Electrolyte-electrode interface plays a critical role in the electrochemical performance of all-solid-state Li-ion batteries. In this work, a mesoscale study is presented to investigate lithium transport and stress in the solid electrolyte based positive electrode during discharge. It is found that increasing electrolyte-electrode interface contact facilitates Li intercalation into the electrode and alleviates the stresses in both the electrode and the electrolyte. Using small electrode particles helps to improve rate capability and avoid interfacial failures due to the volume change of electrode particles. Interface stress strongly depends on the mechanical properties of the two components. In addition, this study demonstrates the importance of electrolyte network through the porous active particle backbone. (C) The Author(s) 2018. Published by ECS.