Synthesis and Optimization of ZnMn₂O₄ Cathode Material for Zinc-Ion Battery by Citric Acid Sol-Gel Method

Abstract

Zinc manganese spinel composite oxide ZnMn2O4 is an important inorganic material, which is rich in natural resources and environment-friendly. Herein, pure phase ZnMn2O4 was prepared by a simple sol-gel process as cathode material for zinc ion batteries. In order to improve the cycle performance of the material while maintaining the capacity, acetonitrile/aqueous co-solvent electrolyte (0.5M Zn(CF3SO3)2/AN-H2O) was used as the electrolyte of the zinc ion battery. The influence of different experimental conditions on the electrochemical properties of ZnMn2O4 was studied by orthogonal experiment. In order to improve its electrochemical performance and cycling ability, the non-equivalent substitution of pure ZnMn2O4 was performed by adding Al3+. The non-equivalent substitution of Al3+ reduced the cell volume of ZnMn2O4 and the mixed manganese valence appeared. The specific capacity of initial discharge increases from 52.9 mAh·g-1 to 109.4 mAh·g-1 at 0.05C, and the cycle stability is also greatly improved. After 100 cycles, the capacity retention rate was 82.3%. This work shows that ZnMn2O4 is a promising cathode material for zinc ion batteries, which expands the application of spinel oxide in zinc ion batteries.

Hierarchical CaMn2O4/C Network Framework toward Aqueous Zn Ion Hybrid Capacitors as Competitive Cathodes

“…When the current density is again returned to 0.4 A g −1 , a reversible specific capacity as high as 275.0 mAh g −1 is remained by CaMn2O4/C cathode. This excellent rate performance, as summarized in Figure 5d, is also comparable to many other cathode materials recently reported in the literature, such as Ca0.28MnO2•0.5 H2O [25], ZMO@Ti3C2Tx [27], ZMO QD@C [30], ZMO [31], and K, Fe-ZMO [32]. More surprisingly, our fabricated CaMn2O4/C cathode exhibits robust electrochemical stability with an exceptionally long lifetime of 5000 cycles at 2.0 A g −1 with a retained reversible capacity of 195.6 mAh g −1 , as illustrated in Figure 5e.…”

“…As illustrated in Figure 4c, the O 1s spectrum of CaMn 2 O 4 /C can be divided into two peaks at 529.2 (metal-oxygen bond) and 531.2 (O-H) eV [25,26]. The Ca spectrum of CaMn 2 O 4 /C, as presented in Figure 4d, is fitted as two peaks corresponding to Ca 2p 3/2 (350.3 eV) and Ca 2p 3/2 (346.8 eV), respectively [27]. The C 1s spectrum (Figure 4e), can be decomposed into three peaks at 284.5, 285.8, and 285.0 eV, corresponding to C-C, O-C=C, and C-O, respectively [26].…”

The Origin of Capacity Degradation and Regulation Strategy in Aqueous Zn-MnO2 Battery with Manganese Acetate

“…Rechargeable aqueous Zn-MnO 2 batteries are considered prospective alternatives for lithium-ion batteries and have garnered considerable attention in recent years owing to the high safety, high theoretical capacity, nontoxicity, and resource-saving with the mildly acidic aqueous electrolyte. [1][2][3][4][5][6] However, the industrialization process of Zn-MnO 2 batteries is hindered by considerable degradation of the capacity associated with the dissolution of MnO 2 . [6][7][8][9] The intervention of manganese sulfate (MnSO 4 ) in the electrolyte has been extensively proven to be an effective method to inhibit the Jahn-Teller effect of MnO 2 .…”

Coral-Like Hierarchical Nanostructured ZnMn2O4/Mn2O3 Composites Synthesized by Zinc-Absent Method as a High-Performance Cathode Material for Aqueous Zinc-Ion Batteries

“…[16][17][18] Secondly, although the safety of aqueous electrolyte is high, the service life of zinc anode is shortened due to the thermodynamic instability of zinc anode and water. [19][20][21] At present, many different materials have been studied and used in AZIBs cathode materials, such as manganese-based oxides, [22][23][24] vanadiumbased oxides, 25,26 and Prussian blue analogues 27 and so on. Among them, manganese-based oxides have the advantages of low cost, low toxicity, rich reserves, multivalent states (Mn 2+ , Mn 3+ , Mn 4+ , Mn 7+ ) and so on.…”