The Energy Materials & Storage Systems (EMS²) group is a dynamic and interdisciplinary research team dedicated to the design, development, and fundamental understanding of next-generation materials for sustainable energy storage technologies. Our mission is to address the critical challenges in energy storage through innovative materials chemistry, advanced characterisation, and device-level integration. Our research spans the entire innovation pipeline, from the design and synthesis of advanced energy materials to the engineering of complete energy-storage devices. We investigate a broad range of electrochemical systems, including aqueous and non-aqueous metal-ion batteries, microbatteries, and emerging energy-storage chemistries. We place a strong emphasis on uncovering charge-storage mechanisms, ion transport behaviour, and degradation pathways by employing in-situ and operando characterisation techniques, enabling us to correlate material structure with real-time electrochemical performance. A particular focus is placed on the development of intrinsically safe battery technologies based on abundant and environmentally benign materials. Through close collaboration with academic and industrial partners worldwide, the EMS² group seeks to translate fundamental discoveries into practical technologies that contribute to a cleaner, smarter, and more sustainable energy future. For further details on our research themes, and recent achievements, please visit the Publications page.
Metai-ion Batteries
Lithium-ion batteries have emerged as the predominant energy storage systems today, finding applications across a wide spectrum, from automobiles to personal gadgets, owing to their high energy density and lightweight properties. We work on the materials for Li-ion battery chemistry to push the boundaries of energy density, rate capability, and safety through rational materials design and interface. Moreover, for many applications-such as mini-grid and off-grid energy storage-the considerations of materials availability, cost-effectiveness, and safety have created a strong demand for alternatives that are both affordable and intrinsically safer. In this context, metal-ion battery chemistries beyond lithium, including Zn-based and Al-based systems, stand out as promising alternative energy storage solutions due to their natural abundance, low cost, excellent safety, long cycling life, straightforward manufacturing, and acceptable storage capability.
Our research focuses on addressing the key challenges in these systems. On the metal anode side, we aim to suppress undesirable side reactions-such as dendrite growth, the hydrogen evolution reaction (HER), passivation, and corrosion-which lead to capacity fade and poor cycling stability. On the cathode side, we strive to boost capacities and stabilities through the development of advanced electrode materials and interfacial strategies. Through a holistic approach to both anode and cathode, we seek to realize high-performance, durable, and safe metal-ion batteries for next-generation energy storage.
Microbatteries
With the rapid growth of the Internet of Things, the key trends in microelectronics are clear - miniaturization, flexibility, and integration are leading the way. Various microelectronic devices, including wearables, implants, micro-robots, and micro-sensors, have made significant advances and are set to become essential parts of our everyday lives. These tiny devices excel in complex tasks such as data processing and wireless signal transmission, paving the way for major innovations in areas like health monitoring, medical diagnosis, and disease treatment. However, powering these devices seamlessly requires an efficient energy supply unit. Our research is dedicated to developing microscale batteries, known as Microbatteries Advanced Functional Materials. We place particular emphasis on planar device configurations, in which electrodes are arranged in an interdigitated electrode (IDE) pattern on a single substrate, forming a flat and efficient architecture. This design offers significant advantages over conventional sandwich-type batteries, including improved control over key parameters such as internal resistance and ionic diffusion distance, while eliminating the need for a separator. Most importantly, it provides a practical solution for reducing battery size and integrating them seamlessly with on-chip microelectronic devices. The processing and precise loading of energy materials onto microelectrodes are critical to optimizing charge storage performance.
Given the critical constraint of limited areal footprint in on-chip energy storage, a major challenge lies in enhancing energy performance without increasing device size. Equally important are improving ion transport, ensuring high electrical conductivity, and maintaining structural integrity for long-term operation. One promising strategy is the use of porous, periodic IDEs as current collectors, which support efficient active material loading - particularly beneficial for charge storage materials with inherently low conductivity. Electrodeposition from aqueous solutions is well-suited for fabricating such structures, leveraging the aqueous electrolyte’s wide solvent window to reduce metal ions without solvent degradation. However, at high cathodic overpotentials, H⁺ ions are also reduced to H₂ gas, forming bubbles that interfere with uniform metal deposition. Interestingly, these hydrogen bubbles can serve as dynamic templates during deposition - a process known as Dynamic Hydrogen Bubble Templating (DHBT). DHBT offers several advantages: it removes the need for additional templating agents or processing steps, generates pores in situ during deposition, and enhances efficiency while lowering material and operational costs. The method is versatile, scalable, and environmentally friendly, as it reuses hydrogen gas as a transient template Advanced Functional Materials.
We apply DHBT to engineer porous IDEs for high-performance microscale energy storage systems.
A key factor in advancing microbattey lies in the architecture of current collectors and the integration of high-performance electrode materials. While hybrid materials offer significant promise due to their synergistic charge storage capabilities, incorporating them into microscale electrodes - especially those with complex geometries - remains a major challenge. Traditional fabrication methods, such as electrodeposition, are often incompatible with these materials and unsuitable for flexible or irregular microelectrode designs. To overcome these limitations, we are leveraging the micro-plotter technique, an innovative direct-write approach that enables precise deposition of a wide range of hybrid materials onto microelectrodes, regardless of their pattern, shape, or substrate. This method offers several key advantages: Material Versatility, Design Flexibility, Scalability and Compatibility. Through the micro-plotter technique, we open new pathways for the fabrication of next-generation on-chip microscale energy storage devices ACS Nano, combining compactness, flexibility, and high performance in a fully printed, customizable format.
Our technique introduces a versatile direct-write approach that enables precise deposition of diverse materials on arbitrary patterns, shapes, and substrates, enabling an entirely printed fabrication strategy.
Mechanistic Insights
Understanding how energy materials function under realistic operating conditions is central to our research. Our goal is to uncover the underlying mechanisms that control energy storage, charge transport, interfacial reactions, and degradation in advanced electrochemical systems. To achieve this, we combine advanced electrochemical techniques with state-of-the-art ex-situ/in-situ and operando characterisation tools to monitor materials and interfaces in real time during operation. These approaches enable us to directly observe ion transport pathways, charge-transfer kinetics, phase transformations, structural evolution, and reaction intermediates that develop during battery cycling. A major focus of our research is understanding the dynamic behaviour of electrode–electrolyte interfaces, which often dictate the long-term stability, efficiency, and safety of energy-storage devices. We investigate key phenomena including metal plating and stripping, dendrite growth, electrolyte decomposition, passivation processes, solid-electrolyte interphase (SEI) formation and evolution, ion solvation structures, and interfacial reaction kinetics across multiple length scales. Our research also extends to understanding redox reaction pathways, charge-storage mechanisms, and the role of material architecture in determining electrochemical performance. By correlating structural, chemical, and electrochemical changes during operation, we establish clear structure–property–performance relationships that provide fundamental insights into device behaviour. In addition to experimental investigations, we actively collaborate with leading theoretical modelling and computational simulation groups to obtain atomic- and molecular-level understanding of electrochemical processes. Through the integration of simulations with experimental observations, we are able to reveal reaction mechanisms, ion transport dynamics, interfacial interactions, and material degradation pathways that are otherwise difficult to access experimentally.
EMS² group research is funded by
