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 core research spans a wide range of electrochemical energy storage systems, including Zn-ion batteries, Li-ion batteries, and metal-ion capacitors. 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 key focus of the group is the development of on-chip and micro-scale energy storage systems. We aim to integrate microbatteries directly into systems-on-a-chip platforms to power emerging miniaturised technologies such as wearable electronics, implantable medical devices, microrobots, and distributed microsensors. In addition, we are pioneering research into light-accelerated energy storage systems, exploring new concepts for harvesting ambient energy to enable autonomous, maintenance-free operation of off-grid IoT devices. 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.

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. 

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.

Aqueous Rechargeable 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. However, concerns regarding their availability, cost-effectiveness, and safety have led to a demand for cost-effective and safer alternatives in certain applications, such as mini-grid and off-grid energy storage. Alternatively, aqueous zinc-ion batteries stand out as alternative energy storage systems with excellent safety, cycling life, straightforward manufacturing, and acceptable storage capability. inc-ion batteries have attracted growing research interest due to their advantages: i) zinc-ion batteries can be manufactured in an open environment without the necessity for an inert environment, reducing the cost parity compared to air-sensitive batteries. ii) The Zn anode exhibits higher capacities (820 mAh/g and 5855 mAh/cm3) and can be operated in inexpensive aqueous electrolytes (e.g., ZnSO4). iii) The higher reserves (79 ppm) and reasonably lower costs (0.5–1.5 $/lb) of Zn make it more attractive than Li. These key features make Zinc-ion batteries especially attractive for residential and commercial energy storage that satisfies most of the criteria required for stationary mini-grid scale and off-grid storage systems. Moreover, they can be an alternative for mini-stationary backup or storage systems from renewable energy sources, including wind energy and solar energy storage.

While Zn metal serves as an optimal choice for the anode of zinc-ion batteries, it encounters a significant challenge in the form of dendrite growth due to the presence of aqueous electrolytes. This issue leads to undesirable side reactions, including the growth of Zn dendrites, the hydrogen evolution reaction (HER), passivation, and corrosion, ultimately resulting in diminished capacity over prolonged cycling periods. To tackle the problems of dendrite growth and HER, We apply artificial surface coatings on Zn anodes Chemical Engineering Journal, as the application of artificial coatings onto the Zn surface offers a direct and practical solution that can be implemented on an industrial scale. By creating a physical barrier between the electrolyte and the Zn electrode, these coatings effectively reduce the likelihood of direct contact, thereby minimizing the occurrence of HER.

Light-Accelerated Batteries

Can we truly achieve standalone light-rechargeable energy storage devices without relying on solar cells? Current technologies that integrate solar cells with batteries for storing solar energy face challenges, often requiring additional electronics to match the voltage outputs of solar cells with the input needs of batteries. This results in increased costs, energy losses, and bulkiness, making them unsuitable for applications like advanced on-chip smart devices and off-grid mini-scale systems. Our research aims to push boundaries, foster new ideas, and open new fields by developing innovative solutions to these challenges, enhancing our lives through the effective use of green solar energy. Some battery materials exhibit semiconductive properties and generate photocurrent when exposed to light. We explore the interaction between light and semiconducting battery materials during the charge storage process and design photoelectrode materials that facilitate efficient charge transfer Energy & Environmental Science. 

EMS² group research is funded by