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Dual‐Carbon‐Confined Fe 7 S 8 Anodes with Enhanced Electrochemical Catalytic Conversion Process for Ultralong Lithium Storage
Author(s) -
Zhang YuJiao,
Chang Wei,
Qu Jin,
Hao ShuMeng,
Ji QiuYu,
Jiang ZhiGuo,
Yu ZhongZhen
Publication year - 2018
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201804221
Subject(s) - anode , materials science , graphene , electrochemistry , lithium (medication) , chemical engineering , carbon fibers , electrolyte , amorphous carbon , catalysis , nanoparticle , electrode , nanotechnology , inorganic chemistry , amorphous solid , chemistry , composite material , organic chemistry , composite number , medicine , endocrinology , engineering
Although the electrochemical catalytic conversion process is effective in increasing the reversible capacity of lithium‐ion batteries, the low contact efficiency between metal catalyst and substrate and pulverization of the solid electrolyte interface (SEI) film without protection are not beneficial for the electrochemical reactions. Herein, Fe 7 S 8 nanoparticles are confined by both reduced graphene oxide (RGO) and in‐situ‐formed amorphous carbon (C) to form dual‐carbon‐confined Fe 7 S 8 as a lithium‐ion anode. The dual‐carbon‐confined structure provides a confined space to prevent pulverization of the SEI film and increases the local concentration of intermediate phases, which could be electrocatalytically decomposed by Fe nanoparticles formed in situ to increase the reversibility of the electrochemical reactions and gain high reversible capacity. In addition, the dual‐carbon‐confined structure ensures fast transfer of electrons and boosts transport of lithium ions due to the highly conductive dual‐carbon shell. Thus, the Fe 7 S 8 /C/RGO anode delivers an excellent rate performance and long cycling stability. At current densities of 2000 and 5000 mA g −1 , the reversible capacities are 520 mA h g −1 over 1500 cycles and 294 mA h g −1 over 2000 cycles, respectively.