In modern aluminiumAluminium reduction cellsAluminium reduction cells, cathode voltage drop (CVD)Cathode Voltage Drop (CVD) contributes approximately 12–15% of the total ohmic losses, with 35–40% of this drop originating from the cast ironIron joint between the collector bar and cathode block. To address this issue, a fully coupled thermal–electrical–mechanical finite elementFinite element model was developed to simulate contact pressureContact pressure, voltage dropVoltage drop, and temperature distribution across the joint. The model uses an augmented Lagrangian contact formulation to accurately represent thermo-mechanical interactions. The contact stiffnessContact stiffness value is calculated and iteratively updated to prevent penetrationPenetration between the contact and target surfaces. This approach ensures realistic pressure distribution. The electrical contact resistance is modelled as a function of both contact pressureContact pressure and temperature. The paper will describe the model and its validation against a high-amperage cell data and present an analysis to improve joint design for CVDCathode Voltage Drop (CVD) reduction, thereby improving energy efficiencyEnergy efficiency.