Layered sodium vanadate (NaV8O20) nanobelts: a new high-performing pseudocapacitive material for sodium-ion storage applications

Abstract

Multifunctional layered nanostructures have attracted great attention for next-generation electrochemical supercapacitors and metal-ion batteries. Herein, we use a hydrothermal method to demonstrate the synthesis of 1D and layered sodium vanadate (NaV8O20) nanobelts architecture. These NaV8O20 nanobelts demonstrate outstanding electrochemical performance in supercapacitors (SCs) and sodium-ion batteries (SIBs). The possible formation mechanism of NaV8O20 nanobelts is briefly discussed. Benefiting from the 1D and layered nanostructure, pre-inserted cations, significantly enhanced electrochemical conductivity, and high electroactive surface area, the prepared NaV8O20 electrode material exhibited excellent charge storage capacity, favorable rate, and cyclic stability performance. The NaV8O20 nanobelts displayed outstanding electrochemical characteristics, including 676 F g-1 of specific capacitance, 45 W h kg-1 of energy density and 5224 W kg-1 of power density. Additionally, on testing in Na-ion batteries, the NaV8O20 nanobelts exhibit a discharge capacity of 110 mA h g-1 at 10 mA g-1 and retain similar to 52% capacity after 100 cycles. Along with this, the galvanostatic intermittent titration technique (GITT) measurements reveal a high diffusion coefficient for Na+ ions, highlighting the efficient Na+ ions transportation within the NaV8O20 structure. To our knowledge, this is the first report on the use of NaV8O20 nanobelts for both SIBs and SCs, marking a significant contribution to the development of multifunctional materials for energy storage applications.