Chemical Preintercalation of H₂V₃O₈‐reduced Graphene Oxide Composites for Improved Na‐ and Li‐ion Battery Cathodes

Abstract

Due to a growing demand for sustainable electrical energy storage alternatives to Li‐ion batteries (LIBs), Na‐ion batteries (SIBs) are of great interest because of the abundance of Na+. By modifying layered H2V3O8 by preintercalation and composite formation, improved electrochemical properties were obtained in LIBs. In analogy, a scalable soft chemistry synthesis is developed, to chemically presodiate H2V3O8 for the first time, in addition to a composite formation reaction with reduced graphene oxide (rGO). Crystal structure and morphology of all compounds are determined and their electrochemical properties as cathode are evaluated with respect to both Na+ and Li+ intercalation. The combination of preintercalation and composite formation leads to excellent initial capacities of 96 mAh ⋅ g−1 for SIBs and 371 mAh ⋅ g−1 for LIBs (58 % and 48 % higher than unmodified H2V3O8) at a practical current density of 100 mA ⋅ g−1, demonstrating that H2V3O8 is a promising cathode material for SIBs and LIBs.

Structural, Morphological and Interfacial Investigation of H2V3O8 upon Mg2+ Intercalation

“…[11,21] Within this class, H 2 V 3 O 8 (V 3 O 7 • H 2 O), in short HVO, is a very promising member. Indeed, HVO has already attracted attention as a host cathode for monovalent and Na + [25,26] ) and divalent ions (Zn 2 + ), [27] and only very recently, it has been shown to be able to intercalate Mg 2 + ions. [28,29] In fact, HVO's theoretical specific capacity of 190 mAh g À 1 or 380 mAh g À 1 , per 1 equiv.…”

Integration of H2V3O8 nanowires and a GaN thin film for self-powered UV photodetectors

“…Hence, HVO NWs have been successfully synthesized by a variety of methods and reported as the cathode material for rechargeable batteries. [19][20][21] The optoelectronic application of HVO has not yet been explored in detail. Based on the strategy of building a built-in electric field to achieve the self-powered phenomenon, the HVO NWs can assemble with conventional semiconductors such as GaN to form a Schottky junction.…”