High Energy Non-Aqueous Al-S Battery
Advanced high energy storage systems, beyond Li-ion technology, are highly desired to meet the demands of high performance electronic devices and future electric vehicles. Aluminum is the third most abundant element and the most abundant metal in the earth’s crust. A rechargeable battery that utilizes an aluminum-based redox couple, which involves three electron transfers during electrochemical charge/discharge reactions, is desired and attractive for research. The low cost, suitable redox potential (E0 (Al3+/Al) =-1.676 Vs. NHE), and high charge density are all factors that have fueled this interest over the years. Sulfur has likewise received great attention as a cathode for Li-S and Na-S batteries because of its high charge-storage capacity, high natural abundance, low cost and environmental friendliness.
In our study we present a new class of high energy system, a non-aqueous aluminum – sulfur battery. This battery is based on the coupling of Al metal anode and sulfur-carbon blend as the cathodic material. The system is employing electrolyte blend of AlCl3 and EMI∙Cl ionic liquid, where its composition controls its Lewis acidity. Our preliminary results show that the Al-S cell exhibits discharge voltage of around 1.2V, and a specific energy greater than 1700 Wh/kg, which exceeds most of today’s state-of-the-art batteries. Battery operation mechanism, product characteristics and limiting factors are studied using spectroscopic and electrochemical tool. This type of battery would be cheaper compare to current Li-ion and Li-S batteries, would be less prone to safety problems, and may lead to a major advance in the search for better batteries.