학술논문

Characterisation of defects in porous silicon as an anode material using positron annihilation Doppler Broadening Spectroscopy
Document Type
Original Paper
Source
Applied Nanoscience. 12(11):3399-3408
Subject
Silicon lithium alloy
Silicon anode
Positron annihilation
Porous silicon
Language
English
ISSN
2190-5509
2190-5517
Abstract
Here we present Positron Annihilation Doppler Broadening Spectroscopy (PADBS) as a powerful method to analyse the origin and development of defect processes in porous silicon structures as a result of alloying with lithium for the use in battery anode applications. Several prepared anodes were lithiated (discharged against Li+/Li) and de-lithiated (charged) with different capacities followed by a distinct treatment procedure and an analysis using the Delft Variable Energy Positron Beam. The results presented here show that we can distinguish two different processes attributed to (1) structural changes in silicon as a result of the alloying process, and (2) the formation of defects that initiate degradation of the material. The limit at which the porous material can be used for at least the first two cycles without the occurrence of damage can thus be accurately determined by using the PADBS technique.