There’s Gold in That There Battery Waste

Every year, millions of tons of sodium sulfate waste are generated throughout the lithium-ion battery supply chain. And although the chemical compound seems relatively innocuous — it looks just like table salt and is not particularly toxic — the sheer amount that’s produced via mining, cathode production, and battery recycling is a problem. Dumping it in rivers or oceans would obviously be disruptive to ecosystems (although that’s generally what happens in China), and with landfills running short on space, there are fewer options there, as well.

That is where Aepnus Technology is attempting to come in. The startup emerged from stealth today with $8 million in seed funding led by Clean Energy Ventures and supported by a number of other cleantech investors, including Lowercarbon Capital and Voyager Ventures. The company uses a novel electrolysis process to convert sodium sulfate waste into sodium hydroxide and sulfuric acid, which are themselves essential chemicals for battery production.

“It's a fully circular approach,” Bilen Akuzum, Aepnus’ co-founder and CTO, told me. “Rather than in the current paradigm where companies are buying chemicals and having to deal with disposing of the waste, we can co-locate with them and they give us the waste, and we give them back the chemicals.” This recycling process, he says, can happen an indefinite number of times.

Akuzum told me that companies using Aepnus’ tech can “speed up their environmental permits because they're not going to be producing that waste anymore. Instead, they can just turn it into value.” In an ideal scenario, this could increase domestic production of critical minerals and battery components, which will decrease the U.S.’s reliance on China, a major goal of the Biden administration. On-site chemicals production will also help to decarbonize the supply chain, as it eliminates the need for these substances to be trucked into remote mining sites or out to battery manufacturing and recycling facilities.

To do the chemical recycling, Aepnus has developed an electrolysis system that it says is 50% more efficient than the processes normally used to produce sodium hydroxide, and is uniquely tailored to process sodium sulfate waste. Energy nerds might associate electrolysis with the pricey production of green hydrogen, but this has actually always been the process by which sodium hydroxide is made.

Making sulfuric acid, however, doesn’t traditionally involve electrolysis, but because sodium hydroxide is the more valuable of the two chemicals, combining their production via a single, more efficient electrochemical process gives Aepnus a much better chance at being cost competitive with other chemical producers than, say, the likelihood of green hydrogen being cost competitive with natural gas. Akuzum told me that the company’s electrolyzers can operate at lower voltages and higher temperatures than the industry standard, thereby increasing efficiency, and don’t require rare earth elements, thereby reducing costs.

Ultimately, Akuzum said that Aepnus aims to become an electrolyzer manufacturer rather than a chemicals producer. “We just want to be the technology provider and almost like application agnostic in a sense that this [the battery industry] is just the first market that we're going after,” Akuzum told me, citing a number of other potential markets such as textile and pigment manufacturing, which also produce sodium sulfate waste.

The company is currently working to get initial customers onboard for pilot demonstrations, which are planned to take place over the next 18 months. In the extended near term, Aepnus wants to expand its platform to produce a greater variety of chemicals. As the tech scales and is deployed across various industries, the company says it has potential to mitigate a total of 3 gigatons of greenhouse gas emissions between now and 2050, as calculated by Clean Energy Ventures’ Simple Emissions Reduction Calculator .

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