Reconstruction of Electric Double Layer on the Anode Interface by Localized Electronic Structure Engineering for Aqueous Zn Ion Batteries

Abstract The electric double layer (EDL) at the electrode/electrolyte interface plays a crucial role to the electrochemical reactions of zinc ion batteries. For Zn anode, the EDL consists of H 2 O dipoles, which can cause Zn corrosion and passivation. Herein, the localized electronic‐rich (LER) structure performing as soild electrolyte interphase (SEI) changes the electron distribution, leading to the rapid capture of Zn 2+ , thus promoting the desolvation of the cH 2 O shell. Moreover, the LER generates an electrostatic repulsion effect to SO 4 2− . Consequently, a unique H 2 O‐poor EDL is reconstructed with the distribution of Zn 2+ ‐H 2 O‐SO 4 2− , which inhibits side reactions and improves the deposition kinetics of Zn 2+ . In situ Raman intuitively confirms that the zinc‐ion‐flux is uniform during the whole electroplating process. LER as regulator for EDL structure, leads to smooth and fast Zn 2+ deposition. The performance enhancement is demonstrated by LER@Zn//LER@Zn cells, which exhibit exceptional lifespan for 4800 h. Furthermore, the LER@Zn///MnO 2 cell shows improved cycling stability over 1500 cycles, with a high capacity of 124 mAh g −1 at 5 C.