ADVERTISEMENT

Watching Inside A Battery During The Charge/Discharge Cycle

Energy storage is one of the most important aspects of our highly demanding society. In the last decades, the search for appropriate energy storage materials has become of paramount importance to fulfill the increasing needs of electrical power. As such, energy storage has become a key research topic, and political authorities have created dedicated programs for the development of sustainable energy production technologies as well as for developing efficient-energy storage devices.

The market of metal-ion batteries is dominated by ubiquitous Li-ion batteries, which constitute around 60% of the global market. However, in recent years, an increasing interest in the replacement of Li by other alkali and alkaline earth metals such as Na, K, Mg, and Ca has emerged. In this respect, due to the large natural abundance and lower cost of Na compared to Li, Na-ion batteries are considered as a convenient alternative, especially for grid energy storage.

ADVERTISEMENT

Batteries are complex devices exhibiting structures at several length scales, from the atomic level, at which electrochemical reactions take place, to the micrometer range through the nanoscale. This accounts for the need to address the structural modifications that batteries undergo during operation, which are in part responsible for the loss of performance, limiting its lifetime at all the length scales involved.

On the other hand, the technology of Na-ion batteries is not as mature as that of Li-ion batteries, and a big research effort is being invested so as to optimize these devices. In recent years, TiO2 nanoparticles have emerged as a promising anode material for Na-ion batteries, although the exact working mechanism remains elusive. In this sense, there is a need for conducting operando studies, i.e., investigating the complete assembled device during the charge-discharge cycles. These kinds of studies provide a much deeper knowledge of the exact working mechanism as well as on the changes occurring to the device. As such, they allow for the search of new strategies for optimizing the performance of Na-ion batteries as well as for extending its lifetime.

Recently, we have carried out an operando investigation on the morphological changes experienced by a Na-ion battery with TiO2 nanoparticles as anode material. Most of the operando experiments performed to-date address the structural alteration of the crystalline structure of the active material. However, as previously mentioned, the batteries possess structures at several length scales. In particular, little attention has been paid to the nanometer-range morphological modifications of the nanoparticulate anode material, though it may have implications on the battery performance. This is the length scale we have focused on.

By employing synchrotron X-ray scattering, we have followed in real time the changes in the arrangement of the TiO2 nanoparticles while cycling the battery. In particular, changes in the interparticle distance have been observed whereas the nanoparticle size remained constant. Furthermore, evidence of nanoparticle aggregation have been observed. Altogether, the results suggest that two different phenomena, not previously reported, are occurring simultaneously: swelling of the electrode and nanoparticle aggregation. Both phenomena irreversibly change the morphology of the battery at the nanoscale, which might have an impact on the battery capacity loss on cycling.

ADVERTISEMENT

Finally, operando studies have emerged as an invaluable tool for deepening our knowledge of energy storage devices since they provide a much accurate picture of the physical phenomena involved during the charge-discharge cycles. In the near future, these will provide new insights into the physics of energy storage devices.

These findings are described in the article entitled Operando monitoring the nanometric morphological evolution of TiO2 nanoparticles in a Na-ion battery, recently published in the journal Materials Today Energy.

Comments

READ THIS NEXT

What Do Mice Eat?

What do mice eat? Truthfully, mice will eat just about anything they can. Mice are omnivorous, so they will eat […]

Catalysts In The Chemical Industry

The chemical industry influences all our lives daily, everything from the components in the screen you are reading this article […]

The Geographic Regions Of The World

The geographic regions of the world can be divided into ten regions: Africa, Asia, Central America, Eastern Europe, European Union, […]

My Science Life: Scott Johnson, Director Of The School Of Earth & Climate Sciences University Of Maine

Welcome to the My Science Life feature of Dr. Scott E. Johnson, Professor of Tectonics and Structural Geology, and Director […]

Exploring Spatial Representation In Artificial Intelligence Systems

Artificial Intelligence has made great progress in the last decade, in particular, thanks to recent developments in machine learning. As a consequence, […]

New Study On CBD, A Marijuana Extract, Shows Signs Of Easing Anxiety

Marijuana is slowly becoming legal in some forms across the United States. Emerging research is showing that the components of […]

The Importance Of Addressing Insecure Employment To Improve Population Mental Health

Economic insecurity arises from a fear of being exposed to adverse economic events from which an individual may have difficulty […]

Science Trends is a popular source of science news and education around the world. We cover everything from solar power cell technology to climate change to cancer research. We help hundreds of thousands of people every month learn about the world we live in and the latest scientific breakthroughs. Want to know more?