Finding the Source of Dendrites in Lithium-Ion Batteries
Lithium-ion batteries surround us today, thanks to their high energy densities and quick charging and discharging. As impressive as they may seem now though, they could be better if not for one problem. Researchers at Berkeley Lab have recently analyzed lithium-ion electrodes using microtomography to reveal the source of that problem, and potentially how to fix it.
Many lithium-ion batteries use graphite electrodes, but if lithium metal electrodes were used instead, higher energy densities could be achieved. The problem is that fibers of lithium, called dendrites, will eventually form and connect the electrodes within the battery, causing a potentially dangerous short circuit. Many attempts to prevent this from happening have been tried with limited success, and the Berkeley researchers may have an explanation for why. According to their microtomography data, and contrary to popular belief, the dendrites first form inside of the electrode and only appear outside of it at advanced stages of development.
By looking closely at where the dendrite structures first formed beneath the electrode's surface, the researchers may have found a path to a means to prevent them. The dendrites all appeared to form at non-conductive contaminants within the electrodes, so by removing those it may be possible to prevent dendrites from forming, and thus allow lithium metal anodes to be used.
Source: Berkeley Lab