Breaking the Intrinsic Strength-Ductility Tradeoff in Graphene-Metal Composites.

Small carbon materials, such as graphene, offer excellent mechanical strength. Micro/nano carbon materials are often dispersed into a metal matrix to form bulk composites with mechanical enhancement. Despite technical progress, such composites intrinsically suffer from a trade-off condition between strength and ductility because the load transfer path forms between mechanically strong yet chemically inert micro/nano carbon materials or between the carbon-metal interfaces.

Ultrastable Silicon Anode by Three-Dimensional Nanoarchitecture Design.

State-of-the-art carbonaceous anodes are approaching their achievable performance limit in Li-ion batteries (LIBs). Silicon has been recognized as one of the most promising anodes for next-generation LIBs because of its advantageous specific capacity and secure working potential. However, the practical implementation of silicon anodes needs to overcome the challenges of substantial volume changes, intrinsic low conductivity, and unstable solid electrolyte interphase (SEI) films.

Inlaid ReS Quantum Dots in Monolayer MoS.

Two-dimensional (2D) transition-metal dichalcogenides (TMDs) are prospective materials for quantum devices owing to their inherent 2D confinements. They also provide a platform to realize even lower-dimensional in-plane electron confinement, for example, 0D quantum dots, for exotic physical properties. However, fabrication of such laterally confined monolayer (1L) nanostructure in 1L crystals remains challenging.

Extraordinary tensile strength and ductility of scalable nanoporous graphene.

While the compressive strength-density scaling relationship of ultralight cellular graphene materials has been extensively investigated, high tensile strength and ductility have not been realized in the theoretically strongest carbon materials because of high flaw sensitivity under tension and weak van der Waals interplanar bonding between graphene sheets. In this study, we report that large-scale ultralight nanoporous graphene with three-dimensional bicontinuous nanoarchitecture shows orders of magnitude higher strength and elastic modulus than all reported ultralight carbon materials under both compression and tension. The high-strength nanoporous graphene also exhibits excellent tensile ductility and work hardening, which are comparable to well-designed metamaterials but until now had not been realized in ultralight cellular materials.

Lithium intercalation into bilayer graphene.

The real capacity of graphene and the lithium-storage process in graphite are two currently perplexing problems in the field of lithium ion batteries. Here we demonstrate a three-dimensional bilayer graphene foam with few defects and a predominant Bernal stacking configuration, and systematically investigate its lithium-storage capacity, process, kinetics, and resistances. We clarify that lithium atoms can be stored only in the graphene interlayer and propose the first ever planar lithium-intercalation model for graphenic carbons.

Lithiophilic 3D Nanoporous Nitrogen-Doped Graphene for Dendrite-Free and Ultrahigh-Rate Lithium-Metal Anodes.

The key bottlenecks hindering the practical implementations of lithium-metal anodes in high-energy-density rechargeable batteries are the uncontrolled dendrite growth and infinite volume changes during charging and discharging, which lead to short lifespan and catastrophic safety hazards. In principle, these problems can be mitigated or even solved by loading lithium into a high-surface-area, conductive, and lithiophilic porous scaffold. However, a suitable material that can synchronously host a large loading amount of lithium and endure a large current density has not been achieved.

One-Dimensional Atomic Segregation at Semiconductor-Metal Interfaces of Polymorphic Transition Metal Dichalcogenide Monolayers.

Interface segregation is a powerful approach to tailor properties of bulk materials by interface engineering. Nevertheless, little is known about the chemical inhomogeneity at interfaces of polymorphic two-dimensional transition metal dichalcogenides (TMDs) and its influence on the properties of the 2D materials. Here we report one-dimensional monatomic segregation at coherent semiconductor-metal 1H/1T interfaces of Mo-doped WS monolayers.

Low-Temperature Carbide-Mediated Growth of Bicontinuous Nitrogen-Doped Mesoporous Graphene as an Efficient Oxygen Reduction Electrocatalyst.

Nitrogen-doped graphene exhibits high electrocatalytic activity toward the oxygen reduction reaction (ORR), which is essential for many renewable energy technologies. To maximize the catalytic efficiency, it is desirable to have both a high concentration of robust nitrogen dopants and a large accessible surface of the graphene electrodes for rapid access of oxygen to the active sites. Here, 3D bicontinuous nitrogen-doped mesoporous graphene synthesized by a low-temperature carbide-mediated graphene-growth method is reported.

Nanoporous Metal Papers for Scalable Hierarchical Electrode.

are developed using Japanese washi paper as a template to create hierarchical porous electrodes. This method is used to create a trimodal -nanoporous Au electrode, as a well as a hierarchical NiMn electrode that achieves high electrochemical capacitance and a rapid rate of oxygen evolution.