Biomass derivative/graphene aerogels for binder-free supercapacitors

Advanced self-supported electrode materials of various morphologies have recently presented bendable, stretchable and processable features with exceptional application potential in flexible and wearable energy storage devices. Although biomasses and related wastes as abundant natural sources are the ideal low-cost raw materials, their derivatives generally suffer from insufficiently electrically conductive or inadequately mechanically robust, which is generally required to be further processed into electrodes with binders and conductive agents. To break through such barrier, in this contribution, a universal approach is reported to manipulate the three-dimensional (3D) biomass-derived carbon networks into binder-free supercapacitors using in situ graphene aerogel. Such interfacial management has shown remarkable improvements in the chemical composition, surface area and pore size distribution, enabling the self-supported biomass-derived carbon network/graphene aerogel of hierarchical 3D interconnected structures to deliver considerable enhancement in the charge transfer and capacitive storage (up to 320 and 200 F g^-1 at 0.1 and 10 A g^-1, respectively). The results of the binder-free flexible all-solid state devices and electrical power based on three devices in the series circuit promise an exceptionally universal stage for engineering advanced energy storage devices with rich natural sources as well as recycling biomasses and wastes for extended applications.