Flexible Electronic Systems via Electrohydrodynamic Jet Printing: A MnSe@rGO Cathode for Aqueous Zinc-Ion Batteries
Shang Wang, Guifang Zeng, Qing Sun, Yan Feng, Xinxin Wang, Xinyang Ma, Jing Li, He Zhang, Jiayue Wen, Jiayun Feng, Lijie Ci, Andreu Cabot, Yanhong Tian
Abstract
Aqueous zinc-ion batteries (ZIBs) are promising candidates to power flexible integrated functional systems because they are safe and environmentally friendly. Among the numerous cathode materials proposed, Mn-based compounds, particularly MnO 2, have attracted special attention because of their high energy density, nontoxicity, and low cost. However, the cathode materials reported so far are characterized by sluggish Zn 2+ storage kinetics and moderate stabilities. Herein, a ZIB cathode based on reduced graphene oxide (rGO)-coated MnSe nanoparticles (MnSe@rGO) is proposed. After MnSe was activated to α-MnO 2, the ZIB exhibits a specific capacity of up to 290 mAh g –1 . The mechanism underlying the improvement in the electrochemical performance of the MnSe@rGO based electrode is investigated using a series of electrochemical tests and first-principles calculations. Additionally, in situ Raman spectroscopy is used to track the phase transition of the MnSe@rGO cathodes during the initial activation, proving the structural evolution from the LO to MO 6 mode. Because of the high mechanical stability of MnSe@rGO, flexible miniaturized energy storage devices can be successfully printed using a high-precision electrohydrodynamic (EHD) jet printer and integrated with a touch-controlled light-emitting diode array system, demonstrating the application of flexible EHD jet-printed microbatteries.