Aluminum electrolytes for Al dual-ion batteries

Abstract

In the search for sustainable energy storage systems, aluminum dual-ion batteries have recently attracted considerable attention due to their low cost, safety, high energy density (up to 70 kWh kg −1), energy efficiency (80-90%) and long cycling life (thousands of cycles and potentially more), which are needed attributes for grid-level stationary energy storage. Overall, such batteries are composed of aluminum foil as the anode and various types of carbonaceous and organic substances as the cathode, which are immersed in an aluminum electrolyte that supports efficient and dendrite-free aluminum electroplating/stripping upon cycling. Here, we review current research pursuits and present the limitations of aluminum electrolytes for aluminum dual-ion batteries. Particular emphasis is given to the aluminum plating/stripping mechanism in aluminum electrolytes, and its contribution to the total charge storage electrolyte capacity. To this end, we survey the prospects of these stationary storage systems, emphasizing the practical hurdles of aluminum electrolytes that remain to be addressed. T he integration of intermittent renewables into the grid is directly linked to the deployment of stationary energy storage systems at the terawatt scale, enabling grid stabilization. From this perspective, in addition to conventional energy storage means, such as pumpedstorage hydroelectricity (PSH), stationary batteries will be of significant importance 1. Loosely speaking, the assessment of the battery technologies for stationary storage applications can be made by comparing their capital cost (¢ kW −1 h −1 cycle −1) to that of PSH, which is presently the predominant stationary storage system. Consequently, stationary batteries should possess an exceptional cycling stability (thousands of cycles), environmental friendliness, low CO 2 footprint, and low cost. In this framework, the exploration of batteries composed of Na 2,3 , K 4 , Mg 5,6 , and Al 7-9 as earth-abundant metals has become a primary research target in recent years. Notably, batteries that employ Al metal as an anode can harness numerous advantages, such as a high charge storage capacity of 2977 mAh g −1 of Al, its natural abundance, and safety 10-15. Furthermore, Al can be reversibly deposited and stripped in chloroaluminate ionic liquids with a high coulombic efficiency and without the formation of dendrites 16,17. In this context, a new electrochemical concept called the aluminum dual-ion battery (ADIB) has recently attracted significant attention. ADIBs have a high potential for grid-scale energy storage applications

Metal-ion batteries for electric vehicles: current state of the technology, issues and future perspectives

“…In this framework, they noted the oxidation stability issues in the current collectors that cause a severe decrease in the coulombic efficiency of ADIBs will have a profound effect on their electrochemical performance. 48 Still deep research into AIBs has recognized various primitive & technical challenges for which solutions are being sought. The advancement in this area is since 2010 and found unmatchable excellent properties for being useful in electric vehicles.…”

Amidine-based ionic liquid analogues with AlCl3: a credible new electrolyte for rechargeable Al batteries

“…A very encouraging option are Al-based batteries. 5 Al is inexpensive, highly abundant, and possesses an energy density close to Li. 6 Like Li, however, Al systems require non-aqueous chemistries, as the reduction potential of Al is more negative than that for hydrogen evolution in aqueous-based electrolytes.…”

Deep eutectics and analogues as electrolytes in batteries

“…205,206 The coordination behavior of AlCl3:G2 was found to be similar to that of AlCl3:amide with the [AlCl 2 • (G2) 2 ] + cations as the active species, paired with the AlCl 4 − anions. 207,208 Finally, mixtures of AlCl3 and γ-butyrolactone (GBL) at different composition were also recently tested for Al deposition. 209 Like AlCl3:amide electrolytes, the molar ratio plays a key role: at relatively low AlCl3 concentration (AlCl3:GBL molar ratio in the range 1:10 to 1:2.…”