Selective preparation of graphene- and rope-like NanoCarbons from camellia wastes as high performance electrode materials for energy storage

摘要

Nano-carbon materials have been extensively applied in energy storage and conversion devices like supercapacitors and lithium ion batteries. However, it is still a challenge to prepare nanocarbons in large scales from cheap resources. In this paper we introduce facile methods to selectively produce graphenelike nanosheets and rope-like nanocarbons from camellia fruits which are natural bio-wastes. The graphene-like carbons were synthesized thourgh hydrothermal treatment of camellia fruits in a KOH aqueous solution and evaluated as electrode materials for supercapacitors. The rope-like porous carbons were obtained by electrochemical cathodic polarization treatment of camellia fruits in a molten salt of KCI-CaCl2 and tested as anode materials for lithium ion batteries. The nanocarbons derived from camellia fruits have been intensively characterized by XRD, TEM, HRTEM and Raman, etc. Both carbon nanomaterials exhibited very promising electrochemical performance with high energy density, excellent rate capability, and stable cycling due to the favorable hierarchical nanostructures. These results clearly demonstrated that the naturally abundant and cheap camellia fruits can be utilized as biomass resources for the large-scale fabrication of nanocabons, which possess attractive performance as electrode materials for supercapacitors and batteries. (C) 2019 Elsevier B.V. All rights reserved.