Novel Fe trihalides solid molten salt-FeX3 (X = F, Cl, Br) via one-step method with low temperature as anodes of lithium-ion batteries

Abstract

Cost-effective metal trihalides exhibiting high specific capacity hold significant promise as anodes in lithium-ion batteries (LIBs). Within this study, the spotlight falls on innovative anode materials, denoted as solid molten salts (SMS-FeX3, X = F, Cl, Br), which are synthesized through the utilization of transition metal trihalides. SMS-FeX3 anodes offer a range of advantages, including facile synthesis, environmental sustainability, and the electrochemical benefits stemming from the superior conductivity and electrochemical performance of solid molten salts. Leveraging the synergistic interaction between Fe trihalides (FeF3, FeCl3, FeBr3) and N-Methyl-2-Pyrrolidone (NMP), these SMS materials exhibit exceptional electrochemical performance and remarkable cycle stability. Furthermore, a comprehensive comparison among the three Fe trihalides underscores their distinct characteristics: SMS-FeF3 showcases a consistent Coulombic Efficiency of approximately 100 % throughout 400 cycles. SMS-FeCl3 stands out with an initial specific capacity of 1258 mAh/g at 100 mA g−1, sustaining at 900 mAh/g after 400 cycles. Meanwhile, SMS-FeBr3, serving as a comparative material, exhibits commendable rate performance even at 2000 mA g−1. These captivating and pioneering SMS-FeX3 anode materials offer a fresh perspective on the anode fabrication of LIBs, bearing exceptional promise for practical applications.