Fabrication And Performance Of Carbon-Metal Oxide Composite As Interlayer For Lithium-sulfur Battery

Because the high energy density and environmental friendly,Li-S batteries have drawn widespread concern separator.It is a kind of very promising new energy storage devices.as an important part of Li-S cell,However,the poor electrical conductivity and low utilization of sulfur and the polysulfide shuttle effect cause the unstable circulation problems.In order to overcome the affect of the shuttle effect,the modified separator is designed to improve the cycle stability,and it has become the latest hotspot lithium-sulfur battery research.we use the oxide/carbon composite material to modify the separator and characterize the morphology and structure of them.We test the performance of lithium-sulfur battery with different-materials-modified separator and analyze mechanism which is the modified separator impact on the Li-S battery performance.We use a kind of one-step reaction process to preparing a kind of MnO2 nanosheet and apply it in the Li-S battery separator modification.We find that MnO2 nanosheet and TiO2 have good inhibition to prevent the shuttling effect.MWCNT/MnO2 nanosheet composite material shows high specific capacity which is higher than MWCNT and MnO2 nanosheet after 100 cycles.Charge-discharge test results show that graphene/metal oxide and MWCNT/metal oxide composite material-modified separator have better performance than pure metal oxide-modified separator.Battery with Graphene/TiO2 and MWCNT/MnO2 nanosheet composite-modified separator's specific capacity are 84.7% and 78.2% higher than the normal Li-S batteries.They have high initial discharge capacity and low capacity fading.During the hydrothermal process,adding some KMnO4,we got the hydrogel.After the drying and annealing process,we synthesized the dense composite material GN/MnO.This kind of porous material can be used as a interlayer in lithium-sulfur battery which improve the cycling performance of lithium-sulfur battery.