Silicon nanoflakes a game-changer for battery sector?

Japan: A joint research team from Tohoku University and Osaka University in Japan has developed a cost-effective way to recycle silicon sawdust into high-performance anode material for lithium-ion batteries.

The innovative mass-producible, bead-milling method yields nanoflakes with an ‘extremely small thickness’ of 15-17 nm and a diameter of 0.2-1 μm, according to researchers.

In tests, the best samples can retain constant capacity over 800 cycles with great efficiency – said to be more than three times better than conventional graphite. World production of silicon metal was 1 766 400 tons in 2014, the researchers point out.

Approximately 10% is of a high-purity grade suitable for the production of silicon wafers used in the semiconductor industry – for example, for integrated circuits and photovoltaic cells.

Besides entailing a high energy-consuming manufacturing process, up to 55% of costly silicon is simply lost as sawdust in the cutting process. The wasted material could well satisfy global demand for anode materials for lithium-ion batteries, researchers contend.

The work is a part of the Dynamic Alliance for Open Innovation Bridging Human, Environment and Materials research project.