Kraft lignin (KL) was activated using selected ionic liquids (ILs). The activated form of the biopolymer, due to the presence of carbonyl groups, can be used in electrochemical tests. To increase the application potential of the system in electrochemistry, activated lignin forms were combined with manganese dioxide, and the most important physicochemical and morphological-microstructural properties of the novel, functional hybrid systems were determined using Fourier transform infrared spectroscopy (FTIR), elemental analysis (EA), scanning electron microscopy (SEM), zeta potential analysis, thermal stability (TGA/DTG) and porous structure analysis. An investigation was also made of the practical application of the hybrid materials in the production of lithium ion batteries. The capacity of the anode (MnO₂/activated lignin), working at a low current regime of 50 mA·g-1, was ca. 610 mAh·g-1, while a current of 1000 mA·g-1 resulted in a capacity of 570 mAh·g-1. Superior cyclic stability and rate capability indicate that this may be a promising electrode material for use in high-performance lithium ion batteries.
Keywords: electrochemical properties; ionic liquids; kraft lignin; manganese oxide; physicochemical and structural characteristics.