Marine algae inspired pre-treated SnO2 nanorods bundle as negative electrode for Li-ion capacitor and battery: An approach beyond intercalation

Abstract Group IV elements in the form of metal or metal oxides have been intensively investigated as high performance negative electrodes for charge storage devices owing to its high theoretical capacity and relatively lower cost. In addition, such elements especially Sn based derivatives are found to be better alternatives for traditional topotactic insertion anodes like graphite and Li 4 Ti 5 O 12 . In the present work, we report the scalable synthesis of marine inspired SnO 2 nanorods bundles by precipitation technique. The preliminary electrochemical performance of SnO 2 (half-cell studies with Li) is examined as anode at different electrolyte solutions and various loading of conductive additives. The fabrication of Li-ion capacitor (LIC) has been made using pre-lithiated SnO 2 as anode with bio-waste (Jackfruit skin) derived activated carbon as cathode under the optimized mass loadings. The LIC can deliver the maximum energy density of ∼187 Wh kg −1 with an ∼82% of initial energy retention after 10,000 charge-discharge cycles. Furthermore, the pre-treated SnO 2 also investigated as negative electrode with homemade high voltage spinel (Li 0.995 V 0.005 Ni 0.5 Mn 1.5 O 4 ) towards the construction of high-energy Li-ion battery (LIB). Similar to the LIC, the mass loading of LIB has been adjusted based on the half-cell performance with Li. The LIB can work in the potential of ∼4.27 V with energy density of ∼400 Wh kg −1 (based on total mass loading of both electrodes).