Indian Institute of Technology (IIT) Madras researchers have for the first time fabricated a rechargeable iron ion battery using mild steel as the anode. The iron ion battery is cost-effective and the amount of energy that can be stored in the battery is also high.

Lithium ion battery vs Iron ion battery

• While lithium ions are the charge carriers in lithium ion battery, the Fe2+ ions perform that function in the case of iron ion battery
• When fabricated under controlled conditions, the amount of energy that can be drawn from the iron ion battery is 220 Wh per kg, which is 55-60% of lithium ion battery’s performance. The energy density of lithium ion battery is around 350 Wh per kg.
• The redox potential of iron ion is higher than lithium ion and the radius of the Fe2+ ion is nearly the same as that of the lithium ion
• Iron is more stable during the charging process and therefore prevents short-circuiting of the batteries. Thus, when compared with the popular lithium metal-based batteries, we are able to cut down the cost and make it safer to handle

Why india need such batteries

• With the world turning its attention to electric vehicles, the focus is on developing batteries that are cheaper
• With no lithium reserves in India and shortage of lithium reserves in the world, the stress is on developing rechargeable batteries of comparable performance using materials other than lithium