Thin film coating and its application in energy storage system

Abstract

With the constantly increasing worldwide need for energy, fossil-based fuels (coal, petroleum, and natural gas) as our main energy sources are rapidly decreasing, while their combustion is increasing the output of greenhouse gases and other pollutants in our environment. Therefore, there is an urgent need to seek renewable clean energy sources like, solar energy, wind energy etc. as alternatives. Energy storage is a critical issue in supporting the extensive applications of these renewable energy sources. Batteries are used widely to store electrical energy in the form of chemical energy. Currently, Li-ion batteries have been extensively investigated as the principal electrical energy storage (EES) system due to their outstanding energy and power density. But, their main disadvantages include high cost, limited lithium resources in the earth’s crust, reliability and safety. Due to the low cost, higher safety, low-flammability, lower reactivity, environmental friendliness and natural abundance of aluminium, the Al-ion battery has displayed excellent prospects. However, there is a requirement for better cathode material for the Al-ion battery system in terms of better capacity, higher safety, lower cost and longer recyclability (or lifetime). Here, we report on a novel Al-ion battery using SiC nanoparticles as the cathode against an aluminum metal anode in an ionic liquid based electrolyte. Silicon carbide (SiC) has been regarded as one of the most promising electrode materials due to its high theoretical capacity, in addition to its non-toxicity, environmental friendliness and low cost. It has been observed that the Al-ion battery (using SiC as cathode) delivered first discharge capacity of 97mAh/g with capacity fading in subsequent cycles. Further, it has been demonstrated that epitaxial graphene on silicon carbide (EG/SiC) delivered first discharge capacity of 121mAh/g. So, with the thin coating of graphene on SiC, the first discharge capacity has been increased significantly (almost 25%).