Ternary battery, fuel cell car welcome policy

Lithium-sulfur batteries have become a research hotspot because of their high theoretical energy density, low cost and environmental friendliness. However, most of the high-capacity, long-cycle lithium-sulfur batteries that have been reported so far have low sulfur content and cannot meet the needs of practical applications. In order to solve the above problems, Fang et al. prepared a full graphene positive lithium-sulfur battery with porous graphene (HPG) loaded active material sulfur and high conductive graphene (HCG) as a current collector with a porosity of 3.51 cm 3 g ^-1 . Partially oxidized graphene (POG) acts as a polysulfide adsorption layer with a loading capacity of up to 80% and an areal density of 5 mg cm ^-2 .

Preparation of HPG: HPG was prepared by thermal stripping of graphite oxide. First, the graphite is oxidized using the modified Hummer method. Further, the graphite oxide was thermally stripped in air at 300 ° C for 5 minutes, and then heated to 1000 ° C at a rate of 2 ° C / min in an Ar atmosphere for 3 hours to obtain HPG. HPG and S were mixed at a ratio of 1:4, ground for 30 minutes, transferred to a hydrothermal kettle, and maintained at 155 ° C for 15 hours to obtain an S/HPG composite.

Preparation of POG adsorption layer: The suspension of GO was freeze-dried to obtain a powder of GO, and the powder of GO was heated to 1000 ° C at a rate of 2 ° C / min for 2 hours to obtain POG, and then dispersed in ethanol, ultrasonic 20 After a minute, vacuum filtration onto a commercial membrane and drying in air at 60 ° C for 24 hours.

Figure 1 Full graphene structure design of sulfur positive electrode

In the obtained total graphene positive electrode, since the HCG is lighter, the energy density of the whole battery is improved, and the POG can be chemically bonded to the polysulfide to suppress the shuttle effect of the polysulfide, even after 400 cycles, the battery is still With stable cycle performance, it provides a solution for more reliable lithium-sulfur batteries.

CA Temporary Fence

Product information: