Green and sustainably designed intercalation-type anodes for emerging lithium dual-ion batteries with high energy density

Abstract

Lithium dual-ion batteries (LiDIBs) have attracted significant attention owing to the growing demand for modern anode materials with high energy density. Herein, rust encapsulated in graphite was achieved by utilizing ammonium bicarbonate (ABC) as a template, which resulted in mesoporous Fe3O4 embedded in expanded carbon (Fe3O4@G (ABC)) via simple ball milling followed by annealing. This self-assembly approach for graphite-encapsulated Fe3O4 composites helps enhance the electrochemical performance, such as the cycling stability and superior rate stability (at 3 A/g), with improved conductivity in LiDIBs. Specifically, Fe3O4@G-1:4(ABC) and Fe3O4@G-1:6(ABC) anodes in a half-cell at 0.1 A/g delivered initial capacities of 1390.6 and 824.4 mA h g(-1), respectively. The optimized anode (Fe3O4@G-1:4(ABC)) coupled with the expanded graphite (EG) cathode in LiDIBs provided a substantial initial specific capacity of 260.9 mA h g(-1) at 1 A/g and a specific capacity regain of 106.3 mA h g(-1) (at 0.1 A/g) after 250 cycles, with a very high energy density of 387.9 Wh kg(-1). The strategically designed Fe3O4@G accelerated Li-ion kinetics, alleviated the volume change, and provided an efficient conductive network with excellent mechanical flexibility, resulting in exceptional performance in LiDIBs. Various postmortem analyses of the anode and cathode (XRD, Raman, EDS, and XPS) are presented to explain the intercalation-type electrochemical mechanisms of LiDIBs. This study offers several advantages, including safety, low cost, sustainability, environmental friendliness, and high energy density. (C) 2023 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.