Title : Lithium-property-driven strategies for enhanced cyclability of lithium metal anodes

Abstract:

With the rising global energy demand, particularly for transportation and large-scale storage, lithium metal batteries have emerged as a promising system owing to their high theoretical capacity. However, their commercialization remains hindered by the irreversible loss of active Li during cycling, which leads to continuous decay of battery capacity. In this talk, I will present material-property-driven approaches aimed at enhancing reversibility of lithium metal anodes, with an emphasis on techniques to understand their instability and advanced engineering strategies for longer cycling. 

First, we introduce a new technique to understand irreversible behavior of lithium metal anodes – formation of inactive lithium. By redox staining, nanoparticles (NPs) of high Z elements on metallic Li (Li⁰) surface effectively visualize Li⁰ spatially and chemically. Multimodal analysis on a series of electrolytes provided spatial distribution of inactive Li⁰ at multiscale, providing insights on the correlation between cycling parameters and their formation. Our technique represents a new analytical characterization tool to spatially track previously “invisible” internal components in batteries.

Second, we propose a new concept of current collector (CC) to compensate for the capacity loss – prelithiated CC with on-demand Li extraction capability. Using metastable Li-Cu alloy as a new current collector, we demonstrate its capability for compensating for the loss of lithium at any stage, which helps extending the cycle life of batteries. In addition, mechanistic understanding on the formation of Li-Cu alloy has been investigated both experimentally and theoretically. 

Collectively, this work provides a comprehensive framework to understand and overcome capacity loss. By developing advanced engineering strategies based on material properties of lithium, we offer new directions toward the practical application of metal anodes with high energy density.