Contribution of Cation Addition to MnO 2 Nanosheets on Stable Co 3 O 4 Nanowires for Aqueous Zinc-Ion Battery

Bamboo-like MnO2⋅Co3O4: High-performance catalysts for the oxidative removal of toluene

The manganese-cobalt mixed oxide nanorods were fabricated using a hydrothermal method with different metal precursors (KMnO4 and MnSO4·H2O for MnOx and Co(NO3)2⋅6H2O and CoCl2⋅6H2O for Co3O4). Bamboo-like MnO2⋅Co3O4 (B-MnO2⋅Co3O4 (S)) was derived from repeated hydrothermal treatments with Co3O4@MnO2 and MnSO4⋅H2O, whereas Co3O4@MnO2 nanorods were derived from hydrothermal treatment with Co3O4 nanorods and KMnO4. The study shows that manganese oxide was tetragonal, while the cobalt oxide was found to be cubic in the crystalline arrangement. Mn surface ions were present in multiple oxidation states (e.g., Mn4+ and Mn3+) and surface oxygen deficiencies. The content of adsorbed oxygen species and reducibility at low temperature declined in the sequence of B-MnO2⋅Co3O4 (S) > Co3O4@MnO2 > MnO2 > Co3O4, matching the changing trend in activity. Among all the samples, B-MnO2⋅Co3O4 (S) showed the preeminent catalytic performance for the oxidation of toluene (T10% = 187°C, T50% = 276°C, and T90% = 339°C). In addition, the B-MnO2⋅Co3O4 (S) sample also exhibited good H2O-, CO2-, and SO2-resistant performance. The good catalytic performance of B-MnO2⋅Co3O4 (S) is due to the high concentration of adsorbed oxygen species and good reducibility at low temperature. Toluene oxidation over B-MnO2⋅Co3O4 (S) proceeds through the adsorption of O2 and toluene to form O*, OH*, and H2C(C6H5)* species, which then react to produce benzyl alcohol, benzoic acid, and benzaldehyde, ultimately converting to CO2 and H2O. The findings suggest that B-MnO2⋅Co3O4 (S) has promising potential for use as an effective catalyst in practical applications.

A Synergistic Strategy of Organic Molecules Introduced a High Zn2+ Flux Solid Electrolyte Interphase for Stable Aqueous Zinc-Ion Batteries

Aqueous rechargeable zinc-ion batteries (ARZIBs) are considered as attractive candidates for the next generation of high-safety and low-cost energy storage in large-scale power grids. However, challenges such as the dendrites and the corrosion on the zinc (Zn) surface result in short battery life and low reversibility of Zn plating/stripping. In this work, a method of preconditioning of a zinc anode in hybrid electrolytes (based on poly(ethylene glycol)-200 and H₂O) to form a solid electrolyte interphase (SEI) that prevents anode corrosion and dendrites is proposed. Though surface composition analysis and density functional theory calculation, this SEI has dense organic and inorganic components due to the induction of organic molecules and anions and has rapid kinetic and high-throughput properties for the transport of zinc ions. As a result, the SEI-modified Zn anode can maintain a low-voltage hysteresis stable cycle for more than 1600 h in aqueous electrolyte. The anode also exhibits impressive reversibility with a high Coulomobic efficiency of 99.23% over 1300 cycles. Furthermore, the ARZIB encapsulated by this anode and Mn-doped V₆O₁₃ cathode enables an outstanding electrochemical stability (181.8 mAh g^-1 after 800 cycles at room temperature, 102.2 mAh g^-1 after 1000 cycles at -15 °C). This work provides an intriguing idea for the stability maintenance of the anode for ARZIBs or other metal-ion batteries.

Bulk-phase and interface stability strategies of manganese oxide cathodes for aqueous Zn-MnOx batteries

The cyclic stability of the MnO_x cathodes for rechargeable zinc ion batteries have substantial obstacles due to Mn³⁺ disproportionation produces Mn²⁺ caused by Jahn Teller lattice distortion effect in the process of Zn²⁺ inter/deintercalation. This mini review summarized bulk-phase and interface stability strategies of manganese oxide cathodes for aqueous Zn-MnO_x batteries from the regulation of bulk electronic state of manganese oxide improves its structural stability and the formation of beneficial SEI layer at the interface of electrolyte. It provides theoretical support for the design of manganese oxide cathode materials for aqueous zinc ion batteries with high stability.

Zn-Based Deep Eutectic Solvent as the Stabilizing Electrolyte for Zn Metal Anode in Rechargeable Aqueous Batteries

Owing to its low cost and high safety, metallic zinc has received considerable attention as an anode material for zinc aqueous batteries (ZIBs). However, the Zn metal instability as a result ultrafast of obstinate dendrite formation, free-water-induced parasite reactions, and corrosive electrolytes has detrimental effects on the implementation of ZIBs. We present an alternative stable electrolyte for ZIBs based on a zinc chloride/ethylene glycol deep eutectic solvent (DES). This electrolyte consists of abundant low-cost materials and a utilizable Zn2+ concentration of approximately 1 M. It combines the advantages of the aqueous and DES media to provide safe and reversible Zn plating/stripping with a two-fold increase in the cycling life compared to that of conventional aqueous electrolytes. With these advantages, the Zn symmetric cell operates at 0.2 mA cm-2 for 300 h. Due to its high efficiency and compositional versatility, this electrolyte enables the investigation of a non-aqueous electrolyte family for ZIBs that fulfill grid-scale electrical energy storage requirements.

Mechanism orienting structure construction of electrodes for aqueous electrochemical energy storage systems: a review

Aqueous electrochemical energy storage systems (AEESS) are considered as the most promising energy storage devices for large-scale energy storage. AEESSs, including batteries and supercapacitors, have received extensive attention due to their low cost, eco-friendliness, and high safety. However, the insufficient energy densities of the state-of-the-art AEESSs limit their practical applications which are mainly dominated by the electrochemical performances of individual electrode materials. Understanding the underlying relationship between structures, reaction mechanisms, and performances can further lead to the design and optimization of structures of the electrodes instructively, thereby harvesting favorable performances. This review classified the intrinsic logic of structure-mechanism-performance by taking some prevailing mechanisms with some classical structures of materials as examples. Moreover, some problem-oriented structural engineering strategies are proposed aiming to optimize their performance. Finally, comprehensive structural design engineering and some suggestions for fine modifications of electrode materials at the atomic and molecular levels are proposed to combine the advantages of supercapacitor- and battery-type materials for designing excellent electrode materials for AEESSs.

Nanostructure Nickel-Based Selenides as Cathode Materials for Hybrid Battery-Supercapacitors

Supercapacitors (SCs) have attracted many attentions and already became part of some high-power derived devices such as Tesla's electric cars because of their higher power density. Among all types of electrical energy storage devices, battery-supercapacitors are the most promising for superior performance characteristics, including short charging time, high power density, safety, easy fabrication procedures, and long operational life. An SC usually consists of two foremost components, namely electrode materials, and electrolyte. The selection of appropriate electrode materials with rational nanostructured designs have resulted in improved electrochemical properties for high performance and has reduced the cost of SCs. In this review, we mainly spotlight the nickel-based selenides nanostructured which applied as high-performance cathode materials for SCs. Different nickel-based selenides materials are highlighted in various categories, such as nickel-cobalt-based bimetallic chalcogenides and nickel-M based selenides. Also, we mentioned material modification for this material type. Finally, the designing strategy and future improvements on nickel-based selenides materials for the application of SCs are also discussed.