Recent Advances on Spinel Zinc Manganate Cathode Materials for Zinc‐Ion Batteries

Abstract

Zinc metal is abundant in nature, non‐toxic, harmless, and cheap. Zinc‐ion batteries (ZIBs) have also emerged as the times require, which has attracted scholars′ research interest. In the zinc‐ion batteries, the cathode material is indispensable. Manganese oxides are widely used in electrode materials because of their various valence states (+2, +3, +4, +7). ZnMn2O4 (ZMO) is a mixed metal oxide with a spinel structure similar to LiMn2O4. Due to the synergistic effect of Zn and Mn, it has the advantages of high theoretical capacity. In recent years, researchers have gradually applied ZnMn2O4 to zinc ion batteries. In order to obtain high‐energy‐density zinc ion batteries, it is also very important to match electrolytes with a wide operating voltage window and develop a highly reversible anode. In the first instance, we investigate the research progress of spinel ZnMn2O4 as a reliable candidate material for zinc ion batteries. Later on, we review the optimization and modification measures of anode and electrolyte to improve the electrochemical properties of spinel ZnMn2O4. On this basis, we propose the reasonable research direction and development prospects for this material. It is hoped that there will be a help to researchers in this field.

Modulating the Proton‐Conducting Lanes in Spinel ZnMn2O4through Off‐Stoichiometry

“…[ 53 ] This is consistent with the scenario of less rigid MnO framework in spinel structure upon the removal of Zn 2+ ions at the tetrahedral sites, given the fact that each ZnO 4 tetrahedron is corner‐shared with the MnO 6 octahedra and helps to build rigid MnO framework (Figure 1g). [ 54 ]…”

Review on Recent Developments, Challenges, and Perspectives of Mn-Based Oxide Cathode Materials for Aqueous Zinc-Ion Batteries and the Status of Mn Resources in China

“…The trivalent Mn at the octahedral position and the divalent Zn at the tetrahedral position can effectively provide stable Zn 2+ in the aqueous ZIB. 88 However, the rapid capacity decay of ZnMn 2 O 4 severely limits its commercial application due to low conductivity and structural degradation. Gao et al 89 applied a common one-step hydrothermal method to rationally synthesize ZMO nanoparticles (∼20 nm) on carbon nanotube (ZMO/CNTs) heterostructures to achieve stable high-speed Zn 2+ storage.…”

“…ZnMn 2 O 4 with a spinel structure is a promising cathode material for AZIBs due to its high capacity, high output voltage, and rich content. The trivalent Mn at the octahedral position and the divalent Zn at the tetrahedral position can effectively provide stable Zn 2+ in the aqueous ZIB . However, the rapid capacity decay of ZnMn 2 O 4 severely limits its commercial application due to low conductivity and structural degradation.…”

Design of manganese dioxide for supercapacitors and zinc-ion batteries: similarities and differences

“…Based on the statistics summarized in Figure 1C and D, it is very interesting to find that the commonly used electrode materials for SCs, including nanocarbon, conducting polymers, transition metal oxides (RuO 2 and MnO 2 ), transition metal dichalcogenides (TMDs) and transition metal carbides/nitrides (MXenes), are also suitable for ZIBs. Among these materials, the most studied one is manganese dioxide (MnO 2 ) because of its natural abundance, non-toxicity, wide potential window and high theoretical capacitance/capacity [42][43][44][45][46][47] . For example, α-MnO 2 nanoneedles synthesized by a microwave-assisted method were used as SC materials and delivered 289 F g -1 at 0.5 A g -1 in 1 M Na 2 SO 4 and maintained 88% after cycling 10,000 times [48] .…”