Hope for better batteries – researchers follow the charging and discharging of silicon electrodes live

Using silicon as a material for electrodes in lithium-ion batteries promises a significant increase in battery amp-hour capacity.The shortcoming of this material is that it is easily damaged by the stress caused by charging and discharging.Scientists at the Helmholtz-Zentrum Berlin für Materialien und Energie (HZB) have now succeeded for the first time in observing this process directly on crystalline silicon electrodes in detail.Operando experiments using the BESSY II synchrotronprovided new insights into how fractures occur in silicon – and also how the material can nevertheless be utilised advantageously.

Whether in smartphones or electric cars – wherever mobile electric power needs to be available, it usually comes from rechargeable lithium-ion batteries. One of the two electrodes inside these batteries consists of graphite in which lithium ions are lodged, thereby storing electrical energy. The disadvantage of this carbon material is that its energy storage capacity is quite small – which makes frequent recharging of the battery necessary. For this reason, researchers worldwide are searching for alternative electrode materials to lengthen the battery charge/discharge cycles.

Read more on the Helmholtz Zentrum Berlin website

Image: The design of the experimental set-up shows how the structure of the silicon electrode periodically changes during charging and discharging on the basis of voltage measurements. © HZB