Silicon-Based Anode Batteries Can Be Made From Used Glass Bottles
A team of researchers at University of California Riverside (UCR) developed new batteries that contain nano-silicon anodes that are critical for lithium-ion. Their batteries, made from waste glass bottles, store four times the energy than the conventional batteries. Given that lithium-ion is used in almost all electronic devices, using more efficient, low-cost batteries as well as reducing waste is a win for all.
Lithium-ion batteries are made with a lithium cathode and a graphite anode whereas the new batteries contain silicon anodes. While the silicon anodes can ideally store up to 10 times the energy than a graphite anode, they aren’t as durable and the expansion and contraction of the material can make them unstable. The resulting increase and decrease forms cracks which can lead to low battery performance, create short circuits and eventually stop the battery from operating. However, reducing the size of silicon particles to nanoscale will significantly reduce the risk of instability thus giving the batteries at least four times the energy as found by the team. Figure 1 shows the materials, three processes and the final coin batteries developed by the team.
Although the idea of using silicon-based anode to boost lithium-ion performance has been around for a long time, the UCR team’s efficient and low-cost eco-friendly method of developing the batteries sets them apart from other research teams. Last year, a research team at the University of Waterloo developed a new approach to dealing with the loss of energy of silicon during expansion and contraction. They used a flash heat treatment for the fabricated silicon anodes in the lithium-ion batteries to minimize the instability.
This design by Waterloo’s research team claimed to have more than 1000 mAh/g over 2275 cycles with a coulombic efficiency of 99.9% which is the efficiency of the charge transferred within a system. These values are significantly higher than the UCR’s design which had a coulombic efficiency of 85% after the first cycle. However the latter are using glass bottles and green technology to make their battery and given that more than 100 cell batteries can be made from just one bottle, the team has surely made a significant discovery for the next-generation batteries.