Three-dimensional hierarchical porous lignin-derived carbon/WO3 for high-performance solid-state planar micro-supercapacitor

The development of advanced energy storage systems, such as rechargeable batteries and supercapacitors (SCs), is one of the great challenges related to energy demand with the rapid development of world economy. Herein, a three-dimensional hierarchical porous lignin-derived carbon/WO 3 (HPC/WO 3 ) was prepared by carbonization and solvothermal process. This electrode material for supercapacitor can be operated at a wide voltage window range of −0.4 V to 1.0 V. More importantly, 3HPC/WO 3 with ultrahigh mass loading (~3.56 mg cm −2 ) has excellent specific capacitance of 432 F g −1 at 0.5 A g −1 and cycling stability of 86.6% after 10,000 cycles at 10 A g −1 . The as-assembled asymmetrical supercapacitor shows an energy density of 34.2 W h kg −1 at a power density of 237 W kg −1 and energy density of 16 W h kg −1 at a power density is 14,300 W kg −1 . A solid-state planar micro-supercapacitor (MSC) was fabricated using HPC/WO 3 nanocomposites. Moreover, the calculated specific capacity of MSC was 20 mF cm −2 in polyvinyl alcohol–sulfuric acid gel electrolyte. Overall, through the reasonable design of HPC/WO 3 nanocomposite materials and the efficient assembly of MSCs, the performance of the device was greatly improved, thus providing a clear strategy for the development of energy storage devices.