Carrageenan as A Sacrificial Binder for 5 V LiNi 0.5 Mn 1.5 O 4 Cathodes in Lithium-Ion Batteries

• Published in: Advanced materials (Weinheim) 2023-11, Vol.35 (45), p.e2303787
• Main Authors: Chang, Barsa, Yun, Dae Hui, Hwang, Insu, Seo, Joon Kyo, Kang, Joonhee, Noh, Gyeongho, Choi, Sunghun, Choi, Jang Wook
• Format: Article
• Language: English
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.202303787

5 V-class LiNi Mn O (LNMO) with its spinel symmetry is a promising cathode material for lithium-ion batteries. However, the high-voltage operation of LNMO renders it vulnerable to interfacial degradation involving electrolyte decomposition, which hinders long-term and high-rate cycling. Herein, we overcome this longstanding challenge presented by LNMO by incorporating a sacrificial binder, namely, λ-carrageenan (CRN), a sulfated polysaccharide. This binder not only uniformly covers the LNMO surface via hydrogen bonding and ion-dipole interaction but also offers an ionically conductive cathode-electrolyte interphase layer containing LiSO F, a product of the electrochemical decomposition of the sulfate group. Taking advantage of these two auspicious properties, the CRN-based electrode exhibited cycling and rate performance far superior to that of its counterparts based on the conventional poly(vinylidene difluoride) and sodium alginate binders. This study introduces a new concept, namely "sacrificial" binder, for battery electrodes known to deliver superior electrochemical performance but be adversely affected by interfacial instability. This article is protected by copyright. All rights reserved.