. By modeling an anticyclone of comparable size and position at three horizontal resolutions the authors verify the resolution requirements for capturing the observed variability in dynamical quantities, and quantify the role of ageostrophic motions on the vertical transport associated with the anticyclone. Results indicate that different submesoscale processes contribute to the vertical transport depending on depth and distance from the eddy center, with frontogenesis playing a key role. Vertical transport by anticyclones cannot be reliably estimated by coarse-resolution or even mesoscale-resolving models, with important implications for global estimates of the eddy-driven vertical pumping of biophysical and chemical tracers.