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Single Nickel Atoms on Nitrogen‐Doped Graphene Enabling Enhanced Kinetics of Lithium–Sulfur Batteries
Author(s) -
Zhang Linlin,
Liu Daobin,
Muhammad Zahir,
Wan Fang,
Xie Wei,
Wang Yijing,
Song Li,
Niu Zhiqiang,
Chen Jun
Publication year - 2019
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.201903955
Subject(s) - polysulfide , materials science , graphene , nickel , electrochemistry , separator (oil production) , lithium (medication) , chemical engineering , sulfur , doping , nitrogen , catalysis , ion , inorganic chemistry , nanotechnology , electrode , chemistry , electrolyte , metallurgy , organic chemistry , thermodynamics , optoelectronics , medicine , physics , endocrinology , engineering
Lithium–sulfur (Li–S) batteries have arousing interest because of their high theoretical energy density. However, they often suffer from sluggish conversion of lithium polysulfides (LiPS) during the charge/discharge process. Single nickel (Ni) atoms on nitrogen‐doped graphene (Ni@NG) with Ni–N 4 structure are prepared and introduced to modify the separators of Li–S batteries. The oxidized Ni sites of the Ni–N 4 structure act as polysulfide traps, efficiently accommodating polysulfide ion electrons by forming strong S x 2− ⋅⋅⋅NiN bonding. Additionally, charge transfer between the LiPS and oxidized Ni sites endows the LiPS on Ni@NG with low free energy and decomposition energy barrier in an electrochemical process, accelerating the kinetic conversion of LiPS during the charge/discharge process. Furthermore, the large binding energy of LiPS on Ni@NG also shows its ability to immobilize the LiPS and further suppresses the undesirable shuttle effect. Therefore, a Li–S battery based on a Ni@NG modified separator exhibits excellent rate performance and stable cycling life with only 0.06% capacity decay per cycle. It affords fresh insights for developing single‐atom catalysts to accelerate the kinetic conversion of LiPS for highly stable Li–S batteries.