Electrochemical analysis of Na0.7Co1-xNbxO2(x = 0, 0.05) as cathode materials in sodium-ion batteries

Abstract

Sodium-ion batteries (SIBs) have received significant attention as promising alternative for energy storage applications owing to the large availability and low cost of sodium. In this paper we study the electrochemical behavior of Na 0.7 Co 1-x Nb x O 2 (x = 0 and 0.05 samples), synthesized via solid-state reaction. The Rietveld refinement of x-ray diffraction pattern reveals the hexagonal crystal symmetry with P63/mmc space group. The Na 0.7 Co 0.95 Nb 0.05 O 2 cathode exhibits a specific capacity of about 91 mAhg -1 at a current density of 6mAg -1 , whereas Na 0.7 CoO 2 exhibits comparatively low specific capacity (70 mAhg -1 at a current density of 6mAg -1 ). The cyclic voltammetry (CV) and electron impedance spectroscopy (EIS) were performed to determine the diffusion coefficient of Na, which found to be in the range of 10 !! − 10 !!" cm 2 s -1 .

A comprehensive review on recent advances of polyanionic cathode materials in Na‐ion batteries for cost effective energy storage applications

“…In general, the cathode materials are classified as layered, Prussian blue analogues, organic, and polyanionic compounds, as shown in Figure 3(a). The layered oxides have been studied extensively as potential electrode materials (Chandra et al, 2020;Chandra, Shukla, Rashid, et al, 2018;Chandra, Shukla, Saroha, et al, 2018;Han et al, 2015;Pati et al, 2020;Saroha et al, 2019;Wani et al, 2021) and reference therein; however, the Na-ion intercalation mechanism in these materials undergo irreversible/multiple phase transitions, which can potentially lead to structural/ thermal/storage instability and unfavorable for battery performance (P.-F. Wang, You, et al, 2017;Y. Sun et al, 2019).…”