Phase‐Resolved Finite Element Modeling of Electronic Transport in Hierarchical MoSe ₂ @ CoSe /N‐Doped Carbon Nanocomposites for Energy Storage and Electrocatalysis

Understanding electronic transport in hierarchical multicomponent nanocomposites is critical for the rational design of high‐performance materials for energy storage and electrocatalysis; however, conventional experimental techniques provide only bulk‐averaged information and fail to resolve phase‐specific transport limitations. In this work, a hierarchical mesoporous MoSe 2 @CoSe/N‐doped carbon nanocomposite is investigated through an integrated experimental–computational framework, with a particular emphasis on phase‐resolved electronic transport. A realistic three‐dimensional finite element model is developed to explicitly decouple the electronic contributions of MoSe 2 , CoSe, and the N‐doped carbon matrix under steady‐state conditions. The simulations reveal that, despite constituting only ∼25 vol% of the composite, the N‐doped carbon and CoSe phases collectively conduct more than 80% of the total electronic current, while MoSe 2 primarily functions as the electrochemically active host. The optimized architecture exhibits an effective electronic conductivity of ∼1.7 × 10 5 S m −1 with a maximum internal potential gradient limited to ∼0.9 × 10 7 V m −1 , indicating highly uniform current redistribution. Sensitivity analyses further demonstrate that minor deviations in phase ratio or interfacial quality can reduce the effective conductivity by up to ∼40%, highlighting critical nanoscale electrical bottlenecks. These numerical predictions are in excellent agreement with experimental results, including a reversible capacity of 485 mAh g −1 , 91.4% capacity retention after 300 cycles at 2 A g −1 , and a low hydrogen evolution overpotential of 64 mV at 10 mA cm −2 . This study establishes a predictive structure–transport–performance framework for the engineering design of hierarchical selenide‐based nanocomposites.