Hydrazine fuel cell

Like all fuel cells , a hydrazine fuel cell converts chemical energy into electrical energy . To do this, it uses hydrazine as an energy supplier (“ fuel ”) and, in the case of the hydrazine-oxygen fuel cell, air or oxygen as an oxidizing agent . A hydrazine hydrogen peroxide fuel cell has also been developed. Hydrazine fuel cells are of particular historical interest and are suitable for possible military applications. The high toxicity of hydrazine , which is also considered carcinogenic , prevents it from being widely used.

The reversible cell voltage of a hydrazine-oxygen fuel cell is around 1.6  V , which is higher than that of many other fuel cells. In addition, the possible current densities are extremely high.

Historical

The Puch MS 25 developed by Karl Kordesch in the 1950s with a hydrazine-air fuel cell.

In 1966 Karl Kordesch drove a motorcycle powered by hydrazine and hydrazine fuel cells. He drove it over 480 km (300 miles) at a speed of approx. 40 km / h (approx. 25 miles per hour) and indicated the consumption with approx. 3.8 l (1  gal) of hydrazine for approx. 320 km ( 200 miles). In 1967, Kordesch published a description of the hydrazine air fuel cell and the 300 W unit developed by Union Carbide Corporation . Also Varta and Siemens worked for a time of hydrazine fuel cells. In 2012, Daihatsu introduced a concept vehicle that was fueled with hyrazine hydrate. A specially designed tank bound the hydrazine in a polymer.

Reaction equations

For the reaction in alkaline solutions - the fuel cell is then an alkaline fuel cell - the reaction equations apply:

• Anode , negative pole: ${\displaystyle {\ce {N2H4 + 4 OH- -> N2 + 4 H2O + 4e-}}}$
• Cathode , positive pole: ${\displaystyle {\ce {O2 + 2 H2O + 4 e- -> 4 OH-}}}$
• Overall reaction: ${\displaystyle {\ce {N2H4 + O2 -> N2 + 2 H2O}}}$

Values ​​between 1.56 V and 1.57 V and 1.61 V are specified for the reversible cell voltage. It is also possible to operate hydrazine fuel cells with acidic electrolytes, but for this a particularly corrosion-resistant catalyst, usually platinum , must be used. In alkaline electrolytes, noble metals such as silver or palladium can alternatively serve as catalysts.

For the hydrazine hydrogen peroxide fuel cell the reaction equation is:

• Overall reaction: ${\displaystyle {\ce {N2H4 + 2 H2O2 -> N2 + 4 H2O}}}$

The reversible cell voltage for this reaction is 2.13 V. In practice, the open-circuit voltage is just under 1.8 V, while in operation in 2 MN ₂ H ₄ or 2 MH ₂ O ₂ at a current density of 128 mA per cm ² a cell voltage of approx. 0.96 V was reached.

Individual evidence

1. ^ ^{A b c d e} Neil V. Rees, Richard G. Compton: Carbon-free energy: a review of ammonia and hydrazine-based electrochemical fuel cells . In: The Royal Society of Chemistry (Ed.): Energy & Environmental Science . tape 4 , no. 4 , 2011, ISSN  1754-5692 , p. 1255-1260 , doi : 10.1039 / c0ee00809e ( rsc.org ).
2. ↑ ^{a b c d} Noriko Hikosaka Behling: History of Alkaline Fuel Cells . In: Fuel Cells . Elsevier, 2013, ISBN 978-0-444-56325-5 , pp. 37-51 , doi : 10.1016 / b978-0-444-56325-5.00003-x ( elsevier.com ).
3. ^ ^{A b} GE Evans, Karl V. Kordesch: Hydrazine-Air Fuel Cells . Hydrazine-air fuel cells emerge from the laboratory. In: Science . tape 158 , no. 3805 , December 1, 1967, ISSN  0036-8075 , p. 1148–1152 , doi : 10.1126 / science.158.3805.1148 ( sciencemag.org ).
4. ↑ Vincent Rice: Daihatsu Kei concepts bet on hydrazine as future fuel. In: Automotive. New Atlas / Gizmag Ltd., April 2, 2012, accessed June 21, 2019 .  
5. ↑ Aaron Turpen: Daihatsu experimenting with hydrazine as a fuel cell Possibility. In: Torque News. Hareyan Publishing, LLC, February 14, 2012, accessed June 21, 2019 .  
6. ↑ ^{a b c} Alexey Serov, Chan Kwak: Direct hydrazine fuel cells: A review . In: Applied Catalysis B: Environmental . tape 98 , no. 1-2 . Elsevier, July 2010, ISSN  0926-3373 , p. 1–9 , doi : 10.1016 / j.apcatb.2010.05.005 ( elsevier.com ).
7. ↑ M. Abdolmaleki, I. Ahadzadeh, H. Goudarziafshar: Direct hydrazine-hydrogen peroxide fuel cell using carbon supported Co @ Au core-shell nano Catalyst . In: International Journal of Hydrogen Energy . tape 42 , no. June 23 , 2017, p. 15623–15631 , doi : 10.1016 / j.ijhydene.2017.05.059 ( elsevier.com ).