CIC energiGUNE, the Basque research center of reference in electrochemical energy storage and conversion and thermal energy storage and conversion, has achieved significant scientific progress in the development of all-solid-state lithium metal batteries (ASSB). These include new solutions to improve solid–solid interfaces and guidelines for manufacturing positive electrodes. Both advances have been published in two prestigious Elsevier journals: Chemical Engineering Journal and Solid State Ionics.

This research has been conducted within the framework of OASIS, a subproject of the collaborative FASSION initiative, focused on the development of advanced ultra-fast sintering techniques. The Functional and Structured Ceramics Processing and Characterization group (ProCaCef) of the Aragón Institute of Nanoscience and Materials coordinates FASSION, with CIC energiGUNE leading the OASIS subproject.

Specifically, the aim of OASIS is to improve the manufacturing process of oxide-based full cells using cold sintering. This technique enables both the cathode and the electrolyte to be processed in a single manufacturing step at temperatures below 500 °C, thereby reducing production costs.

In addition, the project aims to develop new halide electrolytes with high ionic conductivity and electrochemical stability using low-cost, scalable methods. This will allow efficient ionic transport and optimal current exchange during cycling—key factors for achieving high current densities in the cells.

As a result, OASIS will improve electrochemical performance, reduce manufacturing costs, and enhance interfacial stability in solid-state batteries. It will also enable the development of new solid halide electrolytes, moving toward the fabrication of high-voltage solid-state batteries.

Regarding FASSION, its central objective is to develop advanced ultra-fast sintering techniques for processing ceramics intended for high-performance solid-state energy conversion devices, including solid oxide fuel cells (SOFC), solid oxide electrolysis cells (SOEC), and all-solid-state lithium metal batteries (ASSB). In this context, the work carried out in OASIS is essential, as it focuses on oxide- and halide-based solid-state batteries and, more specifically, on overcoming the current bottleneck in processing oxide-based full cells. To achieve this, both sintering temperature and processing time will be reduced.