Needs for multi-scale study in PEMFCs

The objective of CL modeling is to establish relations between fabrication procedures and conditions, structure, effective properties of transport and reactions, and performance, which evolves over a wide range of scales, from atomistic-dominated processes at supported catalyst nanoparticles to the operation in a fuel cell at the macroscopic device level. As discussed above, separate approaches in theory and modeling are considered at different scales, which allow one to focus on essential features under specific conditions. For example, atomistic scale models can predict physical properties of materials with ideal, theoretical or proposed micro-structures imder 

In the following, the key issues and related models at different scales in PEMFCs are outlined in Section 3.2. In Section 3.3, the multi-scale strategies across neighboring scales are summarized and compared. The typical applications based on coarse-grained molecular dynamics (CG-MD) method areal so exhibited to discuss the multi-scale modeling techniques in PEMFC. However, there are still some major challenges and limitations in these modeling and simulations, as summarized in Section 3.4. 

---