Real-Time Imaging Analysis on Dendrite Formation of Aluminium Metal Anodes

Abstract

In recent years, rechargeable batteries are one of the most attractive options for both grid electrical energy storage and electrical vehicle (EV) applications due to the steadily increasing demands. Aluminum is the most abundant metal in the earth’s crust. Rechargeable aluminum-ion batteries (AIBs) is a promising research for future energy storage technologies due to its impressive advantages such as high anode capacity (gravimetric capacity of 2980 mAh g−1, and volumetric capacity of 8040 mAh cm−3), cost effectiveness, and safety. A recent study reported by Dai et al. cooperate with ITRI opened a new stage for this topic by employing an AlCl3/[EMIm]Cl ionic liquid electrolyte and graphitic cathode. This pioneering work has been stimulating various research enthusiasms in aluminum-ion batteries (AIBs). At present, there are multiple challenges that need to be overcome in AIBs, including, for example, decomposition of the electrolyte material, small charge-discharge voltage window of the battery, and small energy/power densities, (compared with commercially available lithium batteries). The occurrence of aluminum dendrites, which could cause safety hazards, on the other hand, has not drawn sufficient attention. In this study, we studied in real-time using optical microscopy the occurrence of dendritic aluminum electrochemical plating and its dendrite formation mechanisms. In particular, extensive real-time optical microscopy imaging and post mortem SEM analyses are carried out in conjunction with electrochemical characterizations to reveal the underlying mechanisms for the resulting effects. Figure 1