Flexible graphene devices related to energy conversion and storage

Graphene is a unique and attractive energy material because of its atom-thick two-dimensional structure and excellent properties. Graphene sheets are also mechanically strong and flexible. Thus, graphene materials are expected to have wide and practical applications in bendable, foldable and/or stretchable devices related to energy conversion and storage. We present a review on the recent advancements in flexible graphene energy devices including photovoltaic devices, fuel cells, nanogenerators (NGs), supercapacitors (SCs) and batteries, and the devices related to energy conversion such as organic light-emitting diodes (OLEDs), photodetectors and actuators. The strategies for synthesizing flexible graphene materials will be summarized and the challenges facing the design and construction of the devices will be discussed.