At the Advanced Battery Power conference, we present the findings of the COBRA project, which is part of the European Union’s Horizon 2020 program. The objective of this project is to develop an innovative cobalt-free Li-ion battery technology to overcome the constraints of current electric vehicle batteries. Our approach focuses on enhancing the safety aspects of the battery system comprehensively. To make the battery systems more sustainable, we employed renewable and environmentally friendly silica-coated wood materials to manufacture battery modules and packs. The enhanced performance of this advanced wood-based materials was assessed by understanding the failure propagations that occur during the thermal runaway of multiple cells in the battery pack. The silica-coated wood not only effectively prevents the spread of fire for a certain duration but also acts as a thermal barrier by limiting heat transfer to neighboring components. When exposed to fire, the silica-coated wooden parts develop a glass-like layer, which makes the wooden element partially brittle but structurally stable. Even after the complete incineration of the entire battery systems, the module housings made of silica-coated wood remained structurally intact and prevented the thermal runaway of the neighboring modules. We hope this will pave the new way for the practical utilization of sustainable wood-based materials to enhance battery safety.