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On the Cycling Performance of Na‐O 2 Cells: Revealing the Impact of the Superoxide Crossover toward the Metallic Na Electrode
Author(s) -
Lin Xiaoting,
Sun Qian,
Yadegari Hossein,
Yang Xiaofei,
Zhao Yang,
Wang Changhong,
Liang Jianneng,
Koo Alicia,
Li Ruying,
Sun Xueliang
Publication year - 2018
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201801904
Subject(s) - anode , faraday efficiency , materials science , cathode , electrode , battery (electricity) , cycling , metal , energy storage , chemical engineering , nanotechnology , metallurgy , chemistry , power (physics) , physics , archaeology , quantum mechanics , history , engineering
Na‐O 2 batteries have attracted extensive attention as promising candidates for large‐scale energy storage due to their ultrahigh theoretical energy density. However, the poor cycling performance of Na‐O 2 batteries is one of the major challenges facing its future development. A novel Na‐O 2 battery using electrically connected carbon paper with Na metal as a protected anode is presented in this study. The O 2 − crossover from the cathode to anode partially contributes to the limited Coulombic efficiency, as well as the Na corrosion during the cycling process. For the cells with protected Na, the carbon paper maintains a pseudo‐equal potential with the Na metal and works as an artificial protective layer to suppress the detrimental side reactions caused by O 2 − and O 2 crossover toward the Na electrode. Furthermore, the short‐circuiting issue caused by Na dendrite growth also can be completely resolved. Consequently, the Na‐O 2 cells with protected Na exhibit two times higher discharge capacity and cycling stability compared with the cells using bare Na. These results indicate the crucial role of the Na anode in determining the overall cell performance and a rational design of anode can dramatically contribute to develop advanced Na‐O 2 batteries with longer lifespans and better cycling performance.