Study On The Interactions Between Metal Boron-hydrides And Carbon Materials And Their Energy Storage Characteristics

Metal boron hydride has high hydrogen content and can be used as an excellent hydrogen storage medium,but its thermal stability limits its practical application.The addition of carbon materials can effectively improve the hydrogen storage performance of metal boron hydride,which may be due to the catalysis of nanometer,interface or catalysis of C.Therefore,based on the review of recent research progress,graphite,single-walled carbon nanotubes,multi-walled carbon nanotubes and graphene were selected with the aid of Powder X-ray diffraction?XRD?,X-ray Energy dispersive Spectrometer?EDS?,constant capacity-pressure difference sievert?PCT?,Scanning electron microscopy?TEM?,cyclic voltammetry?CV?,by means of constant current charge and discharge and electrochemical impedance spectroscopy?EIS?,the intrinsic interaction between the in-situ metal boron hydride and the different carbon materials was studied,and the hydrogen storage properties of metal boron hydride and the effect on the electrochemical properties of the carbon materials were investigated.The main contents of this thesis are as follows:?1?Graphite as a carbon source,LiBH₄ and KCl as in-situ reaction,through the addition of graphite as a catalyst through the mechanical ball mill method.To investigate the effect of graphite on this kind of metal halide and Li BH₄,by comparing the hydrogen storage performance of each metal halide and LiBH₄ product,the effect of graphite addition on the hydrogen storage property of the material can be obtained.The results showed that the carbon material had a catalytic effect on the in-situ reaction of boron hydride,and the hydrogen storage capacity of boron hydride was improved remarkably.On the other hand,the in-situ reaction of boron hydride has the dissociation effect on carbon material.?2?Different carbon materials as the carbon source of the composite system,the method of mechanical ball milling was used to prepare the in-situ reaction system of boron hydride KCl+LiBH₄?B instead?Composites with a mass ratio of 5:5 to carbon material.The electrode material was obtained by heat treatment of the material under 500?heating for 3hours.By studying the electrochemical properties of carbon materials,the in-situ reaction of boron hydride and metal halide can improve the electrochemical properties of carbon materials as anode materials for lithium ion batteries.?3?Graphite as a carbon source.The composite material was made into anode material of lithium ion battery and the mechanism of improving the electrochemical performance of boron hydride in situ reaction was studied by adjusting the relative content of graphite in in-situ reaction system of boron hydride.In the carbon material and boron hydride in situ reaction system,the electrochemical properties of G/B=1:9 material is the best one.The less the relative content of carbon material,the better the electrochemical performance of the carbon material.