Synthesis And Electrochemical Property Of Two-Dimensional Nanoporous Materials Based On Acetic Acid

It is urgent to develop new energy technology for the energy crisis.The green storage device–supercapacitors attract the public attention,which are long life,simple and efficient and low cost.Electrode materials are the key to Supercapacitors?SCs?.In the reported electrode materials,two–dimensional nanostructured materials have become the current research focus.Cobaltate materials are a kind of supercapacitor electrode material with low cost and environmental friendliness,and it has problems such as poor conduction performance,partial non–uniform dispersion unstable contact surface performance and insufficient capacity.One of the effective ways to solve the problem is to use a simple method to synthesize the two–dimensional porous nanoscale structure,and to improve the ratio of capacitance through the coordination effect.In this paper,2D porous thin sheets of?–Ni?OH?₂ and MCo₂O₄?M=Zn,Ni,Co,Mg and Cu?were successfully prepared by a one-step hydrothermal method,and the electrochemical properties of the prepared materials were studied.This article includes the following three aspects:Firstly,synthesis and electrochemical properties of 2D porous?-Ni?OH?₂ sheets.In this chapter,a large area systhesis of 2D porous?-Ni?OH?₂ nanostructure,which is assembled by 3D nanoarray as the basic unit,is synthesized by using the active agent without template hydrothermal method.The raw materials are CH₃COOH and Ni?NO₃?₂.The microstructure of the material can be controlled variables which are temperature,concentration and time.The best product of morphology can be obtained when the temperature is 200°C.Electrochemical performance teats indicate that the specific capacitance of 1747.5 F/g at the current density of 1.02 mA/cm² and good rate capability of 67.4%retain from 1.02 to 10.2 mA/cm².The corresponding assembled asymmetric supercapacitor achieves a high voltage of 1.8 V and an energy density of23.45 Wh/kg with a maximum power density of 9 KW/kg.Secondly,synthesis and electrochemical properties of 2D porous ZnCo₂O₄ sheets.In this chapter,the porous nanomaterial ZnCo₂O₄ is synthesized by simple and effective one–step hydrothermal decomposition,and the high–performance asymmetric supercapacitor is constructed.In addition,the raw materials are CH₃COOH,Zn?NO₃?₂and Co?NO₃?₂.The resulting delivers a high capacitance of 2.72 F/cm² at 2.02 mA/cm²and high rate capability of 59.76%from 1.01 to 10.1 mA/cm² and superior cycling performance of 3.5%loss after 5000 cycles.Furthermore,an assembled ASC device exhibits high energy density of 33.98 and 9.78 Wh/kg at power density of 8 and 0.8KW/kg,respectively.Finally,synthesis and electrochemical properties of 2D porous MCo₂O₄?M=Ni,Cu and Mg?sheets.In this chapter,the thermal barrier of Co-M carboxyl group was introduced by using the above green and environment–friendly low cost method to reduce the thermal barrier of Co,and the structure of porous MCo₂O₄ nano–chip array was successfully synthesized.In addition,the raw materials are CH₃COOH,M?NO₃?₂.The resulting delivers a high capacitance of 2096.8?2543.4?1611.714 F/g at 1 F/g about MCO₂O₄?M=Ni,Cu and Mg?.Furthermore,an assembled ASC device?NiCo₂O₄//active carbon?AC??exhibits high energy density of 43.82 Wh/kg and high capacitance at current density of 1 A/g.Besides,the NiCo₂O₄ material also has high coulombic efficiency.To summary,a series of 2D porous thin sheets of?-Ni?OH?₂ and MCo₂O₄?M=Zn,Ni,Co,Mg and Cu?have been synthesized by a mild one step hydrothermal method.In6 M KOH electrolyte,the designed ASC exhibits excellent electrochemical performance and analyses the effect of material structure on the properties,thus promoting the understanding of the energy storage process.