Thermodynamic assessment and optimization of a pressurized fluidized bed oxy-fuel combustion power plant with CO2 capture
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Engineering topics
Publications and source records attributed to Yu, Ran.
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We report that electrochemical performances of lithium-sulfur batteries have received much progress in recent years. However, their practical deployment encounters challenges with respect to optimizing the cell-fabrication parameters (e.g., amounts of the active material and electrolyte). We present here an “ant-nest-like” cathode substrate with unique architecture to synchronously attain high electrochemical performance and necessary cell-fabrication parameters. The cells with a high sulfur loading (11.5 mg cm -2 ), a high sulfur content (75 wt.%), and a low electrolyte/sulfur ratio (9 μL mg -1 ) display a high areal capacity and energy density of, respectively, 7 mA h cm -2 and 14 mW h cm -2 with a capacity retention of 70% after 150 cycles. Moreover, the cells exhibit a low self-discharge behavior with a low self-discharge constant of 0.0013 per day and a long rest period of one month. Lastly, these dynamic and static electrochemical stabilities are attributed to the ant-nest-like structure and low surface area of the cathode substrate that allows, respectively, the accommodation and encapsulation of a high amount of active material and reduces the consumption of electrolyte.
Lithium–sulfur batteries with a high theoretical energy density would be a promising next-generation energy-storage system if their cell-fabrication parameters (e.g., sulfur loading/content and the electrolyte/sulfur ratio) are improved to a practically necessary level. In this article, we report the design of a three-dimensional core–shell carbon substrate, integrating a porous internal core with a conductive external carbon nanofiber shell. Such a carbon substrate encapsulates a high amount of sulfur as the active material core to form a high-loading core–shell cathode, attaining an ultra-high sulfur loading and content of, respectively, 23 mg cm -2 and 75 wt%. With distinguishable internal and external regions, the carbon substrate facilitates the redox reactions and hinders the polysulfide diffusion. Therefore, the core–shell cathodes exhibit a high areal capacity and energy density of, respectively, 14 mA h cm -2 and 27 mW h cm -2 during cycling. During resting, they achieve a long shelf-life of one month with a low capacity-fade rate of 0.25% per day.