Lamellar hierarchical lignin-derived porous carbon activating the capacitive property of polyaniline for high-performance supercapacitors

Abstract

Lignin porous carbons show good potential as carbon electrode materials for supercapacitors, but face the problem of low capacitance. Combining lignin porous carbons with polyaniline can achieve high capacitance. However, capacitance degradation resulting from the poor compatibility between lignin porous carbons and polyaniline has been the major obstacle for their application. In this work, three lignin porous carbons with different geometries were used as the hosts to anchor polyaniline for carbon/polyaniline composites via in- situ oxidative polymerization, and the compatibility between lignin porous carbons and polyaniline was investigated. It was determined the lamellar hierarchical lignin porous carbon with crumpled nanosheets can provide a large accessible surface area for the heterogeneous nucleation of aniline, which ensures uniform loading of interpenetrating polyaniline nanofibers. Benefiting from the interpenetrating conductive network and enhanced compatibility, the lamellar hierarchical porous carbon/polyaniline composite possesses a high capacitance of up to 643 F/g at 1.0 A/g and a sufficient capacitance of 390 F/g at 30.0 A/g. This work therefore provides design guidance for carbon hosts in high-performance supercapacitor composite electrodes.