Unveiling the Aqueous Battery-Type Energy Storage Systems Through UiO-66/Se/PANI Composite

Abstract

In pursuing efficient energy storage systems, extensive research has focused on novel materials and composites. Metal-organic frameworks (MOFs), particularly UiO-66, have emerged as attractive prospects due to their unique properties. In this study, we used solvothermal techniques to synthesize UiO-66, UiO-66/Se, and UiO-66/Se/PANI materials, which were subsequently characterized using various methods. X-ray photoelectron spectroscopy and Raman spectroscopy were used to identify the nature of the defects and the surface functional groups present in the UiO-66/Se/PANI composite. X-ray diffraction analysis revealed a significant degree of crystallinity, while transmission electron microscopy (TEM) and field-emission scanning electron microscopy (FE-SEM) provided additional insights into the structural characteristics of the materials. When utilized as the battery-type supercapacitors’ electrode material, the UiO-66/Se/PANI composite demonstrated exceptional capacity performance, reaching 607.3 C g^− 1 (168.7 mAh g^− 1) at 1 A g^− 1, along with outstanding coulombic efficiency and capacity retention even at a high current of 5 A g^− 1. An asymmetric device was constructed to investigate practical applications. In this device, UiO-66/Se/PANI was utilized as the positive electrode, while commercial activated carbon was the negative electrode. This device exhibited remarkable performance metrics, including a specific energy of 35.2 Wh kg^− 1, a specific power of 977.02 W kg^− 1, and a capacity retention rate of 79% after 5000 cycles, with a high coulombic efficiency of 99.5%. For application in zinc alkaline battery, UiO-66/Se/PANI demonstrated a 126 mAh g^− 1 capacity and demonstrated a high cycling lifespan, with 95.5% capacity retention after 1000 cycles and 93.6% rate properties. It also revealed a tremendous specific energy of 65.5 Wh kg^− 1 at the current density of 0.5 A g^− 1. This work encourages the development of novel cathode materials for alkaline zinc batteries and high-performance aqueous battery-type supercapacitors.