Preparation Nano Carbon/Metal Oxide (Hydroxide) Composite Materials And Their Energy Storage Performance Research

The exhaustion of fossil energy and increasingly serious environmental crisis along with the use of fossil energy force us to speed up the pace of transformation of energy system, looking for a clean and renewable energy system to replace the fossil energy system.Looking for energy system transformation, governments around the world focus their attention on the electric energy storage system and develop it vigorously. As an important part of the the electric energy storage system supercapacitor has attracted increasing attention in recent years.Electrode material is an important part of supercapacitor.The development of the elecrode material play a pivotal role in the development of supercapacitor.In this paper, we design and synthesize nano carbon/metal oxide hydroxide composite material, and the energy storage properties of the composites has been investigated. The specific studies are as follows:1, We have developed a widespread in situ growth process to prepare a hierarchical three-dimensional (3D) composite composed with layered double hydroxide (LDHs) nanosheet arrays grown on nanocarbon material modified by surfactant.By using this method we successfully obtained KS-6/NiAl-LDHs and CNTs/NiAl-LDHs composite material by in situ grown NiAl-LDHs nanoarrays on different nano carbon material. The obtained KS-6/NiAl-LDHs and CNTs/NiAl-LDHs composite exhibited high-capacitance performance with a specific capacitance of 1402.5 F·g-1 and 1138.1 F·g-1 respectively at a current density of 1 A·g-1.Moreover, the composite exhibited excellent cycling performance with specific capacitance remaining at 108.6% and 76.9% respectively after 1000 cycles at a current density of 5 A·g-1.2, Expanded graphite/nickel aluminum layered double hydroxides (EG/NiAl-LDHs) composite material is achieved by in situ growth of NiAl-LDHs in the interlayer of expanded graphite (EG) with the help of vacuum-assisted technique.The net-like macropores structure of the EG is preserved completely which provide storage space for electrolyte so that the obtained composite exhibited excellent rate performance. The obtained composite exhibited high-capacitance performance with a specific capacitance of 602.2 F·g-1 at a current density of 1 A·g-1 and the specific capacitance still remains 78.5% when the current density is increased to 20A·g-1. Moreover, the composite exhibited excellent cycling performance with specific capacitance remaining 99.8% after 5000 cycles at 20 A·g-1.3, CNTs were prepared by catalytic chemical vapor deposition of complex carbon source with a series of Ni-based LDHs and Ni-based LDHs growth on the substrate as catalyst precursor. The diameter of the obtained CNTs is about 40 nm.The obtained CNTs mix with catalyst composite materials exhibit excellent electrochemical performance when it is as anode material for lithium ion batteries. The powder NiMgAl-LDHs catalytic grown CNTs composites achieve a discharge specific capacity of 254.5 mAh·g-1 in the first cycle and a reversible discharge specific capacity of 108.7 mAh·g-1 at a current density of 200 mA·g-1. The composite exhibited excellent cycling performance with specific capacitance remaining 109.2 mAh·g-1 after 200 cycles at 200 mA·g-1.The CF/NiCo-LDHs catalytic grown CNTs composites achieve a discharge specific capacity of 828 mAh·g-1 in the first cycle and a reversible discharge specific capacity of 800 mAh·g-1 in the 20 cycle at a current density of 800 mA·g-1.