The Cost Conundrum: Why Lithium-Ion Can’t Be Everywhere
If there’s one thing holding back batteries, it’s cost. The most widespread type of battery, lithium-ion, still costs around $140 per kilowatt-hour for a pack. While that’s low enough to have triggered quickening adoption of electric vehicles, even the cheapest lithium-ion chemistries are still too expensive to put a big battery in every home to protect against blackouts.
Enter Sodium-Ion: A Complementary Technology
Instead, manufacturers have started to explore sodium-ion batteries, not as a replacement, but as a complement to lithium-ion. "When produced at the same scale, sodium-ion should be about half of where lithium-iron-phosphate is in terms of cost to produce because the raw materials are a hundred times cheaper," Darren Tan, co-founder and CEO of Unigrid, told TechCrunch.
The Challenges: Density, Power Output, and Safety
Despite the promise, sodium-ion isn’t quite ready for widespread use. Batteries made with it are not very dense, making them too large and too heavy for EVs. Plus, many variants behave differently from lithium-ion when they’re charging and discharging, meaning packs made with sodium-ion need new electronics to manage them.
Unigrid’s Breakthrough: A New Chemistry Based on Sodium-Chromium-Oxide
Tan’s startup thinks it has solved those problems by using a new chemistry based on sodium-chromium-oxide in one half of the battery and tin in the other (though Tan emphasizes the company can substitute other materials on either side). Unigrid’s batteries don’t take up any more space than a lithium-iron-phosphate cell, sometimes less. Plus, their power output mimics that of lithium-ion so the company can use the same electronics, and they are made with widely available materials.
Chromium: A Game-Changer for Sodium-Ion
"Chromium is produced at twice the quantity of copper each year," Tan said. This abundance of chromium makes it an ideal material for Unigrid’s sodium-ion batteries.
The Goal: Safer Batteries for Widespread Distributed Energy Storage
Unigrid’s batteries won’t go into thermal runaway and catch fire until the internal temperature rises to several hundred degrees Celsius, Tan said. "Sodium-ion should not just be like lithium-ion, it should be way safer such that we can put it in buildings, hospitals, data centers, so we can achieve widespread distributed energy storage," he said.
The Business Model: Collaboration with Existing Manufacturers
To deliver that many batteries, Unigrid isn’t going to be building its own factories. Instead, it’ll be working with smaller battery manufacturers that exist simply to make other companies’ designs. Think of them like TSMC, which produces computer chips for companies like Apple and Qualcomm.
The Road Ahead: Scaling Up Production and Deployment
Unigrid is now focused on scaling up production and deployment of its sodium-ion batteries. With the support of existing manufacturers and a new business model that prioritizes collaboration over competition, Tan believes Unigrid can make a significant impact in the battery market.
The Future of Batteries: A New Era for Energy Storage
Unigrid’s breakthrough with sodium-ion batteries marks a new era for energy storage. By addressing the challenges associated with lithium-ion and creating a safer, more cost-effective alternative, Unigrid is poised to revolutionize the way we store energy.
