Review—Progress in Electrolytes for Rechargeable Aluminium Batteries

Abstract

The growing demand for safe, sustainable and energy-dense energy storage devices has spurred intensive investigations into post-lithium battery technologies. Rechargeable aluminium batteries are promising candidates for future electrochemical energy storage systems due to the high theoretical volumetric capacity of aluminium and its natural abundance in the Earth’s crust, but their practical application is currently hindered by the limitations of presently available electrolytes. In this review, we highlight the key considerations needed to optimise the electrolyte design in relation to the aluminium battery system and critically assess the current state of knowledge and new concepts in liquid and quasi-solid polymer electrolytes, focusing primarily on non-aqueous systems. We then discuss the challenges and approaches in developing polymer electrolytes and finally provide an overview of the opportunities in quasi-solid electrolytes which could pave the way to achieving further improvements in aluminium batteries.

Aluminum Electrodeposition from Chloride-Rich and Chloride-Free Organic Electrolytes

“…5,6 However, making use of Al's remarkable capacity is challenging due to its relatively small ionic radius and high charge density, which inevitably leads to the formation of Alion complexes rather than "free" Al ions in commonly employed chloroaluminate ionic liquids, diminishing the expected capacities of rechargeable Al batteries. 7 In spite of the recent advances in developing cathode materials, 8,9 and electrolytes, 6,10 the rechargeable Al battery remains in its infancy. 11 Accordingly, breaking new ground in Al-ion electrolyte chemistries for rechargeable Al batteries is of utmost significance.…”

“…The pursuit of high energy density for electrification of the transportation system and the demand for intermittent grid storage along with the significant uncertainty in material supplies for lithium-ion batteries , are propelling research efforts toward multivalent ion battery technologies, including those based on magnesium (Mg), calcium (Ca), and aluminum (Al). , Among post-lithium (Li) ion batteries, Al is of particular interest because of its superior theoretical volumetric capacity and low-cost compared with Li and other post-Li battery metals on account of its trivalency and high abundance. , However, making use of Al’s remarkable capacity is challenging due to its relatively small ionic radius and high charge density, which inevitably leads to the formation of Al-ion complexes rather than “free” Al ions in commonly employed chloroaluminate ionic liquids, diminishing the expected capacities of rechargeable Al batteries . In spite of the recent advances in developing cathode materials, , and electrolytes, , the rechargeable Al battery remains in its infancy . Accordingly, breaking new ground in Al-ion electrolyte chemistries for rechargeable Al batteries is of utmost significance.…”

Nb2CTx MXene Cathode for High-Capacity Rechargeable Aluminum Batteries with Prolonged Cycle Lifetime

“…The fast development of electric vehicles, electronic devices, and electrical facilities has been prompting the rapid growth of safe and economic energy storage/conversion systems for the past decade. , The future development of well-marketed Li-ion batteries is hindered by several drawbacks, including safety issues, high price, and shortage of lithium metal resources. Recently, aluminum-ion batteries (Al batteries) have raised much attention due to the high theoretical volumetric capacity and specific capacity attained by aluminum anodes (8046 mAh cm –3 and 2980 mAh g –1 , respectively).…”

High Performance and Long‐cycle Life Rechargeable Aluminum Ion Battery: Recent Progress, Perspectives and Challenges

“…[37,76] Imidazolium-based chloroaluminate ILs are now the most often used electrolytes in AIBs research, although they have significant disadvantages, chiefly due to their high cost, hygroscopicity, and corrosivity. [77] It is therefore critical to assess the state of electrolyte research and novel concepts in order to identify alternatives and opportunities for further advancement. Some performance parameters are tabulated in Table 1.…”