| With the increasing progress of the time and the rapid development of science and technology,people have put forward higher requirements on the capacity of portable electronic devices and electronic products such as electric steam,so the application of lithium-ion battery has been highly concerned in these fields.The choice of electrode materials greatly affects the performance of lithium-ion batteries.In the transition metal sulfide,molybdenum disulfide can achieve a higher battery specific capacity(669.7 m Ah g-1)due to its special lithium storage mechanism,but there are still these problems prone to agglomeration and cycle instability that need to be solved.Graphene,carbon nanotubes and other carbon materials themselves have good electrical conductivity,strong electrocatalytic effect,Molybdenum disulfide（Mo S2）with its doping together can effectively improve the electrochemical performance of the battery.The research subjects of this paper are molybdenum disulfide,and its composites with graphene and carbon nanotubes.The molecular information and structural characteristics of the material are analyzed,and its electrochemistry properties are detected and analyzed.The main research contents of this paper are as follows:（1）Ammonium molybdate and thiourea and graphite oxide are used as reactants to prepare for molybdenum/graphene material（Mo S2/GN）by hydrothermal reduction reaction.Then,molybdenum disulfide and graphene oxide are prepared as a flexible material（Mo S2/GN-F）by vacuum extraction and heating and reduction.The micro morphology of Mo S2/GN and Mo S2/GN-F presents a layered nanoflower structure,whose surface is coated with thin graphene,and the whole flower cluster is about 200 nm in diameter.The combination of the two forms a 3D conductive grid,It is conducive to the free migration and storage of electrons and lithium ions in the grid,and the theoretical specific capacity is greatly improved.Mo S2/gn-F film material has good flexibility and can be folded repeatedly and cut at will.As the cathode material of lithium ion battery,the Mo S2/GN-F and Mo S2/GN electrode show high battery theoretical specific capacity.Mo S2/GN-F electrode shows the specific capacity of 1148.3 m Ah g-1 in the first cycle discharge,and the Mo S2/GN electrode is920.0 m Ah g-1,Compared with simple Mo S2 electrode,it is increased by 26.8%and 8.62%respectively.（2）In order to improve the conductivity between molybdenum disulfide and graphene sheets,on the basis of the preparation of molybdenum disulfide-graphene composite and adding carbon nanotube,molybdenum disulfide-graphene-carbon nanotube composite（Mo S2/GN/CNT）is prepared by hydrothermal method.Mo S2 nanosheets of 200-300 nm are formed in the Mo S2/GN/CNT composite material,interspersed with irregularly folded carbon nanotubes.The electrochemical performance test results shows that in Mo S2/GN/CNT//Li half batteries,Mo S2/GN/CNT electrode shows a high initial discharge capacity of 1286.9 m Ah g-1,and the discharge capacity of the next two circles gradually decreases to 1244.3 m Ah g-1 and1205.2 m Ah g-1 respectively.After 100 cycles at constant current density of 400 m A g-1,the discharge capacity of Mo S2/GN/CNT electrode is basically stable at 802.4 m Ah·g–1,delivering excellent electrochemical performance in repeated charge and discharge process,compared with simple Mo S2 electrode,it is increased by 72.5%and 25.8%respectively.In the Li Co O2//Mo S2/GN/CNT full cell,the current density is at 100,200,400,800,1600 and 2000m A g-1,the Mo S2/GN/CNT electrodes achieves 1289.7,1076.9,917.2,7797.3,655.7 and501.3 m Ah·g–1.When the current is restored to 200 m A·g–1,the discharge ratio capacity of the Mo S2/GN/CNT electrode is 744.9 m Ah·g–1,indicating the excellent multiplier performance of the Li Co O2//Mo S2/GN/CNT full battery. |
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