Sintering Processes for Industrial Relevant Glass-Ceramic Electrolyte for All-Solid-State Batteries

摘要

State-of-the-art lithium ion batteries have limited optimization potential in terms of energy and power density. Furthermore, flammable liquid electrolytes will always be a significant risk within high performance applications like automotive. The most promising solution to overcome these limitations are all-solid-state batteries. Electrolytes enabling all-solid-state batteries can be divided into organic and inorganic, the latter into sulfidic, nitridic and oxidic materials. Oxidic solid electrolytes distinguish themselves with regard to large electrochemical windows, sufficiently high conductivities and the low interface resistances against lithium metal. At SCHOTT, oxidic glass-ceramic particles have the potential to be produced at an industrial scale and are already available on a kilogram-scale. Present challenges are the incorporation of solid electrolytes into the cell as a separator as well as in the combination with different cathode materials as a cathode composite. Two mean concepts exist to overcome such challenges: One is to combine the hard particles with a soft polymer to improve flexibility and wettability while enhancing conductivity and battery performance. Another one is to sinter the electrolytes by themselves or in the presence of cathode materials enabling good contact and therefrom low interface resistances between the particles as well as highest safety due to the realization of highly dense battery components. In this contribution we will report latest improvements on sintering of glass-ceramic electrolytes. The influence of particle size distribution and microstructure on sintering times are investigated. Especially enhanced density, conductivity and reduced sintering temperature compared with classical ceramic sintering routes will be highlighted. Our results indicate that oxidic glass-ceramic electrolytes are suitable materials enabling all-solid-state batteries.