Bituminous Coal as Low-Cost Anode Materials for Sodium-Ion and Lithium-Ion Batteries

Abstract

The expanding market for secondary batteries is attentive for novel carbonaceous anode materials due to the continuing demand for energy storage systems that grant access for mobile applications, transportation, and stationary systems. Accordingly, natural high-volatile bituminous coal analyzed in its raw and thermally processed states in half-cells for energy storage (sodium- and lithium-ion batteries) is presented. Thermal annealing is carried out at various temperatures (800, 1000, and 1200 °C) and in different annealing atmospheres (argon and nitrogen). Morphology and structural alterations are observed and detected via scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD), Raman, elemental analysis, and textural porosity evaluations. Electrochemical experiments show satisfactory reversible capacities (223 mAh g−1 vs Na and 409 mAh g−1 vs Li) and retentions remarkable for low-temperature annealed samples. Exploiting this neglected carbonaceous mining ore debris provides prospective ecological, economic, and energetic assertions. This work also discusses the positive influence of annealing under a nitrogen atmosphere at reduced temperatures (800 °C).