Only in China are produced about 59 million tons of fish year, of which 58% is not consumed as food and ends up becoming biological waste.
Now, scientists from the University of Córdoba, the Chinese University of Xiamen and the Wentworth Institute of Technology (Boston, USA), have managed to take advantage of different parts collected from the port of Shapowei in tilapia, a common fish from whose waste – guts, head, scales and fins – collagen has been extracted for use in energy storage systems.
The fish waste they are rich in nitrogen, oxygen, hydrogen The carbon, useful elements in batteries due to their electronegativity, stable nature and thermal stability. As explained by the researcher in charge of the project at the UCO, Gregorio Ortiz, collagen It has been used as an anode (negative pole) and subjected to different laboratory tests to estimate how it would function when combined with conventional cathodes (positive pole).
The study has experimented with lithium batteries, used worldwide, and with sodium and magnesium devices, two of the main candidates called for replace a concentrated lithium in few countries and whose availability may be in short supply in the future.
According to the conclusions of the work, the capacity values achieved in the three cases are very similar, and even higher in some ranges, than those obtained with other chemically synthesized materials, with the advantage that, on this occasion, the anode of the battery comes from a sustainable material and that often turns into millions of tons of waste.
The work, for which the University of Córdoba has developed the electrochemical study and analyzed the different reaction mechanisms, opens a new way to make use of this waste as a sustainable energy storage material.
But nevertheless, there is still a journey so that these batteries can be commercialized. “In the study we have analyzed the energy density at the cell level, based on the mass of the electrodes. To be able to market them, we would have to consider the mass of the assembly ”, adds Gregorio Ortiz.
In that case, these new devices could be useful as support in wind or photovoltaic energy storage, systems in which large volumes of available material are necessary.
A new use for a new challenge
This is the first time that collagen from fish waste It is used for use in batteries. This material, however, had already been used previously in other sectors of the industry.
Palladium doped, this marine residue has proven useful as a catalyst to remove benzene, a volatile polluting compound that causes health and environmental problems.
Now, research collects this enriched collagen to give it a new use that, according to the conclusion of the researcher in charge at the UCO, “could pose a new challenge for the industry and provide economic and environmental benefits long-term”.