Facilitating sustainable oxygen-redox chemistry for P3-type cathode materials for sodium-ion batteries
- 저자명
Jae HyeonJo, Hee Jae Kim, Ji Ung Choi, Natalia Voronina, Kug-Seung Lee, Kyuwook Ihm, Han-Koo Lee, Hee-Dae Lim, Hyungseok Kim, Hun-Gi Jung, Kyung Yoon Chung, Hitoshi Yashiro, Seung-Taek Myung
- 저널명
Energy Storage Materials
- 게재권/집
46(2022)
- 페이지
329 ~ 343
- 발표일
2022-01-17
- URLhttps://doi.org/10.1016/j.ensm.2022.01.028
Herein, the surface of the P3-Na0.6[Mn0.6Co0.2Mg0.2]O2 cathode material is fortified by introducing an ionic-conducting sodium-phosphate nanolayer (NaPO3, ≈10-nm thickness). This layer facilitates Na+-ion diffusion owing to its sufficiently high ionic conductivity (≈10–6 S cm–1). Moreover, the NaPO3 coating layer prevents the precipitation of surface byproducts generated from reaction with the electrolyte. The NaPO3-coated P3-Na0.6[Mn0.6Co0.2Mg0.2]O2 electrode can thus retain over 80% of the first capacity after 200 cycles not only at 0.1C but also at a high rate (5C), with a capacity retention of 88% after 300 cycles. Reversible transition-metal and oxygen redox are evidenced by X-ray absorption near-edge spectroscopy, X-ray photoelectron spectroscopy, time-of-flight secondary-ion mass spectroscopy, and operando differential electrochemical mass spectroscopy, which reveal mitigated surface-byproduct formation. These findings demonstrate the possibility of the use of oxygen redox for high-energy SIBs, ensuring long term cyclability.