Due to an effective synthesis strategy, two kinds of hierarchical porous activated carbons were derived via KOH and H3PO4 activation and carbonization processes from baobab fruit shells (BFSs) used as a green and low-cost biomass precursor. The physicochemical properties and the morphological structure of the baobab fruit shell derived carbons (BFSCs) were systematically studied by scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectra, nitrogen adsorption/desorption isotherms and X-ray photoelectron spectroscopy (XPS) techniques. The biomass-derived activated carbons, BFSC1 (using KOH activation), and BFSC2 (using H3PO4 activation), obtained exhibit high specific capacitances of 233.48 F g(-1) and 355.8 F g(-1) at a current density of 1 A g(-1), respectively, due to their different surface structures and high specific surface areas. Furthermore, the as-assembled, flexible all-solid-state super capacitor devices based on the BFSC electrodes exhibit a high specific capacitance of 58.67 F g(-1) at 1 A g(-1) and a high energy density of 20.86 Wh kg(-1), at a power density of 400 W kg(-1). This facile route highlights the exciting possibility of utilizing waste baobab fruit shells to produce low-cost, green and high-performance carbon-based electrode materials for sustainable electrochemical energy storage systems. (C) 2018 Published by Elsevier Inc.