Evaluation of concepts for hydrogen – chlorine fuel cells

Abstract

Three different concepts for H 2 -Cl 2 fuel cells have been evaluated. An ordinary PEM fuel cell based on a Nafion membrane, a fuel cell based on a combination of circulating hydrochloric acid and a Nafion membrane and a system based on a phosphoric acid doped Polybenzimidazole (PBI) membrane. None of the investigated systems were able to demonstrate stable operation under the conditions used in this study, due to electrocatalyst corrosion, membrane dehydration and/or electrode flooding. All systems studied achieved open circuit voltages close to the reversible thermodynamic value for production of aqueous hydrochloric acid, suggesting formation of dissolved HCl in the electrolyte and fast electrode kinetics.

The Chemistry of Redox‐Flow Batteries

“…[207] Ac omparison of three different cell designs led to the identification of the different advantages and disadvantages of the system. [208] In ac onventional PEM fuel-cell design, high HCl concentrations and associated dehydration of the membrane lead to higher cell resistance and power losses.C orrosion problems were increasingly found with the use of ac ell with al ow concentration of HCl. Acell with amembrane of polybenzimidazole modified by phosphoric acid achieved long-term stability,b ut lower performance values,w hich was probably due to the formation of higher phosphoric acid polymers in the membrane: reaction, while the mass transport to the electrode is also greatly increased because of the higher solubility of the iron compound compared to O 2 .Compared to Cl 2 -and Br 2 -based systems,t he iron compounds used have low toxicity and are much cheaper than vanadium.…”

A single chamber stackable microbial fuel cell with air cathode

“…Internal resistance (the sum of electrolyte and electric contact resistance) was measured using a current interruption technique with a potentiostat (EA161, eDAQ) (Thomassen et al 2006). If the MFC produced a stable current of I (A) prior to the circuit disconnection and the cell voltage rose instantaneously by the amount of DV (V) after interruption, the internal resistance R (X) could be calculated using R = DV/I, when the power density normalized to reactor volume (volumetric power density) was calculated using the formula P max,V = V 2 /(R ex Á V reactor ), where V (V) is the voltage, R ex (X) is the external resistance, and V reactor (m 3 ) is the volume of the reactor; the power density normalized to cathode surface area (surface power density) was calculated using the formula P max,S = V 2 /(R ex Á A), where A (m 2 ) is the projected area of cathode.…”

“…Biotechnol Lett (2009) 31:387-393 391 overestimate the internal resistance for series linking due to the lateral charge flow between units ( Thomassen et al 2006). Therefore, only a relative comparison between different operations of series linking, rather than an absolute comparison, is meaningful.…”

Silicon modified ultrafiltration-based proton-conductive membranes with improved performance for H2/Cl2 fuel cell application

“…However, hydrogen chloride produced in the H 2 /Cl 2 fuel cell removes most water from the membrane even with a high degree of humidification [2], due to its highly hygroscopic nature. In order to obtain a proper water management, the strategy is to dissolve the chlorine reactant in the aqueous solution of hydrochloric acid [3,4] or apply composite aqueous acid/membrane electrolyte in the fuel cell [1, 2,5]. The proton-conducting membrane (PCM) in such H 2 / Cl 2 fuel cell not only transfers protons, but also prevents the acid solution from crossing over the membrane, as well as in the direct methanol fuel cell (DMFC) and other directoxidation fuel cells.…”