Single Semi‐Metallic Selenium Atoms on Ti3C2 MXene Nanosheets as Excellent Cathode for Lithium–Oxygen Batteries. (12th May 2021)

• Record Type: Journal Article
• Authors: Zhao, Danyang; Wang, Peng; Di, Haoxiang; Zhang, Peng; Hui, Xiaobin; Yin, Longwei
• Is Part Of: Advanced functional materials. Volume 31:Number 29(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-05-12
• Subjects: electrochemical catalytic activities -- lithium–oxygen batteries -- oxygen evolution kinetics -- oxygen reduction kinetics -- single atom; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.202010544
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: Rechargeable Li–O2 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–O2 batteries is of great challenge and importance. Herein, a CO2 ‐assisted thermal‐reaction strategy is developed to fabricate isolated semi‐metallic selenium single‐atom‐doped Ti3 C2 MXene catalyst (SASe‐Ti3 C2 ) as cathodes for high‐performance Li–O2 batteries. The isolated moieties of single Se atom catalysis centers can function as active catalytic centers to drastically enhance the intrinsic LiO2 ‐absorption ability and thus fundamentally modulate the formation/decomposition mechanism of lithium peroxide (Li2 O2 ) discharge product, thus demonstrating greatly enhanced redox kinetics and efficiently ameliorated overpotentials. Theoretical simulations reveal that the interaction between Se‐involved moieties and Ti3 C2 substrate greatly enhances the intrinsic LiO2 ‐absorption ability and fundamentally promotes the charge transfer between electrode and Li2 O2 product, deeply ameliorating the round‐trip overpotential. The well‐designed SASe–Ti3 C2 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–O2 batteries. The promising results will shed light on the design of highly efficient catalysts for oxygen‐involved systems of future investigation. Abstract : Ti3 C2 MXene confining isolated semi‐metallic selenium atom (SASe–Ti3 C2 ) catalysts, which are synthesized via a CO2 ‐assisted thermal‐reaction strategy, are first published in Li–O2 batteries as high‐performance cathodes. The SASe–Ti3 C2 catalysts can drastically enhance the intrinsic LiO2 ‐absorption ability and thus fundamentally modulate the formation/decomposition mechanism of lithium peroxide discharge product, which could further demonstrate greatly enhanced redox kinetics and efficiently ameliorated overpotentials.