Spontaneous polarization guides uniform Al deposition in porous anodes for rechargeable aluminum batteries.

Rechargeable aluminum batteries (RABs) hold substantial promise for large-scale energy storage. However, the pore architecture of porous anodes exacerbates concentration polarization and disrupts the electrode/electrolyte interface, thereby inducing the rapid growth of Al dendrites. These dendrites obstruct pores, penetrate the separator, and consume active species, ultimately undermining cycling stability. Herein, the spontaneous polarization electric field generated by barium titanate (BT) is utilized to achieve uniform distribution of active ions within the system and dynamically regulate the electrode/electrolyte interface. The porous structure modified by BT forms a three-dimensional electric field network, guiding Al x Cl y - to uniformly migrate to multiple deposition sites; the three-dimensional deposition space provided by the porous skeleton transforms Al deposition from "two-dimensional planar deposition" to "three-dimensional cooperative growth". This study provides insights into the rational design of porous electrodes for RABs and the optimization of electrode/electrolyte interfaces to enhance electrochemical performance.