Deconvolution of Composition and Crystallite Size of Silver Hollandite Nanorods: Influence on Electrochemistry. Issue 14 (16th December 2017)

• Record Type: Journal Article
• Authors: Durham, Jessica L.; Huang, Jianping; Zhang, Bingjie; Wu, Lijun; Tong, Xiao; Pelliccione, Christopher J.; Zhu, Yimei; Takeuchi, Esther S.; Marschilok, Amy C.; Takeuchi, Kenneth J.
• Is Part Of: Journal of the Electrochemical Society. Volume 164:Issue 14(2017)
• Page Start: A3814
• Page End: A3823
• Publication Date: 2017-12-16
• Subjects: crystallite size -- manganese oxide -- silver hollandite; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/2.1371714jes
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : Silver hollandite (Ag1.4 Mn8 O16 ) has been synthesized by an aqueous, low-temperature co-precipitation technique to afford silver hollandite with distinct crystallite sizes (10 and 15 nm, identified as S-Ag1.4 Mn8 O16 and L-Ag1.4 Mn8 O16, respectively) and equivalent silver content ( x ), allowing for the deconvolution of electrochemical effects related to crystallite size and silver content. The as-prepared silver hollandite materials were confirmed to be structurally analogous. Notably, TEM imaging reveals a high degree of bundling of S-Ag1.4 Mn8 O16 nanorods compared to L-Ag1.4 Mn8 O16 which facilitates more intimate connection of the S-Ag1.4 Mn8 O16 material with enhanced interparticle contact. The electrochemical behavior and lithium diffusion properties were investigated by galvanostatic cycling, CV, electrochemical impedance, pulsed-discharge experiments, and ex-situ XAS analysis of cycled cathodes. Lithium based electrochemical cells containing S-Ag1.4 Mn8 O16 delivered a capacity 15X higher than L-Ag1.4 Mn8 O16 on cycle 1. Ex-situ XAS demonstrated structural change for S-Ag1.4 Mn8 O16 and formation of Ag 0 on insertion of 3.8 Li + intercalation. However, the samples of L-Ag1.4 Mn8 O16 were lithiated by a more limited 0.25 molar equivalents, where no significant structural changes were observed. The findings affirm crystallite size significantly impacts electrochemistry independent of cation occupancy of the α-MnO2 type structure.