Efficient vapor-solid fluorination synthesis of MOF-derived MnF2/C for superior lithium storage with boosted kinetics

Abstract

Transition metal fluorides have attracted widespread interest in recent years on account of their high energy density. However, their low conductivity and poor cyclability limit their development in next-generation power batteries. Herein, two methods (vapor-solid method and traditional calcination fluorination method) were used to successfully synthesize the manganese fluoride nanoparticle anode material attached on in-situ multi-vacancy carbon. Experimental data shows that vapor-solid method can provide more additional active sites, better electrical conductivity and more space to relieve volume expansion when compared to calcined fluorination. Pseudocapacitance analysis show their exceeding theoretical capacity phenomenon. By comparison, it is found that the spherical hollow manganese fluoride nanoparticles embedded carbon anode material obtained by the vapor-solid method exhibits excellent long cycle performance (450 loops at 1 A g−1, and a capacity of up to 864 mAh g−1, at a current density of 2 A g−1 1700 cycles with a capacity of up to 519 mAh g−1).