Synthesis And Application Of Three-dimensional Micro/nano Electrode Materials

Lithium ion secondary batteries have been widely used in a variety of portable electronic products.In recent years,electric vehicles,portable mobile equipment and hybrid vehicle energy storage devices have put forward higher requirements for lithium ion secondary batteries and electrode materials.Carbon-based materials are the most widely used anode materials,but due to their low theoretical capacity,they can,t meet the demand of high power density.The theoretical capacity of metal oxide is high,but the volume expansion is serious in the process of electrochemical cycling,which easily leads to safety accidents.Therefore,it has become a research hotspot in the field of lithium ion secondary batteries to seek the anode material of lithium ion secondary batteries which is more safe,environmentally friendly and has high specific energy.Three-dimensional micro-nano structure anode electrode materials have uniform porosity and large specific surface area,with special physical,chemical and mechanical properties,so it is necessary to explore the application of three-dimensional micro-nano structure materials.Based on this,a series of precursors,mainly Cu and foam Cu,were designed in this work.Graphene quantum dots coated with foam copper with three-dimensional micro/nano continuous channel structure were prepared by hydrothermal method.SnO₂ coated foam Cu was prepared by hydrothermal method.CuO and Cu₂O foam Cu composite electrode materials were prepared by calcining at high temperature.The spherical and lamellar mixed metal oxide composites with micro-nano size were obtained.The effects of anodic oxidation voltage,hydrothermal temperature,hydrothermal time on the composition,structure and electrochemical properties of the materials were studied.Experiments show that these three-dimensional micro-nano structural materials,as foam materials for lithium ion batteries,can effectively limit the volume expansion during the electrochemical cycle,significantly improve the transmission rate of lithium ions,and improve the charge and discharge capacity.