Licube bets $50 billion lithium-6 market arrives by 2040

Licube's co-founder and CEO Yohei Kiguchi puts the market for fusion-grade lithium-6 at $50 billion by 2040. "If fusion comes online, it should be a $50 billion market by 2040," Kiguchi told TechCrunch. The startup is one of 20 companies pitching onstage at TechCrunch Disrupt in San Francisco as part of the Startup Battlefield competition.

The company, which licensed its core technology from Hirosaki University in Japan, wants to become the fuel supplier to the fusion power industry. Its product is purified lithium-6, the isotope that fusion plants need to breed their own fuel.

Why do fusion plants need lithium-6?

Most planned fusion plants would run on two fuels: deuterium and tritium. Deuterium is easy to source. Tritium is extremely rare in nature, and it's an open secret in the fusion world that there isn't enough of it to power every planned plant.

The workaround is to make tritium inside the power plant itself. A fusion reaction emits fast-moving neutrons. Startups plan to surround the reactor with a blanket of lithium so that when a neutron strikes a lithium atom, the atom splits into helium and tritium. The plant then collects, purifies and feeds that tritium back into the reactor.

Not all lithium does this job equally well. Natural lithium comes in two forms, lithium-6 and lithium-7, named for their weights. Lithium-6 captures neutrons and produces tritium far more effectively. But it makes up only about 7.5% of natural lithium. The rest is the heavier lithium-7.

Separating the two is difficult. There is little capacity to do it today. The world doesn't have enough lithium-6 either.

How does the technology work?

Licube's core technology is based on the electrolyzer, a device that uses electrical current to drive chemical reactions. The process works in three steps:

• Lithium dissolves in a liquid on one side of a ceramic membrane.
• Electrical current flows across the membrane, and lithium-6 moves faster than lithium-7.
• Licube draws off the liquid and separates the lithium-6.

The goal is to enrich the lithium to at least 99.995% lithium-6. Fusion companies can feed that highly enriched material into their fuel breeding systems.

What happens if fusion arrives late?

Fusion startups remain years away from building their first power plants, even though the technology could capture a significant chunk of the multi-trillion-dollar energy market. Kiguchi acknowledged the timing risk directly. "Fusion is the biggest market in the future, but we also understand the future might be late by a few years," he said.

Until fusion becomes a major market, Licube plans to use the same purification technology to serve other industries: semiconductors, pharmaceuticals, fission reactors and spacecraft.

That plan gives the company revenue options while fusion developers work toward the grid.

Why did the founder start Licube?

Kiguchi came to the idea after visiting ITER, the experimental fusion reactor under construction in southern France. He was living a couple of hours' drive away in Monaco after retiring from his previous company, Enechange, an energy-switching platform network in Japan.

"I found out that I was too young to retire," he said. "I'm an energy guy. I want to do something bigger."

If fusion plants scale this decade, the bottleneck may not be the reactor. It may be the 7.5% of natural lithium that can breed their fuel — and Licube is positioning itself to sell exactly that.