Cold Sintering Composite Structures

Pennsylvania State University (Penn State) will develop a process for cold-sintering of ceramic ion conductors below 200°C to achieve a commercially viable process for integration into batteries. Compared to liquid electrolytes, ceramics and ceramic composites exhibit various advantages, such as lower flammability, and larger electrochemical and thermal stability. One challenge with traditional ceramics is the propagation of lithium dendrites, branchlike metal fibers that short-circuit battery cells. Penn State will create ceramic and ceramic/polymer composite electrolytes that resist dendrite growth by creating optimized microstructures via cold sintering. Sintering is the process of compacting and forming a solid mass by heat and/or pressure without melting it to the point of changing it to a liquid, similar to pressing a snowball together from loose snow. However, the high temperature required for traditional sintering of ceramics limits opportunities for integration in electrochemical systems and leads to high processing costs. Cold-sintering below 200°C changes the ability to control grain boundaries within ceramic materials, creates opportunities to tune interfaces, and opens the door for integration of different materials. It also allows large area co-processing of organic and inorganic materials in a one-step process, leading to savings in fabricating costs by eliminating the separate ceramic sintering steps and high-temperature processing.