Lithia-Based Nanocomposites Activated by Li2RuO3 for New Cathode Materials Rooted in the Oxygen Redox Reaction

Byeong Gwan Lee,Yong Joon Park

doi:10.1186/s11671-019-3223-4

Abstract

Lithia-based materials are promising cathodes based on an anionic (oxygen) redox reaction for lithium ion batteries due to their high capacity and stable cyclic performance. In this study, the properties of a lithia-based cathode activated by Li2RuO3 were characterized. Ru-based oxides are expected to act as good catalysts because they can play a role in stabilizing the anion redox reaction. Their high electronic conductivity is also attractive because it can compensate for the low conductivity of lithia. The lithia/Li2RuO3 nanocomposites show stable cyclic performance until a capacity limit of 500 mAh g−1 is reached, which is below the theoretical capacity (897 mAh g−1) but superior to other lithia-based cathodes. In the XPS analysis, while the Ru 3d peaks in the spectra barely changed, peroxo-like (O2)n− species reversibly formed and dissociated during cycling. This clearly confirms that the capacity of the lithia/Li2RuO3 nanocomposites can mostly be attributed to the anionic (oxygen) redox reaction.

Highlights

Our society is becoming increasingly more reliant on energy storage systems (ESSs) due to greater use of cell phones, laptops, and electric vehicles
A lithia/Li2RuO3 nanocomposite was prepared through a milling process, and the structural and electrochemical performance was characterized
The lithia/Li2RuO3 nanocomposites show stable cyclic performance until the limited capacity is reached at 500 mAh g−1

Summary

Introduction

Our society is becoming increasingly more reliant on energy storage systems (ESSs) due to greater use of cell phones, laptops, and electric vehicles. Electricity generated from eco-friendly power generation systems needs to be stored in large energy storage systems (ESSs). These examples of ESSs are mostly based on secondary battery systems, which has led to rapid growth of the market share of Li-ion batteries (LIBs), considered the most advanced secondary battery. The energy density of current LIBs is not sufficient to meet the requirements of many applications [1,2,3,4,5,6,7]. Much research has focused on improvement of the energy density of battery systems. Development of a superior cathode material exhibiting higher reversible capacity than conventional transition metal-based oxides is of great research interest [1,2,3,4,5,6,7]

Methods

Results

Conclusion