Lithiophilic Mo_2C Clusters-Embedded Carbon Nanofibers for High Energy Density Lithium Metal Batteries

摘要

Lithium metal anodes are widely regarded as the ideal candidate for the nextgeneration of high-energy-density lithium batteries. Here, a 3D host made oflithiophilic Mo_2C clusters-embedded carbon nanofibers (Mo_2C@CNF) isdeveloped. The uniformly dispersed clusters and large specific surface areasof Mo_2C@CNF provide numerous nucleation sites for lithium deposition.Mo_2C clusters exhibit ultralow nucleation overpotential compared to Moo_2,which is also supported by density functional theory calculations.Furthermore, the transition metal element serves as a catalyst for theformation of a stable and robust solid electrolyte interphase layer containingLiF on Mo_2C@CNF, effectively mitigating the occurrence of dead lithium andenhancing the Coulombic efficiency during prolonged operation. As a result,the Mo_2C@CNF composite delivers superior electrochemical performance(>1600 h) at 1 mA cm~(?2) and lower nucleation overpotential (13 mV) forlithium plating. The Li/Mo_2C@CNF anode coupled with the commercialLiFePO_4 cathode exhibits excellent cycling stability (300 cycles at 1 C) andhigh rate capability at low N/P ratios.