In the segment 'A Look Around Innovation,' we introduce research and development (R&D) sites that have led to real-world applications. In the 30th installment of this series, JST News interviewed CEO/CTO Tsuyoshi Hoshino of LiSTie Inc., a company developing a technology capable of selectively extracting ultra-high-purity lithium ions, currently advancing the commercialization of its proprietary technology alongside its engineered extraction systems. Lithium is an essential metal used in batteries for smartphones and electric vehicles and demand for lithium is rapidly increasing. While environmental pollution and labor issues in the lithium refining process remain major concerns, meeting the surging demand and ensuring supply chain stability are also critical issues that need to be addressed immediately.
New technology for refining and extraction — The key: A specialized ion-conductive membrane
About a 30-minute ride from central Tokyo, the Tsukuba Express takes you to Kashiwanoha-campus Station, where commercial facilities, residences and greenery coexist comfortably. LiSTie Inc., located near this station, develops technologies for extract high-purity lithium. Lithium-ion batteries (LIBs), valued for their high energy density and compact design, have become integral to modern life. Driven by the rise of electric vehicles, the demand for large storage batteries is expected to grow for the purpose of storing electricity generated by solar power during the day and supplying power when needed. Lithium is also essential for fusion energy (nuclear fusion) power generation, which is likely to be realized in the not-too-distant future.
One of the major challenges surrounding lithium use lies in its supply chain. While lithium salt lakes and mines are distributed globally, for example, in Chile, Argentina and China. However, lithium refining is heavily concentrated in China. "There are also concerns beyond the geopolitical risk. Lithium carbonate extracted from salt lakes and mines needs to be refined into lithium hydroxide before it can be used. But this refining process requires large amounts of energy, time and chemicals, which also creates a harsh working environment. We urgently need a lithium refining method with a smaller environmental footprint," says Hoshino.
Given the continuous expansion of the lithium-ion battery (LIB) recycling market, Hoshino is working on developing a new system. This system aims to efficiently remove impurities and extract high-purity lithium from feedstocks such as retired LIBs, with the goal of supplying recycled lithium at scale.
The key to this efficient lithium extraction process is a special ion-conductive ceramics membrane. During the manufacturing of the ceramic plates—which consist of lithium, lanthanum, and titanium—lithium vacancies are intentionally created by making the elements non-stoichiometric (meaning a deliberate shortage of lithium). As a result, these vacancies serve as "preferential pathways" that allow only lithium ions to pass through. Under the influence of an electric field or a concentration gradient, lithium ions embed themselves into the vacancies one by one and migrate directionally, before being smoothly released on the other side of the membrane (Figure 1). Unlike separation technologies that rely on physical filtration through microscopic pores, the membrane offers extremely high selectivity, allowing it to selectively extract high-purity lithium from solutions containing impurities.
Less than 1 mm thick, the membrane significantly enhances ion mobility. Meanwhile, its unique material characteristics ensure that no elements other than lithium can pass through, achieving both high purity and high efficiency (right).
At first, however, the painfully slow permeation rate proved to be the ultimate bottleneck for commercial viability. To solve this problem, Hoshino initially tried scaling up the surface area of the membrane and changing the temperature, but these efforts yielded little return. The turning point came when he innovatively treated the ceramic membrane's surface with hydrochloric acid to form an adsorption layer. By lowering the energy barrier for entry, this treatment sent the lithium permeation rate skyrocketing roughly 100-fold. Furthermore, testing revealed that the system hits its sweet spot when temperatures are kept between 80℃ and 90℃. The optimized ceramic membrane offers excellent feedstock flexibility. It is equally effective for both the recycling of battery manufacturing waste and retired battery scrap, as well as the refining and purification of virgin lithium ore from salt lake brines and mines.
Launch of Containerized Unit Demonstration — Strategically Positioning for the Global Refining Market
This core technology was developed by Hoshino during his tenure at the National Institutes for Quantum Science and Technology (QST). In 2019, Hoshino advanced the technology toward practical viability under the JST's START program (Program for Creating STart-ups from Advanced Research and Technology). In 2023, he founded LiSTie as a QST-certified venture. His original research focused on extracting lithium from seawater, aiming to supply critical fuel for commercial fusion energy generation. "But the practical application of fusion energy is still on the horizon, with earliest deployment expected in the 2030s. Meanwhile, the rapid growth of large-scale LIBs, especially for electric vehicles, is projected to trigger a severe lithium supply-demand imbalance as early as the 2030s. I realized I needed to seek a way to bring my technology for societal benefit much sooner, which became the core inspiration behind founding LiSTie," he says. The name combines Lithium, Sustainable and Tie, representing its vision to connect and pass its technology on to future generations. Currently, LiSTie is accelerating its research and development while simultaneously conducting commercial feasibility studies.
The system for extracting lithium was named LiSMIC (Li Separation Method by Ionic Conductor) unit. Hoshino plans to commercialize the technology as a containerized system (Figure 2 left). Designed to match the dimensions of a standard 40-foot container (about 2 meters in width and height and 12 meters in length), the system is highly portable and allows for seamless deployment. The core philosophy behind this design is to allow rapid transport directly to salt lakes and lithium mining sites, for immediate, on-site operations.
As a first step toward commercialization, the research team built a testing unit and began bench-scale demonstrations in May 2026 (Figure 3). Building on these results, the team plans to manufacture a half-size container, paving the way for full commercialization by 2028. "A single LiSMIC unit would provide sufficient capacity for a Japanese recycling operator, whereas a major project, such as refining lithium at a salt lake in Chile, would require approximately 400 units to be deployed. " Hoshino added. "To achieve that scale, deep collaboration with major players is essential." In fact, winning the 2025 "STI for SDGs" JST President's Award has already catalyzed LiSTie's initiatives to partner with major industry players.
Isotopes Essential for Fusion Power Generation — Future Solutions for Global Energy Challenges
LiSTie aims to go public by 2030. By that time, a massive wave of early-generation electric vehicles (EVs) is expected to reach the end of their lifecycles, a shift that Hoshino expects will drive the widespread adoption of LiSMIC units. In tandem with this commercial timeline, he is actively pursuing his founding vision: developing lithium refining technologies tailored for next-generation commercial nuclear fusion.
Nuclear fusion is widely seen as the ultimate source of clean energy, but it relies entirely on two hydrogen isotopes: deuterium and tritium. Tritium is formed through the reaction of lithium-6 (6Li) with neutrons generated in a fusion reactor. The challenge comes down to sourcing this isotope, because lithium-7 (7Li) accounts for 92.4 % of the total lithium in seawater, while lithium-6 (6Li) makes up just 7.6%. "Lithium-6 passes through our modified ceramic membranes slightly faster than lithium-7. By lining up the membranes in series for multi-stage filtration, the concentration of lithium-6 will gradually increase up to 90 %. " Hoshino explained. "We believe LiSMIC can help secure a reliable supply of materials needed for future fusion energy systems."
With a clear vision to commercialize sustainable fusion energy and tackle global energy challenges, Hoshino and his team are engineering a brighter future with their technology.
(Article: Keiichi Motohashi, Photography: Erika Shimamoto)