The Experts below are selected from a list of 57801 Experts worldwide ranked by ideXlab platform
Hai Yang - One of the best experts on this subject based on the ideXlab platform.
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a facile strategy toward sodium ion batteries with ultra long cycle life and high initial coulombic efficiency free standing porous carbon nanofiber film derived from bacterial cellulose
Energy Storage Materials, 2019Co-Authors: Hai YangAbstract:Abstract Sodium-ion batteries (NIBs) has been considered as the most promising next generation low cost and environmentally friendly electrochemical energy storage system for smart-grid applications. To meet the requirements of practical application of NIBs, development the advanced Carbon-Based Anode with both ultra-long cycle life and high initial Coulombic Efficiency (ICE) is one of the most critical challenges. Here, we realized free-standing and binder-free carbon nanofiber (CNFs) electrode with high ICE (93% at 0.2 A g−1) and long cycle life at high rate (105 mA h g−1 at 10 A g−1 after 10,000 cycles) by simply carbonization bacterial cellulose (BC) film. The carbonization temperature effects the local graphitic-like domains of carbon, resulting in the different electrochemical performance of the CNFs. The optimized carbonization temperature is 1300 °C. The study shows sodium ions could adsorption-co-intercalation of solvent and sodium ions in ether-based electrolytes, leading to high ICE and long cycle life at high rate capability. This approach not only provides a facile way for practical application of flexible NIBs but also paves a way to fabricate other flexible films for widely applications.
Qianwang Chen - One of the best experts on this subject based on the ideXlab platform.
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experimental and theoretical investigations of nitro group doped porous carbon as a high performance lithium ion battery Anode
Journal of Materials Chemistry, 2015Co-Authors: Yang Yang, Fangcai Zheng, Qianwang ChenAbstract:Doping is an effective solution to improve the capacity of carbon based Anode materials such as introducing nitrogen, boron, sulfur, and phosphorus heteroatoms into the graphite lattice. However, most of the previous doping methods are confined to the crystal lattice and edge doping is rarely studied. Here, using first-principles quantum chemical calculations, we studied the lithium adsorption ability of various functional groups (NH2, NO2, SO3H, Cl, Br, I, OH, and P) which were doped at the edge of graphene sheets. Among all the groups, the nitro-group shows the best lithium adsorption properties. On the basis of theoretical predictions, we successfully synthesized nitro group edge modified porous carbon through the pyrolysis of Cu-based metal–organic frameworks (MOFs) at 600 °C under a nitrogen atmosphere and post-acid treatment. As an Anode material for lithium ion batteries, it retains a capacity of 588 mA g−1 after 1500 cycles at a high current density of 1 A g−1. The lithium anodic performance of nitro-group doped carbon is superior to other edge doped carbon based materials reported in the literature such as halogen, sulfur and phosphorus. The excellent cycling performance at high current densities is ascribed to the improved lithium adsorption ability of the nitro-group doped at the edge of carbon.
Xudong Hu - One of the best experts on this subject based on the ideXlab platform.
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nitrogen rich hierarchically porous carbon as a high rate Anode material with ultra stable cyclability and high capacity for capacitive sodium ion batteries
Nano Energy, 2019Co-Authors: Xudong Hu, Brian Evanko, Chunming Zheng, Wenbin Hu, Galen D StuckyAbstract:Abstract Carbon-Based Anode materials hold a promising future for sodium-ion batteries (SIBs) due to their natural abundance and low cost of development. In spite of carbon's important role in the commercialization of lithium-ion batteries (LIBs), further exploration is necessary in order to find high-performance, high-rate carbon Anode materials for SIBs. A honeycomb-like, nitrogen-rich (17.72 at%), hierarchically porous, and highly disordered carbonaceous material (N-HC) with an expanded interlayer distance (0.44 nm in average) is synthesized by spray drying and subsequent pyrolysis under flowing NH3. The hierarchically porous structure and rich nitrogen doping result in a large specific surface area (722 m2 g−1), more defects and active sites, and greater functional interface accessibility for the active porous carbonaceous material and electrolyte. When N-HC is used as the Anode material for SIBs, the batteries display favorable discharge capacities (255.9 mA h g−1 in the 3000th cycle at 500 mA g−1) and good capacitive-energy-storage behavior (67% at a scan rate of 0.5 mV s−1) with excellent high-rate performance and ultra-stable cyclability over 10,000 cycles at 5000 mA g−1. Our results show that the combination of the hierarchically porous structure and nitrogen doping leads to improved energy storage by increasing the capacitive energy storage, which enhances the high-rate performance of N-HC. To further enhance the performance of the material, an electrical pretreatment is employed to increase the initial Coulombic efficiency of N-HC to 79.5%, a record high for an SIB cell. A full cell with an N-HC Anode and a Na3V2(PO4)3/C cathode shows a high capacity with a favorable cyclability (238.7 mA h g−1 after 100 cycles at 100 mA g−1 and a capacity retention of 95.3% compared to the second cycle).
Sven Kerzenmacher - One of the best experts on this subject based on the ideXlab platform.
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systematic screening of carbon based Anode materials for microbial fuel cells with shewanella oneidensis mr 1
Bioresource Technology, 2013Co-Authors: Elena Kipf, Julia Koch, Bettina Geiger, Johannes Erben, Katrin Richter, Johannes Gescher, Roland Zengerle, Sven KerzenmacherAbstract:We present a systematic screening of Carbon-Based Anode materials for microbial fuel cells with Shewanella oneidensis MR-1. Under anoxic conditions nanoporous activated carbon cloth is a superior Anode material in terms of current density normalized to the projected Anode area and Anode volume (24.0±0.3 μA cm(-2) and 482±7 μA cm(-3) at -0.2 vs. SCE, respectively). The good performance can be attributed to the high specific surface area of the material, which is available for mediated electron transfer through self-secreted flavins. Under aerated conditions no influence of the specific surface area is observed, which we attribute to a shift from primary indirect electron transfer by mediators to direct electron transfer via adherent cells. Furthermore, we show that an aerated initial growth phase enhances the current density under subsequent anoxic conditions fivefold when compared to a similar experiment that was conducted under permanently anoxic conditions.
Galen D Stucky - One of the best experts on this subject based on the ideXlab platform.
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nitrogen rich hierarchically porous carbon as a high rate Anode material with ultra stable cyclability and high capacity for capacitive sodium ion batteries
Nano Energy, 2019Co-Authors: Xudong Hu, Brian Evanko, Chunming Zheng, Wenbin Hu, Galen D StuckyAbstract:Abstract Carbon-Based Anode materials hold a promising future for sodium-ion batteries (SIBs) due to their natural abundance and low cost of development. In spite of carbon's important role in the commercialization of lithium-ion batteries (LIBs), further exploration is necessary in order to find high-performance, high-rate carbon Anode materials for SIBs. A honeycomb-like, nitrogen-rich (17.72 at%), hierarchically porous, and highly disordered carbonaceous material (N-HC) with an expanded interlayer distance (0.44 nm in average) is synthesized by spray drying and subsequent pyrolysis under flowing NH3. The hierarchically porous structure and rich nitrogen doping result in a large specific surface area (722 m2 g−1), more defects and active sites, and greater functional interface accessibility for the active porous carbonaceous material and electrolyte. When N-HC is used as the Anode material for SIBs, the batteries display favorable discharge capacities (255.9 mA h g−1 in the 3000th cycle at 500 mA g−1) and good capacitive-energy-storage behavior (67% at a scan rate of 0.5 mV s−1) with excellent high-rate performance and ultra-stable cyclability over 10,000 cycles at 5000 mA g−1. Our results show that the combination of the hierarchically porous structure and nitrogen doping leads to improved energy storage by increasing the capacitive energy storage, which enhances the high-rate performance of N-HC. To further enhance the performance of the material, an electrical pretreatment is employed to increase the initial Coulombic efficiency of N-HC to 79.5%, a record high for an SIB cell. A full cell with an N-HC Anode and a Na3V2(PO4)3/C cathode shows a high capacity with a favorable cyclability (238.7 mA h g−1 after 100 cycles at 100 mA g−1 and a capacity retention of 95.3% compared to the second cycle).