Abstract Coal is a low-cost and abundant natural resource for energy and chemicals generation, as well as production of various carbon materials. Herein, interconnected porous graphene with 3D structures has been fabricated from graphitized coal through the combination of liquid intercalation/oxidation, thermal exfoliation and chemical activation. Compared with conventional graphene prepared from crystalline flake graphite, the as-obtained graphene from graphitized coal possesses unique 3D interconnected structures, which can provide high ion-accessible surface area (2428.6 m2 g−1) and large pore volume (1.82 cm3 g−1). The supercapacitor from coal-based graphene shows high specific capacitance of 225 F g−1 at 0.5 A g−1 and high capacitance retention of 63% at 100 A g−1 in 6 M KOH aqueous electrolyte. The energy density of coal-based graphene is evaluated to be 79.4 Wh kg−1 in EMIMBF4 ionic liquid electrolyte. Our strategy may open up a new avenue for massive preparation of hierarchical porous graphene for high-performance supercapacitors.

中文翻译：

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用于超高能量密度超级电容器的具有分级多孔结构的活性煤基石墨烯

摘要 煤炭是一种成本低廉、储量丰富的自然资源，可用于能源和化学品的生产以及各种碳材料的生产。在此，具有 3D 结构的互连多孔石墨烯已通过液体嵌入/氧化、热剥离和化学活化的组合由石墨化煤制成。与由晶状鳞片石墨制备的常规石墨烯相比，从石墨化煤中获得的石墨烯具有独特的 3D 互连结构，可提供高离子可及表面积（2428.6 m2 g-1）和大孔体积（1.82 cm3 g-1） ）。由煤基石墨烯制成的超级电容器在 0.5 A g-1 时显示出 225 F g-1 的高比电容，在 6 M KOH 水性电解质中在 100 A g-1 时显示出 63% 的高电容保持率。在 EMIMBF4 离子液体电解质中，煤基石墨烯的能量密度评估为 79.4 Wh kg-1。我们的策略可能为大规模制备用于高性能超级电容器的分层多孔石墨烯开辟了一条新途径。