TY  - JOUR
AU  - Voronina, Natalia
AU  - Kim, Hee Jae
AU  - Konarov, Aishuak
AU  - Yaqoob, Najma
AU  - Lee, Kug-Seung
AU  - Kaghazchi, Payam
AU  - Guillon, Olivier
AU  - Myung, Seung-Taek
TI  - Electronic Structure Engineering of Honeycomb Layered Cathode Material for Sodium‐Ion Batteries
JO  - Advanced energy materials
VL  - 11
IS  - 14
SN  - 1614-6840
CY  - Weinheim
PB  - Wiley-VCH
M1  - FZJ-2021-03252
SP  - 2003399 -
PY  - 2021
AB  - In this work, the rational design of O′3-type Na[Ni2/3−xCoxSb1/3]O2, a solid solution of Na[Ni2/3Sb1/3]O2–Na[Co2/3Sb1/3]O2, is introduced. Because of the difficulty of the Co3+/2+ redox reaction, the electronic structures of Na[Ni2/3−xCoxSb1/3]O2 compounds are engineered to build electroconducting networks in the oxide matrix through electrochemical oxidation of Co2+ to Co3+, after which the formed Co3+ does not participate in the electrochemical reaction but improves the electrical conductivity in the structure. Density functional theory calculations reveal a reduced bandgap energy after the formation of Co3+ during desodiation of Na1−y[Ni2/3−xCoxSb1/3]O2. Using the oxidized Co3+ species while improving the electrical conductivity, the Na[Ni2/3−xCoxSb1/3]O2 (x = 1/6) electrode exhibits excellent cyclability for 1000 cycles with ≈72.5% capacity retention at 2C (400 mA g−1) and activity even at 50C (10 A g−1) in Na cells. Operando X-ray diffraction and ex situ X-ray absorption near-edge structure investigations reveal suppressed lattice variations upon charge and discharge compared with those of Na[Ni2/3Sb1/3]O2 achieved by the presence of the electrochemical-driven Co3+ in the structure. These findings offer a new strategy for the development of cathode materials for sodium-ion batteries, providing important insight into their structural transformations and the electronic nature of advanced cathode materials.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000620225300001
DO  - DOI:10.1002/aenm.202003399
UR  - https://juser.fz-juelich.de/record/894489
ER  -