Impossible Mining CEO Oliver Gunasekara pulled me aside at last week’s TechCrunch Climate event with a fascinating pitch. Turns out there are a lot of valuable metals on the ocean floor — materials like nickel and cobalt, which are key to tackling the growing demand for lithium ion batteries.

The San Jose–based Y Combinator graduate believes it has developed a method to mine the depths of the ocean for polymetallic nodule rocks without harming the fragile ecosystem in the process. It’s been something of a hot button topic in recent years — for obvious reasons — including a statement from 622 marine science and policy experts who called for a pause on the practice.

The company’s chief sustainability officer Renee Grogan noted in a release late last year,

The deep-sea mining industry should not be granted leave to mirror the impacts of terrestrial mining. For an industry that has not yet begun, the bar should be set higher. Rather than banning deep-sea mining, let’s challenge the industry: Go back to the drawing board — design it in a way that doesn’t cause serious harm. That’s what Impossible Mining is aiming to achieve.

On its site, Impossible describes a process that employs bacterial respiration to “liberate” these metals from rocks. The technology was impressive enough to earn the company a new round of $10.1 million, led by angel investor Justin Hamilton and featuring a number of additional YC investors.

“The US needs independent, secure access to critical battery metals,” Gunasekara says in a release. “We are excited to accelerate the production of our deep water robots with this injection of capital, and to prove to both regulators and stakeholders that we can achieve what dredge-based technology can’t — the preservation of the seafloor environment.”

The funding will go toward additional development (hence the very clear render at the top of this post) and testing for the startup’s underwater robotic extraction system.