According to the team, nanoparticles are needed in order for silicon to work in batteries and it found that electrochemically produced nanoporous silicon particles sized between 10 and 20µm and with the right porosity were most suitable for use in batteries. This, they note, is significant as micron sized particles are easier and safer to process than nanoparticles.
“In our research, we were able to combine the best of nano- and micro-technologies: nano-level functionality combined with micro-level processability, and all this without compromising performance,” said researcher Timo Ikonen.
In the next stage of its work, the team will combine silicon with small amounts of carbon nanotubes enhance electrical conductivity and mechanical durability.
“We now have a good understanding of the material properties required in large-scale use of silicon in Li-ion batteries,” said Professor Vesa-Pekka Lehto. “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.”
