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

Abstract

AbstractThe 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 H2O 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 Zn2+, thus promoting the desolvation of the cH2O shell. Moreover, the LER generates an electrostatic repulsion effect to SO42−. Consequently, a unique H2O‐poor EDL is reconstructed with the distribution of Zn2+‐H2O‐SO42−, which inhibits side reactions and improves the deposition kinetics of Zn2+. 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 Zn2+ deposition. The performance enhancement is demonstrated by LER@Zn//LER@Zn cells, which exhibit exceptional lifespan for 4800 h. Furthermore, the LER@Zn///MnO2 cell shows improved cycling stability over 1500 cycles, with a high capacity of 124 mAh g−1 at 5 C.