Nitrogen-doped carbon microfiber networks decorated with CuO/Cu clusters as self-supported anode materials for potassium ion batteries

In light of the sluggish potassiation kinetics in potassium ion batteries, herein, we report a self-supported anode material composed of CuO/Cu clusters distributed in nitrogen-doped carbon microfibers (CuO/Cu-NCNFs electrode) via a simple electrospinning technology. By this way, a three-dimensional conductive networks interwoven by CuO/Cu-NCNFs microfibers were successfully obtained. As expected, this self-supported anodematerials for potassiumion batteries reveals better electrochemical performance compared with nitrogen-doped carbon microfibers (NCNFs). There is still a reversible capacity of 205.9 mAh g(-1) remained for the CuO/Cu-NCNFs electrode undergoing 100 cycles at 100 mA g(-1). With the in-depth investigation, the CuO/Cu-NCNFs show more obvious pseudocapacitive characteristic than that of NCNFs. The improved capacitive contribution discloses the reason for the fast kinetics of CuO/Cu-NCNFs. It is believed that the presence of CuO/Cu significantly favors the advancement of mechanical property and stability of microfiber networks, giving rise to the fast kinetics of CuO/Cu-NCNFs. It can be predicted that this innovative potocol of CuO/Cu-NCNFs microfiber frameworks will provide explicit direction toward engineering high performance electrode materials for potassium ion batteries. (C) 2020 Elsevier B.V. All rights reserved.