Metallophilic Non-van der Waals Roll-ups Engineered for Long-Life Metal Batteries

Metal hybrid electrodes are promising for high-energy-density batteries owing to their high theoretical capacities. However, their practical employment is hampered by the inherent incompatibility between molten metals and composite materials resulting from the high surface tensions. Herein, unique metallophilic non-van der Waals (non-vdW) roll-ups of transition metal carbides are produced via metal-bonding adjacent atomic layers in scrolled MXenes, featuring a nano-sized hollow structure and abundant surface dangling bonds as well as remarkable thermal stability up to 800 °C. These features enable the formation of chemical bonding and strong capillary forces between the non-vdW roll-ups and molten metals such as Li, Ga, Mg, and their alloys, leading to the unexpected metallophilic property. As a result, the surface tensions of metal-based composites are significantly reduced, facilitating the fabrication of thin metal hybrid foils with high mechanical tensile strengths. For instance, a Mg foil incorporated with non-vdW Al-V₂CT_x roll-ups exhibits a high tensile strength up to 204 MPa, ≈2 times that of bare Mg. When employed as an anode in magnesium batteries, the full cell coupled with the Mo₆S₈ cathode delivers long-term cycling stability with ≈90.0% capacity retention after 500 cycles at 1 C, attributed to the low diffusion resistance of the hybrid electrode.