Novel Ni–Fe-Layered Double Hydroxide Microspheres with Reduced Graphene Oxide for Rechargeable Aluminum Batteries

Rechargeable aluminum batteries (RABs) have been intensively studied recently in virtue of high volumetric energy density and cheapness. However, limited options for suitable cathode materials is the major obstacle to their large-scale application. Herein, nickel-iron layered double hydroxide (NiFe–LDH) microspheres with reduced graphene oxide (rGO) are reported as cathode for RABs. It is demonstrated that NiFe–LDH can provide large interlayer spacing for aluminum ions to interact, and the introduction of rGO endows NiFe–LDH with excellent structure stability, electronic conduction, and electrochemical reaction kinetics. The aluminum battery with a NiFe–LDH/rGO cathode delivers a high reversible capacity of 131 mA h g⁻¹ at 1 A g⁻¹ with nearly 100% coulombic efficiency after 100 cycles. The characterization results reveal that the reversible Al³⁺ insertion/extraction along with the multielectron redox reactions occurs in the NiFe–LDH/rGO during the cycling process. The aforementioned strategies shed new light on the selection of compatible cathodes for RABs.