Sodium-ion batteries made from agricultural waste

The batteries offer cost reductions compared to now-ubiquitous lithium-ion batteries

Spotted: Lithium-ion, or Li-ion, batteries are currently used in a huge variety of electric devices, as well as in electric vehicles (EVs). However, they have several disadvantages, including the need for control systems to manage their level of charge and environmental and resource scarcity concerns relating to the extraction and processing of the materials used to make them.  

Sodium-ion (Na-ion) batteries are one possible alternative. While they have a lower energy density and energy efficiency than Li-ion batteries, they cost less and have better safety characteristics, while offering similar power delivery. And, crucially, the key materials for Na-ion batteries are naturally abundant, unlike the scarce elements, such as lithium, cobalt, and nickel, that go into Li-ion batteries.

Now, startup Indi Energy has developed an Na-ion battery that can be used for a range of applications, from two- and four-wheeler vehicles to energy storage systems for solar and wind generation. These are 25 to 35 per cent cheaper than today’s commercial Li-ion batteries and have a lower weight and volume than other Na-ion batteries on the market, which is what makes them suitable for a wide range of uses. They also charge and discharge very quickly.

In addition to developing its own Na-ion electrolyte and cathode, Indi Energy has created an anode composed of hard carbon, called BioBlack, derived from bio and agricultural waste. It is therefore simultaneously providing a solution to another key environmental issue in India, a country that produces more than 620 million tonnes of agri-waste each year.

The resulting batteries deliver similar battery performance as Li-ion batteries but at a much lower cost. They can also be manufactured in existing Li-ion manufacturing facilities, without the need to change equipment.

The drive to find a sustainable alternative to Li-ion has led to a number of recent innovations. Some of the most promising include a cost-effective sodium-carbon battery and sodium cells designed especially for use with solar power.

Written By: Lisa Magloff