Electrode–electrolyte interphases in sustainable aqueous alkali-ion batteries

Aqueous Li-ion batteries have recently experienced intense revival because of their unique performance metrics of high environmental sustainability, low toxicity and cost.

The limited water electrochemical stability window (ESW) of 1.23 V is however a major hurdle significantly compromising their energy density. Modern Li-ion batteries therefore operate with organic electrolytes with a thermodynamically much broader ESW > 3 V.

Electrolytes can however also be kinetically stabilized by introducing a stabilizing barrier towards the electrodes, a so called solid-electrolyte interphase (SEI), which dramatically reduces the rate of side-reactions, but maintains the dis-/charge reactions of the battery cell.

Decades of research have been dedicated to the SEI in organic electrolytes, but much less so to their aqueous counterparts. This is the gap that I intend to fill.

The proposed project aims for fundamental understanding of the SEI in dilute aqueous alkali-ion batteries by comprehensively and systematically studying the impact of electrolyte salts, additives, and electrode surface coatings on the largest challenge, namely the hydrogen evolution reaction.

Autonomous robotic screening will be combined with advanced operando characterizations to gain new insights into the formation and evolution of the SEI.

Ultimately, the project aims to provide scientific design principles for more durable and inexpensive future-generation aqueous batteries to power a more sustainable society.