Lithium-ion batteries are widely used in our daily life. With the emerging demand for high-capacity energy storage devices from emerging electronic products such as portable electronic devices and electric vehicles, traditional lithium-ion batteries are far from meeting our energy storage needs. Sulfur batteries are considered as one of the most promising high-capacity storage systems because of their high theoretical specific capacity and energy density, as well as their low cost and environmental friendliness. However, there are still some technologies for the commercial application of lithium-sulfur batteries. Challenges such as insulation of sulfur and solid discharge products, shuttle effects of soluble polysulfides, and changes in the size of sulfur during charging and discharging. These problems often lead to low sulfur utilization, poor cycle life, and even a series of safety issues. How to significantly increase the energy density of lithium-sulfur batteries while increasing their stability has become one of the current research hotspots.
Under the support of the National Natural Science Foundation of China and the Chinese Academy of Sciences’ Strategic Pilot Science and Technology Project, the research team of the State Key Laboratory of Structural Chemistry of the Fujian Institute for the Study of Structures of the Chinese Academy of Sciences Wang Ruihu's research group Xiao Zhubing and others synthesized the vanadium sulfide-supported product through a simple hydrothermal reaction. The layered materials of graphene oxide (rGO-VS2) were reduced, and a series of rGO-VS2/S cathode materials with rGO-VS2 sheets and sulfur monolayers alternately and closely packed were prepared. rGO-VS2 sheets and activity The alternately formed sandwich structure of the sulfur layer can withstand the volume change of the active material during the charge-discharge cycle by the elastic shrinkage expansion in the three-dimensional direction. At the same time, the vanadium sulfide has a high polarity, conductivity and electrocatalytic activity, and a small amount of vanadium sulfide load. The polysulfide shuttle effect can be effectively suppressed on the graphene sheet to promote the redox reaction of the entire sulfur element layer, thereby improving the utilization of the sulfur active material and the cycle stability. The load of 89 wt% sulfur on rGO-VS2/S With a high tap density of 1.84 g cm-3, its volumetric capacity reaches 1182.1 mA h cm-3 at 0.1 C discharge, and it remains 100 cycles. At 1050 mA h cm-3. This study shows that introduction of electrocatalytic components with high conductivity and strong polysulfide adsorption capacity in a retractable sandwich structure can lead to lithium-sulfur battery cathode materials with superior performance. Lifetime, high-energy-density lithium-sulfur batteries provide new ideas. The research results were published in the form of a cover article on Advanced Energy Materials and introduced by MaterialsViewsChina. The first author of the paper is Dr. Cheng Zhibin.
