Diagnosing and Combating Efficiency Loss in Lithium Metal Batteries

The next-generation of “beyond Li-ion” battery architectures, such as Li-air and Li-S, typically require a lithium metal anode. Unfortunately these anodes present significant challenges compared to the graphite electrodes used presently, as the reactive Li metal surface rapidly degrades over repeated charge-discharge cycles due to Li dendrite growth. These dendrites ultimately lead to Li loss due to becoming disconnected from the electrode and by causing electrolyte depletion, and thus permanently reduce the cell capacity.

A number of strategies have been proposed to combat this loss, including using high concentration lithium electrolytes or engineering the electrode surface. A fundamental problem many of these strategies have is that they rely on us merely inferring their effect on the dynamics at the electrode surface, hindering their informed further development. With recent advances in transmission electron microscopy (TEM), it is now possible to directly image Li deposition in-situ and at the nanoscale under conditions that are representative of an active battery. The project will exploit this in-situ TEM technique to directly image the effectiveness of strategies in suppressing Li dendrite growth.  In particular, the project will explore how different approaches lead to improvements in Li electrode stability, and whether the many disparate approaches toward dendrite suppression have any unifying underlying concepts that can be recognised through direct imaging of Li electroplating dynamics.