MXene-based polymer brushes decorated with small-sized Ag nanoparticles enabled high-performance lithium host for stable lithium metal battery

Li metal stands out as a promising anode material for next-generation energy storage devices. Nevertheless, the application of Li metal anode is hampered by some severe issues of uncontrolled dendrite growth and infinite volume expansion during cycling. In this study, a high-performance Li metal host consisting of poly(4-vinylpyridine) grafted Ti3C2 MXene molecular brushes decorated with uniformly distributed small-sized Ag nanoparticles was prepared. Benefiting from the synergetic effect between Ti3C2-g-PV4P sheets and Ag nanoparticles, dendrite-free Li deposition was achieved with a low nucleation overpotential (∼3.2 mV) and high Coulombic efficiencies (>98% after 200 cycles). The full cells assembled with the Li@host anode and LiFePO4 cathode delivered a high discharge capacity (102.8 mAh g−1 at 5 C) and excellent cycling stability (137.8 mAh g−1 after 150 cycles at 1 C). This work demonstrates a perspective design and application of Li metal host materials.