Fe2O3 Nanoparticle Seed Catalysts Enhance Cyclability on Deep (Dis)charge in Aprotic LiO2 Batteries. Issue 18 (12th March 2018)

• Record Type: Journal Article
• Authors: Li, Zhaolong; Ganapathy, Swapna; Xu, Yaolin; Zhu, Quanyao; Chen, Wen; Kochetkov, Ivan; George, Chandramohan; Nazar, Linda F.; Wagemaker, Marnix
• Is Part Of: Advanced energy materials. Volume 8:Issue 18(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-03-12
• Subjects: aprotic LiO2 batteries -- deep (dis)charge -- epitaxial growth mechanism -- Fe2O3 seed catalysts; Energy harvesting -- Materials -- Periodicals; Energy conversion -- Materials -- Periodicals; Energy storage -- Materials -- Periodicals; Photovoltaics -- Periodicals; Fuel cells -- Periodicals; Thermoelectric materials -- Periodicals; 621.31
• DOI: 10.1002/aenm.201703513
• Languages: English
• ISSNs: 1614-6832

Abstract

Abstract: Although the high energy density of LiO2 chemistry is promising for vehicle electrification, the poor stability and parasitic reactions associated with carbon‐based cathodes and the insulating nature of discharge products limit their rechargeability and energy density. In this study, a cathode material consisting of α‐Fe2 O3 nanoseeds and carbon nanotubes (CNT) is presented, which achieves excellent cycling stability on deep (dis)charge with high capacity. The initial capacity of Fe2 O3 /CNT electrode reaches 805 mA h g −1 (0.7 mA h cm −2 ) at 0.2 mA cm −2, while maintaining a capacity of 1098 mA h g −1 (0.95 mA h cm −2 ) after 50 cycles. The operando structural, spectroscopic, and morphological analysis on the evolution of Li2 O2 indicates preferential Li2 O2 growth on the Fe2 O3 . The similar d ‐ spacing of the (100) Li2 O2 and (104) Fe2 O3 planes suggest that the latter epitaxially induces Li2 O2 nucleation. This results in larger Li2 O2 primary crystallites and smaller secondary particles compared to that deposited on CNT, which enhances the reversibility of the Li2 O2 formation and leads to more stable interfaces within the electrode. The mechanistic insights into dual‐functional materials that act both as stable host substrates and promote redox reactions in LiO2 batteries represent new opportunities for optimizing the discharge product morphology, leading to high cycling stability and coulombic efficiency. Abstract : The Fe2 O3 /CNT cathode in LiO2 batteries is demonstrated to offer high cyclability and coulombic efficiency in potential limited (dis)charge cycles. This is achived via epitaxially induced nucleation and growth of smaller and more isoptropic Li2 O2 crytallites on the Fe2 O3 seed crystal catalyst, owing to their similar lattice d‐spacing.