Preparation Of New Energy Storage Nanomaterials Based On Laser Ablation In Liquid And Their Physicochemical Properties

Laser ablation in liquid（LAL）,as a simple,quick and environmental-friendly method of preparing nanomaterials,is of great importance in the field of synthesizing unique nanomaterials and novel structure,due to its extreme thermodynamic conditions and rapid quenching of the non-equilibrium dynamic process.Based on LAL technique,in combination with other conventional wet chemical synthesis methods,this thesis made efforts on the preparation and application of several kinds of functional nanomaterials,including composite nanostructure,self-assembly nanostructure,doped nanostructure and corresponding application in electrochemical capacitors,lithium ion battery and rechargeable zinc-air battery.Main innovative research results are as follows:（1）A new method for preporation of MoS₂/Co₃O₄ composite nanostructure was proposed.Firstly,we used the 1064 nm wavelength laser to ablate the cobalt target in deionized water and got the uniform size distributed Co（OH）₂ nanoparticles with positively surface charged.Then,mixing and stirring with the negatively surface charged MoS₂ nanosheets,the ultrafine Co（OH）₂ nanoparticles decorated MoS₂ nanosheets could be obtained according to electrostatic incorporation.Finally,MoS₂/Co₃O₄ composite nanostructure formed after been stored at 70 ℃,the method turned out to be simple and effective;Electrochemical test results showed that the MoS₂/Co₃O₄ composite nanostructure electrode had higher specific capacity and better charge-discharge cyclic performance than pure-phase Co₃O₄ electrode due to the synergistic effect between the MoS₂ and Co₃O₄.（2）A novel method was developed to prepare metastable phase TT-Nb₂O₅ nanopillar with single crystal structure.Briefly,the high-activity Nb colloid obtained through LAL was used as non-ion precursors,then carried out the hydrothermal treatment;Finally,a metastable phase of TT-Nb₂O₅ single crystal nanopillar was obtained;Its structural evolution and self-assembly process were discussed detailedly,also we combined the products with graphene and assembled into the self-supported membrane,directly used as anode materials for lithium ion battery,avoiding the use of conductive carbon black and coupling agent,results showed that the button battery had high first-discharge capacity and excellent charge-discharge cyclic performance.（3）A simple,mild and one-step approach for synthesis of flower-like Co doped Ni（OH）₂ nanosheet structure was designed.The high-activity Co colloid obtained through LAL was used as non-ion dopant source,followed by an aging treatment in a Ni（NO₃）₂ and Na₂S₂O₃ hybrid medium at room temperature,then flower-like Co doped Ni（OH）₂ nanosheet structure formed without using other additional extreme conditions such as high temperature and high pressure.Electrochemical testing results showed that the product Co doped Ni（OH）₂ electrode had excellent electrochemical capacitor performance due to the remarkable improvement in the electrical conductivity of Ni（OH）₂ after doping with Co element as well as the unique surface microstructure features of the product.（4）Based on the doping approach above,a more uniform morphology of Fe doped Ni（OH）₂ flower-like nanosheets were prepared by changing the reaction environment（deionized water and ethanol mixed solution）,and electrochemical testing results showed that the product had better OER electrocatalytic performance than commercial RuO₂.（5）The influences of LAL-induced high-activity Mn colloid used as non-ion dopant source on the morphology of doped Ni（OH）₂ was investigated.The high-activity Mn colloid obtained through LAL was selected as non-ion dopant source,deionized water acted as reaction medium,then Ni（NO₃）₂ and Na₂S₂O₃ were added,followed by room temperature aging for ten days,the results showed that Mn doped Ni（OH）₂ with nanowire morphology was obtained.