Embarking towards a sustainable future

carbon capture &

process intensification

renewable energy

storage & utilization

Research Overview

Materials Design and Electrochemical Engineering at the Energy-Environment Nexus​

The energy-environment nexus is critical as strategies to meet the growing worldwide energy demand are developed. To ensure sustainable growth and development, energy productions must have a minimal environmental impact. In the short term, fossil fuels will remain dominant such that efficient carbon capture technology is a priority for conventional power generation. In the long term, renewable energies need to be adopted, which requires high-capacity energy storage units to compensate for their intermittent nature.

Materials Innovations and Fundamental Understandings for Energy Storage

Lithium-ion batteries have had a profound impact on our daily life, but their capacity is approaching the theoretical limits with narrow room to satisfy our unprecedented demand. Thus, battery chemistries beyond Li-ion need to be developed.

Li metal is the ultimate anode of choice due to its highest theoretical capacity (more than ten times the value of the state-of-art graphite) and lowest electrochemical potential among all the candidates. Despite five decades of research, there remained no workable solution to the challenges of the Li metal anode, the major two of which are its high reactivity and infinite relative volume change during cycling.

Correspondingly, my PhD research focuses on tackling the key challenges of Li metal anode from the following perspectives: 

1) Minimizing the volume change by rationally-designed Li-scaffold composite. 

      Surface characterizations and modifications are explored to manipulate the scaffolds' wetting properties by molten Li. 

2) Control and homogenize the surface reactivity of Li via artificial solid-electrolyte interface  (SEI) designs.

3) Exploring novel electrolyte additives to modify the SEI formation process and its fundamental understanding

       based on electrochemical, surface-sensitive and microscopy techniques. 

Electrochemically-Mediated Carbon Capture

Anthropogenic carbon dioxide (CO2) emissions present a serious challenge to our society. One of the foremost mitigation strategies involves carbon capture, particularly from large stationary emission sources, followed by sequestration or utilization. The incumbent technology for carbon capture is wet chemical amine scrubbing, which is challenged by its high energy-intensity and large foot print.

Electrochemically mediated separations offer a low-temperature, ambient-pressure alternative for carbon capture, representing a promising yet largely uncharted research area. By being electrically driven, these systems can be controlled precisely to reduce energy losses, are modular and thus easy to implement, and possess great adaptability to the multi-scale nature of carbon capture. 

For my postdoc research, I am exploring different redox chemistries that can reversibly bind and release CO2 upon apply electrochemical potentials.  I am also interested in designing a continuous, membrane-based process for electrochemically-mediated carbon capture. In such device, a pattern of cells with opposite polarity, gated by smart gating membranes that can dynamically control gas passage, allows an effectively continuous operation of carbon capture and release for process intensification, bringing new opportunities to acid gas separation.

© 2020 by Yayuan Liu