First AIE probe for lithium-metal anodes

Formation of lithium dendrites and byproducts on the Li anode surface affects the performance and safety of lithium metal batteries (LMBs). In order to visually and semi-quantitatively analyze the lithium dendrites and byproducts, as well as their distributions and morphology on lithium anodes, we designed a first aggregation-induced emission (AIE) fluorescence probe, TPECatechol. The catechol moiety of this probe can react rapidly with active lithium or lithium dendrites, leading to a clearly discernable fluorescence change, while the emission of the probe does not change when treated with byproducts. Based on the different fluorescences, the distribution and relative number of components on cycled Li anodes can be distinguished instantaneously and conveniently, without changing the morphology of electrodes. These delicate details are hoped to provide constructive guidance on the life expectancy and safe current threshold of LMBs. Therefore, this AIE fluorescence probe may become a powerful technology for the mechanism analysis and predictive diagnosis of LMBs.