%0 Thesis
%A Yan, Gang
%T Mechanical Behavior of Solid Electrolyte Materials for Lithium-ion Batteries
%V 500
%I RWTH Aachen
%V Dissertation
%C Jülich
%M FZJ-2020-02641
%@ 978-3-95806-484-3
%B Schriften des Forschungszentrums Jülich Reihe Energie & Umwelt / Energy & Environment
%P x, 139 S.
%D 2020
%Z RWTH Aachen, Diss., 2020
%X All solid-state lithium-ion batteries (ASSLIBs) being based on solid state electrolytes are at present regarded as a promising alternative for conventional batteries on account of their higher ionic  conductivity,  energy  density  as  well  as  higher  chemical  stability  and  safety.  The  solid electrolytes are expected to possess enhanced ionic conductivity and in addition a mechanical stability  that  warrants  a  safer  separation  of  electrodes  and  is  envisaged  to  permit  them  to withstand long-term cycling operation. However, in contrast to the widely investigated electro-chemical  properties  of  solid  electrolytes,  the  mechanical  properties,  which  are  important  for long-term  reliability,  need  to  be  studied  deeper.  Hence,  the  main  aim  of  this  work  is  the mechanical characterization of respective ceramic materials as candidates for solid electrolytes and  the  relationship  to  materials’  microstructures.  For  this  purpose  three  types  of  solid electrolytes,  NASICON  type  Li$_{1+x}$Al$_{x}$Ti$_{2-x}$(PO$_{4)3}$  (LATP),  garnet  type  Li$_{7}$La$_{3}$Zr$_{2}$O$_{12}$  (LLZO), perovskite  type  Li$_{0.350}$La$_{0.557}$TiO$_{3}$  (LLTO),  were  chosen  due  to  their  previously  verified promising electro-chemical properties.  With  the  aim  of  understanding  the  mechanical  properties  of  the  LATP  material,  LATPs sintered at different temperatures (950 –1100 °C) were characterized via indentation method in this work. The results revealed that LATP sintered at higher temperature possesses higher elastic modulus, hardness and fracture toughness. The anisotropy of the mechanical properties of the solid electrolyte material LATP sintered at 1100 °C was investigated in this work via indentation mapping  test  in  a  depth  control  mode  at  room  temperature  with  associated  EBSD characterization.  The  experimentally  derived  elastic  modulus  and  hardness  of  LATP  show similar trends, i.e. that the rotation angle between two prismatic type planes had no detectable influence, whereas when the rotation angle from basal plane to prismatic plane increased, elastic modulus and hardness value decrease conspicuously.  Furthermore, to assess the fracture reliability of electrolytes, Li$_{1.5}$Al$_{0.5}$Ti$_{1.5}$P$_{3}$O$_{12}$ mixed with SiO$_{2}$ (LATP:Si) and a LLZO material were selected to investigate the macroscopic mechanical properties,  concentrating  on  fracture  strength  and  Weibull  modulus.  The  Weibull  moduli  of LATP:Si and LLZO are in a similar range as for other ceramic materials, whereas the fractur [...]
%F PUB:(DE-HGF)3 ; PUB:(DE-HGF)11
%9 BookDissertation / PhD Thesis
%U https://juser.fz-juelich.de/record/878123