Aim 4: Interface

Reveal the local structure and chemistry of the liquid/solid interfaces under electrified operating conditions and correlate to electrochemical performance.

The Aim 4 team seeks to reveal the local atomic arrangement and chemistry of the liquid/solid interfaces of the aqueous battery under normal, electrified operating conditions and to correlate them with the battery’s electrochemical performance.

Electrified liquid/solid interfaces facilitate the electron and ion transfer processes fundamental to battery function. In 1853, the German physicist Hermann von Helmholtz recognized the importance of how ions and molecules in solution are arranged at these interfaces, collectively describing them as the electrical double layer.

Further complicating the interfaces are the presence of a solid electrolyte interphase, a nanometers-thick surface film which develops during cycling that further governs electron and ion transport. Despite their long history, key aspects of the electrical double layer and solid electrolyte interphase at electrified liquid/solid interfaces remain unclear.

The Aim 4 team expects to produce the first molecular-scale images of the electrified interface in the battery under operating conditions, which will provide direct insights for the fundamental ion and electron-transfer processes that underpin aqueous battery chemistries.