Rechargeable lithium–sulfur (Li–S) batteries hold great potential for next-generation high-performance energy storage systems because of their high theoretical specific energy, low materials cost, and environmental safety. One of the major obstacles for its commercialization is the rapid capacity fading due to polysulfide dissolution and uncontrolled redeposition. Various porous carbon structures have been used to improve the performance of Li–S batteries, as polysulfides could be trapped inside the carbon matrix. However, polysulfides still diffuse out for a prolonged time if there is no effective capping layer surrounding the carbon/sulfur particles. Here we explore the application of conducting polymer to minimize the diffusion of polysulfides out of the mesoporous carbon matrix by coating poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate) (PEDOT:PSS) onto mesoporous carbon/sulfur particles. After surface coating, coulomb efficiency of the sulfur electrode was improved from 93% to 97%, and capacity decay was reduced from 40%/100 cycles to 15%/100 cycles. Moreover, the discharge capacity with the polymer coating was ∼10% higher than the bare counterpart, with an initial discharge capacity of 1140 mAh/g and a stable discharge capacity of >600 mAh/g after 150 cycles at C/5 rate. We believe that this conductive polymer coating method represents an exciting direction for enhancing the device performance of Li–S batteries and can be applicable to other electrode materials in lithium ion batteries.

DTI is a valuable method to distinguish postoperative recurrent glioma and radiation injury.

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Electron emission from silicon tips coated with sol-gel ( Ba 0.67 Sr 0.33 ) Ti O 3 ferroelectric thin film Ferroelectricity in sol-gel derived Ba 0.8 Sr 0.2 TiO 3 thin films using a highly diluted precursor solution Periodic ferroelectric multilayers consisting of alternating stack of the dense and porous Ba 0.9 Sr 0.1 TiO 3 layers have been fabricated by spin-coating and annealing sol-gel techniques using one single precursor. With 16 periods, the Ba 0.9 Sr 0.1 TiO 3 multilayers exhibit excellent performance as dielectric mirrors: symmetric peak reflectivities of above 95% and flattopped stop bands of about 75 nm. The reflectance peak position is tunable through varying the spinning rate in the spin-coating process. The lead-free Ba 0.9 Sr 0.1 TiO 3 multilayers show high stability.

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