This novel MFC stack has all of its anodes and most of its cathodes submerged in the same electrolyte without short-circuiting. The rationale behind this design is that a phenomenon of horizontal self-stratification of a liquid feedstock column, i.e. urine, by microbial activity was occurring, similarly to what happens in natural environments colonised by microorganisms. Results have demonstrated that this phenomenon could be used to develop a novel and simplified type of membraneless MFC. Moreover, the stability and power density of this type of design are in the high range of existing more complicated designs. Due to the plurality of microenvironments in its macro structure, the SSC-MFC allows for the scale-up with limited losses in terms of power densities. This results in simplified stacks where all parallel units—consisting of a single cathode over a single anode—share the same embodiment. Results have shown that the performances were dependent of the pulse-feeding mechanism. Interestingly, an ammonium abstraction was measured in the anoxic part of the submerged cathodic layer. This anaerobic ammonium abstraction gives rise to the hypothesis that in such a set-up, part of the cathode operation is ultimately in the nitrogen redox cycle. Further investigations are needed to identify the process of electron and NH4 abstraction at the cathode.