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Ecofriendly Chemical Activation of Overlithiated Layered Oxides by DNA‐Wrapped Carbon Nanotubes
Author(s) -
Kim JuMyung,
Park JaeHo,
Jo Eunmi,
Kim HyungSeok,
Kim SeungHyeok,
Chang Wonyoung,
Chung Kyung Yoon,
Lee SangYoung
Publication year - 2020
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.201903658
Subject(s) - materials science , chemical engineering , carbon nanotube , thermal stability , electrochemistry , stacking , chemical stability , nanotechnology , organic chemistry , chemistry , electrode , engineering
Despite their exceptionally high capacity, overlithiated layered oxides (OLO) have not yet been practically used in lithium‐ion battery cathodes due to necessary toxic/complex chemical activation processes and unsatisfactory electrochemical reliability. Here, a new class of ecofriendly chemical activation strategy based on amphiphilic deoxyribose nucleic acid (DNA)‐wrapped multiwalled carbon nanotubes (MWCNT) is demonstrated. Hydrophobic aromatic bases of DNA have a good affinity for MWCNT via noncovalent π–π stacking interactions, resulting in core (MWCNT)‐shell (DNA) hybrids (i.e., DNA@MWCNT) featuring the predominant presence of hydrophilic phosphate groups (coupled with Na + ) in their outmost layers. Such spatially rearranged Na + –phosphate complexes of the DNA@MWCNT efficiently extract Li + from monoclinic Li 2 MnO 3 of the OLO through cation exchange reaction of Na + –Li + , thereby forming Li 4 Mn 5 O 12 ‐type spinel nanolayers on the OLO surface. The newly formed spinel nanolayers play a crucial role in improving the structural stability of the OLO and suppressing interfacial side reactions with liquid electrolytes, eventually providing significant improvements in the charge/discharge kinetics, cyclability, and thermal stability. This beneficial effect of the DNA@MWCNT‐mediated chemical activation is comprehensively elucidated by an in‐depth structural/electrochemical characterization.