(212e) Impact of Cathode/Solvent Interfaces on the Electrochemical Performance of Na-O2 Batteries. | AIChE

(212e) Impact of Cathode/Solvent Interfaces on the Electrochemical Performance of Na-O2 Batteries.

Authors 

Greeley, J., Purdue University
Nikolla, E., Wayne State University
Aprotic Na-O2 batteries have recently gained significant attention as promising alternatives to commercial Li-ion batteries owing to their high energy densities and reversible redox chemistries1–3. The underlying electrochemistry in these systems is heavily influenced by the glyme-ether electrolyte solvents owing to their solvation properties that vary as a function of their respective chain lengths4. Na-O2 systems with short chain ether electrolyte solvents are challenged by their long-term stability5 whereas, the systems with long chain ether electrolyte solvents lack fundamental understanding in their underlying electrochemistry1. These challenges hamper the development of effective strategies to improve their stability and overall electrochemical efficiency3. Herein, we investigate the effect of the cathode/aprotic electrolyte solvent interface on the mechanism of discharge product formation and overall electrochemical cell performance by varying both the glyme-ether electrolyte solvent and the carbon electrode. Theoretical calculations are coupled with experimental X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) studies to determine the nature of the Na-O2 species formed as a function of the electrolyte solvent and carbon cathode. A link between the nature of the carbon cathode/aprotic solvent interface, discharge mechanism for product formation and the overall electrochemical performance and stability is reported. These insights are critical for the rational design of efficient and stable Na-O2 batteries.

References:

(1) Samira, S., et al., ACS Energy Lett, 2021, 6 (2), 665–674.

(2) Hartmann, P., et al., Nat. Mater. 2013, 12 (3), 228–232.

(3) Bi, X., et.al., Small Methods, 2019, 3 (4), 1800247.

(4) Lutz, L., et.al., The Journal of Physical Chemistry C, 2016, 120 (36), 20068–20076.

(5) Kim, J., et.al., Nat Commun, 2016, 7 (1), 10670.