Work

High Stability and Long Cycle Life of Rechargeable Sodium-Ion Battery Using Manganese Oxide Cathode: A Combined Density Functional Theory (DFT) and Experimental Study

Year: 2021

Type: article

Abstract: High Resolution Image Download MS PowerPoint Slide Sodium-ion batteries (SIBs) can develop cost-effective and safe energy storage technology for substantial energy storage demands. In this work, we have developed manganese oxide (α-MnO 2 ) nanorods for SIB applications. The crystal structure, which is crucial for high-performance energy storage, is examined systematically for the metal oxide cathode. The intercalation of sodium into the α-MnO 2 matrix was studied using the theoretical density functional theory (DFT) studies. The DFT studies predict Na ions’ facile diffusion kinetics through the MnO 2 lattice with an attractively low diffusion barrier (0.21 eV). When employed as a cathode material for SIBs, MnO 2 showed a moderate capacity (109 mAh·g –1 at C/20 current rate) and superior life cyclability (58.6% after 800 cycles) in NaPF 6 /EC+DMC (5% FEC) electrolyte. It shows a much higher capacity of 181 mAh·g –1 (C/20 current rate) in NaClO 4 /PC (5% FEC) electrolyte, though it suffers fast capacity fading (11.5% after 800 cycles). Our findings show that high crystallinity and hierarchical nanorod morphology of the MnO 2 are responsible for better cycling performance in conjunction with fast and sustained charge-discharge behaviors.

Source: ACS Applied Materials & Interfaces

DOI: 10.1021/acsami.0c21081