Preparation Of Composite Materials Based On Three Dimensional Graphene Loaded Lithium Hydroxide And Their Performance In Chemical Heat Storage

Graphene has attracted wide attention owing to its high specific surface area,unique planar structure,as well as its superior mechanical,thermal,and photoelectrical properties.Currently,it has been considered as an ideal carrier for new nanocomposites in the future due to the gradual reduction of its production cost with the deepening of research and technological advancement.The interactions between 3D-structure graphene carrier and active components enable the composite materials.On one hand,the high specific surface area of 3D-structure graphene improves the dispersity of the active components carried.Additionally,the superior thermal conductivity and rich internal porous structure of3D-graphene greatly facilitates the heat and mass transfer of composite.On the other hand,the active components prevent graphene layers from reaggregation,which greatly enhances the overall cycling stability of composite.In a word,the synergistic effect between graphene and the nanoparticles of lithium hydroxide highly enhances the performance of original single active component material,endowing the composites with great potential in the field of energy storage.Based on the modification and preparation technology of graphene carrier,this study firstly improves the structure and performance of the carrier.Then the graphene carrier was mixed and combined with lithium hydroxide by a hydrothermal reaction to prepare a composite with excellent thermal storage performance.The main contents of this research are as follows:?1?The design of 3D-structure graphene carrier.As an alternative to the conventional graphene,functionalized 3D-graphene is expected to be a new carbon-based carrier owing to its high thermal conductivity and carrying capacity.In this study,four new 3D-structure graphene carriers were prepared using a hydrothermal method with graphene oxide solution as reaction precursor.The new carriers,bearing rich oxygen-containing groups on surface and unique internal porous structures,are capable of carrying and dispersing a higher proportion of lithium hydroxide.Moreover,owing to the 3D carbon network structure,the new carriers displayed superior thermal conductivity.The thermal conductivity coefficient analyzer through the heat flux method suggested that the thermal conductivity coefficient of the new carriers reaches 3.593 W/?m·K?.Moreover,according to the results of SEM and TEM,the new carriers present wrinkled surfaces and rich internal pores,signifying the intensive carrying and dispersing capabilities of the carriers to lithium hydroxide.?2?The preparation of a 3D-structure graphene-carried lithium hydroxide monohydrate?3D-GF-LiOH·H₂O?nanocomposite using a hydrothermal method.Under sealed hydrothermal condition at 105?,3D-GF-LiOH·H₂O nanocomposite was prepared by directly mixing the carriers with lithium hydroxide,without any surfactants and complexes.Finally,using TG-DSG,SEM,and TEM,the dispersity and carrying amounts of lithium hydroxide on the surface of carrier were determined,as well as the nanosized effects of active component on the thermal storage density of the nanocomposite.