(3hf) Management of Charge Carriers in Aqueous-Nonaqueous Phases and Interfaces in Electrochemical Systems for Energy Storage and Conversion

The escalating global impact of climate change, driven in large part by fossil fuel combustion and resultant CO₂ emissions, demands urgent innovation in sustainable energy systems. The rapid expansion of renewable energy sources — such as wind and solar — has intensified the need for energy technologies such as grid scale storage systems that can accommodate their inherent intermittency. Concurrently, breakthroughs in electrosynthesis have highlighted the potential of electrochemical systems to convert renewable electricity into valuable chemicals and fuels. In many of these applications, the efficient management of charge carriers, particularly protons and hydroxide ions, is essential for achieving high selectivity, energy efficiency, and operational longevity. The transport and control of ions and electrons across aqueous-nonaqueous and solid-liquid interfaces can further open up the opportunity of using electrochemistry in nonaqueous systems.

This work presents a comprehensive investigation into the control and optimization of transport of protons, hydroxide ions, and ion-coupled electrons across aqueous, nonaqueous, and their interfaces to advance electrochemical technologies for sustainable energy storage and conversion.

As a demonstration of aqueous charge carrier management, we developed mild pH‐decoupling aqueous redox flow batteries (ARFBs) with a practical pH recovery system. By separating the pH conditions of the negolyte and posolyte, the design achieves cell voltages well above 1.23 V. The crossover of proton/hydroxide ions is investigated to assure high Coulombic efficiency and long-term stability, which are essential for scalable grid energy storage. We further introduced electrochemical acid-base generators designed for decoupled carbon management. By minimizing the acid-base crossover, the system produces concentrated acid and base streams at high current efficiency and low energy cost. This device is applied to carbon capture scenarios — from simulated flue gas to direct air capture — demonstrating its potential for integrated decarbonization strategies.

Dive deeper into ion-coupled electron transfer, we reveal that redox mediators that operate via PCET can be considered as hydrogen atom carriers. These redox active molecules are explored to enable efficient pH recovery and electrochemical hydrogen storage. We extend this approach to electrosynthesis by leveraging interfacial PCET at aqueous-nonaqueous interfaces. This work demonstrates how aqueous redox mediators can transfer hydrogen atoms into/onto nonaqueous phases to drive selective hydrogenation reactions, exemplified by the electrification of industrial hydrogen peroxide production and nonaqueous organic hydrogenation.

Collectively, the studies establish a unified framework for managing charge carriers in electrochemical systems, offering key insights into interfacial transport phenomena and laying the groundwork for next‐generation, sustainable energy technologies. The innovations presented here promise to improve both the efficiency and economic viability of energy storage, carbon management, and electrosynthetic processes.

Research Interests

1. The interfacial coupled ion-electron transfer (iCIET) and multi-phase electrochemical systems for electrifying nonaqueous chemistry for electro-synthesis;

2. Electrostatic potential management for thermocatalysis;

3. High temperature, high pressure electrochemistry;

4. Asymmetric electrochemistry.

Teaching Interests

I am comfortable and confident in teaching of:

Undergraduate Level: General Chemistry, Inorganic Chemistry, Organic Chemistry, Analytical Chemistry, Physical Chemistry.

Postgraduate Level: Inorganic/Organic/Analytical Experiments, Electrochemistry, Energy Technology, Instrumental Analysis, Energy Storage Systems, Frontier in Catalysts.