Sucrose-based reticulated vitreous carbon foams and their modification with nickel hexacyanoferrate for energy storage applications

This contribution shows a novel and low-cost strategy for the synthesis of 3D carbon scaffolds, made of reticulated vitreous carbon, (RVC), and their application as substrate in hybrid electrochemical storage devices. Morphological and spectroscopic (Raman, FTIR and XPS) characterization reveal the obtaining of RVC foams with different characteristics such porosity, functional groups and electronic conductivity, inherit from the foams employed as sacrificial polymeric templates during their fabrication. RVC were modified with nickel hexacyanoferrate (NiPBA) to boost their energy storage performance towards Na-ion storage. The electrochemical response of obtained NiPBA/RVC composites exhibits a synergic combination of the energy storage mechanisms and properties of each of the components. Cyclic voltammetry and electrochemical impedance spectroscopy established that the deposition of NiPBA films on 3D carbon foam improves the storage capacity 1.8 times and considerably decreases the impedances involved in the alkaline cation exchange, in comparison to bare RVC obtained from sucrose. The improved performance of RVC F47 as a substrate in energy storage application might be related to interaction of different parameters such graphitization degree, conductivity and oxygenated functional groups on RVC surface. [Display omitted] •RVC substrates were prepared from sucrose using templates with different densities.•The NiPBA was grown on RVC carbons foams by electrodeposition.•Composites store energy by diffusion-controlled redox and superficial confined processes.•NiPBA improve the energy storage performance towards Na-ion storage of bare RVC.•NiPBA/RVC composites exhibit good rate capability and long-term stability.