A scanning transmission X-ray microscope for analysis of chemical states of lithium

January 14, 2021

Lithium-ion batteries (LIB) are widely used for daily products in our life, such as hybrid cars, cell phone, etc. but their charge/discharge process is not fully understood yet. To understand the process, behaviors of lithium ion, distribution and chemical composition and state, should be revealed. A research group in Institute for Molecular Science noticed on a scanning transmission X-ray microscope (STXM, shown in Fig. 1) as a powerful technique to perform X-ray absorption spectroscopy (XAS) with high spatial resolution. By using absorption edge of a specific element, 2-dimensional chemical state of a sample can be obtained. To analyze lithium by the STXM, the Li K absorption edge (55 eV) in low energy region makes it difficult to measure the XAS due to lack of a proper optical element and tremendous higher-order harmonics from a monochromator which contaminate XAS. Therefore, a low-pass filtering zone plate (LPFZP), a focusing optical element of the STXM, was developed to overcome these issues. The LPFZP uses silicon of 200 nm thick as a substrate of the zone plate and the substrate works as a low-pass filter above 100 eV by using Si L2,3 edges. The hybrid optics of the LPFZP can suppress the higher-harmonics without installing an additional optical component into the STXM. As a result, the STXM with the LPFZP suppresses higher-order harmonics down to 0.1% of an original intensity and enables to measure XAS spectra of the Li K-edge. Then the spatial resolution was estimated as 72 nm.

A thin section sample of a test electrode of the LIB was analyzed. The sample is made of Li2CO3 by a focusing ion-beam process. The STXM image at 70 eV and the Li K-edge XAS spectra are shown in Fig. 2(a) and 2(b), respectively. The XAS spectra are successfully obtained from the regions indicated by circles in Fig. 2(a).

To understand the behavior of lithium in the LIB is necessary to improve its performance. Then, the STXM with the LPFZP will be helpful to analyze that with high spatial resolution.

National Institutes of Natural Sciences

Related Lithium Articles from Brightsurf:

Preventing lithium loss for high-capacity lithium-ion batteries
A team of Korean researchers has developed a processing technology for maximizing energy densities of high-capacity batteries.

Using Jenga to explain lithium-ion batteries
Tower block games such as Jenga can be used to explain to schoolchildren how lithium-ion batteries work, meeting an educational need to better understand a power source that has become vital to everyday life.

Powering the future with revolutionary lithium extraction technique
An international research team, led by Australia's Monash University, has pioneered and patented a new filtration technique that could one day slash lithium extraction times and change the way the future is powered.

New lithium batteries from used cell phones
Research from the University of Cordoba (Spain) and San Luis University (Argentina) was able to reuse graphite from cell phones to manufacture environmentally friendly batteries.

Using neutrons and X-rays to analyze the aging of lithium batteries
An international team has used neutron and X-ray tomography to investigate the dynamic processes that lead to capacity degradation at the electrodes in lithium batteries.

Can lithium halt progression of Alzheimer's disease?
In a new study, a team of researchers at McGill University has shown that, when given in a formulation that facilitates passage to the brain, lithium in doses up to 400 times lower than what is currently being prescribed for mood disorders is capable of both halting signs of advanced Alzheimer's pathology and of recovering lost cognitive abilities.

MTU engineers examine lithium battery defects
Lithium dendrites cause poor performance and even explosions in batteries with flammable liquid electrolytes.

New technology for pre-replenishing lithium for lithium ion supercapacitors
Li3N containing electrode is prepared by a commercially adoptable route, using DMF to homogenate the electrode slurry.

Towards new lithium-ion batteries that are safer and more efficient
Researchers have studied 2 types of cathodes that are very similar in their composition, but which show completely different behavior: one of them suffers from the known loss of energy density in the first charge cycle, while the other does not.

Post-lithium technology
Next-generation batteries will probably see the replacement of lithium ions by more abundant and environmentally benign alkali metal or multivalent ions.

Read More: Lithium News and Lithium Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.