A new zinc-ion battery cathode with high-performance: Loofah-like lanthanum manganese perovskite

Abstract

Due to high safety and excellent rate performance, the aqueous Zn-ion battery is a promising energy storage battery for practical application. However, most manganese-based compounds suffer from poor cycling and rate performance. Herein, a new concept of Zn-ions battery is assembled with the loofah-like LaMnO₃ perovskite as a novel cathode, achieving fast ion kinetics through the co-intercalation of Zn²⁺ and H⁺ cations. In this work, the Ni-doping strategy is adopted to improve the electrochemical performance of LaMnO₃ perovskite as a cathode material for Zn-ion batteries. The resultant LaNi_xMn_1-xO₃ (x = 0.2) exhibits a superior capacity of 226 mAh g^-1 after 80 cycles at 100 mA g^-1 and high working voltages at 1.4 V and 1.26 V vs. Zn²⁺/Zn in the electrolyte of 2 M ZnSO₄ + 0.2 M MnSO₄. Even at 500 mA g^-1, the new Zn/LaNi_xMn_1-xO₃ battery still delivers a discharge capacity of 113 mAh g^-1 after 1000 cycles. At medium current density, the electrochemical process of the LaNi_xMn_1-xO₃ (x = 0.2) electrode is co-controlled by the solid diffusive and surface-capacitive process with a fast ion diffusion rate. The lanthanum manganese perovskite is a potential cathode material for Zn-ion batteries with long cycle performance and high rate cyclability. This work significantly opens up the way of perovskite materials as new cathodes for high-rate ZIBs.

Keywords: Cathode materials; LaNi(x)Mn(1-x)O(3); Loofah-like; Perovskite; Zinc-ion battery.