Study on the effects of Doping Argyrodite with LiCl and LiF

Study on the effects of Doping Argyrodite with LiCl and LiF: in a Solid State Lithium Ion Battery

Binti Faisol, Intan (TU Delft Electrical Engineering, Mathematics and Computer Science)

Wagemaker, M. (mentor)
Ganapathy, S. (mentor)
Kelder, E.M. (graduation committee)
van Eijck, L. (graduation committee)

Delft University of Technology

Electrical Engineering | Sustainable Energy Technology

2018-08-13

Solid state lithium ion batteries are generally safer than liquid electrolytes. Li6PS5Cl is a promising electrolyte with an instability in the active material and electrolyte interphase which causes an increase in impedance and capacity loss.
Doping with stable salts of LiCl and LiF could affect the stability. It is found that doping LiCl reduces the specific capacity retention despite having higher ionic conductivity from EIS. With the ex-situ XRD analysis, it is found that the decomposition is less than of pristine argyrodite. This could be due to poor interphase contact. In the case of dopant LiF, small doping of the argyrodite decreases the specific capacity retention of the active material which may be due to lowered ionic conductivity. The higher amount of LiF doped argyrodite improves the specific capacity retention despite the lower ionic conductivities. This could be due high decomposition rate. Alternatively, another doping method was used, but it was found to have higher chemical decomposition despite having good specific capacity retention. To improve the quality of this research, better synthesis of the argyrodite is preferred as this research has side phases. Further analysis that could be included are: TEM, XRD in-operando mode, and EDS.

solid state battery
argyrodite
doping
EIS
XRD
Li6PS5Cl
lithium ion battery

http://resolver.tudelft.nl/uuid:df51abad-e5b0-4d4d-a63f-5cb41a9a9b87

Student theses

master thesis

© 2018 Intan Binti Faisol