Novel Alkaline Zn/Na_0.44MnO₂ Dual-Ion Battery with a High Capacity and Long Cycle Lifespan

Abstract

A rechargeable aqueous Zn/Mn battery is a promising device for large-scale energy storage because of its abundant resources, low cost, and high safety. However, its application is plagued by a poor life cycle because of the electrochemical instability of MnO in aqueous electrolytes. Here, an alkaline Zn-NaMnO dual-ion battery (denoted AZMDIB) is developed for the first time using NaMnO as the cathode, a zinc metal sheet as the anode, and a 6 M NaOH aqueous solution as the electrolyte. When the discharge cutoff voltage is lowered to 0.3 V (vs Zn/Zn), the NaMnO cathode delivers a high capacity of 345.5 mA h g but with a poor cycling performance. The charge-discharge mechanism and structural evolution of the NaMnO cathode in an extended potential window (1.95-0.3 V) are also explored. The NaMnO electrode experiences two different electrochemical processes: Na ions insert/extract reversibly in the potential range of 1.95-1.1 V, and a phase transition occurs from NaMnO to Mn(OH) below 1.1 V. The latter irreversible reaction is probably due to proton insertion, leading to a severe capacity fade. Nevertheless, in a narrower voltage range (2.0-1.1 V), the AZMDIB full cell exhibits a high reversible capacity (80.2 mA h g at 0.5 C), high rate capability (32 mA h g at 50 C), and excellent cycling stability (73% capacity retention over 1000 cycles at 10 C). Benefiting from the merits of environmental friendliness, cost-effectiveness, and high electrochemical performance, the rechargeable AZMDIB is a promising contender for grid-scale energy storage applications.

Electrochemically Derived Graphene‐Like Carbon Film as a Superb Substrate for High‐Performance Aqueous Zn‐Ion Batteries

“…Moreover, a recorded energy density of 511.9 Wh kg −1 was obtained at the power density of 137 W kg −1 , as well as a high power density of 3908 W kg −1 at the energy density of 123.5 Wh kg −1 . Such superior performance is comparable with that of recently reported cathode materials for aqueous ZIBs (Figure d), such as α‐MnO 2 /CNTs, α‐MnO 2 @TiO 2 , β‐MnO 2 , Mn 2 O 3 @ppy, Na 0.44 MnO 2 , K 0.8 Mn 8 O 16 ,15b FeHCF, V 2 O 5 , V 5 O 12 ·6H 2 O, Li x V 2 O 5 ·nH 2 O, and so on. The cycle performance of the GCF based batteries were evaluated in Figure e,f.…”

A review on mechanistic understanding of MnO2in aqueous electrolyte for electrical energy storage systems

“…Aside from Li + ion intercalation, there have been other cation intercalation mechanisms utilised in the manganese oxide system [184][185][186]. Especially, aqueous sodium-ion battery (NIB) has been studied extensively [187][188][189][190][191][192]. Among various NIB systems, NaTi 2 (PO 4 ) 3 / Na 0.44 MnO 2 (NTP/NMO) full cell is known to have the highest specific and volumetric energy density [193,194].…”

Activating C‐Coordinated Iron of Iron Hexacyanoferrate for Zn Hybrid‐Ion Batteries with 10 000‐Cycle Lifespan and Superior Rate Capability

“…The appropriate plating/stripping voltage (≈‐0.76 V vs SHE) of zinc makes it electrochemically stable in water, which enables ZBs to avoid the employment of toxic organic electrolytes and complex assembly processes in glovebox compared with the lithium and sodium counterparts . This advantage of zinc anode enables researchers to pay more attention to develop cathodic host materials . Among these materials, MnO 2 ‐based cathodes possess high specific capacity based on the single electron transfer reaction of Mn(IV)/Mn(III), while the inferior rate capability originating from the sluggish diffusion kinetics remains unsolved .…”