Researchers have created a high performance anode material for lithium-ion batteries using waste silicon (Si) sawdust.
It is energy-consuming and expensive to produce Si wafers with high purity (> 99.99%). On top of that, some 50% of Si is actually discarded as industrial waste in the final cutting process. This waste is about 90 thousand tons a year worldwide, an amount large enough to meet the global demands for anode materials for lithium-ion batteries.
To make this happen, under the project of "Dynamic Alliance for Open Innovation Bridging Human, Environment and Materials," a joint research team from Tohoku University and Osaka University has developed a practical and mass-producible method of recycling the unwanted Si sawdust into a high-performance anode material for lithium-ion batteries.
The team found that the pulverization of the Si sawdust into Si nanoflakes (~16 nm in thickness) and the subsequent carbon coating are effective in fabricating high capacity and durable LIBs. So far, a test half-cell has achieved a constant capacity of 1200 mAh/g over 800 cycles. This capacity is 3.3 times as large as that of conventional graphite (ca. 360 mAh/g).
The proposed method of material recycling is applicable for the mass production of high-performance lithium-ion battery anode materials at a reasonably low cost. The research team expects that it will have great practical use in the battery industry.
Source and images: Tohoku University