Membraneless Fuel Cells convert stored chemical energy into electrical energy without the use of a conducting membrane as with other types of Fuel Cells. In Laminar Flow Fuel Cells (LFFC) this is achieved by exploiting the phenomenon of non-mixing laminar flows where the interface between the two flows works as a proton/ion conductor. The interface allows for high diffusivity and eliminates the need for costly membranes. The operating principles of these cells mean that they can only be built to millimeter-scale sizes. The lack of a membrane means they are cheaper but the size limits their use to portable applications which require small amounts of power.
Another type of membraneless fuel cell is a Mixed Reactant Fuel Cell (MRFC). Unlike LFFCs, MRFCs use a mixed fuel and electrolyte, and are thus not subject to the same limitations. Without a membrane, MRFCs depend on the characteristics of the electrodes to separate the oxidation and reduction reactions. By eliminating the membrane and delivering the reactants as a mixture, MRFCs can potentially be simpler and less costly than conventional fuel cell systems.[1]
The efficiency of these cells is generally much higher than modern electricity producing sources. For example, a fossil fuel power plant system can achieve a 40% electrical conversion efficiency while an outdated nuclear power plant is slightly lower at 32%. GenIII and GenIV Nuclear Fission plants can get up to 90% efficient[citation needed] if using direct conversion or up to 65% efficient if using a magnetohydrodynamic generator as a topping cycle{{Citation needed|reason=again, the numbers seem way off. The best achieved efficiency for initial cycle is about 30%. The capture of residual thermal energy is at best 30% to date, which comes to overall efficiency of 51% at best |date=June 2022}}. Fuel cell systems are capable of reaching efficiencies in the range of 55%–70%. However, as with any process, fuel cells also experience inherent losses due to their design and manufacturing processes.