Preparation And Performance Improvement Of Tungsten Disulfide Electrode Materials

Two-dimensional layered WS₂ materials has been widely used in lubrication,energy storage and catalysis because of its unique structure and excellent photoelectric performance.In order to explore its application in lithium-ion battery energy storage,this paper studied tungsten disulfide in terms of preparation and electrochemical performance improvement.The structure,morphology,composition and properties of the materials were characterized by XRD,SEM,TEM,Raman,EDS and charge-discharge performance test.The specific research contents of this paper are as follows:1)By changing various factors such as raw material type,raw material ratio,sintering temperature and holding time,the optimum process for preparing tungsten disulfide by high temperature solid phase method is explored.The results show that when the ammonium sulphate and thiourea are used as raw materials,the ratio of n _W:n _S=1:20 is selected,and the WS2 particles prepared by sintering at 900°C for 3 h,the products are smaller and have higher purity and electrochemical performance.2)The precursor of?NH₄?₂WS₄ was prepared by using tungsten trioxide and thioacetamide as raw materials.The precursor was subjected to heat treatment to obtain WS₂ negative electrode material.The results show that the WS₂ particles obtained by this method are very agglomerated and WS₂ have more oxygen defects,poor cycle and rate performance.However,the electrochemical properties of the materials are greatly improved after vulcanization at 300°C.3)The electrochemical performance of the tungsten disulfide material is improved by doping different metal ions.When 5%vanadium is doped into tungsten disulfide,the structure and electrochemical properties of the material are optimized.The specific capacity is 1087 mAh/g and the capacity can still reach 610 mAh/g after 130 cycles at different current densities.When 1%iron is doped into the tungsten disulfide,the low-rate electrochemical performance of the material is improved while the high-rate electrochemical performance is lowered.At a current density of 100 mA/g,the specific capacity is 946.3 mAh/g,and the specific capacity becomes 810 mAh/g after 30 cycles,but when the current density reaches 800 mA/g,the specific capacity of the materials can only reach 460 mAh/g.When 10%molybdenum is doped into tungsten disulfide,the electrochemical performance of the material is optimal and the cycling performance and rate performance are greatly improved.The specific capacity can reach 984.6 mAh/g and the capacity can still reach 584.6 mAh/g after cycling 130 times at different current densities.5)The performance of the WS₂ is improved by the combination of carbon.When the mass ratio of carbon is 10%,the electrochemical performance of the materials is optimal.After compounding,the specific capacity of the complex can reach 1108 mAh/g,the discharge capacity can reach 876 mAh/g of 100 mA/g current density after 30 cycles.The capacity can still reach 584.5 mAh/g after 130 cycles at different current densities,it can be seen that the cycling and rate performance of the material are greatly improved.