Population growth around the world and increasing energy consumption have sparked interest in new alternative energy storage materials. The University of Córdoba, together with other international centers, have designed for the first time a more sustainable battery made from fish waste.
Only in China, about 59 million tons of fish are produced per 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 from tilapia, a common fish whose waste - guts, head , scales, and fins - collagen has been extracted for use in energy storage systems.
Fish waste is rich in nitrogen, oxygen, hydrogen or carbon, useful elements in batteries due to its electronegativity, stable nature and thermal stability. According to the researcher responsible for the project at the UCO, Gregorio Ortiz, collagen 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 to replace a concentrated lithium in few countries and whose availability could be scarce 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 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 for the use of this waste as a sustainable energy storage material.
However, there is still a long way to go before 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 a support for storage of wind or photovoltaic energy, 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 has been used for use in batteries. This material, however, had already been used previously in other sectors of the industry.
Doped with palladium, this marine debris has proven useful as a catalyst to remove benzene, a volatile polluting compound that causes environmental and health problems.
Now, research collects this enriched collagen to give it a new use that, according to the researcher in charge at the UCO, “could pose a new challenge for the industry and bring long-term economic and environmental benefits”.
Odoom-Wubah, Tareque & Rubio, Saúl & Tirado, José L. & Ortiz, Gregorio F. & Akoi, Bior & Huang, Jiale & Li, Qingbiao. (2020). "Waste Pd / Fish-Collagen as anode for energy storage".Renewable and Sustainable Energy Reviews. 131. 109968. 10.1016 / j.rser.2020.109968.
The research, funded by the Ministry of Science, Innovation and Universities and with funds from Erasmus Mundus scholarships, has been developing for two years and arose as a result of an international collaboration in 2015 between the University of Córdoba and Xiamen (China).