Graphene has shown great potential in microwave absorption (MA) owing to its high surface area, low density, tunable electrical conductivity and good chemical stability. To fully realize grapheneʼs MA ability, the microstructure of graphene should be carefully addressed. Here we prepared graphene microflowers (Gmfs) with highly porous structure for high-performance MA filler material. The efficient absorption bandwidth (reflection loss ≤ −10 dB) reaches 5.59 GHz and the minimum reflection loss is up to −42.9 dB, showing significant increment compared with stacked graphene. Such performance is higher than most graphene-based materials in the literature. Besides, the low filling content (10 wt%) and low density (40–50 mg cm⁻³) are beneficial for the practical applications. Without compounding with magnetic materials or conductive polymers, Gmfs show outstanding MA performance with the aid of rational microstructure design. Furthermore, Gmfs exhibit advantages in facile processibility and large-scale production compared with other porous graphene materials including aerogels and foams.

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石墨烯因其高表面积，低密度，可调节的电导率和良好的化学稳定性而在微波吸收（MA）中显示出巨大潜力。为了充分实现石墨烯的MA能力，应仔细研究石墨烯的微观结构。在这里，我们制备了具有高度多孔结构的石墨烯微花（Gmfs），用于高性能MA填充材料。有效吸收带宽（反射损耗≤-10 dB）达到5.59 GHz，最小反射损耗高达-42.9 dB，与堆叠的石墨烯相比显示出显着的增加。这种性能高于文献中大多数基于石墨烯的材料。此外，低填充量（10 wt％）和低密度（40-50 mg cm ^-3））对于实际应用是有益的。在不与磁性材料或导电聚合物混合的情况下，借助合理的微结构设计，Gmfs表现出出色的MA性能。此外，与包括气凝胶和泡沫的其他多孔石墨烯材料相比，Gmfs在易加工性和大规模生产方面显示出优势。

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