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Single Semi‐Metallic Selenium Atoms on Ti 3 C 2 MXene Nanosheets as Excellent Cathode for Lithium–Oxygen Batteries
Author(s) -
Zhao Danyang,
Wang Peng,
Di Haoxiang,
Zhang Peng,
Hui Xiaobin,
Yin Longwei
Publication year - 2021
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.202010544
Subject(s) - overpotential , materials science , catalysis , cathode , lithium (medication) , redox , oxygen , electrode , chemical engineering , electrochemistry , chemistry , organic chemistry , medicine , engineering , metallurgy , endocrinology
Rechargeable Li–O 2 batteries are promising due to their superior high energy density but subject to sluggish oxygen reduction/evolution kinetics. Developing highly efficient catalysts to improve catalytic activity and alleviate oxidation–reduction overpotential of Li–O 2 batteries is of great challenge and importance. Herein, a CO 2 ‐assisted thermal‐reaction strategy is developed to fabricate isolated semi‐metallic selenium single‐atom‐doped Ti 3 C 2 MXene catalyst (SASe‐Ti 3 C 2 ) as cathodes for high‐performance Li–O 2 batteries. The isolated moieties of single Se atom catalysis centers can function as active catalytic centers to drastically enhance the intrinsic LiO 2 ‐absorption ability and thus fundamentally modulate the formation/decomposition mechanism of lithium peroxide (Li 2 O 2 ) discharge product, thus demonstrating greatly enhanced redox kinetics and efficiently ameliorated overpotentials. Theoretical simulations reveal that the interaction between Se‐involved moieties and Ti 3 C 2 substrate greatly enhances the intrinsic LiO 2 ‐absorption ability and fundamentally promotes the charge transfer between electrode and Li 2 O 2 product, deeply ameliorating the round‐trip overpotential. The well‐designed SASe–Ti 3 C 2 electrode exhibits decreased charge/discharge polarization (1.10 V vs Li/Li + ), ultrahigh discharge capacity (17 260 mAh g −1 at 100 mA g −1 ), and superior durability (170 cycles at 200 mA g −1 ) as cathode for Li–O 2 batteries. The promising results will shed light on the design of highly efficient catalysts for oxygen‐involved systems of future investigation.