Preintercalation Strategy in Manganese Oxides for Electrochemical Energy Storage: Review and Prospects

Abstract

the past decades, some issues of MnO 2based cathodes still remain due to the low electronic conductivity, [19-21] low utilization of reversible discharge depth, [22,23] sluggish diffusion kinetics, [24-26] and poor structural stability upon cycling, [27-29] which restricts their practical application in the commercial secondary batteries. Taking the Zn-ion batteries as example, the MnO 2 cathode seriously suffer from the above issues, especially the sluggish Zn 2+ diffusion, [30] and structural collapse issue during H + /Zn 2+ intercalation/ extraction cycles. [31-33] Regarding these bottlenecks, researchers have strived to develop strategies that can realize optimizations in capacity, rate, and cycling properties of MnO 2 cathodes, such as surface coating, [34] metal-doping, [35] preintercalation, [36] etc. Among all the strategies, preintercalation strategy provides a basic and effective method for optimizing the structure and electrochemical performance of MnO 2-based cathodes. In recent years, the preintercalation strategy has attracted much attention as an effective approach to enhance the electrochemical performance of cathode materials, including vanadate, [37] manganese oxides, [23] layered LiCoO 2 , [38] etc. Several reviews and prospects have been conducted for MnO 2 materials. Some reviews have mentioned the electrochemical properties and correlated reaction mechanism of MnO 2 materials in aqueous Zn batteries, [29,39,40] and a review by Mai's group offers insights into the rational design of preintercalation electrodes in next-generation rechargeable batteries. [36] However, a review or prospect on the application and mechanism of the preintercalation strategy in MnO 2 materials for nextgeneration batteries is lacking. For MnO 2 electrode materials, many reports on improving the electrochemical properties of materials by applying preintercalation strategy have been emerged in the last 5 years (Table S1 in the Supporting Information). The main feature of the preintercalated MnO 2 materials is that some ions/molecules are preintercalated into the tunnel or interlayer hosts of MnO 2 materials prior to the battery cycling (or during synthesis process). These intercalated guest species, including ions, inorganic/organic molecules, as well as polymers, present electrostatic and physical interactions with the host framework and the inserted carrier ions via chemical bonding or coordination, presenting significant benefiting effect on the inherent structure of hosts and the transport kinetics of carrier ions. Generally, there are several Manganese oxides (MnO 2) are promising cathode materials for various kinds of battery applications, including Li-ion, Na-ion, Mg-ion, and Zn-ion batteries, etc., due to their low-cost and high-capacity. However, the practical application of MnO 2 cathodes has been restricted by some critical issues including low electronic conductivity, low utilization of discharge depth, sluggish diffusion kinetics, and structural instability upon cycling. Preintercalation of ions/molecules ...

Alkali Ions Pre‐Intercalated Layered MnO2 Nanosheet for Zinc‐Ions Storage

“…A decent specific capacity of 84 mAh g −1 was measured after 1000 cycles; as a result of the fast charge/ discharge rate, the capacity retention was improved to reach 91% at the 1000th cycle. This cycling stability compare positively to most of the reported δ-MnO 2 materials for Zn-ion batteries (see Table S1, Supporting Information), [19][20][21][23][24][25] and similar to the previously reported other ions pre-intercalated MnO 2 as cathode for Zn-ion batteries as shown in Table S2, Supporting Information. [9,11,17,18,24,33] The good cycling stability could be explained by the pre-intercalated K + and H 3 O + in the KMO structure, as a result of charge balancing, [28] which acts as pillars to stabilize the layered structures.…”

“…[17,18] It has been reported that the preintercalation of large cations (such as, K + , Ce 3+ , and Ca 2+ ) in MnO 2 during synthetic process can stabilize the structure through coordination of guest-ions with adjacent host atoms. [16,[19][20][21][22][23][24][25] Moreover, the preintercalation of alkaline ion strategy in MnO 2 has also attracted much attention as an effective approach to enhance the electronic conductivity, activating more active sites, and promoting diffusion kinetics. [25] To date, various types of reaction mechanisms have been reported for Mn oxide-based positive electrode of Zn-MnO 2 battery in Zn-containing aqueous electrolyte.…”

“…[16,[19][20][21][22][23][24][25] Moreover, the preintercalation of alkaline ion strategy in MnO 2 has also attracted much attention as an effective approach to enhance the electronic conductivity, activating more active sites, and promoting diffusion kinetics. [25] To date, various types of reaction mechanisms have been reported for Mn oxide-based positive electrode of Zn-MnO 2 battery in Zn-containing aqueous electrolyte. [15,[26][27][28] Pan et al [26] proposed a chemical-assisted conversion reaction mechanism Recently, rechargeable zinc-ion batteries in mild acidic electrolytes have attracted considerable research interest as a result of their high sustainability, safety, and low cost.…”

Structure and Properties of Prussian Blue Analogues in Energy Storage and Conversion Applications

“…Metal substitution control is a general method to tune the electrochemical performance of electrodes. [ 100 ] For the most widely used PBA materials (A x M[Fe(CN) 6 ] y · n H 2 O), there exist two type of transition metal ions in the lattice framework. When M is a transition metal such as Ni, Cu, Zn, N‐coordinated M is electrochemically inert, and only C‐coordinated Fe 2+ can undergo redox conversion.…”

Recent Development of Mn‐based Oxides as Zinc‐Ion Battery Cathode

“…Currently, tunnel α‐MnO 2 and layered δ‐MnO 2 are considered to be the most investigated MnO 2 polymorphs as ZIB cathode, due to their unique structure that can accommodate the Zn 2+ storage [26,40] . However, pristine Mn‐based oxides typically exhibit poor cyclic stability, poor rate performance, and unsatisfactory capacity, which results in the increasing urgency for the implementation of modification strategies, such as interlayer engineering, defect engineering, hybridization, or heteroatom incorporation, to improve the electrochemical performance [2,41–47] . Despite the significant research effort devoted in the development of Mn‐based oxides with the various modification strategies, the lack of clear comparison in the electrochemical performance across the various Mn‐based oxides may lead to the contemplations in the advantages of employing the respective Mn‐based oxide.…”