Rechargeable aluminum ion batteries (AIBs) are one of the most promising battery technologies for future large-scale energy storage due to their high theoretical volumetric capacity, low-cost, and high safety. However, the low capacity of the intercalation-type cathode materials reduces the competitiveness of AIBs in practical applications. Herein, a conversion-type FeF3-expanded graphite (EG) composite is synthesized as a novel cathode material for AIBs with good conductivity and cycle stability. Combined with the introduction of a single-wall carbon nanotube modified separator, the shuttle effect of the intermediate product, FeCl2, is significantly restrained. Moreover, enhanced coulombic efficiency and reversible capacity are achieved. The AIB exhibits a satisfying reversible specific capacity of 266 mAh g−1 at 60 mA g−1 after 200 cycles, and good Coulombic efficiency of nearly 100% after 400 cycles at a current density of 100 mA g−1. Ex situ X-ray diffraction and X-ray photoe
Abstract
Lithium-ion batteries (LIBs) are widely used in electric vehicles and portable electronic devices due to their high energy density, long cycle life, environmental friendliness, and negligible memory effect, though they also suffer from low power density, safety issues, and an aging effect. Cobalt chalcogenides/phosphides as promising anode materials have attracted intensive interests due to their high theoretical capacity based on the conversion mechanism. Cobaltates (XCo O , X = the other metal) have attracted attention because the X element can partially replace the high cost and toxic cobalt element. The serious volume variation during the cycling process has an impact, however, on the lithiation environment of above materials. Hierarchical construction can provide more active sites and shorten the diffusion pathways of Li ions as well as accommodating the volume expansion during lithiation processes. Herein, the research progress on the synthesis methods, structural cha