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Bimetal CoNi Active Sites on Mesoporous Carbon Nanosheets to Kinetically Boost Lithium−Sulfur Batteries
Author(s) -
Luo Rui,
Zhang Zhengchunyu,
Zhang Jing,
Xi Baojuan,
Tian Fang,
Chen Weihua,
Feng Jinkui,
Xiong Shenglin
Publication year - 2021
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.202100414
Subject(s) - polysulfide , separator (oil production) , bimetal , materials science , anode , electrochemistry , chemical engineering , mesoporous material , cathode , composite number , inorganic chemistry , electrode , catalysis , chemistry , composite material , electrolyte , organic chemistry , physics , engineering , thermodynamics
In order to solve the problem that soluble polysulfide intermediates diffuse between cathode and anode during charging and discharging, which leads to rapid attenuation of battery cycle life, the separator modification materials come into people's sight. Herein, a mesoporous carbon‐supported cobalt‐nickel bimetal composite (CoNi@MPC) is synthesized and directly coated on the original separator to serve as a secondary collector for lithium−sulfur batteries. CoNi@MPC exhibits multiple Co‐Ni active sites, able to catalyze the reactions of soluble polysulfides, specifically accelerating the generation and decomposition of insoluble Li 2 S in lithiation and delithiation process testified by the electrochemical results and density functional theory calculation. Relying on the bifunctionality of CoNi@MPC composite, the shuttle effect of lithium polysulfides can be effectively alleviated. Moreover, porous carbon as the conductive scaffold favors the improvement of electronic conductivity. Benefiting from the above advantages, the cell with CoNi@MPC separator indicates significantly enhanced electrochemical performances with excellent cycling life over 500 cycles and superior rate capabilities.