Synthesis And Electrochemical Energy Storage Of GeS₂ And MoO₃

Because of increasing consumption of fossil fuels,environmental problems such as haze and greenhouse effect are becoming more and more serious.In order to alleviate the current situation of environmental deterioration,it is necessary to change the existing unreasonable energy structure,improve energy utilization rate,and develop new sources of energy.Lithium-ion batteries?LIBs?,as green,environmentally friendly and renewable energy storage devices with high energy density and power density,have dominated the market of portable electronic equipment,such as mobile phones and notebook computers.Considering the concerns caused by the scarcity and uneven distribution of lithium sources,researchers have also done a lot of research on sodium ion batteries?SIB?,especially when considering large-scale energy storage.However,the specific capacity of commercial graphite carbon anode materials are only 372 mAh g^-1 for LIBs and 35 mAh g^-1 for SIBs,respectively.Its low specific capacity and energy density cannot meet the requirements of the rapid development of mobile electronic equipment in the future,and there is little room to further improve its capacity.Therefore,the development of new anode materials with high specific capacity and stable cycling performance for LIBs has become one of the focuses of current research work.In this paper,two typical metal-chalcogenide materials,germanium sulfides?GeS₂?and molybdenum trioxide?MoO₃?,were investigated,and their electrochemical properties were applied to anode materials for lithium/sodium ion batteries.The first chapter of this paper briefly introduces the development of batteries,the structural composition and working principle of LIBs and SIBs,and summarizes the research progress of common electrode materials for LIBs and SIBs.Then,it gives a brief introduction to the topic and research content of this paper.The second chapter of this paper mainly introduces the chemical reagent and equipment used in the experiment,the characterization methods of the material phases,the assembly process of lithium/sodium ion batteries,and the testing methods of electrochemical performance.In the third chapter of this paper,two-dimensional?2D?ultra-thin GeS₂ nanosheets were prepared by the topotactic transformation method,and the single-layer thickness was only 1.2 nm.2D ultra-thin nanostructures can alleviate the electrode and electrolyte contact problems faced by bulk materials,and provide shorter transmission/diffusion paths for Li⁺/Na⁺ and electrons,thereby achieving excellent rate performance.The fourth chapter of this paper proposes an effective interlayer engineering strategy.This synthesis strategy is based on the integration of partial reduction and organic molecule intercalation methods.This allowed the interlayer spacing of MoO₃ to gradually increase from 6.92?to 10.40?,and the introduction of organic molecules has produced excellent ion insertion/extraction kinetics,which greatly improves the electrochemical performance of MoO₃ in lithium/sodium ion batteries.Finally,the paper's work is summarized.