Three-dimensional MXene-encapsulated porous Ni-NDC nanosheets as anodes for enhanced lithium-ion batteries

Although metal–organic frameworks have been heavily tested as the anode materials for lithium-ion batteries (LIBs), the poorer conductivity, easy collapse of frameworks, and serious volume expansion limit their further application in LIBs. Herein, we report a facile approach to obtain MXene-encapsulated porous Ni-naphthalene dicarboxylic acid (Ni-NDC) nanosheets by hybridizing ultrathin Ti₃C₂ MXene and three-dimensional (3D) Ni-NDC nanosheet aggregates. In the structure of Ni-NDC/MXene hybrids, the interlayer hydrogen-bond interaction between Ni-NDC and MXene can effectively increase the interlayer spacing and further inhibit the oxidation of pure MXene. Hence, the introduction of MXene (a conductive matrix) could further improve the conductivity of Ni-NDC, avoid self-agglomeration, and buffer the volume expansion of Ni-NDC nanosheets. Benefiting from the synergistic effects between Ni-NDC and MXene, Ni-NDC/MXene hybrid electrode exhibits a reversible discharge capacity (579.8 mA∙h∙g⁻¹ at 100 mA∙g⁻¹ after 100 cycles) and good long-term cycling performance (310 mA∙h∙g⁻¹ at 1 A∙g⁻¹ after 500 cycles).