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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).

Natural graphite is obtained from an abandoned open-cast mine and purified by a simple, eco-friendly and affordable beneficiation process including ball milling and flotation process. Both raw graphite (55 wt %) and its concentrate (85 wt %) were electrochemically tested in order to evaluate these materials as anode materials for Li-ion and Naion batteries. It was found that both raw and purified graphites exhibit good electrochemical activities with respect to lithium and sodium ions through completely different reaction mechanisms. The encouraging results demonstrated in this work suggest that both raw and graphite concentrates after flotation could be used respectively for stationary and embedded applications. This strategy would help in developing local electrical storage systems with a significantly low environmental footprint.

Sodium-ion batteries (NIBs) are promising candidates for specific stationary applications considering their low-cost and costeffective energetic property compared to lithium-ion batteries (LIBs). Additional cost cutbacks are achievable by employing natural materials as active cathode materials for NIBs. In this work, we report the use of natural pyrolusite (β-MnO 2 ) as a precursor for the synthesis of a NaMnO blend (a mixture of layered P2-Na 0.67 Mn 0.85 Al 0.15 O 2 without any doping technique combined with a post-spinel NaMn 2 O 4 without any highpressure synthesis). The synthesized powder was characterized by XRD, evidencing these two phases, along with two additional phases. Tests for Na-ion insertion registered a reversible discharge capacity of 104 mA h/g after 10 cycles with a well-defined plateau at 2.25 V. After 500 cycles at a C/4 current density, a high Coulombic efficiency between 96 and 99% was achieved, with an overall 25% capacity retention loss. These pilot tests are encouraging; they provide economic relief since the natural material is abundant (low-cost). Desirable, energetic assurances and ecological confirmations are obtainable if these materials are implemented in large-scale stationary applications. The synthesis technique does not use any toxic metals or toxic solvents and has limited side product formation.