A Triple-Nanoparticle System for Controlled Graphene Nanosheet Stacking: Enabling K/Na-Ion Battery Anodes with...

Large-ion (K, Na) battery systems mitigate uneven global lithium distribution, while their ability to attain recharge time shorter than refueling would remove the final barrier for secondary batteries to replace petroleum vehicles. However, their large-ion chemistry makes ultra-fast charging an even significant challenge. Controlling and designing the stacking of chemically modified graphene nanosheets (GNS) to tailor multi-dimensional structures offers great potential in this aspect, which is attributed to the large interlayer distance and topological geometry structure for shortening the ion and electron transfer path and strengthening the absorption of ions. Conventional synthesis methods are confined to pristine 2D sublattices, lacking uniform molecular structures and clear self-assembly mechanisms. Herein, a triple-nanoparticles (Tri-NPs) system is proposed to obtain multi-dimensional, well-defined, and accurately stacked GNS structures, including 3D GNS-sieves, 2D GNS-holey nanosheets, and 1D GNS-hollow spheres. Consequently, the 1D GNS-hollow spheres demonstrate a recharging time comparable to refueling petroleum-powered vehicles-merely 3.76 min over 1250 cycles at 15.96 C in potassium-ion batteries (PIBs) and 3.36 min over 3000 cycles at 17.86 C in sodium-ion batteries (SIBs). This opens new perspectives for addressing the long-standing criticism of electric vehicles over prolonged charging times through the development of battery systems featuring high-rate charge-discharge performance and low-cost materials.