Combined ion-conduction and nucleation-guiding in a porous TiOx/Bi-nanocrystal composite for stable lithium metal anodes

A BTO-TiO x /Bi-NC interlayer enables synergistic Li + regulation and guidance. • Li||Li cells achieve 800 h stable cycling in high-voltage ester electrolyte. • Li− S batteries retain 466.53 mAh g −1 after 400 cycles at 3C in ether electrolyte. The practical application of Li metal anodes is hindered by uncontrollable dendrite growth, which stems from the unstable solid electrolyte interphase (SEI) and heterogeneous Li + flux. Herein, we report a porous Bi 4 Ti 3 O 12 (BTO) decorated with in-situ generated titanium oxide and bismuth nanocrystals (denoted as BTO-TiO x /Bi-NC) composite, as a multifunctional interfacial layer to address these challenges. The integrated TiO x ensures high ionic conductivity, while Bi-NC effectively regulate Li + flux, thereby guiding uniform Li + plating/stripping. Moreover, it is hypothesized that the reversible Li 3 Bi alloying reaction during cycling could provide additional nucleation sites, potentially contributing to enhanced Li deposition homogeneity. Benefiting from this rational design, BTO-TiO x /Bi-NC promises the symmetric Li||Li cell exhibiting remarkable stability for 800 h at 1 mA cm −2 in high-voltage ester-based electrolyte. When coupled with an S cathode, the full Li S battery maintains a discharge capacity of 466.53 mAh g −1 after 400 cycles at 3C in ether-based electrolyte, demonstrating excellent long-term cyclability. This work proposes a promising strategy for stabilizing Li metal anodes via combined Li + flux regulation and alloying chemistry, paving the way for durable high-energy-density batteries. Download: Download high-res image (145KB) Download: Download full-size image