Structure Manipulation of C1N1-Derived N-Doped Defective Carbon Nanosheets to Significantly Boost K-Storage Performance

Nanocarbon materials demonstrated huge advantages for K-storage applications due to their wide range of structural tunabilities. However, their K-storage performance was still limited by the underutilization of disordered and ordered carbon structures simultaneously. Here, we developed a C1N1-based reconstruction strategy to fabricate N-doped defective carbon nanosheet (NdC) materials for K-storage. The disordered carbon defects and ordered carbon interlayers were well balanced via choosing suitable precursors for self-condensation generation of the C1N1 skeleton as well as subsequently regulating the high-temperature reconstruction process, resulting in a significantly enhanced intercalation-adsorption K-storage mechanism. As a result, the optimized GNdC materials delivered a high reversible discharging capacity of 620 mA h/g at 50 mA/g and 241 mA h/g even at 1000 mA/g as well as 210 mA h/g after 300 cycles at 500 mA/g. These excellent K-storage properties should be ascribed to the unique order-disorder balanced microstructures with fast surface capacitive-controlled reaction kinetics. This study emphasized the important roles of carbon defects in the K-storage process and provides a deep insight into the understanding of nanocarbon-based K-storage mechanisms.