Ecofriendly Chemical Activation of Overlithiated Layered Oxides by DNA‐Wrapped Carbon Nanotubes
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 Li2MnO3 of the OLO through cation exchange reaction of Na+–Li+, thereby forming Li4Mn5O12‐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.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jan 29, 2020
- Source ID
- 10.1002/aenm.201903658
Entities
People
- Eunmi Jo
- Hyungseok Kim
- Jae‐ho Park
- Ju‐myung Kim
- Kyung Yoon Chung
- Sang-Young Lee
- Seung‐hyeok Kim
- Wonyoung Chang
Organizations
- Army Research Office
- Korea Institute of Science and Technology
- Korea University
- Ministry of Science, ICT and Future Planning
- National Research Foundation of Korea
- Ulsan National Institute of Science and Technology