Highly Redox-active Atomic Centers in Electrode Materials for Rechargeable Batteries

Introduction

Lithium-ion batteries are the state-of-the-art electrochemical energy storage technology, sodium-ion batteries are about to become commercial, and potassium-ion batteries are attracting rapidly increasing interest. All these alkali-ion battery (AIB) technologies, especially the already or soon-to-be commercialized battery chemistries, have one common characteristic making them so successful – the use of insertion-type electrode materials.

Characteristics of Insertion-Type Electrode Materials

These materials provide sufficient space in their crystal structure for the alkali ions to be reversibly inserted, without causing substantial (irreversible) rearrangement. However, the fact that the ions can only occupy specific sites in the host lattice intrinsically limits the amount of ions that can be reversibly inserted.

Project Aim

The aim of this project is the development of a new family of electrode materials for AIBs, which is characterized by an innovative storage mechanism. This mechanism combines the benefits of a stable insertion-type host structure with:

1. Extended redox activity
2. Additional available space for the alkali-ion charge carriers resulting from the introduction of carefully selected atomic redox centres (ARCs).

Methodology

Based on our own preliminary results and new yet to be developed suitable host matrices and ARCs, we will conduct a comprehensive investigation using highly complementary ex/in situ and operando characterization techniques to gain an in-depth understanding of this new mechanism.

Development of Guidelines

We will develop specific guidelines and design criteria for the realization of such novel materials. These criteria and guidelines will be effectively evaluated by designing new materials that benefit from this new charge storage mechanism, thus enabling long-term stable insertion-type AIBs with enhanced energy and power densities.

Expected Outcomes

Moreover, the results obtained will allow for an improved understanding of the redox behaviour of the highly active ARCs at the atomic level – a field of research that has been limited to theoretical studies so far.