Eliminating the bottlenecks in performance of lithium-sulfur batteries


Graphical abstract. Credit: Chem (2022). DOI: 10.1016/j.chempr.2022.03.001

Energy storage in lithium-sulfur batteries is potentially higher than in lithium-ion batteries but they are hampered by a short life. Researchers from Uppsala University in Sweden have now identified the main bottlenecks in performance.

Lithium-sulfur batteries are high on the wish-list for future batteries as they are made from cheaper and more environmentally friendly materials than lithium-ion batteries. They also have higher energy storage capacity and work well at much lower temperatures. However, they suffer from short lifetimes and energy loss. An article just published in the journal Chem by a research group from Uppsala University has now identified the processes that are limiting the performance of the sulfur electrodes that in turn reduces the current that can be delivered. Various different materials are formed during the discharge/charge cycles and these cause various problems. Often a localized shortage of lithium causes a bottleneck.

“Learning about problems allows us to develop new strategies and materials to improve battery performance. Identifying the real bottlenecks is needed to take the next steps. This is big research challenge in a system as complex as lithium-sulfur,” says Daniel Brandell, Professor of Materials Chemistry at Uppsala University who works at the Ångström Advanced Battery Centre.

The study combined various radiation scattering techniques: X-ray analyses were made in Uppsala, Sweden and neutron results came from a large research facility, the Institut Laue Langevin, in Grenoble, France.

“The study demonstrates the importance of using these infrastructures to tackle problems in materials science,” says Professor Adrian Rennie. “These instruments are expensive but are necessary to understand such complex systems as these batteries. Many different reactions happen at the same time and materials are formed and can disappear quickly during operation.”

The study was carried-out as part of a co-operation with Scania CV AB.

“Electric power is needed for the heavy truck business and not just personal vehicles. They must keep up with developments of a range of different batteries that may soon become highly relevant,” says Daniel Brandell.

Quantum dots incorporated magnetic nanoparticles for imaging colon carcinoma cells


201306047919620Engineered multifunctional nanoparticles (NPs) have made a tremendous impact on the biomedical sciences, with advances in imaging, sensing and bioseparation. In particular, the combination of optical and magnetic responses through a single particle system allows us to serve as novel multimodal molecular imaging contrast agents in clinical settings.

Despite of essential medical imaging modalities and of significant clinical application, only few nanocomposites have been developed with dual imaging contrast. A new method for preparing quantum dots (QDs) incorporated magnetic nanoparticles (MNPs) based on layer-by-layer (LbL) self-assembly techniques have developed and used for cancer cells imaging.

Methods:  Here, citrate – capped negatively charged Fe3O4 NPs were prepared and coated with positively – charged hexadecyltrimethyl ammonium bromide (CTAB).

Then, thiol – capped negatively charged CdTe QDs were electrostatically bound with CTAB. Morphological, optical and magnetic properties of the fluorescent magnetic nanoparticles (FMNPs) were characterized.

Prepared FMNPs were additionally conjugated with hCC49 antibodies fragment antigen binding (Fab) having binding affinity to sialylated sugar chain of TAG-72 region of LS174T cancer cells, which was prepared silkworm expression system, and then were used for imaging colon carcinoma cells.

Results:  The prepared nanocomposites were magnetically responsive and fluorescent, simultaneously that are useful for efficient cellular imaging, optical sensing and magnetic separation. Transmission electron microscopy (TEM) and dynamic light scattering (DLS) revealed that the particle size is around 50 nm in diameter with inner magnetic core and outer CdTe QDs core-shell structure.

Cytotoxicity test of prepared FMNPs indicates high viability in Vero cells. NPs conjugated with anti cancer antibodies were successfully labeled on colon carcinoma cells (LS174) in vitro and showed significant specificity to target cells.

Conclusion:  The present report demonstrates a simple synthesis of CdTe QDs-Fe3O4 NPs.

The surface of the prepared FMNPs was enabled simple conjugation to monoclonal antibodies by electrostatic interaction. This property further extended their in vitro applications as cellular imaging contrast agents.

Such labeling of cells with new fluorescent-magneto nanoprobes for living detection is of interest to various biomedical applications and has demonstrated the potential for future medical use.

Author: Syed Rahin AhmedJinhua DongMegumi YuiTatsuya KatoJaebeom LeeEnoch Y Park
Credits/Source: Journal of Nanobiotechnology 2013, 11:28