Minghui Liang

Graphene-based electrode materials for rechargeable lithium batteries

Recent progress in the study of graphene has triggered a gold rush for exploiting its possible applications in various areas. Graphene-containing carbonaceous materials have long been selected as electrodes in rechargeable lithium batteries. However, the understanding of the relationship between material structure and electrode performance is still poor due to the complexity of the carbon structures, which hinders the development of high performance batteries. Now it is time to focus on the structure–property relationship of carbonaceous electrodes again, but from the viewpoint of graphene.

Adaptable Silicon-Carbon Nanocables Sandwiched between Reduced Graphene Oxide Sheets as Lithium Ion Battery Anodes

Silicon has been touted as one of the most promising anode materials for next generation lithium ion batteries. Yet, how to build energetic silicon-based electrode architectures by addressing the structural and interfacial stability issues facing silicon anodes still remains a big challenge. Here, we develop a novel kind of self-supporting binder-free silicon-based anodes via the encapsulation of silicon nanowires (SiNWs) with dual adaptable apparels (overlapped graphene (G) sheaths and reduced graphene oxide (RGO) overcoats). In the resulted architecture (namely, SiNW@G@RGO), the overlapped graphene sheets, as adaptable but sealed sheaths, prevent the direct exposure of encapsulated silicon to the electrolyte and enable the structural and interfacial stabilization of silicon nanowires. Meanwhile, the flexible and conductive RGO overcoats accommodate the volume change of embedded SiNW@G nanocables and thus maintain the structural and electrical integrity of the SiNW@G@RGO. As a result, the SiNW@G@RGO electrodes exhibit high reversible specific capacity of 1600 mAh g⁻¹ at 2.1 A g⁻¹, 80% capacity retention after 100 cycles, and superior rate capability (500 mAh g⁻¹ at 8.4 A g⁻¹) on the basis of the total electrode weight.

Graphene‐Confined Sn Nanosheets with Enhanced Lithium Storage Capability

Novel graphene-confined tin nanosheets (G/Sn/G) are constructed using an elaborately designed glucose-assisted chemical protocol. The as-synthesized G/Sn/G are featured with significantly enhanced lithium storage properties when compared with other graphene-based 0D/2D composite nanostructures, disclosing the merits of the 2D/2D composite featured with a surface-to-surface integration formula between graphene and the second 2D phase.

Reduced Graphene Oxide‐Mediated Growth of Uniform Tin‐Core/Carbon‐Sheath Coaxial Nanocables with Enhanced Lithium Ion Storage Properties

Tin-core/carbon-sheath coaxial nanocables directly integrated into a reduced graphene oxide (RGO) surface are constructed by a new strategy involving a RGO-mediated procedure. The as-synthesized nanocables, with uniform diameter and high aspect ratio, are versatile and exhibit excellent lithium storage properties, as revealed by electrochemical evaluation.

Rod-coating: towards large-area fabrication of uniform reduced graphene oxide films for flexible touch screens.

A novel strategy is developed for the large-scale fabrication of reduced graphene oxide films directly on flexible substrates in a controlled manner by the combination of a rod-coating technique and room-temperature reduction of graphene oxide. The as-prepared films display excellent uniformity, good transparency and conductivity, and great flexibility in a touch screen.

High Volumetric Capacity Silicon-Based Lithium Battery Anodes by Nanoscale System Engineering

The nanostructuring of silicon (Si) has recently received great attention, as it holds potential to deal with the dramatic volume change of Si and thus improve lithium storage performance. Unfortunately, such transformative materials design principle has generally been plagued by the relatively low tap density of Si and hence mediocre volumetric capacity (and also volumetric energy density) of the battery. Here, we propose and demonstrate an electrode consisting of a textured silicon@graphitic carbon nanowire array. Such a unique electrode structure is designed based on a nanoscale system engineering strategy. The resultant electrode prototype exhibits unprecedented lithium storage performance, especially in terms of volumetric capacity, without the expense of compromising other components of the battery. The fabrication method is simple and scalable, providing new avenues for the rational engineering of Si-based electrodes simultaneously at the individual materials unit scale and the materials ensemble scale.

Terephthalonitrile-derived nitrogen-rich networks for high performance supercapacitors

A novel high performance electrode material for supercapacitor applications, terephthalonitrile-derived nitrogen-rich network (TNN), is developed successfully via temperature-dependent cross-linking of terephthalonitrile monomers. This work opens up a new window for seeing a versatile modular toolbox derived from various aromatic nitrile monomers for developing better electrode materials in the future.

Chemical amination of graphene oxides and their extraordinary properties in the detection of lead ions

A strategy for the ultra-sensitive detection of Pb(2+) in aqueous media has been developed. The combination of oxidative exfoliation of graphite and subsequent chemical amination resulted in an amine functionalized graphene oxide, which showed ultra-high sensitivity in detecting Pb(2+), as it is an active material in modified anodic stripping voltammetry. A detection limit of as low as 10(-13) M (0.1 pM) has been reached, which is comparable to the result obtained from atomic absorption spectrometry, but is dramatically lower than that from other reported electrochemical analysis methods. This simple and economic approach opens up a new window for the portable, quick, and ultra-sensitive detection of lead ions.

Functionalization of Self-Assembled Hexa-peri-hexabenzocoronene Fibers with Peptides for Bioprobing

A novel water-soluble hexa-peri-hexabenzocoronene (HBC) derivative with peripheral functional groups, which facilitates a two-step assembly process in water that includes fiber formation via pi stacking and subsequent peptide probing via electrostatic interactions, is reported. In the first step, the HBC derivative self-assembles into water-soluble red-fluorescent fibers that serve as templates for further functionalization with biomolecules. In the second assembly step, the peripheral functional groups bind green-fluorescent fluorescein-conjugated peptides, leading to the formation of well-defined fibers that were visualized as dual-color fibers in double-fluorescence imaging.

High‐Efficiency and Room‐Temperature Reduction of Graphene Oxide: A Facile Green Approach Towards Flexible Graphene Films

A novel, green, and highly efficient strategy for room-temperature reduction of solid-state graphene oxide films has been successfully developed using hydrogen-involved reduction with the assistance of a small amount of Pd catalyst. Based on this approach, flexible reduced graphene oxide films with high conductivity can be achieved and a roll-to-roll technique is expected.