Mechanical and electro-mechanical properties of three-dimensional nanoporous graphene-poly(vinylidene fluoride) composites

PVDF-supported graphene foam as a robust current collector for lithium metal anodes

Lithium metal batteries have drawn much attention due to their ultrahigh energy density. However, the safety hazards and limited lifetime caused by severe lithium dendrite growth during cycling hinder their real application. To address this issue and improve the electrochemical performance of current lithium batteries, a current collector beyond the traditional copper foil for lithium anodes is highly needed. We proposed and prepared a PVDF-supported graphene foam (PSGF) structure as an effective current collector for lithium metal anodes. Because of its structural stability, large surface area, and lithiophilic surface chemistry, the corresponding lithium metal anode (PSGF@Li) shows an extended cycling life (∼1000 h), a decreased voltage hysteresis (∼80 mV) and an improved coulombic efficiency (∼99%). Furthermore, the practical application of the PSGF@Li anode in a full cell system was also demonstrated.

A robust lithium metal anode comprising of PSGF current collector showing long cycling life.

Electromechanical Behaviors of Graphene Reinforced Polymer Composites: A Review

Graphene (including its derivatives)-reinforced polymer composites (GRPCs) have been drawing tremendous attention from academic and industrial communities for developing smart materials and structures. Such interest stems from the excellent combination of the mechanical and electrical properties of these composites while keeping the beneficial intrinsic attributes of the polymers, including flexibility, easy processability, low cost and good biological and chemical compatibility. The electromechanical performances of these GRPCs are of great importance for the design and optimization of engineering structures and components. Extensive work has been devoted to this topic. This paper reviews the recent studies on the electromechanical behaviors of GRPCs. First the methods and techniques to manufacture graphene and GRPCs are introduced, in which the pros and cons of each method are discussed. Then the experimental examination and theoretical modeling on the electromechanical behaviors of the nanocomposites are presented and discussed.

Elastic recovery of polyamide 6 matrix nanocomposites and their basalt fiber co-reinforced hybrids

The improved elastic recovery and a wider range of linear elastic behavior of multiscale hybrid polyamide 6 composites are demonstrated in this study. For the composites, basalt fiber (BF) was used as microsized, and multiwalled carbon nanotubes and surface-treated montmorillonite (MMT) as nanosized reinforcement. The materials were melt compounded, and then specimens were injection molded. To prove increased elastic behavior, a relatively simple and fast cyclic measurement method was applied, where the load was increased in each cycle and 30 s of relaxation time was allowed after unloading. The results showed that both micro- and nanoparticles can broaden the range of the elastic behavior of the polyamide 6 significantly, which is reflected in increased elastic recovery and decreased plastic deformation compliance. Nano- and microsized reinforcing materials also produce a synergistic effect, which can be explained with the physical cross-linking of the nanoparticles.