Rational Construction of 2D Fe3O4@Carbon Core–Shell Nanosheets as Advanced Anode Materials for High‐Performance Lithium‐Ion Half/Full Cells. Issue 36 (29th May 2020)

• Record Type: Journal Article
• Authors: Qu, Dongyang; Sun, Zhonghui; Xu, Jianan; Song, Zhongqian; Kong, Huijun; Zhao, Bolin; Dong, Xiandui; Niu, Li
• Is Part Of: Chemistry. Volume 26:Issue 36(2020)
• Page Start: 8121
• Page End: 8128
• Publication Date: 2020-05-29
• Subjects: core–shell structures -- electrochemistry -- hydrothermal synthesis -- lithium-ion batteries -- nanostructures; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.202000743
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: Transition metal oxides have vastly limited practical application as electrode materials for lithium‐ion batteries (LIBs) due to their rapid capacity decay. Here, a versatile strategy to mitigate the volume expansion and low conductivity of Fe3 O4 by coating a thin carbon layer on the surface of Fe3 O4 nanosheets (NSs) was employed. Owing to the 2D core–shell structure, the Fe3 O4 @C NSs exhibit significantly improved rate performance and cycle capability compared with bare Fe3 O4 NSs. After 200 cycles, the discharge capacity at 0.5 A g −1 was 963 mA h g −1 (93 % retained). Moreover, the reaction mechanism of lithium storage was studied in detail by ex situ XRD and HRTEM. When coupled with a commercial LiFePO4 cathode, the resulting full cell retains a capacity of 133 mA h g −1 after 100 cycles at 0.1 A g −1, which demonstrates its superior energy storage performance. This work provides guidance for constructing 2D metal oxide/carbon composites with high performance and low cost for the field of energy storage. Abstract : Core–shell anodes : 2D Fe2 O3 nanosheets (NSs) were obtained by a hydrothermal method, and a core–shell structure was formed by coating with carbon. In the resulting Fe3 O4 @C NSs, the former has open ion channels with good ion‐transmission and storage characteristics, and the latter provides sufficient space for volume expansion. Fe3 O4 @C exhibits favorable rate performance and improved cycle performance as an anode material for lithium‐ion batteries compared with Fe3 O4 . The reaction mechanism of lithium storage was studied by ex situ XRD and HRTEM.