VIT, Vellore researchers find alternative to lithium-ion batteries, could revolutionise battery market
While lithium batteries are having their time in the market, a lowcost alternative technology could revolutionise the battery technology market and be environment friendly compared to its famed peer. A team of researchers from Vellore Institute of Technology (VIT), Vellore, recently experimented with novel primary cell, based on graphene and Multi-walled carbon nanotube (MWCNT), as intercalation materials. The experiment has been carried out with Al/ Al2O3/Activated carbon (AC).
The team was led by Dr Sambantham Karthikeyan, professor of electrochemistry, School of Advanced Sciences and co-investigator Rajamani Dinakaran, PhD scholar, School of Mechanical Engineering, VIT, Vellore.
“Lithium is widely used. However, it’s a highly explosive material and can cause fire accidents. Researchers have been working to develop an alternative to lithium. Also, raw materials for lithium batteries are expensive and limited in supply,” says Dr Karthikeyan. His team has been experimenting with aluminium as an alternative and found that it had longer life due to the formation of flakelike the structure of graphene and resistivity towards the crystallinity of graphene atoms. The corrosion resistance of Al/Al2O3 and graphene intercalated systems were found high.
Intercalation means that upon discharge, the anode pushes ions into the electrolyte while the cathode sucks up the same ions. Globally, too, experiments are being carried out with various battery chemistries and materials to replicate lithium ions intercalation.
Batteries are widely used in portable electronic devices, electric vehicle and even renewable energy sources to store electrical energy in the electrochemical form. According to industry data, the last two decades have spanned a huge demand for batteries. To cater to this demand and offer efficient power supply and also to overcome the limitations of dry cell batteries such as alkaline, lead-acid, Ni-Cd (nickel cadmium) Ni-Mh
(nickle metal hydride) and Li-Ion(lithium ion) cells have been developed.
The main drawbacks of lithium-ion electrodes is that it has a solid-liquid interphase (SLI) formation during the discharging process leading to dendrite growth, poor cycle performance, volume change, electrode cracks, mechanical strainand induce corrosion. High toxicity and explosive nature of lithium metal when stored in a closed container under vacuum working condition and a separate circuit required to maintain the voltage and current level at optimum conditions, has resulted in researchers looking for an alternative.
Dr Karthikeyan says that the graphene-based cell had a life of 150 days compared to lithium batteries.
“The resultant graphenebased cell exhibited 1.68 V with the extended life of 150 days and assembly of each of two such cells yielded 3.36 V which is equivalent to one Li-Ion batteries. To enhance the life of energy storage devices, it is imperative to use novel dopants and conducting
polymers which will show telling effect on the investigated energy storage devices,” says Dr Desikan Rajagopal, professor of organic chemistry, School of Advanced Sciences, VIT, Vellore, and one of the investigators of the project. As a whole, it is a novel technology which involves non-toxic materials as active intermetallic phases in energy storage devices.
Asked about the cost, Dr Karthikeyan says while a lithium battery may cost upward of ₹5,000, a graphene-based cells can be procured for as low as ₹400, thus, reducing the cost by several notches. “Aluminium is a key raw material and is found in abundance in India. We believe this technology may reduce the cost of batteries and increase the lifespan,” he adds.
The research team believes that the new cells can be used in high voltage application, telecommunication and even the much-hyped electric vehicles as it is scalable and economical. Dr Karthikeyan adds that the institute is also in the process filing for a patent. “We have also got fund from the government to research on the development of the product. We have also submitted a research paper on the same”.
By 2025, it is estimated that the rechargeable battery market will grow considerably, reaching over $100 billion. The share of lithium-ion batteries is estimated at 70%.