Porous α‐MnSe Microsphere Cathode Material for High‐Performance Aluminum Batteries

Abstract

Aluminum batteries (ABs) have been considered as a viable candidate for new‐generation energy‐storage devices due to its low cost and high theoretical volumetric capacity. Despite these advantages, the large‐scale application of ABs is constrained by scarce options of suitable cathode materials. Herein, three‐dimensional nanostructured α‐MnSe microspheres with porous properties are reported as a cathode for ABs. The nanosized and porous structure of α‐MnSe could offer numerous open channels and the short ionic transport path, which would efficiently mitigate volume changes and enhance electrochemical reaction kinetics. Moreover, the pseudocapacitive characteristic of Al3+ storage in α‐MnSe contributes to the fast kinetics of the cathode. It is demonstrated that the reversible Al3+ insertion/extraction occurs in the α‐MnSe cathode during the cycling process. The resulting aluminum battery based on the α‐MnSe cathode, AlCl3/[EMIm]Cl ionic liquid electrolyte, and aluminum anode exhibits an ultrahigh reversible capacity of 408 mA h g−1 at 0.2 A g−1. Even for a current density at 1 A g−1, a discharge capacity of 131 mA h g−1 could be retained with a Coulombic efficiency of 97 % over 150 cycles. This strategy has referential significance in aspects of the selection of compatible cathode for ABs.

Two‐Dimensional Covalent Organic Frameworks with Enhanced Aluminum Storage Properties

“…Moreover, the as‐prepared TpBpy‐COF exhibits a large surface area of 1794 m 2 g −1 (Figure a), which supports the pseudo‐capacitive features. This result is also consistent with the known fact that materials experiencing capacitance‐dominated behavior exhibit outstanding rate capability owing to the fast capacitive reactions . Therefore, the energy storage reaction is supposed to happen through the movement of anions at the surface of COFs, which agrees with the capacitive behavior and remarkable rate performance.…”

“…For further understanding of the charge–discharge mechanism of the COFs–Al batteries, CV curves were recorded at scan rates of 1–10 mV s −1 . As shown in Figure S6, both the anodic (2.0–2.3 V) and cathodic (1.2–1.7 V) peak currents rise with increasing scan rate, implying the increased polarization of the batteries . The capacitive contribution and diffusion contribution to the total capacity at different scan rates are calculated on the basis of the CV curves, and are displayed in Figure d and Figure S7.…”

“…Organics are likely to suffer from insufficient rate capability and cycling stability compared with other types of cathode materials. However, the Al–organic (COFs) battery in this work exhibits a balanced rate capability and cycling stability compared with previous works . The intrinsic structure and electrochemical properties of the TpBpy‐COF were studied systematically.…”

“…AIBs stand out among the various candidates owing to the safety, predominant electrochemical properties, and crustal abundance of Al metal (82 000 ppm for Al vs. 17 ppm for Li, 23 000 ppm for Na, and 29 000 ppm for Mg). However, AIBs are faced with the unsatisfactory rate capability and cycling stability, which are attributed to the sluggish kinetics of the large‐sized chloroaluminate anions (5.28 Å for AlCl 4 − vs. 0.76 Å for Li + ) . Continuous endeavors have been devoted to exploring suitable host materials for AlCl 4 − , such as graphene, conducting polymers, oxides, and chalcogenides .…”

Construction of Interlayer-Expanded MoSe2/Nitrogen-Doped Graphene Heterojunctions for Ultra-Long-Cycling Rechargeable Aluminum Storage

“…Among them, AIBs have attracted extensive attention recently due to their cost-effectiveness, safety, resourceful storage, and sustainability of Al. − In addition, the Al anode electrode exhibits three-electron redox properties during the electrochemical reaction process, which could result in high theoretical energy density (8035 mAh cm –3 ) and specific capacity (2980 mAh g –1 ). , However, the results of previous reports indicate that the electrochemical performance of aluminum batteries is limited by cathode materials. Therefore, works have been focused on further research on cathodes used in previous reports, such as carbon-based materials, − transition-metal dichalcogenides, − metal oxides, , and other materials…”