Unveiling atomic-scale elemental distribution of electrode/electrolyte interfaces and interphase in batteries

Introduction

Developing high-energy-density rechargeable battery technologies is essential to solve energy and environmental problems. However, its development is currently impeded by a poor understanding of elementary processes occurring at electrode/electrolyte interfaces. Several long-standing issues such as short cycle life, low Coulombic efficiency, and hazardous dendrite formation in batteries cannot be fundamentally solved due to the knowledge gap.

Bottleneck in Research

The bottleneck is that interfacial chemistry on the atomic scale is as yet unresolved, owing to the lack of sufficiently suitable analytical capabilities. I will address this gap using atom probe tomography, coupled with a highly innovative cryogenic sample preparation and transfer platform, to provide atomic-scale insights into the solid electrolyte interphase (SEI) formed at the electrode/electrolyte interface.

Key Open Questions

The key open questions to answer are:

1. What is the composition and elemental distribution in a stable SEI?
2. How do ions in the electrolytes affect SEI formation?
3. How does stable SEI inhibit dendrite formation?

My goal is to advance fundamental understanding of SEI formation, establish its structure-property relationships, and elucidate its interplay with other elementary processes occurring at electrode/electrolyte interfaces in a lithium metal battery model system.

Research Objectives

I will:

1. Reveal elemental distribution and compositional details of SEI in/under different electrolytes and working conditions.
2. Unveil compositional evolution of SEI and the electrolytes during charging and discharging.
3. Interrogate their roles in dendrite formation in a half and full battery cell, respectively.

These unique data will shed atomistic insights into how to tailor SEI and electrode/electrolyte interfaces to mitigate long-standing issues. Furthermore, the novel cryogenic platform is not system-specific and will be applicable for studying other liquid- or solid-state electrolyte battery technologies.