“…Generally, LIGNs possess prominent, vertically aligned sharp-edged graphene materials (cf. Figure 2a), resulting in a high aspect ratio [17,18,26,27,28,29,30,31,32,33,34,35,36,37] and therefore excellent FEE performance. The J e versus time curve, measured at an applied field of 0.75 V/μm (Figure 4b), showed that the FEE current density was very stable for a period of 160 min.…”