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采用一步硬模板法炭化酚醛树脂和葡萄糖酸镁制备得到具有大表面积和层次化结构的微孔-中孔炭材料(HMMC)。在炭化过程中,葡萄糖酸镁分解形成纳米氧化镁(MgO)可以作为硬模板。制备得到的HMMC具有高的比表面积(1560m~2·g~(-1)),大的孔容(2.6cm~3·g~(-1)),可以实现较高硫的负载量,并可以提供硫体积膨胀的空间。此外,相互连通的孔结构和炭骨架也能够提供快速的电子和锂离子的传输通道。因此,与硫复合后得到的碳-硫杂化材料(HMMC-S)在0.3C电流密度下,初始放电容量高达939mAh·g~(-1),经150周循环后容量仍有731mAh·g~(-1),每周的容量损失率仅为0.15%。在较高的电流密度2C下,其容量仍可达626mAh·g~(-1),表现出优异的倍率性能和长循环稳定性。
The microporous mesoporous carbon material (HMMC) with large surface area and hierarchical structure was prepared by carbonization of phenolic resin and magnesium gluconate in one-step hard template method. During carbonization, magnesium gluconate is decomposed to form nano-magnesia (MgO) as a hard template. The prepared HMMC has high specific surface area (1560m ~ 2 · g ~ (-1)) and large pore volume (2.6cm ~ 3 · g ~ (-1)), which can achieve higher sulfur loading Sulfur volume can provide room for expansion. In addition, interconnected pore structures and carbon skeletons are also capable of providing fast transport of electrons and lithium ions. Therefore, the initial discharge capacity of the carbon-sulfur hybrid material (HMMC-S) synthesized with sulfur at a current density of 0.3 C is as high as 939 mAh · g -1, and the capacity remains at 731 mAh · g after 150 cycles ~ (-1), weekly capacity loss rate of only 0.15%. At a high current density of 2C, its capacity can still reach 626mAh · g ~ (-1), showing excellent rate performance and long cycle stability.