MnO2-deposited lignin-based carbon nanofiber mats for application as electrodes in symmetric pseudocapacitors.

Low-cost, high-performance electrodes are highly attractive for practical supercapacitor applications. MnO2-deposited carbon nanofiber mats (MnO2-CNFMs) are prepared for use as binder-free supercapacitor electrodes. MnO2 is deposited on the mats in situ by hydrothermally decomposing aqueous KMnO4, leading to the formation of nanocrystals of MnO2. The MnO2-CNFM electrode produced with 38.0μmol KMnO4 (this electrode) shows a high specific capacitance of ~171.6F·g-1 at a scan rate of 5mV·s-1. Moreover, a symmetric supercapacitor with the electrode exhibits a specific capacitance of 67.0F·g-1, an energy density of 6.0Wh·kg-1 and a power density of 160W·kg-1 at a special current of 0.1A·g-1. Further, the symmetric supercapacitor displays excellent cycling stability, retains approximately 99% of the capacitance after 1000cycles. The simplicity and ease of preparation of the MnO2-CNFMs as well as their suitability for use in coin-type supercapacitor cells make them ideal for application in cost-effective and high-performance electrodes for supercapacitors.