Microbattery technology overview and associated multilayer encapsulation process

Lithium microbatteries with different positive electrode materials (V2O5, LiCoO2, TiOS) in association with a solid electrolyte (LiPONB) and a lithium negative electrode are very promising energy storage systems that can fit all the applications requirements. One of the challenges of the technology is related to the fact that lithium microbatteries are easily degraded in atmosphere. Indeed, these devices require encapsulation with a barrier material, which exhibits extremely low permeation rates for water vapour and oxygen. To obtain such a high barrier, we chose to direct our studies on layers deposited by plasma-enhanced chemical vapour deposition (PECVD), and more particularly on amorphous materials like silicon oxide (SiOx) and silicon nitride (SiNx). Both the active layers of the microbattery architecture and the multilayer encapsulation stack will be discussed.