Bacterial Cellulose-Polyaniline Composite Derived Hierarchical Nitrogen-Doped Porous Carbon Nanofibers as Anode for High-Rate Lithium-Ion Batteries

An increasing demand for lithium-ion batteries with high energy storage and a high-power rating, to enable applications such as electric vehicles, demands electrode materials with large charge storage capability and faster kinetics. We demonstrate the synthesis and utilization of the hierarchical porous carbon structures derived from bacterial cellulose-polyaniline nanocomposites as a promising anode material for high-rate lithium-ion batteries. Microstructural analysis of the derived carbon revealed the inheritance of fibrous backbone from bacterial cellulose along with the nanogranular structure of polyaniline. The structural characterization of as-derived porous carbon structures is performed by XRD, Raman spectroscopy, and XPS, and the electrochemical properties are analyzed by cyclic voltammetry, galvanostatic charge-discharge studies, and impedance spectroscopy. These nitrogen-doped carbon structures unveiled high reversible capacities of 432, 276, and 127 mAh/g at a 1C, 5C, and 10C rate, respectively, with an excellent capacity retention. Furthermore, first principle calculations are performed which indicate that the presence of oxidized, pyrrolic, and pyridinic nitrogen in carbon significantly enhances the lithium adsorption (nearly double than that of pristine carbon). Therefore, the enhanced electrochemical performance may be attributed to the combined effect of nitrogen doping and interconnected micromeso porous (hierarchical) network present in the hard carbon anode material.