In situ neutron powder diffraction studies of lithium-ion batteries

Abstract

Neutron powder diffraction (NPD) offers many advantages in the analysis of battery materials. Understanding the relationship between the structural transformations of electrode materials and their electrochemical performance within lithium-ion batteries is crucial for further development of these technologies and is the overall goal of in situ NPD experiments. In this work, we present NPD data of electrode materials within batteries that are collected in situ during electrochemical cycling, including the commercially available materials LiCoO 2 , LiMn 2 O 4 , LiFePO 4 and graphite and the YFe(CN) 6 and FeFe(CN) 6 materials that are not commercially available. Using these data, we illustrate the experimental approach and requirements for the collection of in situ NPD data of sufficient quality for detailed structural analyses of the electrode components of interest within batteries.

The use of deuterated ethyl acetate in highly concentrated electrolyte as a low-cost solvent for in situ neutron diffraction measurements of Li-ion battery electrodes

“…This can be done with an array of in situ techniques such as in situ X-ray diffraction [13][14][15][16][17][18][19][20] and in situ neutron diffraction [21][22][23][24][25][26][27].…”

In situ methods for Li-ion battery research: A review of recent developments

“…However, the technique can be used in addition to XRD, especially to study light elements such as lithium, as neutrons interact with the nucleus and its cross section rather than with the electrons surrounding the atom as is the case for X-rays [89]. Since the neutron cross section has similar but varying sizes for light and heavy isotopes throughout the periodic system, neutrons are sensitive to light elements (e.g.…”

“…For instance, the technique is very sensitive to the hydrogen present in the separators and liquid electrolytes of commercial cells, which unfortunately gives rise to large background signals from incoherently scattered neutrons [93e95]. The use of custom-made cells with low H-content components that mimic, for example, cylindrical 18650-type commercial batteries leads to a significant increase of the signal-to-noise ratio [89]. A common strategy to lower the H-content is the use of deuterated electrolytes and special fluorinated separators [89,96,97].…”

“…The use of custom-made cells with low H-content components that mimic, for example, cylindrical 18650-type commercial batteries leads to a significant increase of the signal-to-noise ratio [89]. A common strategy to lower the H-content is the use of deuterated electrolytes and special fluorinated separators [89,96,97]. A remaining issue is however the presence of many cell components in the pathway of the neutron beam.…”

Insight Into the Formation of Lithium Alloys in All-Solid-State Thin Film Lithium Batteries

“…Several in situ structural studies of LIB systems have been carried out using both synchrotron X-ray diffraction (XRD) and neutron powder diffraction (NPD) (Sharma and Peterson, 2012;Hu et al, 2013;Pang et al, 2015;Sharma et al, 2015a;Goonetilleke et al, 2017). These studies allow the structural changes which take place in active materials to be related to the devices' electrochemical activity in real-time.…”