A facile fabrication of lightweight current collector based on used newspaper for flexible zinc-ion hybrid supercapacitors

Abstract

The current collector in an electrode plays a crucial role in current transmission, mechanical support, and ion transport. However, most current collectors do not significantly contribute to the device's overall capacity. Therefore, reducing the weight of the current collector can effectively increase the energy density of the device. Here, we propose a simple and inexpensive method to convert used newspapers into flexible collectors by using pencil drawing, which can effectively reduce the weight of collectors. In addition, the graphite coating drawn by pencil can effectively guide the uniform nucleation of Zn2+ and achieve high reversibility and dendrite-free nature of the zinc anode. Benefiting from this strategy, the as-prepared zinc-ion hybrid supercapacitor exhibited a capacity of 81.29 mAh g−1 at 0.2 A g−1, with a maximum energy density of 65.03 Wh kg−1 and a power density of 159.80 W kg−1. Furthermore, it displayed a capacity retention rate of 77% at 1.5 A g−1 after 5000 cycles. This work may also have significance for the study of the lightweighting of other flexible energy storage devices.