Elucidating zinc-ion battery mechanisms in freestanding carbon electrode architectures decorated with nanocrystalline ZnMn2O4. Issue 8 (26th March 2021)

• Record Type: Journal Article
• Authors: Sassin, Megan B.; Helms, Maya E.; Parker, Joseph F.; Chervin, Christopher N.; DeBlock, Ryan H.; Ko, Jesse S.; Rolison, Debra R.; Long, Jeffrey W.
• Is Part Of: Materials advances. Volume 2:Issue 8(2021)
• Page Start: 2730
• Page End: 2738
• Publication Date: 2021-03-26
• Subjects: 620.11
• DOI: 10.1039/d1ma00159k
• Languages: English
• ISSNs: 2633-5409

Abstract

Abstract : H + insertion/Zn4 (OH)6 SO4 precipitation is the dominant charge-storage mechanism of crystalline ZnMn2 O4 @CNF in ZnSO4 (aq), despite specific Zn 2+ lattice sites. Abstract : Rechargeable zinc-ion batteries represent an emerging energy-storage technology that offers the advantages of low cost, use of abundant and nontoxic materials, and competitive energy content in lightly packaged forms. Nanoscale manganese oxides are among the most promising positive-electrode materials for zinc-ion cells, and their performance is further enhanced when these oxides are expressed as conformal deposits on porous carbon architectures, such as carbon nanfoam paper (CNF). We describe an "in-place" conversion of nanometric birnessite Na + -MnO x @CNF to crystalline spinel ZnMn2 O4 @CNF, a manganese oxide polymorph that nominally contains sites for Zn 2+ insertion. The ZnMn2 O4 @CNF cathodes are electrochemically conditioned in two-terminal cells and ex situ characterized using X-ray diffraction, scanning electron microscopy, energy-dispersive spectroscopy, and X-ray photoelectron spectroscopy. Despite specific Zn 2+ insertion sites in ZnMn2 O4, we demonstrate that the predominant discharge mechanism involves coupled insertion of protons and precipitation of Zn4 (OH)6 SO4 · x H2 O; upon recharge, protons deinsert and Zn4 (OH)6 SO4 dissolves.