Future Days Battery Edition recap, part 2: Emerging materials in electrochemical energy storage

On May 21, Malvern Panalytical hosted the Future Days: Focus on Battery virtual event, featuring a range of speakers from across industry and academia. Read on for a recap of Dr Xuehang Wang‘s session on new materials for high-rate energy storage.

Looking for the video? Watch the recording of this session and more from Future Days: Battery Edition here.

Summary and Q&A

The Electrochemical Energy Storage Group at Delft University works with a variety of battery types, including solid-state batteries and high-rate GE storage devices. Using Malvern Panalytical instruments, the team employs characterization methods to gain a deeper understanding of energy storage processes. This is applied to real battery applications, such as zinc batteries, pseudo capacitors, and Elysium software batteries.

Dr. Wang’s session explored pseudocapacitive or high-rate energy storage, combining high capacity, high rate capability, and high reversibility. Her team examined two emerging pseudocapacitive materials: a 2D transition metal carbide, Mxene, and a conjugated polyelectrolyte (CPE).

By combining a CPE-based positive electrode with an MXene-based negative electrode, the team constructed a flexible energy storage cell that can be formed into a thin, foldable film. The thin-film cell can bridge the gap between commercial thin-film batteries and electrical double-layer capacitors. In ammonium-ion storage, the cell showed a significantly high rate of performance, with 80-90% of the capacity retained and an extremely long cycling life.

As a result of this experiment, both MXene and CPE proved to be promising pseudo-capacity materials that can achieve high energy and high power. Dr Wang also highlighted the importance of the proper application of characterization methods in order to understand the mechanism correctly.

Below is a summary of the questions and answers shared during this session.

For MXene size, how can I achieve tens of nanometers using probe sonication for a long time?  

Sonication can be used for a relatively long time, but it does bring the risk of oxidization. With proper protections and a slightly shorter time, 10 nanometers is achievable.

Do you believe that using an organic electrolyte might pose greater safety risks and environmental challenges?

Organic electrolyte battery systems can indeed be flammable, but for the pseudo-capacitor, we will still accumulate heat, but it’s not as dangerous. Replacing the solvents can also help with this.

Your group is covering both theory and experimentation. Why that combination?

First, we need to synthesize the material and then match the material with different electrolytes, and it’s very clear that by matching the electrolyte with different electrodes, the electrochemical behavior is dramatically different. With only the electrochemical mass, we cannot fully understand what has happened in the system. This is where we apply the characterization methods from Malvern Panalytical. Through X-ray diffraction, we can identify the number of ions between the layers, and place this data into a simulation that gives us microscopic images of what’s happening inside.

You can watch the recording of this session and more from Future Days: Battery Edition here.

Further reading

• Recap: Future Days Battery Edition 2025
• Future Days Battery Edition recap, part 1: Trends in battery production and materials