Array structured NiAl-layered double hydroxides grown on graphene by atomic layer deposition as chloride-ion battery cathode
Guoqing Zhao, Zhen Deng, Gengping Wan, Jinchuan Zhao, Guizhen Wang
Abstract
Novel and promising chloride ion batteries (CIBs) that can operate at room temperature have attracted great attentions, due to the sustainable chloride-containing resources and high theoretical energy density. To achieve the superior electrochemical properties of CIBs, the structure design of electrode materials is essential. Herein, 2D NiAl-layered double hydroxide (NiAl-LDH) nanoarrays derived from Al 2 O 3 are in-situ grafted to graphene (G) by atomic layer deposition (ALD) and hydrothermal method. The achieved NiAl-LDH@G hybrids with 2D NiAl-LDH arrays grown perpendicularly on graphene surface, can efficiently prevent the stacking of LDHs and enlarge specific surface area to provide more active sites. The NiAl-LDH@G cathode exhibits a maximum discharge capacity of 223.3 mAh g −1 and an excellent reversible capacity of 107 mAh g −1 over 500 cycles at 100 mA g −1 with a high coulombic efficiency around 96%, whereas pure NiAl-LDH has a discharge capacity of only 48.8 mAh g −1 and a coulombic efficiency (CE) of about 78%. More importantly, the NiAl-LDH@G electrode has a stable voltage at 1.9 V and an outstanding discharge capacity of higher than 72 mAh g −1 after 120 days. Additionally, XRD, XPS, and EDS have been employed to unveil the electrochemical reaction and Cl – storage mechanism of the NiAl-LDH@G cathode in CIBs. This work opens a facile and reasonable way for improving electrochemical performance at anion-type rechargeable batteries in terms of cathode material design and mechanism interpretation. • Graphene with grafted NiAl-layered double hydroxide (NiAl-LDH@G) was achieved. • Atomic layer deposition and hydrothermal method was used to prepare NiAl-LDH@G. • NiAl-LDH@G shows excellent electrochemical property by offering numerous active sites. • NiAl-LDH@G cathode has discharge capacity of 223.3 mAh g −1 and coulombic efficiency nearly 100 %. • NiAl-LDH@G electrode has stable voltage at 1.9 V and discharge capacity of >72 mAh g −1 after 120 days.