In-Situ Synthesis of FeF3/Graphene Composite for High-Rate Lithium Secondary Batteries

Improved Electrochemical Performance of FeF3 by Inlaying in a Nitrogen‐Doped Carbon Matrix

“…[70] Meanwhile, the addition of carbon increased the surface area of composites and significantly enhanced the contact area between the electrolyte and the FeF 3 particles. [11,32,46] Figure 5b shows the F00 delivered a discharge capacity of about 97.3 mAh g À 1 at 0.1 C (1 C = 237 mA g À 1 ). [32] Furthermore, FCN exhibited higher capacity because of that Ndoped carbon not only has good electronic conductivity, [39,71,72] but also N atoms acted as anchors sites, which benefited to the adsorption of Li + and limited them to the vicinity of the grain surface, thereby promoting the electrochemical reaction.…”

“…And the rapid insertion/deintercalation of Li + would cause the volume of FeF 3 to change constantly, resulting in the collapse of crystal structure. [11,32,46] Figure 5b shows the F00 delivered a discharge capacity of about 97.3 mAh g À 1 at 0.1 C (1 C = 237 mA g À 1 ). Meanwhile, FC0 and FCN exhibit a larger capacity of about 152.1 and 184.9 mAh g À 1 , respectively, with long and stable platforms.…”

“…[4][5][6] In this case, the conversion reaction involving multiple-electrons have received much attention because it can deliver high specific capacity. [10][11][12] However, the strong ionic character of FeÀ F bonds lead to poor electronic conductivity and inferior kinetics, which greatly limits the capacity for storing lithium. [5,8] Among them, iron fluoride (FeF 3 ) has been widely studied because the high theoretical capacity of 712 mAh g À 1 (delivering three electrons) and working potential (about 3.0 V for the redox reaction).…”

“…[9] Its rich resources, good thermal stability and non-toxic properties provide favorable conditions for large-scale use. [10][11][12] However, the strong ionic character of FeÀ F bonds lead to poor electronic conductivity and inferior kinetics, which greatly limits the capacity for storing lithium. [13] In addition, poor cyclic stability caused by the structure collapse also restricts its commercialization.…”

High-Performance Cathode Material of FeF3·0.33H2O Modified with Carbon Nanotubes and Graphene for Lithium-Ion Batteries

“…Graphene, with its large specific area, can promote sufficient contact at the electrode and electrolyte interface, and the graphene network plays an important role in electron transfer and ion migration. Furthermore, graphene provides excellent mechanical stability, which contributes to the bend and stretch of electrode [ 32 , 33 ].…”