Towards re-electrification of hydrogen obtained from the power-to-gas process by highly efficient H2/O2 polymer electrolyte fuel cells

In the power-to-gas process, hydrogen, produced by water electrolysis, is used as storage for excess, fluctuating renewable electric power. Reconversion of hydrogen back to electricity with the maximum possible efficiency is one pre-requisite to render hydrogen storage technically and economically viable. Pure oxygen is a byproduct in the electrolysis of water. The use of pure oxygen as the oxidant in a polymer electrolyte fuel cell (PEFC) is a possible way of increasing the conversion efficiency of hydrogen to power, by reducing the fuel cell's cathodic kinetic overvoltage, which is the most important energy loss process in low temperature PEFCs. As we demonstrate in this work, when using pure oxygen, either high efficiencies at current densities around 1 A cm−2 are obtained or a very high power density operation (up to 1.6 W cm−2 at cell voltages above 0.62 V) can be reached, giving the technology a broad window of operation and application. The fuel cell stack durability is assessed in accelerated long-term tests of up to 2700 h. The potential of the technology is demonstrated with the realization of a complete 25 kW prototype system delivering a peak efficiency of 69% LHV (57% HHV).

[1]  H. Ha,et al.  Investigation of oxygen gain in polymer electrolyte membrane fuel cells , 2004 .

[2]  M. Jentsch,et al.  Optimal Use of Power-to-Gas Energy Storage Systems in an 85% Renewable Energy Scenario , 2014 .

[3]  Thomas J. Schmidt,et al.  Electrocatalysis for Polymer Electrolyte Fuel Cells: Recent Achievements and Future Challenges , 2012 .

[4]  Hubert A. Gasteiger,et al.  Determination of Catalyst Unique Parameters for the Oxygen Reduction Reaction in a PEMFC , 2006 .

[5]  Hubert A. Gasteiger,et al.  Handbook of Fuel Cells , 2010 .

[6]  H. Gasteiger,et al.  Activity benchmarks and requirements for Pt, Pt-alloy, and non-Pt oxygen reduction catalysts for PEMFCs , 2005 .

[7]  Jun Shen,et al.  A review of PEM fuel cell durability: Degradation mechanisms and mitigation strategies , 2008 .

[8]  Alexander Wokaun,et al.  In-Plane Effects in Large-Scale PEFCs II. The Influence of Cooling Strategy on Cell Performance , 2006 .

[9]  Daniel Walser,et al.  Consumption and Efficiency of a Passenger Car with a Hydrogen/Oxygen PEFC based Hybrid Electric Drivetrain , 2007 .

[10]  S. Narayanan,et al.  Analysis of the Performance of Nafion-Based Hydrogen–Oxygen Fuel Cells , 2009 .

[11]  A. Parthasarathy,et al.  Pressure Dependence of the Oxygen Reduction Reaction at the Platinum Microelectrode/Nafion Interface: Electrode Kinetics and Mass Transport , 1992 .

[12]  Philipp Dietrich,et al.  On the Efficiency of an Advanced Automotive Fuel Cell System , 2007 .

[13]  Chakib Bouallou,et al.  Model-based behaviour of a high temperature electrolyser system operated at various loads , 2013 .

[14]  Gerda Gahleitner.  Hydrogen from renewable electricity: An international review of power-to-gas pilot plants for stationary applications , 2013 .

[15]  V. Radmilović,et al.  Oxygen Reduction on Carbon-Supported Pt−Ni and Pt−Co Alloy Catalysts , 2002 .

[16]  M. Perry,et al.  Oxygen gain analysis for proton exchange membrane fuel cells , 2012 .

[17]  Gunter Sattler.  PEFCs for naval ships and submarines : many tasks, one solution , 1998 .

[18]  Minoru Inaba,et al.  Gas crossover and membrane degradation in polymer electrolyte fuel cells , 2006 .

[19]  Sally M. Benson,et al.  The energetic implications of curtailing versus storing solar- and wind-generated electricity , 2013 .

[20]  K. Porter,et al.  Wind Energy Curtailment Case Studies: May 2008 - May 2009 , 2009 .

[21]  Sanjeev Mukerjee,et al.  Enhanced electrocatalysis of oxygen reduction on platinum alloys in proton exchange membrane fuel cells , 1993 .