Understanding sodium-ion battery anodes through operando spectroscopic techniques

• Published in: Electrochimica acta Vol. 319; pp. 791 - 800
• Main Authors: Rodriguez, Jassiel R., Aguirre, Sandra B., Pol, Vilas G.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-10-2019; Elsevier BV
• Subjects: Alloy systems; Anodes; Chemical evolution; Chemical reactions; Crystal structure; Fine structure; Fundamental understanding; Ion charge; Molecular structure; NMR; Nuclear magnetic resonance; Operando methodology; Organic chemistry; Oxidation; Phase transitions; Raman spectroscopy; Rechargeable batteries; Sodium-ion batteries; Sodium-ion battery anodes; Spectroscopy techniques; Spectrum analysis; Valence; X ray absorption; X ray powder diffraction; Fundamental understanding; Operando methodology; Spectroscopy techniques; Sodium-ion battery anodes
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2019.07.030

Advanced operando spectroscopic techniques monitor real-time changes in crystal structure, oxidation state, coordination environments, and chemical evolution of Na-ion host anodes during charge-discharge cycles. Operando spectroscopy techniques include Raman spectroscopy, nuclear magnetic resonance, powder X-ray diffraction, X-ray adsorption fine structure, X-ray absorption near edge and extended X-ray absorption fine structure, which provide outstanding scientific understanding of anodes for the next generation of Na-ion batteries. This review systematically summarizes intercalation, alloying, and conversion anodes investigated through operando spectroscopy techniques. These have generated a profound and fundamental understanding of diverse phenomena occurring on the active material surface and/or bulk during the electrochemical reaction conditions, such as phase transitions, side reactions, lattice parameter changes, and molecular scale structure-reactivity relationships.
•Operando spectroscopies reveal the different phenomena inside an anode during sodiation.•Operando spectroscopies have disclosed the growth mechanisms of Na dendrites.•Operando spectroscopies monitor the crystalline structure evolution in real time.•Operando spectroscopies expose the electronic state and local structural changes during reaction.