Silicon could solve issues with lithium-ion battery development, paving way for increased renewables generation
Silicon could present a solution to problems hampering the development of next generation lithium-ion batteries, presenting a promising step forward for the renewable energy sector, new research has revealed.
In a study carried out by the University of Eastern Finland, the suitability of using electrochemically produced nanoporous silicon for Li-ion batteries was analysed by replacing graphite anodes on li-ion batteries with silicon.
The use of silicon resulted in a four-fold increase in anode capacity, resulting in improved energy density and storage capabilities.
One of the main findings of the study was that with the right porosity, silicon particles sized between 10 and 20 micrometres were the most suitable ones to be used in batteries. Micrometre-sized particles are easier and safer to process than nanoparticles, and also present a better choice from the viewpoint of battery material recyclability.
“We were able to combine the best of nano- and micro-technologies: nano-level functionality combined with micro-level processability, all this without compromising performance,” says Timo Ikonen, one of the project researchers from the University of Eastern Finland.
The findings, which were published in Scientific Reports, are significant as in the past, it has been generally understood that in order for silicon to work in batteries, nanoparticles are required, and this brings about many challenged in terms of the production, price and safety of the material.
“Small amounts of silicon are already used in Tesla's batteries to increase their energy density, but it’s very challenging to further increase the amount,” says Ikonen.
As a next step for the project, the researchers plan to combine silicon with small amounts of carbon nanotubes in order to further enhance the electrical conductivity and mechanical durability of the material.
“We now have a good understanding of the material properties required in large-scale use of silicon in Li-ion batteries,” says professor Vesa-Pekka Lehto from the University of Eastern Finland. “However, the silicon we’ve been using is too expensive for commercial use, and that’s why we are now looking into the possibility of manufacturing a similar material from agricultural waste, for example from barley husk ash.”
As the world moves towards a more climate-neutral society, renewable and emission-free sources of energy, such as wind and solar power, will become increasingly widespread. The supply of energy from these sources, however, is intermittent, and technological storage solutions are needed to safeguard the availability of energy also when it’s not sunny or windy.
For renewable energy storage, lithium-ion batteries are widely considered to pose the best solution – offering longer lifespans, and higher energy and power densities than other methods of energy storage.