A team of researchers from IIT Kharagpur led by Prof. Amreesh Chandra, Department of Physics has used nano-materials to develop Na-ion-based batteries and supercapacitors for next-generation Na-ion based energy storage technologies and their use in e-vehicles. The low-cost Na-ion-based technologies can be charged rapidly and are expected to reduce the cost of the e-cycles significantly.

Under the ‘Materials for Energy Storage Program’ and support from Technology Mission Division (TMD) of the Department of Science and Technology, Government of India, the team has used sodium iron phosphates and sodium manganese phosphates, which they synthesized to obtain Na-ion-based batteries and supercapacitors.

Supercapacitors are modern electrochemical devices, which are attracting attention because of their high-power density, energy density and excellent cyclic stability. The rapidly growing consumer market of portable electronics is seeking affordable and efficient alternatives for Li-batteries or supercapacitors. His team has also developed a large number of nanomaterials that can be rapidly charged and then integrated them in e-cycles.

These sodium materials are cheaper than Li-based materials, high performing, and can be scaled up to industrial-level production. The Na-ion cell can also be totally discharged to zero volt, similar to a capacitor, making it a safer option in comparison with many other storage technologies. These sodium materials were combined with various novel architectures of carbon to develop a battery.

Compared to other reported metal oxides, the electrochemical performance of NaMnPO₄ shows a much more stable tolerance towards varying magnetic fields. One of the challenges for the industry has been the current generation of lithium-ion batteries used in electric vehicles that are still expensive and as a result, e-bicycles continue to be seen as a premium product for consumers in a market like India. Moreover, electric bicycles can also play a big role in making green mobility accessible and make customers switch over to clean vehicles easily.

Commenting on the potential of the research, Prof. Amreesh Chandra, Department of Physics, IIT Kharagpur said, “Sodium ion batteries and supercapacitors can now compete with their illustrious counterparts i.e., Li-ion based energy storage devices. Combination of novel nanostructures of Na-based oxides and carbon leads to high energy and power density devices. These energy storage devices can be used easily in electric vehicles and many other applications and will eliminate our dependence on imported lithium, which is found only in a selected few countries of the world.”

The sodium materials are cheaper than Li-based materials, high performing, and can be scaled up to industrial-level production. The Na-ion cell can also be totally discharged to zero volt, similar to a capacitor, making it a safer option in comparison with many other storage technologies.