Spatially Configuring RGO Interlayers With PANI/Lignin Nanoparticles Toward High‐Performance Asymmetric Supercapacitors

The high‐performance flexible solid‐state asymmetric supercapacitor (FSAC) plays a critical role in advancing the innovation of next‐generation portable electronics. However, FSACs face challenges in achieving high capacitance and energy density. Herein, we develop a novel electrode strategy by self‐assembling polyaniline (PANI)/lignin conjugated porous nanoparticles (PLNPs) and reduced graphene oxide (RGO). The PLNPs are homogeneously distributed between RGO layers through hydrogen bonding and π‐π interactions to configure the interlayer spacing spatially. As a result, the composite film achieves a high area‐specific capacitance of 1151 mF cm −2 , which is 10 times higher than that of the pure RGO film. Moreover, the film exhibits excellent rate performance (~74%) and cycling stability (~76.88% after 10 000 cycles). The assembled flexible asymmetric supercapacitor (PLNPs@RGO//Ti 3 C 2 Tx) exhibits a specific capacitance of 113.87 F g −1 and a high energy density of 35.58 Wh kg −1 (177.92 μWh cm −2 ). This novel PLNPs@RGO composite film opens up a new window in the development of high‐performance FSACs.