采用氧化镁模板耦合原位氢氧化钾活化法制备了超级电容器用煤焦油基相互连接的类石墨烯纳米片(IGNSs)。所制备的IGNS具有高达2887 m2？g？1的比表面积和大量的分级短孔。当作为超级电容器的电极材料时，在6 mol？L？1 KOH电解液中，于0.05 A？g？1的电流密度下，IGNS显示出313 F？g？1的高比容；在20 A？g？1的电流密度下，IGNS的比电容为261 F？g？1，显示了好的倍率性能；经过10000次循环测试后，其容量保持率为92.7%，展现了优异的循环稳定性。这一工作为从芳烃分子大规模生产高性能储能用类石墨烯纳米片提供了一种简单的方法。
The rapid economic development has necessitated increased environmental protection and tremendous efforts have been devoted to designing and preparing environmentally friendly energy storage and conversion devices, including batteries, supercapacitors (SCs), and solar cells. As useful energy storage and conversion devices, SCs have received significant attention due to their high power density, long cycle stability, and rapid charging rate. The performance of SCs largely depends on the electrode materials, which can be composed of metal oxides, conducting polymers, carbon materials, and their composites. Carbon materials, including carbon nanotubes, carbon fibers, porous carbons, template carbons, and graphene-like carbon nanosheets (GCNSs), have attracted significant attention owing to their tailorable pore size and excellent physiochemical stability. GCNSs are considered to be outstanding carbon materials for use in high-performance SC because of their large specific surface area and high electrical conductivity. To date, many carbon precursors have been used to synthesize GCNSs for SCs such as coal, biomass, and chemical by-products. In particular, cheap and abundant chemical by-products for the synthesis of carbon materials can reduce preparation costs and environmental pollution as well as achieve high value-added chemicals. Coal tar, a by-product of the coal coking process, is rich in aromatic polycyclic hydrocarbon molecules, which can be polymerized, carbonized, and activated to synthesize GCNSs for SCs. In addition, MgO particles can be used as templates due to their stable properties and low-cost compared with other metal oxide templates (e.g. Fe2O3, NiO, or CuO), imparting space confinement and structure guidance during the preparation of GCNSs. Herein, we report a facile method for the preparation of interconnected graphene-like nanosheets (IGNSs) from coal tar by MgO templating combined with in-situ KOH activation. The IGNSs were obtained after the impurity removal by repeated washing with dilute acid. The as-synthesized IGNSs feature high specific surface area of up to 2887 m2？g？1 and abundant hierarchical short pores, which provide abundant active sites for ion adsorption, supply plentiful channels for fast ion transport and boost electrical conductivity.