Next-generation high-energy batteries require rechargeable metal anodes, but hazardous dendrites tend to form during recharging, causing short-circuit risk and capacity loss, even with hard and stiff ceramic electrolytes, by mechanisms that still remain elusive. In this talk, we will demonstrate a rigorous analysis of the lithium dendrite formation in liquid and solid electrolytes, through the intimate combination of operando experiments and transport models. Our results demonstrated the necessity to differentiate Li whiskers from Li dendrites, induced from different physical processes. Resolving the interfacial instability and metal whiskers led to an ideally smooth, non-porous, ingot-type Na metal plating, which enabled the anode-free Na metal full cells with a record-high retention rate of 99.93% per cycle at 3C charge and discharge. Chronopotentiometry tests of this ideal metal electrode revealed an inverse correlation between the penetration overpotential and the pore size of the separator, which can be captured by a new model that we named the Young-Laplace overpotential. Novel electrochemical tests of garnet-type cubic Li7-xLa3Zr2-xTaxO12 ceramic electrolytes confirmed a similar polarization and dendrite initiation mechanism through grain boundaries. Our theoretical and experimental discoveries suggest that the success of alkali metal batteries relies on the rational control of both the interfacial kinetics and the bulk ion transport.

Predictable roles of ion polarization in the interfacial instabilities of alkali metal anodes

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.