Rational Design of Flexible, Self-Supporting, and Binder-Free Prussian White/KetjenBlack/MXene Composite Electrode for Sodium-Ion Batteries with Boosted Electrochemical Performance

Abstract

Due to their cost-effectiveness, abundant resources, and suitable working potential, sodium-ion batteries are anticipated to establish themselves as a leading technology in the realm of grid energy storage. However, sodium-ion batteries still encounter challenges, including issues related to low energy density and constrained cycling performance. In this study, a self-supported electrode composed of Prussian white/KetjenBlack/MXene (TK−PW) is proposed. In the TK−PW electrode, the MXene layer is coated with Prussian white nanoparticles and KetjenBlack with high conductivity, which is conducive to rapid Na+ dynamics and effectively alleviates the expansion of the electrode. Notably, the electrode preparation method is uncomplicated and economically efficient, enabling large-scale production. Electrochemical testing demonstrates that the TK−PW electrode retains 74.9% of capacity after 200 cycles, with a discharge capacity of 69.7 mAh·g−1 at 1000 mA·g−1. Furthermore, a full cell is constructed, employing a hard carbon anode and TK−PW cathode to validate the practical application potential of the TK−PW electrode.

Keywords

• sodium-ion batteries
• Ti₃C₂T_x MXene
• Prussian white
• energy density