What About Manganese? Toward Rocking Chair Aqueous Mn-Ion Batteries

Abstract

The emerging interest in aqueous rechargeable batteries has led to significant progress in the development of next-generation electrolytes and electrode materials enabling reversible and stable insertion of various multivalent ions into the electrode's bulk. Yet, despite its abundance, high salt solubility, and small ionic radius, the use of manganese ions for energy storage purposes has not received sufficient attention. Herein, we present the use of Mo 6 S 8 (Chevrel phase) as an anode for Mn 2+ insertion. By careful optimization of the electrolyte solution, high-capacity values exceeding 90 mAh/g and long-term stability (more than 1500 cycles) have been obtained. Based on in situ XRD analysis, the charging mechanism and the associated structural changes occurring during Mn 2+ insertion have been carefully studied. Finally, we demonstrate for the first time a rocking chair aqueous Mn-ion battery comprising a Chevrel anode and NiHCF cathode.

An Energetic Aqueous Mn Metal Anode

“…However, due to the thermodynamic instability of aqueous electrolytes and the relatively low redox potential of a Mn anode, severe side reactions are triggered between the Mn metal and the electrolyte, limiting the Coulombic efficiency (CE) and cycle life of the Mn anode. , This has been a primary reason for the previous neglect of Mn metal anodes (Figure ). Based on this, we analyze the critical factors affecting the cyclic reversibility of a Mn anode, primarily stemming from three aspects: hydrogen evolution reaction (HER), corrosion, and dendrite formation.…”

Suppressing the Shuttle Effect of Aqueous Zinc–Iodine Batteries: Progress and Prospects

“…The traditional "rocking chair battery" mainly relies on the embedding and deembedding of ions for energy storage. The de-embedding of ions may cause the volume expansion of the cathode material, which may even cause the structural collapse of the cathode material as the cycling process proceeds, resulting in a poor cycle life of the battery [42]. The energy storage mechanism of the zinc-iodine battery is different, as it relies on a more stable conversion reaction mechanism: the conversion of Zn 2+ /Zn at the anode and the conversion of iodine substances on the surface of the cathode for energy storage [43,44].…”

Advanced V-based materials for multivalent-ion storage applications

“…Unlike Mg and Al metals with high redox potentials, metal Mn with lower redox potentials is a promising candidate material [119] . Furthermore, Mn has high abundance, good salt solubility, and a small ion radius [120] .…”

“…A Mn 0.18 V 2 O 5 •nH 2 O cathode delivered 83.3 mAh g -1 at 5.0 A g -1 in 1 M Mn(CF 3 SO 3 ) 2 aqueous solution and held 86.7% capacity after 200 cycles at 5.0 A g -1 [121] . Yang et al used V 2 O 5 as a cathode, sucrose as a water-splitting inhibitor, and sodium perchlorate (NaClO 4 ) and glycine as electrolytes; a strong organic-inorganic interface is formed on Mn metal [119] . The assembled Mn||V 2 O 5 battery delivers 180 mAh g -1 at 0.5 A g -1 and maintains approximately 100% capacity after 200 cycles at 1.5 A g -1 .…”