Morphology Selection Kinetics of Li Sphere via Interface Regulation at High Current Density for Pragmatic Li Metal Batteries

Uncontrollable lithium dendrite growth and severe Li/electrolyte side reactions under high operating current densities seriously hinder the development of high-performance Li metal batteries (LMBs). To address the aforementioned critical issues, spherical Li nuclei are designed via an all-in-one nitrocellulose (NC)/LiFSI electrolyte to achieve high-energy/power-density and long-cycle LMBs. First, the synergistic effect of LiFSI induced LiF-rich interface and the nitro group in the NC scaffold promote uniform Li nucleation, resulting in spherical nuclei morphology instead of dendritic even under high current densities. Moreover, NC exhibits strong adsorption energy on the electrode surface, which facilitates the formation of an organic protection layer to suppress side reactions, which enables highly reversible Li cycling, even in a lean-electrolyte environment. With the assistance of the unique interphase, the Li|Li symmetric cells using NC/LiFSI electrolyte can stably run at a high current density of 10 mA cm(-2). Moreover, the assembled Li|LiFePO4 pouch cell achieves excellent cycling stability of 210 cycles with 100% capacity retention. This finding provides a new strategy relying on electrolyte engineering to achieve high-energy/power-density and long-cycling-life LMBs.

Automated summary

The use of spherical lithium nuclei in combination with NC/LiFSI electrolyte allows for high stability and cycling performance under high current densities in lithium metal batteries.