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MoSe 2 @CNT Core–Shell Nanostructures as Grain Promoters Featuring a Direct Li 2 O 2 Formation/Decomposition Catalytic Capability in Lithium‐Oxygen Batteries
Author(s) -
He Biao,
Li Gaoyang,
Li Jiajia,
Wang Jun,
Tong Hui,
Fan Yuqi,
Wang Weiliang,
Sun Shuhui,
Dang Feng
Publication year - 2021
Publication title -
advanced energy materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.08
H-Index - 220
eISSN - 1614-6840
pISSN - 1614-6832
DOI - 10.1002/aenm.202003263
Subject(s) - materials science , nucleation , cathode , chemical engineering , lithium (medication) , electrolyte , oxygen evolution , catalysis , nanotechnology , electrochemistry , electrode , chemistry , medicine , biochemistry , organic chemistry , engineering , endocrinology
For lithium‐oxygen batteries (LOBs), the strong oxidant intermediate and byproducts during the charge/discharge process are the main reasons for the degradation of the electrochemical performance. Searching for highly efficient catalysts for the direct formation/decomposition of Li 2 O 2 is essential for the development of LOBs. In this study, core–shell nanostructured MoSe 2 @CNT with uniform MoSe 2 coating layers are purposefully synthesized through a facile hydrothermal strategy to address the negative intermediate and side‐product issues, therefore enhancing the battery performance. The continuous and multiwalled MoSe 2 layers can not only work as grain promoters that induce the initial nucleation and growth of equiaxed Li 2 O 2 grains on the cathode surface even under a high rate, but also prevent the byproducts formation from corrosive issues between carbon and electrolyte. Moreover, density functional theory (DFT) calculations reveal the intrinsic layer dependent direct formation/decomposition catalytic capability of 2D MoSe 2 and the LiO 2 avoidable reaction pathway during the discharge/charge process, theoretically revealing the direct epitaxial growth mechanisms of Li 2 O 2 . As a consequence, the MoSe 2 @CNT cathode exhibited a superior specific capacity over 32 000 mAh g −1 , excellent rate capabilities, and ultralong cycle life of 280 cycles at a high rate of 500 mA g −1 .