Continuous fabrication of a MnS/Co nanofibrous air electrode for wide integration of rechargeable zinc-air batteries.

Exploring highly efficient bifunctional electrocatalysts toward the oxygen reduction and evolution reactions is essential for the realization of high-performance rechargeable zinc-air batteries. Herein, a novel nanofibrous bifunctional electrocatalyst film, consisting of metallic manganese sulfide and cobalt encapsulated by nitrogen-doped carbon nanofibers (CMS/NCNF), is prepared through a continuous electrospinning method followed by carbonization treatment. The CMS/NCNF bifunctional catalyst shows both comparable ORR and OER performances to those of commercial precious metal-based catalysts.

Defect Engineering of Chalcogen-Tailored Oxygen Electrocatalysts for Rechargeable Quasi-Solid-State Zinc-Air Batteries.

A critical bottleneck limiting the performance of rechargeable zinc-air batteries lies in the inefficient bifunctional electrocatalysts for the oxygen reduction and evolution reactions at the air electrodes. Hybridizing transition-metal oxides with functional graphene materials has shown great advantages due to their catalytic synergism. However, both the mediocre catalytic activity of metal oxides and the restricted 2D mass/charge transfer of graphene render these hybrid catalysts inefficient.

Hot-Chemistry Structural Phase Transformation in Single-Crystal Chalcogenides for Long-Life Lithium Ion Batteries.

Tuned chalcogenide single crystals rooted in sulfur-doped graphene were prepared by high-temperature solution chemistry. We present a facile route to synthesize a rod-on-sheet-like nanohybrid as an active anode material and demonstrate its superior performance in lithium ion batteries (LIBs). This nanohybrid contains a nanoassembly of one-dimensional (1D) single-crystalline, orthorhombic SnS onto two-dimensional (2D) sulfur-doped graphene.

In Situ Polymer Graphenization Ingrained with Nanoporosity in a Nitrogenous Electrocatalyst Boosting the Performance of Polymer-Electrolyte-Membrane Fuel Cells.

Rich, porous graphene frameworks decorated with uniformly dispersed active sites are prepared by using polyaniline as a graphene precursor and introducing phenanthroline as a pore-forming agent. The unprecedented fuel-cell performance of this electrocatalyst is linked to the graphene frameworks with vast distribution of pore sizes, which maximizes the active-sites accessibility, facilitates mass-transport properties, and improves the carbon corrosion resistance.

Carbon-Coated Silicon Nanowires on Carbon Fabric as Self-Supported Electrodes for Flexible Lithium-Ion Batteries.

A novel self-supported electrode with long cycling life and high mass loading was developed based on carbon-coated Si nanowires grown in situ on highly conductive and flexible carbon fabric substrates through a nickel-catalyzed one-pot atmospheric pressure chemical vapor deposition. The high-quality carbon coated Si nanowires resulted in high reversible specific capacity (∼3500 mA h g at 100 mA g), while the three-dimensional electrode's unique architecture leads to a significantly improved robustness and a high degree of electrode stability. An exceptionally long cyclability with a capacity retention of ∼66% over 500 cycles at 1.

Zinc-Air Batteries: Flexible Rechargeable Zinc-Air Batteries through Morphological Emulation of Human Hair Array (Adv. Mater. 30/2016).

On page 6421, Z. Chen and co-workers describe an electrically rechargeable, nanoarchitectured air electrode that morphologically emulates a human-hair array for solid-state zinc-air batteries. Grown directly on a stainless-steel mesh, the hair-like array can effectively catalyze molecular oxygen to water.

Flexible Rechargeable Zinc-Air Batteries through Morphological Emulation of Human Hair Array.

An electrically rechargeable, nanoarchitectured air electrode that morphologically emulates a human hair array is demonstrated in a zinc-air battery. The hair-like array of mesoporous cobalt oxide nanopetals in nitrogen-doped carbon nanotubes is grown directly on a stainless-steel mesh. This electrode produces both flexibility and improved battery performance, and thus fully manifests the advantages of flexible rechargeable zinc-air batteries in practical applications.

Co-N Decorated Hierarchically Porous Graphene Aerogel for Efficient Oxygen Reduction Reaction in Acid.

Nitrogen-functionalized graphene materials have been demonstrated as promising electrocatalyst for the oxygen reduction reaction (ORR), owning to their respectable activity and excellent stability in alkaline electrolyte. However, they exhibit unacceptable catalytic activity in acid medium. Here, a hierarchically porous Co-N functionalized graphene aerogel is prepared as an efficient catalyst for the ORR in acid electrolyte.

Sulfur Nanogranular Film-Coated Three-Dimensional Graphene Sponge-Based High Power Lithium Sulfur Battery.

To meet the requirements of both high energy and power density with cycle durability of modern EVs, we prepared a novel nanosulfur granular assembled film coated on the three-dimensional graphene sponge (3D-GS) composite as a high-performance active material for rechargeable lithium sulfur batteries. Instead of conventional graphene powder, three-dimensional rGO sponge (3D-rGO) is employed for the composite synthesis, resulting in a sulfur film directly in contact with the underlying graphene layer. This significantly improves the overall electrical conductivity, strategically addressing challenges of conventional composites of low sulfur utilization and dissolution of polysulfides.

Evidence of covalent synergy in silicon-sulfur-graphene yielding highly efficient and long-life lithium-ion batteries.

Silicon has the potential to revolutionize the energy storage capacities of lithium-ion batteries to meet the ever increasing power demands of next generation technologies. To avoid the operational stability problems of silicon-based anodes, we propose synergistic physicochemical alteration of electrode structures during their design. This capitalizes on covalent interaction of Si nanoparticles with sulfur-doped graphene and with cyclized polyacrylonitrile to provide a robust nanoarchitecture.

Flexible High-Energy Polymer-Electrolyte-Based Rechargeable Zinc-Air Batteries.

A thin-film, flexible, and rechargeable zinc-air battery having high energy density is reported particularly for emerging portable and wearable electronic applications. This freeform battery design is the first demonstrated by sandwiching a porous-gelled polymer electrolyte with a freestanding zinc film and a bifunctional catalytic electrode film. The flexibility of both the electrode films and polymer electrolyte membrane gives great freedom in tailoring the battery geometry and performance.

Multigrain platinum nanowires consisting of oriented nanoparticles anchored on sulfur-doped graphene as a highly active and durable oxygen reduction electrocatalyst.

Direct growth of multigrain platinum nanowires on sulfur-doped graphene (PtNW/SG) is reported. The growth mechanism, including Pt nanoparticle nucleation on SG, followed by nanoparticle attachment with orientation along the <111> direction is highlighted. PtNW/SG demonstrates improved Pt mass and specific activity compared with commercial catalysts toward oxygen reduction, in addition to dramatically improved stability through accelerated durability testing.

Subeutectic growth of single-crystal silicon nanowires grown on and wrapped with graphene nanosheets: high-performance anode material for lithium-ion battery.

A novel one-pot synthesis for the subeutectic growth of (111) oriented Si nanowires on an in situ formed nickel nanoparticle catalyst prepared from an inexpensive nickel nitrate precursor is developed. Additionally, anchoring the nickel nanoparticles to a simultaneously reduced graphene oxide support created synergy between the individual components of the c-SiNW-G composite, which greatly improved the reversible charge capacity and it is retention at high current density when applied as an anode for a Li-ion battery. The c-SiNW-G electrodes for Li-ion battery achieved excellent high-rate performance, producing a stable reversible capacity of 550 mAh g(-1) after 100 cycles at 6.

Engineered Si electrode nanoarchitecture: a scalable postfabrication treatment for the production of next-generation Li-ion batteries.

A novel, economical flash heat treatment of the fabricated silicon based electrodes is introduced to boost the performance and cycle capability of Li-ion batteries. The treatment reveals a high mass fraction of Si, improved interfacial contact, synergistic SiO2/C coating, and a conductive cellular network for improved conductivity, as well as flexibility for stress compensation. The enhanced electrodes achieve a first cycle efficiency of ∼84% and a maximum charge capacity of 3525 mA h g(-1), almost 84% of silicon's theoretical maximum.