P2-Na_0.67Mn_0.85Al_0.15O₂ and NaMn₂O₄ Blend as Cathode Materials for Sodium-Ion Batteries Using a Natural β-MnO₂ Precursor

Abstract

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.

Effect of Mg Substitution on Structural Stabilization of NaxMnO2 Cathode for Na‐Ion Batteries

“…These bands are related to mode E 2g and E 1g of bending vibrations of Mn–O in octahedrons. [ 43 ] Additional peaks in the Na 0.67 Mg 0.2 Mn 0.8 O 2 spectrum indicate substitution of magnesium (bending vibrations of Mg–O in octahedrons). [ 44 ]…”

Recent Advances on High‐Capacity Sodium Manganese‐Based Oxide Cathodes for Sodium‐ion Batteries

“…A solid-state reaction without any high-pressure synthesis and doping technique was recently proposed by Abou-Rieily et al to prepare NaMn 2 O 4 . [146] In the experiment, natural pyrolusite (β-MnO 2 ) was used as the precursor, and a phase mixture of P2-Na 0.67 Mn 0.85 Al 0.15 O 2 and NaMn 2 O 4 was prepared by high temperature calcination. The electrochemical performance of the mixture at 2-4 V is shown in Figure 13b, and the sodiation displays a specific discharge capacity of 74 mAh g À 1 in the first cycle.…”

“…A solid‐state reaction without any high‐pressure synthesis and doping technique was recently proposed by Abou‐Rieily et al. to prepare NaMn 2 O 4 [146] . In the experiment, natural pyrolusite (β‐MnO 2 ) was used as the precursor, and a phase mixture of P2‐Na 0.67 Mn 0.85 Al 0.15 O 2 and NaMn 2 O 4 was prepared by high temperature calcination.…”

“…Copyright 2013, American Chemistry Society. Electrochemical characterization of sodium manganese oxide mixture: (b) rate capability up to 3 C and (c) relative capacity retention and Coulombic efficiency at C/4 vs. Na [146]. Reproduced with permission from Ref [146]…”

Unfolding the structural features of NASICON materials for sodium‐ion full cells

“…It is generally accepted that it is important to determine the electrochemical properties, specific energy density, specific power, and cyclic performance of cathode materials for estimation of the performance and cost of SIBs. Cathode materials are generally characterized into three categories: layered metal oxide, [12][13][14][15][16][17] Prussian blue analogs, [18][19][20][21][22][23][24][25] and polyanions. [26][27][28][29][30] Layered metal oxides have a high specific capacity of 120-220 mAh g −1 .…”