Graphene/polymer composites for energy applications

Abstract

Graphene has wide potential applications in energyrelated systems, mainly because of its unique atom-thick twodimensional structure, high electrical or thermal conductivity, optical transparency, great mechanical strength, inherent flexibility, and huge specific surface area. For this purpose, graphene materials are frequently blended with polymers to form composites, especially when fabricating flexible devices. Graphene/polymer composites have been explored as electrodes of supercapacitors or lithium ion batteries, counter electrodes of dye-sensitized solar cells, transparent conducting electrodes and active layers of organic solar cells, catalytic electrodes, and polymer electrolyte membranes of fuel cells. In this review, we summarize the recent advances on the synthesis and applications of graphene/polymer composites for energy applications. The challenges and prospects in this field have also been discussed. V C 2012 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013, 51, 231-253 KEYWORDS: composites; energy; fuel cell; graphene; lithium ion battery; redox polymers; solar cell; supercapacitor; synthesis INTRODUCTION Energy is one of the most important recent topics of concern to human society. To replace conventional fossil fuels, clean and renewable energies based on sunlight, wind, new chemicals, and biofuels are urgently demanded. Therefore, materials that can directly convert or store renewable energies are being extensively studied. Among them, graphene has recently attracted a great deal of attention because of its unique atom-thick two-dimensional (2D) structure 1,2 and excellent electrical, 2 thermal, 3 optical, and mechanical properties. 4,5 Graphene is a promising material for applications in various energy-related systems such as supercapacitors, 6-9 secondary batteries, 10-14 solar cells, 15-17 and fuel cells. [18][19][20] For this purpose, graphene materials are frequently blended with polymers to form functional composites. [21][22][23] The polymer component can improve the processability and/or flexibility of graphene materials, and also possibly provide them with new functions. To date, various graphene composites with insulating or conducting polymers (CPs) have been prepared through noncovalent 22 or covalent approaches. 24 They have also been applied as electrodes for supercapacitors and lithium ion batteries (LIBs), 25-29 counter electrodes of dye-sensitized solar cells (DSSCs), 15,30,31 and transparent conducting electrodes (TCEs) 32,33 or active layers of organic solar cells, 34 catalytic electrodes, and polymer electrolyte membranes of fuel cells. [35][36][37] This review focuses on summarizing the recent advances in the synthesis of graphene/polymer composites and their energy applications.

Liquid Crystalline Graphene Oxide/PEDOT:PSS Self-Assembled 3D Architecture for Binder-Free Supercapacitor Electrodes

“…Due to the slow diffusion effect of electrolyte ions, however, CP dominated supercapacitors showed insufficient power performance and volumetric variations during cycling due to failure of the electrode structure caused by fast charge/discharge (Snook et al, 2011;Sun and Shi, 2013). Despite these issues, CPs have become attractive as a secondary component in supercapacitor electrodes, such as a surface coating on electric double layer capacitor (EDLC) materials (i.e., graphene) (Wang et al, 2012).…”

Development of an Ultrafast Low-Energy Electron Diffraction Setup

“…At very low volumetric fractions of graphene, significant increases in tensile strength, Young's modulus, as well as thermal and electric conductivity have been reported [98]. The resulting features make these new materials interesting for a wide range of applications, as, for example, conductive plastics and ink as used in electromagnetic interference shielding [77], or implementation into energy conversion [99], energy storage [100] and non-volatile memory devices [101].…”

Flexible Electrodes and Electrolytes for Energy Storage

“…Highly conductive GNs also act as a conducting matrix in such hybrid structures, which has a direct impact on improving the coulombic efficiency, rate capability and cycle life. A synergistic effect can be driven from both components in the graphene-based composite materials [33][34][35][36][37].…”