Flash sintering and investigation on NASICON electroceramic
PhD Student: Yimin Zhu
PhD Supervisor: Dr. Katharina Marquardt
NASICON (sodium super ion conductor) ceramic is an electrolyte material for all-solid-state ion-batteries. Compared with traditional liquid-electrolytes, it promises safety, better electrochemical stability, and lower costs. The application of NASICON is limited by the high resistance originates from the electrolyte internal grain boundaries and electrolyte-electrode interfaces.
Conventional sintering of NASICON requires high temperatures and long sample soaking time. It not only consumes much energy and time, but also causes grain growth and coarsening, which result in poor grain boundary condition. A novel sintering method called flash sintering (FS) has received much interest in the past decade. In FS, sintering is realized by passing a high current through the sample at a low temperature for less than 1 min. FS is a rapid sintering technique that does not trigger much grain growth; It can produce ceramics having extremely high density. Meanwhile it saves costs due to its short processing time.
In this PhD project, we will develop an FS machine for NASICON ceramic and use modern characterization techniques to quantitatively investigate the microstructure properties of the product. We are particularly interested in the influence of grain boundary and solid interface conditions on electrochemical performance of NASICON.