NiMn-Cl Layered Double Hydroxide/Carbon Nanotube Networks for High-Performance Chloride Ion Batteries

As one kind of promising energy storage device, chloride ion batteries (CIBs) have attracted extensive attention due to their sustainability, safety, and high theoretical volumetric energy density. However, the limited cathode materials with low structural stability and poor cyclic performance hinder the development of CIBs. In this work, NiMn layered double hydroxide (LDH) nanoplates with Cl– intercalation were grafted on carbon nanotube (CNT) backbone by a coprecipitation method. The as-prepared NiMn-Cl LDH/CNT hybrid material displays a cross-linked network with well-defined core–shell configuration and enlarged surface area. Under the electrochemical cycling, Cl– (de)intercalation causes the reversible evolution of the basal distance and the redox reaction of Ni and Mn on the host layer of NiMn-Cl LDH. Because of the improved electric conductivity by the introduction of CNT, the NiMn-Cl LDH/CNT hybrid exhibits enhanced rate performance and satisfied Cl– migration coefficients of 10–10–10–12 cm2 s–1. Besides, the reversible reaction mechanism of Cl– (de)intercalation endows the LDH/CNT hybrid a stable capacity of ∼130 mAh g–1 after 150 cycles. The robust layered structure and highly reversible redox pairs enable the NiMn-Cl LDH/CNT hybrid to show high capacity and long cycle life, making this kind of hybrid material a promising cathode material for CIBs.