Direct construction of MXene 3D fibre whiskers on the surface of aqueous zinc anodes by electrostatic spinning

Dendritic problems on the anodes of aqueous zinc batteries limit their development, resulting in reduced stability and lifetime. In this paper, a dual-function molecular sieve is proposed. The molecular sieve consists of 3D fibrous whiskers compounded with 2D MXene, with the zinc foil used directly as a receptor plate and assembled directly on the surface as a zinc anode by electrostatic spinning. Zinc ion transport through 3D fibrous whiskers promotes homogeneous ion flux, while Ti3C2Tx MXene and its abundant functional groups provide a highly reversible zinc plating/stripping process; the low lattice mismatch (∼10%) allows uniform nucleation of the transported Zn along the (0002) face. The synergistic action of the two inhibits the proliferation of dendrites on the zinc anode. Consequently, MF@Zn∥MF@Zn symmetric cells achieved stable cycling for 200 h at high current densities of 5 mA - 5 mAh cm−2. Due to the smooth growth effect of MXene, 3D nucleation behaviour and remarkably low nucleation currents (10 mA) were observed in the Chrono Amps method (CA) method. Matched with carbon cathode, MF@Zn∥C shows the superior capacity and almost 100% retention after 2000 cycles compared to RZn. The experimental results confirm that MF@Zn 3D fibre whiskers constructed directly on zinc foil can significantly improve the performance of the cells, providing a new idea for other researchers.