Interlayer Engineering of ?-MoO₃ Modulates Selective Hydronium Intercalation in Neutral Aqueous Electrolyte.

ABSTRACT: Among various charge-carrier ions for aqueous batteries, non-metal hydronium (H₃ O⁺ ) with small ionic size and fast diffusion kinetics empowers H₃ O⁺ -intercalation electrodes with high rate performance and fast-charging capability. However, pure H₃ O⁺ charge carriers for inorganic electrode materials have only been observed in corrosive acidic electrolytes, rather than in mild neutral electrolytes. Herein, we report how selective H₃ O⁺ intercalation in a neutral ZnCl₂ electrolyte can be achieved for water-proton co-intercalated ?-MoO₃ (denoted WP-MoO₃ ). H₂ O molecules located between MoO₃ interlayers block Zn²⁺ intercalation pathways while allowing smooth H₃ O⁺ intercalation/diffusion through a Grotthuss proton-conduction mechanism. Compared to ?-MoO₃ with a Zn²⁺ -intercalation mechanism, WP-MoO₃ delivers the substantially enhanced specific capacity (356.8 vs. 184.0?mA?h?g^-1 ), rate capability (77.5?% vs. 42.2?% from 0.4 to 4.8?A?g^-1 ), and cycling stability (83?% vs. 13?% over 1000?cycles). This work demonstrates the possibility of modulating electrochemical intercalating ions by interlayer engineering, to construct high-rate and long-life electrodes for aqueous batteries.

SUBMITTER: Zhang H 

PROVIDER: S-EPMC7839748 | biostudies-literature | 2020 Sep

REPOSITORIES: biostudies-literature