TY - JOUR
T1 - Selective TiO2 Nanolayer Coating by Polydopamine Modification for Highly Stable Ni-Rich Layered Oxides
AU - Kim, Hyeongwoo
AU - Jang, Jihye
AU - Byun, Dongjin
AU - Kim, Hyung Seok
AU - Choi, Wonchang
N1 - Funding Information:
This research was supported by the Basic Science Research Program of the National Research Foundation (NRF), funded by the Ministry of Science & ICT and Future Planning (NRF-2018R1A2B2007081). The authors declare no competing financial interest.
PY - 2019/12/19
Y1 - 2019/12/19
N2 - Ni-rich layered oxides are promising cathode materials for developing high-energy lithium-ion batteries. To overcome the major challenge of surface degradation, a TiO2 surface coating based on polydopamine (PDA) modification was investigated in this study. The PDA precoating layer had abundant OH catechol groups, which attracted Ti(OEt)4 molecules in ethanol solvent and contributed towards obtaining a uniform TiO2 nanolayer after calcination. Owing to the uniform coating of the TiO2 nanolayer, TiO2-coated PDA-LiNi0.6Co0.2Mn0.2O2 (TiO2-PNCM) displayed an excellent electrochemical stability during cycling under high voltage (3.0–4.5 V vs. Li+/Li), during which the cathode material undergoes a highly oxidative charge process. In addition, TiO2-PNCM exhibited excellent cyclability at elevated temperature (60 °C) compared with the bare NCM. The surface degradation of the Ni-rich cathode material, which is accelerated under harsh cycling conditions, was effectively suppressed after the formation of an ultra-thin TiO2 coating layer.
AB - Ni-rich layered oxides are promising cathode materials for developing high-energy lithium-ion batteries. To overcome the major challenge of surface degradation, a TiO2 surface coating based on polydopamine (PDA) modification was investigated in this study. The PDA precoating layer had abundant OH catechol groups, which attracted Ti(OEt)4 molecules in ethanol solvent and contributed towards obtaining a uniform TiO2 nanolayer after calcination. Owing to the uniform coating of the TiO2 nanolayer, TiO2-coated PDA-LiNi0.6Co0.2Mn0.2O2 (TiO2-PNCM) displayed an excellent electrochemical stability during cycling under high voltage (3.0–4.5 V vs. Li+/Li), during which the cathode material undergoes a highly oxidative charge process. In addition, TiO2-PNCM exhibited excellent cyclability at elevated temperature (60 °C) compared with the bare NCM. The surface degradation of the Ni-rich cathode material, which is accelerated under harsh cycling conditions, was effectively suppressed after the formation of an ultra-thin TiO2 coating layer.
KW - Ni-rich layered oxides
KW - cathode materials
KW - lithium-ion batteries
KW - polydopamine
KW - surface modification
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U2 - 10.1002/cssc.201902998
DO - 10.1002/cssc.201902998
M3 - Article
C2 - 31721457
AN - SCOPUS:85075711546
SN - 1864-5631
VL - 12
SP - 5253
EP - 5264
JO - ChemSusChem
JF - ChemSusChem
IS - 24
ER -