Ecofriendly Chemical Activation of Overlithiated Layered Oxides by DNA‐Wrapped Carbon Nanotubes. Issue 9 (29th January 2020)

• Record Type: Journal Article
• Authors: Kim, Ju‐Myung; Park, Jae‐Ho; Jo, Eunmi; Kim, Hyung‐Seok; Kim, Seung‐Hyeok; Chang, Wonyoung; Chung, Kyung Yoon; Lee, Sang‐Young
• Is Part Of: Advanced energy materials. Volume 10:Issue 9(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-01-29
• Subjects: carbon nanotubes -- chemical activation -- deoxyribonucleic acid -- lithium‐ion battery cathodes -- overlithiated layered oxides; Energy harvesting -- Materials -- Periodicals; Energy conversion -- Materials -- Periodicals; Energy storage -- Materials -- Periodicals; Photovoltaics -- Periodicals; Fuel cells -- Periodicals; Thermoelectric materials -- Periodicals; 621.31
• DOI: 10.1002/aenm.201903658
• Languages: English
• ISSNs: 1614-6832

Abstract

Abstract: 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 Li2 MnO3 of the OLO through cation exchange reaction of Na + –Li +, thereby forming Li4 Mn5 O12 ‐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. Abstract : DNA‐wrapped multiwalled carbon nanotubes (MWCNT) (DNA@MWCNT) are presented as an ecofriendly chemical activation strategy for overlithiated layered oxides (OLO) cathode materials. The Li4 Mn5 O12 ‐type spinel nanolayers are formed on the OLO surface through a cation exchange reaction of Na + (from phosphate complexes of DNA@MWCNT)–Li + (from OLO). The spinel nanolayers significantly improve the charge–discharge kinetics, cyclability, and thermal stability. This unique behavior is comprehensively investigated by in‐depth structural/electrochemical characterization.