Suppressing passivation layer of Al anode in aqueous electrolytes by complexation of H2PO4− to Al3+ and an electrochromic Al ion battery

Anode Materials for Rechargeable Aqueous Al‐Ion Batteries: Progress and Prospects

“…For example, Lv et al used H 3 PO 4 as a cosolvent with Al(TOF) 3 aqueous solution to form a hybrid electrolyte that can effectively reduce the thickness of the passivation layer on the Al anode surface (Figure 6a). [65] Al stripping/plating test in pristine 5 M Al(TOF) 3 and 5 M Al(TOF) 3 /1 M H 3 PO 4 hybrid electrolyte were compared (Figure 6b). Unlike the irreversible behaviour of Al anode in pristine 5 M Al(TOF) 3 electrolyte after cycled 90 h, the Al anode in hybrid electrolyte exhibits more stable polarisation voltage with a much longer cycle life of 160 h. This is because crystalline AlPO 4 is formed in the passivation layer on the Al anode in the hybrid electrolyte, hindering the corrosion reaction of the Al metal in the electrolyte.…”

“…For example, Lv et al . used H 3 PO 4 as a cosolvent with Al(TOF) 3 aqueous solution to form a hybrid electrolyte that can effectively reduce the thickness of the passivation layer on the Al anode surface (Figure 6a) [65] . Al stripping/plating test in pristine 5 M Al(TOF) 3 and 5 M Al(TOF) 3 /1 M H 3 PO 4 hybrid electrolyte were compared (Figure 6b).…”

“… (a) Schematic diagram of the formation of passivation layer via using 5 M Al(TOF) 3 /1 M H 3 PO 4 hybrid electrolyte, (b) Al stripping/plating behaviour comparison at 1 mA cm −2 with a capacity of 1 mAh, (c) Electrochemical stability window of aqueous 5 M Al(TOF) 3 (black line) and 5 M Al(TOF) 3 /1 M H 3 PO 4 (red line) hybrid electrolyte, and (d) Schematic illustration of the different solvation states of the electrolytes. Reproduced with permission [65] . Copyright 2021, Elsevier.…”

Organic electrochromic energy storage materials and device design

“…Therefore, the cycle stability of aluminum ion battery is very poor (Sun et al, 2020a). Lv et al (2021) assembled stream ECAIB using high concentration organic aluminum salt (5 MAl(TOF)3 and 1 M H3PO4) as mixed electrolyte, PANI as cathode and aluminum as anode, which shows effective inhibition effect on the formation of aluminum passivation. This phenomenon is attributed to the formation of complex ions between Al 3+ , H 2 PO 4 − , TOF − in the electrolyte, which accelerates the reaction kinetics and improves the cyclic stability and rate performance of ECAIB.…”

Relieving hydrogen evolution and anodic corrosion of aqueous aluminum batteries with hybrid electrolytes

“…The storage of Al 3+ in aqueous electrolytes was firstly reported in 2012. 11 Since then, Al storage behaviors in various aqueous electrolytes, including AlCl 3 solution, 12–17 Al(NO 3 ) 3 solution, 2 and Al 2 (SO 4 ) 3 solution, 12,18,19 were successively reported. Nonetheless, all these batteries are half-batteries, which is limited by the failure of Al anode electrochemistry.…”