Solution combustion growth of porous ZnMn2O4 on carbon cloth to enhance zinc ions storage performance

Abstract

As a positive electrode material for zinc ions storage, the large-scale application of ZnMn2O4 is severely impeded by its low conductivity and inferior cyclic durability. In this study, porous ZnMn2O4 was successfully grown on carbon cloth (ZnMn2O4@CC) for the first time using a solution combustion strategy. In the proposed combustion system, zinc nitrate and manganous nitrate were used as the oxidizing agents, while glucose served as the fuel. The in-situ growth of porous ZnMn2O4 on carbon fiber resulted in a binder-free electrode, with a coaxial core-shell architecture, improving both the structure stability and the electrode's conductivity. Compared to ZnMn2O4 powder, the zinc ions storage performance of ZnMn2O4@CC was significantly enhanced. The ZnMn2O4@CC delivered a 1st discharge-specific capacity of 281.7 mAh g−1 at 100 mA g−1, with 112.2 mAh g−1 of capacity at 500 mA g−1 after 300 cycles. The fabricated ZnMn2O4, with a large specific surface and plentiful mesopores, facilitated the wetting and penetration of the electrolyte. In addition, the porous feature can buffer the stress during the charging and discharging processes, enhancing specific capacity and cycle ability. This work not only introduces a novel method for preparing binder-free electrodes but also explores the potential application of such electrodes in zinc-ion batteries.