Making batteries stronger and more durable

The current lithium-ion batteries in our cell phones or laptops can sustain for four to five hours after a full charge (assuming continuous use of the device). On the other hand, lithium-sulfur batteries would be able to sustain for almost double that time, as was demonstrated by a leading lithium-sulfur battery manufacturing company.

However, metal-sulfur batteries suffer from several problems such as poor electronic conductivity of active material, gradual dissolution of intermediate products into the electrolyte from the cathode and the dendritic growth associated with pristine lithium metal anode.

Figure 1: How a metal-sulfur battery works

Figure 2: Graphical representation of the research project

This is what motivated Arnab Ghosh, a research scholar with the IITB-Monash Research Academy, to work on a project titled, ‘Design of high energy metal-sulfur batteries’ that focuses on how to mitigate these problems and push metal-sulfur batteries a step ahead towards their practical application.

Says Arnab, “Lithium-sulfur batteries are considered one of the strong candidates to replace currently available rechargeable lithium-ion batteries. The existing lithium-ion batteries cannot meet our ever-increasing energy demand near future, while it is believed that practical lithium-sulfur batteries would have at least twice the capacity and energy density of lithium-ion batteries. Considering the potential viability of the lithium-sulfur batteries, I believe that my research work on sulfur-based cathode materials is important not only as a PhD topic, but can also contribute towards practical application of lithium-sulfur batteries in terms of developing low-cost battery material through facile synthesis strategy.”

During his research so far, Arnab has successfully synthesized a low-cost cathode material for lithium-sulfur batteries following a facile approach. “Our synthesis strategy might encourage the direct utilization of sulfur powder (the petroleum waste) in rechargeable lithium-sulfur batteries,” he says. “Encouragingly, the lithium-sulfur batteries containing our as-synthesized cathode material could run for more than 500 charge/discharge cycles delivering adequate specific capacity and with an extremely low rate of capacity decay (0.02% per cycle).”

The IITB-Monash Research Academy is a collaboration between India and Australia that endeavours to strengthen scientific relationships between the two countries. Graduate research scholars like Arnab study for a dually-badged PhD from both IIT Bombay and Monash University, spending time at both institutions to enrich their research experience.

Says Prof Murali Sastry, CEO of the Academy, “Devices have become an indispensable part of our lives. And batteries are an indispensable part of devices. Today’s research challenges require a multi-disciplinary approach. And the way in which the IITB-Monash Research Academy has been set up makes it possible for such multi-disciplinary investigations to be carried out. I am convinced that researchers like Arnab will help the Academy create significant science, societal and industry impact in the future.”

Research scholar: Arnab Ghosh, IITB-Monash Research Academy

Project title: Design of high energy lithium- and sodium-sulfur batteries

Supervisors: Prof. Sagar Mitra (IIT Bombay), Prof. Doug MacFarlane (Monash University) and Dr. Mega Kar (Monash University)

Contact details:

This story was written by Mr Krishna Warrier based on inputs from the research student, his supervisors, and the IITB-Monash Research Academy. Copyright IITB-Monash Research Academy.