Spinel zinc manganate-based high-capacity and high-stability non-aqueous zinc-ion batteries

Abstract

For aqueous zinc ion batteries (ZIBs), poor cyclability originates from undesired side reactions, leading to dendrite formation and thermodynamic instability. Strategies such as surface modifications of electrodes, utilization of electrolyte additives, and tuning the crystallinity and electronic structure have been previously adopted to prevent such issues. Despite significant research in this area, achieving high efficiency by suppressing dendrite growth and long-term durability is still challenging. In recent years, non-aqueous (NA) electrolyte-based ZIBs have emerged due to their advantages of high voltage window stability, alleviating dendrite formation, and compatibility of high voltage host materials with NA electrolytes. Here, we used an NA electrolyte for a spinel zinc manganate (ZMO) based ZIB. In this work, we have synthesized zinc manganate on carbon cloth (ZMC) via a simple and facile electrodeposition method. The synthesized cathode was assembled with a metallic zinc anode, which exhibited outstanding cycling stability for 1000 cycles with a minimal capacity fading of 12% and almost 100% coulombic efficiency. The ZIB exhibits the highest specific energy (SE) of 632 W h kg⁻¹ and specific power (SP) of 1277 W kg⁻¹. The chemical kinetics of the zinc ion have been probed by studying cyclic voltammetry and discharge curves for the galvanostatic intermittent titration technique (GITT). Furthermore, ex situ investigations were carried out to get details about the charge storage mechanisms during various stages of charge–discharge. These studies underpin the origin of high stability and excellent discharge capacity and bring up-to-date electrochemical reactions within NA ZIBs.