Liquid Fuel Cells

Dear Colleagues,

Towards the commercialization of fuel cell products in the coming years, fuel cell systems are being redefined by means of lowering the cost of basic elements such as electrolytes, membranes, electrodes, and catalyst materials, and by increasing their power density and long-term stability. Among different kinds of fuel cells, low-temperature polymer electrolyte membrane fuel cells (PEMFCs) are of major importance, but their problems related to hydrogen storage and distribution are forcing the development of liquid fuels such as methanol, ethanol, isopropanol, formic acid, ammonia, hydrazine, borohydride, and others. Some of these fuels are cheaper, easier to handle, transport, and store, and have higher theoretical energy conversion efficiency than hydrogen. During the last two decades, four long-term markets and energy solutions in which fuel cell systems may play an important role were identified: lowest cost energy to end users, combined heat and power or high-value premium power solutions, peak-shaving technologies, and load-management and grid-power support for varying supply. Accordingly, fuel cell systems are being redefined in the direction of the commercialization of the required fuel cell products, namely for the four primary sub-systems: cell (anode, electrolyte, cathode, and supporting structures), stack (interconnectors, flow configurations, contact layers, current collectors), BOP (balance of plant), and external BOP, which provides connections to the exterior. It is thus clear that materials R&D is critical in the development of fuel cells. However, other issues—namely, cost, reliability, and lifetime; competitive manufacturing; operation and disposal chains; shortage and recycling of materials, etc.—need attention for a better commercialization, and have been more successfully solved in the case of fuel cells operating on liquid fuels. Regenerative organic fuel cells that can also function as  electrolyzers built using acidic or alkaline electrolyte, known as “regenerative fuel cells” (RFCs), are also known. The RFC has been a dream of many hydrogen technology enthusiasts as it can be an ideal solution for maximizing the benefits of the variable renewable energy (VRE) sources such as solar and wind. This Special Issue encourages the submission of relevant papers (short communications, full, progress, or review papers) focusing on electrochemical studies and the physicochemical characterization of active materials and sub-systems for liquid-feed fuel cell systems. In particular, this SI focuses on research and development related to:

• Fuels for liquid fuel cells;
• Direct liquid fuel cells;
• Regenerative organic fuel cells;
• Processes for electrode preparation;
• Electrochemical techniques of analysis;                          
• Nonplatinum-based nanostructured electrocatalysts;
• Design and fabrication of nanoporous metallic electrocatalysts;
• Macroporous substrate materials;
• Advanced single and double-layer gas diffusion layers;
• Manufacturing methods for metallic bipolar plates;
• Carbon and noncarbon hybrid support materials;
• Degradation mechanisms, focused on the support degradation;
• Novel spectroscopy and microscopy characterizations;
• Air, heat, and water management.

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Energies is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

• Electrochemistry and electrochemical protocols
• Processes for electrode preparation
• Fuel cell design, materials and components
• Liquid fuels
• Synthesis of nanostructured electrocatalysts
• Ionic membranes
• Metallic bipolar plates
• Thermal and water management
• Cell/electrodes characterization
• Support degradation
• MEAs design and performance