Self‐Adaptive and Electric Field‐Driven Protective Layer with Anchored Lithium Deposition Enable Stable Lithium Metal Anode

Abstract

Lithium metal battery has great development potential because of its lowest electrochemical potential and highest theoretical capacity. However, the uneven deposition of Li+ flux in the process of deposition and stripping induces the vigorous growth of lithium dendrites, which results in severely battery performance degradation and serious safety hazards. Here, the tetragonal BaTiO3 polarized by high voltage corona was used to build an artificial protective layer with uniform positive polarization direction, which enables uniform Li+ flux. In contrast to traditional strategies of using protective layer, which can guide the uniform deposition of lithium metal. The ferroelectric protective layer can accurately anchor the Li+ and achieve bottom deposition of lithium due to the automatic adjustment of the electric field. Simultaneously, the huge volume changes caused by Li+ migration change of the lithium metal anode during charging and discharging is functioned to excite the piezoelectric effect of the protective layer, and achieve seamless dynamic tuning of lithium deposition/stripping. This dynamic effect can accurately anchor and capture Li+. Finally, the layer‐modified Li anode enables reversible Li plating/stripping over 1500 h at 1 mA cm−2 and 50 °C in symmetric cells. In addition, the assembled Li‐S full cell exhibits over 300 cycles with N/P ≈ 1.35. This work provides a new perspective on the uniform Li+ flux at the Li‐anode interface of the artificial protective layer.