Neutron reflectometry studies on the lithiation of amorphous silicon electrodes in lithium-ion batteries

Abstract

Neutron reflectometry is used to study in situ the intercalation of lithium into amorphous silicon electrodes. The experiments are done using a closed three-electrode electrochemical cell setup. As a working electrode, an about 40 nm thick amorphous silicon layer is used that is deposited on a 1 cm thick quartz substrate coated with palladium as a current collector. The counter electrode and the reference electrode are made of lithium metal. Propylene carbonate with 1 M LiClO4 is used as an electrolyte. The utility of the cell is demonstrated during neutron reflectometry measurements where Li is intercalated at a constant current of 100 μA (7.8 μA cm(-2)) for different time steps. The results show (a) that the change in Li content in amorphous silicon and the corresponding volume expansion can be monitored, (b) that the formation of the solid electrolyte interphase becomes visible and (c) that an irreversible capacity loss is present.

A hybrid Si@FeSiy/SiOx anode structure for high performance lithium-ion batteries via ammonia-assisted one-pot synthesis

“…However, a-Si shows better pulverization resistance due to less volume expansion upon Li insertion. 8 Moreover, a-Si provides more pathways for lithium insertion/extraction compared with c-Si.…”

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

“…To prevent loss of intensity, isotopically enriched 7 Li electrodes can be applied, as 6 Li species are able to absorb neutrons [99]. To investigate thin films electrodes, custommade electrochemical cells are used [100,101]. These cells allow the substrate, onto which the electrode of interest has been deposited, to be mounted.…”

Recent Advances in Designing High‐Capacity Anode Nanomaterials for Li‐Ion Batteries and Their Atomic‐Scale Storage Mechanism Studies

“…For example, spherical aberration‐corrected STEM,177 cryo‐EM, 3D imaging techniques,72 neutron reflectometry,178, 179 NMR spectroscopy,180, 181, 182 AFM,183, 184, 185 Raman spectroscopy,186, 187 and X‐ray absorption spectroscopy188 have been widely applied for these in situ studies. In this section, we will focus on the spherical aberration‐corrected STEM, cryoelectron microscopy, and 3D imaging techniques.…”