TY  - JOUR
AU  - Wang, Wenhui
AU  - Zhang, Jiaolong
AU  - Li, Chaolin
AU  - Kou, Xiaohang
AU  - Li, Baohua
AU  - Yu, Denis Y. W.
PY  - 2023
TI  - P2-Na2/3Ni2/3Te1/3O2 Cathode for Na-ion Batteries with High Voltage and Excellent Stability
JO  - Energy & Environmental Materials
SN  - 2575-0348
VL  - 6
IS  - 2
AB  - Air-stable layered structured cathodes with high voltage and good cycling stability are highly desired for the practical application of Na-ion batteries. Herein, we report a P2-Na2/3Ni2/3Te1/3O2 cathode that is stable in ambient air with an average operating voltage of ~3.8 V, demonstrating excellent cycling stability with a capacity retention of more than 92.7% after 500 cycles at 20 mA g−1 and good rate capability with 91.9% capacity utilization at 500 mA g−1 with respect to capacity at 5 mA g−1 between 2.0 and 4.0 V. When the upper cutoff voltage is increased to 4.4 V, P2-Na2/3Ni2/3Te1/3O2 delivers a reversible capacity of 71.9 mAh g−1 and retains 91.8% of the capacity after 100 cycles at 20 mA g−1. The charge compensation during charge/discharge is mainly due to the redox couple of Ni2+/Ni3+ in the host with a small amount of contribution from oxygen. The stable structure of the material without phase transformation and with small volume change during charge-discharge allows it to give excellent cycle performance especially when the upper cutoff voltage is not higher than 4.2 V.
UR  - https://doi.org/10.1002/eem2.12314
DO  - 10.1002/eem2.12314