Graphite intercalation compounds are promising anode materials for potassium-ion batteries, but still have problems of sluggish kinetics and a large volume expansion upon potassiation. Porous carbons with a large ion-accessible area used as anode materials can have a high gravimetric capacity and structural stability. However, to avoid a low volumetric performance in porous carbons, an electrode must have both a high density and fast ion-transport channels and these pose stringent requirements for the pore structure. Here we use a flowable sulfur template to produce continually- and precisely-tunable pores in three-dimensional graphene assemblies. During capillary drying of graphene hydrogel, sulfur accompanied with the shrinking graphene sheets controls the formation of pores with precise sizes by tuning the usage. The pores formed are open and interlinked due to the existence of a flowable sulfur template in the graphene network. This obtained graphene-assembly with well-controlled interconnected pores is used as potassium-ion battery anodes and gives a stable cycling performance (500 cycles) and an ultrahigh volumetric capacity.

石墨插层化合物是用于钾离子电池的有希望的阳极材料，但是仍然存在动力学缓慢和在钾化时体积膨胀大的问题。具有大的离子可及面积的多孔碳用作阳极材料可以具有高的重力容量和结构稳定性。然而，为了避免多孔碳的低体积性能，电极必须同时具有高密度和快速的离子传输通道，并且这些对孔结构提出了严格的要求。在这里，我们使用可流动的硫模板在三维石墨烯组件中产生连续可调的孔。在石墨烯水凝胶的毛细管干燥过程中，硫与收缩的石墨烯片一起可通过调节用量来控制具有精确尺寸的孔的形成。由于石墨烯网络中存在可流动的硫模板，因此形成的孔是开放的和相互连接的。所得的具有良好控制的互连孔的石墨烯组件用作钾离子电池阳极，并具有稳定的循环性能（500个循环）和超高的体积容量。