posted on 2022-09-07, 17:11authored byLi Ting Gao, Pingyuan Huang, Zhan-Sheng Guo
Li metal has attracted considerable
attention as the
preferred
anode material for high-energy batteries. However, Li dendrites have
limited the development of Li-metal batteries. Herein, the effects
of tuning the porous separator microstructure (SM) for guiding Li
dendrite growth and reviving dead Li are revealed using a mechano-electrochemical
phase-field model. A strategy of guiding, instead of suppression,
was applied to avoid disordered Li dendrite growth. By analyzing the
effects of the number of layers, thickness, degree of staggered overlap
in the separator, interlayer spacing, and porosity of SM on Li dendrite
behavior, we discovered that applying a rationally designed SM can
finely guide the Li nucleation and growth direction toward dense deposition.
The revival of dead Li was also observed via an in situ experiment
on Li dendrites. The reactivation of dead Li after it recontacts Li
metal was verified. These findings not only provide fundamental information
for the tuning of the SM but can also help better understand the dendrite
growth of other alkali metal-ion batteries.