Lithium anode stability enhanced by micro-potentials from spontaneous polarization in BaTiO3 films

Lithium metal is widely recognized as an ideal anode material due to its high specific capacity and low redox potential. However, challenges such as severe lithium dendrite growth have significantly impeded its practical applications. Herein, we introduce a BaTiO₃ (BTO) ferroelectric thin film into the lithium anode. During the charge/discharge cycles, the BTO film generates a micro-potential in the direction opposite to the applied electric field, owing to its spontaneous polarization. The micro-potential effectively reduces the electric field gradient, thereby suppressing inhomogeneous nucleation and the growth of lithium dendrites. Consequently, the incorporation of the BTO ferroelectric thin film significantly enhances the cycling performance of the batteries. The half cells demonstrate stable operation after more than 100 cycles at high capacity of 4 mAh cm⁻². Furthermore, the LiFePO₄ (LFP) full cell delivers a specific capacity of 146.6 mAh g⁻¹ after 300 cycles. This work demonstrates a promising strategy for the development of lithium batteries with improved longevity and enhanced capacity.