Electrode interfaces and electrode assemblies for performing transcranial direct current stimulation. The electrode interfaces include a body configured to be coupled to an electrode for delivery of electrical current therethrough. The body includes a non-contact surface and a contact surface opposing the non-contact surface. The body defines a plurality of conductivity passages extending therethrough from the non-contact surface to the contact surface. Each conductivity passage is disposed along a central axis and includes at least one branching inlet and at least one branching subpassage extending from the at least one branching inlet to the contact surface. Each branching subpassage defines a plurality of branches, and each branch diverges from the central axis and then extends to the contact surface. The electrode assemblies include a neurostimulation device, at least two electrodes coupled to the neurostimulation device, and an electrode interface including a body coupled to each electrode.