Silver ferrite/maghemite composites and mixtures: Impact of one-pot composite preparation on battery-relevant electrochemistry. (March 2018)

• Record Type: Journal Article
• Authors: Durham, Jessica L.; Pelliccione, Christopher J.; Zhang, Wei; Poyraz, Altug S.; Lin, Zhou; Tong, Xiao; Wang, Feng; Takeuchi, Esther S.; Marschilok, Amy C.; Takeuchi, Kenneth J.
• Is Part Of: Applied materials today. Volume 10(2018)
• Page Start: 142
• Page End: 152
• Publication Date: 2018-03
• Subjects: Silver ferrite -- Delafossite -- Lithium battery -- Composite -- One-pot synthesis; Materials science -- Periodicals; Materials -- Research -- Periodicals; 620.1105
• DOI: 10.1016/j.apmt.2016.12.003
• Languages: English
• ISSNs: 2352-9407

Abstract

Graphical abstract: Highlights: One-pot co-precipitation is described for silver ferrite/maghemite composite preparation. One-pot Ag0.2 FeO1.6 delivers an energy density ∼2× higher than the mechanical mixture. Non-stoichiometric, low temperature, one-pot synthesis may translate well to industrial scales. Abstract: A series of silver ferrite/maghemite composite materials (Ag x FeO y, where Ag x FeO y = composites of x AgFeO2 + [(1 − x )/2] γ-Fe2 O3 and y = 2 − (1 − x )/2) have been prepared via a non-stoichiometric, one-pot co-precipitation strategy. The impact of a one-pot composite preparation on electrochemistry was determined by comparison to a mechanical mixture of nanocrystalline AgFeO2 and γ-Fe2 O3 powders, which were combined to afford an overall composition of Ag0.2 FeO1.6 . Notably, following 30 discharge-charge cycles, the one-pot Ag0.2 FeO1.6 composite delivers an energy density (156 mWh/g) profoundly higher than the mechanical mixture Ag0.2 FeO1.6 (67 mWh/g). Ag x FeO y composites with the lowest Ag ( x ) content and smallest crystallite size, Ag0.2 FeO1.6, deliver twice the discharge energy density (169 mWh/g) of stoichiometric AgFeO2 with no maghemite component and exhibited good capacity retention over 50 cycles. The notable electrochemistry of one-pot Ag x FeO y composites may involve reduced AgFeO2 and γ-Fe2 O3 aggregate sizes and a concomitant increase in AgFeO2 /γ-Fe2 O3 crystallite contact not achievable through mechanical mixing.