The bare LiFePO4 and LiFePO4/C composites with network structure were prepared by solid-state reaction. The crystalline structures, morphologies and specific surface areas of the materials were investigated by X-ray d...The bare LiFePO4 and LiFePO4/C composites with network structure were prepared by solid-state reaction. The crystalline structures, morphologies and specific surface areas of the materials were investigated by X-ray diffractometry(XRD), scanning electron microscopy(SEM) and multi-point brunauer emmett and teller(BET) method. The results show that the LiFePO4/C composite with the best network structure is obtained by adding 10% phenolic resin carbon. Its electronic conductivity increases to 2.86×10-2 S/cm. It possesses the highest specific surface area of 115.65 m2/g, which exhibits the highest discharge specific capacity of 164.33 mA·h/g at C/10 rate and 149.12 mA·h/g at 1 C rate. The discharge capacity is completely recovered when C/10 rate is applied again.展开更多
锂硫电池因其能量密度高、成本低等优势被认为是最具希望的下一代储能器件之一,然而其正极材料的发展和应用仍面临诸多挑战.本文通过将剥离的Ti_(3)C_(2)纳米片在NaOH溶液中刻蚀得到具有交联结构的Ti_(3)C_(2)纳米线,并利用熔融浸渍法...锂硫电池因其能量密度高、成本低等优势被认为是最具希望的下一代储能器件之一,然而其正极材料的发展和应用仍面临诸多挑战.本文通过将剥离的Ti_(3)C_(2)纳米片在NaOH溶液中刻蚀得到具有交联结构的Ti_(3)C_(2)纳米线,并利用熔融浸渍法负载硫颗粒,用作锂硫电池的正极材料.具有极性表面的Ti_(3)C_(2)可有效捕获多硫化锂中间体,从而抑制多硫化锂的穿梭效应.与Ti_(3)C_(2)纳米片相比,具有交联网络状结构的Ti_(3)C_(2)纳米线具有更大的比表面积和多孔结构,可以有效提供固硫所需的空间,并容纳硫在锂化过程中的体积膨胀.其较大的比表面积有利于Ti_(3)C_(2)纳米线对多硫化锂的捕获,其多孔结构有利于锂离子的扩散.Ti_(3)C_(2)纳米线/硫复合物展现出优异的电化学性能,在0.2 C的倍率下,100次循环后,其可逆容量为658 mAh g^(−1);在1 C倍率下,300次循环后,Ti_(3)C_(2)纳米线/硫复合物仍能保持436 mAh g^(−1)的可逆容量.展开更多
基金Project(50672024) supported by the National Natural Science Foundation of ChinaProject(06FJ2006) supported by the Applied Basic Research of Hunan Province, China
文摘The bare LiFePO4 and LiFePO4/C composites with network structure were prepared by solid-state reaction. The crystalline structures, morphologies and specific surface areas of the materials were investigated by X-ray diffractometry(XRD), scanning electron microscopy(SEM) and multi-point brunauer emmett and teller(BET) method. The results show that the LiFePO4/C composite with the best network structure is obtained by adding 10% phenolic resin carbon. Its electronic conductivity increases to 2.86×10-2 S/cm. It possesses the highest specific surface area of 115.65 m2/g, which exhibits the highest discharge specific capacity of 164.33 mA·h/g at C/10 rate and 149.12 mA·h/g at 1 C rate. The discharge capacity is completely recovered when C/10 rate is applied again.
文摘锂硫电池因其能量密度高、成本低等优势被认为是最具希望的下一代储能器件之一,然而其正极材料的发展和应用仍面临诸多挑战.本文通过将剥离的Ti_(3)C_(2)纳米片在NaOH溶液中刻蚀得到具有交联结构的Ti_(3)C_(2)纳米线,并利用熔融浸渍法负载硫颗粒,用作锂硫电池的正极材料.具有极性表面的Ti_(3)C_(2)可有效捕获多硫化锂中间体,从而抑制多硫化锂的穿梭效应.与Ti_(3)C_(2)纳米片相比,具有交联网络状结构的Ti_(3)C_(2)纳米线具有更大的比表面积和多孔结构,可以有效提供固硫所需的空间,并容纳硫在锂化过程中的体积膨胀.其较大的比表面积有利于Ti_(3)C_(2)纳米线对多硫化锂的捕获,其多孔结构有利于锂离子的扩散.Ti_(3)C_(2)纳米线/硫复合物展现出优异的电化学性能,在0.2 C的倍率下,100次循环后,其可逆容量为658 mAh g^(−1);在1 C倍率下,300次循环后,Ti_(3)C_(2)纳米线/硫复合物仍能保持436 mAh g^(−1)的可逆容量.
