Xps peak sulphur
In spite of these advantages, practical applications of Li-S batteries are hindered owing to the following critical issues which lead to low active material utilization and poor cyclability: (1) low electronic and ionic conductivity of sulfur (5 × 10 −30 S cm −1) and its discharge products Li 2S/Li 2S 2 (2) severe dissolution of intermediate polysulfides in electrolyte, forming the so-called shuttle effect and (3) large volumetric expansion (~ 76%) during the discharge of cell. Furthermore, from a practical perspective, element sulfur is naturally abundant, low cost, nontoxic, and environmentally friendly compared with other traditional transition metal oxide cathode materials. Lithium-sulfur (Li-S) batteries have become one of the most promising candidates for next-generation lithium secondary batteries due to their high theoretical capacity (1675 mAh g −1) and theoretical energy density (2600 Wh kg −1, 2800 Wh l −1, respectively).
#Xps peak sulphur portable
The development of portable electronics, electric vehicles (EVs), and smart grid systems has been continuously demanding rechargeable batteries with high energy density, long life span, and low cost. Activated carbon aerogels with high surface area and unique three-dimensional (3D) interconnected hierarchical porous structure offer an efficient conductive network for sulfur, and a highly conductive PANi-coating layer further enhances conductivity of the electrode and prevents the dissolution of polysulfide species. The excellent electrochemical performance of can be attributed to the synergistic effect of hierarchical porous nanonetwork structure and PANi coating. Furthermore, this composite exhibits a discharge capacity of 926 mAh g −1 at the initial cycle and 615 mAh g −1 after 700 cycles at 1C rate, revealing an extremely low capacity decay rate (0.48‰ per cycle). The obtained composite delivers a high reversible capacity up to 1208 mAh g −1 at 0.2C and maintains 542 mAh g −1 even at a high rate (3C). Based on this substrate, a polyaniline (PANi)-coated activated carbon aerogel/sulfur composite is prepared via a simple two-step procedure, including melt-infiltration of sublimed sulfur into ACA-500, followed by an in situ polymerization of aniline on the surface of ACA-500-S composite. An activated carbon aerogel (ACA-500) with high surface area (1765 m 2 g −1), pore volume (2.04 cm 3 g −1), and hierarchical porous nanonetwork structure is prepared through direct activation of organic aerogel (RC-500) with a low potassium hydroxide ratio (1:1).