Preparation And Electrochemical Properties Of Nickel-aluminum Layered Double Hydroxide Composite Electrode Materials

Supercapacitors（SCs）are receiving attention as electrochemical energy storage devices that can supply high-power density,long working life,and environmental friendliness,etc.Nevertheless,the lower energy density of SCs compared with batteries limits their application field,so the development of higher energy density SCs has research significance and application value.The performance of electrode materials affects the performance of energy storage devices,among which nickel-aluminum layered double hydroxide（NiAl LDH）has become a promising electrode material for SCs because of its low production cost,strong electrochemical activity,and high theoretical capacity as an electrode material.However,NiAl LDH has problems such as low electrical conductivity and easy agglomeration,which restrict its development as a high-performance SCs electrode material.As a result,the performance of NiAl LDH in the field of energy storage can be improved by modifying the microstructure of NiAl LDH and compounding materials with high conductivity and high stability.This paper focuses on NiAl LDH composite electrode materials as the object of research exploration,to explore the improvement of performance of different materials composite,to explore the improvement of performance of different materials composite,and the main research contents are as follows:（1）The rGO@NiAl LDH electrode materials were prepared simply and quickly by one-step hydrothermal treatment,and study the difference of electrode material performance under different graphene oxide（GO）addition and hydrothermal time.The electrochemical tests showed that rGO@NiAl LDH has a specific capacity of 236.3 m Ah g^-1 at 1 A g^-1 and an initial capacity retention of 80.2%after 5000 cycles.The ASC（rGO@NiAl LDH//AC）assembled with activated carbon（AC）has an energy density of 41.3 Wh kg^-1 at 800 W kg^-1 and an initial capacity retention of 84.4%after 5000 cycles.（2）The Co-MOF@Mn₃O₄@NiAl LDH electrode material was prepared by electrodeposition of Mn₃O₄ particles and hydrothermal growth of NiAl LDH on the Co-MOF framework.The effect of different hydrothermal temperatures on the performance and the difference of performance between NiAl LDH@Co-MOF and NiAl LDH@Mn₃O₄ were also investigated.The electrochemical tests showed that Co-MOF@Mn₃O₄@NiAl LDH has excellent performance with a specific capacity of 364.2 m Ah g^-1 at 1 A g^-1 and an initial capacity retention of 74.6%after 5000 cycles.The ASC（Co-MOF@Mn₃O₄@NiAl LDH//AC）assembled with AC has an excellent energy density of 60.9 Wh kg^-1 at 849.9 W kg^-1 and an initial capacity retention of 82.9%after 5000 cycles.（3）The Ni-Co-S@NiAl LDH electrode material was prepared by preparing Ni-Co-S arrays from Co-MOF arrays through annealing and hydrothermal sulfidation and then electrodepositing NiAl LDH to obtain it.The precursor and electrodeposition time process were also studied.The electrochemical tests showed that Ni-Co-S@NiAl LDH has excellent performance with a specific capacity of 250.6 m Ah g^-1 at 1 A g^-1,a multiplicative performance of 78.7%at 20 A g^-1,and an initial capacity retention of 83.1%after 5000 cycles.The ASC（Ni-Co-S@NiAl LDH//AC）assembled with AC has a high energy density of 45.3 Wh kg^-1 at 850W kg^-1 and an initial capacity retention of 86.3%after 5000 cycles.