Lithium-ion batteries power our phones, our electric vehicles, and a fast-growing share of the grid-scale storage keeping the lights on as renewable energy expands. For decades, they have dominated the energy storage industry and remain the default assumption behind most clean energy planning.
But some of the assumptions built around lithium-ion are under pressure. Brooks Sherman, a strategy and business development professional whose MBA capstone examined next-generation battery markets, has been tracing those pressures and asking what a more resilient storage future might look like.
“The conversation around energy storage is still dominated by lithium-ion, and for good reason. It’s a proven, commercially viable technology,” says Sherman, who completed an MBA in Sustainable Innovation at the University of Vermont’s Grossman School of Business. “But when you look at the structural pressures building around supply chains, environmental impact, and the specific demands of grid-scale storage, it becomes clear that lithium-ion isn’t the only answer, nor should it be.”
The Cracks in Lithium’s Foundation
The case for diversification starts with current supply chain concentration. In the research he completed for his capstone, Sherman examined how:
- China dominates rare earth element extraction and refinement, refining roughly 59% of the world’s lithium, 68% of its nickel, and 73% of its cobalt
- That concentration in a single country creates vulnerabilities that go well beyond pricing
Trade policy shifts, geopolitical friction, or domestic economic disruptions in any major refining nation can ripple through global supply chains within weeks, as recent export controls and regional conflicts show.
Then there are the environmental costs. Lithium extraction, whether through hard rock mining or brine evaporation, carries significant water contamination and depletion risks. In South America’s Lithium Triangle, intensive mining operations have strained freshwater resources and created ongoing tensions with local communities.
These aren’t abstract sustainability concerns. They’re operational and reputational risks that energy companies and their investors are beginning to price into their decisions, and that affect our most ubiquitous devices.
Lithium Ion Battery Alternatives: Three Emerging Chemistries
What’s different about this moment compared with earlier rounds of battery hype is that several alternative chemistries are reaching commercial viability at the same time.
In the market research he completed for his capstone, Sherman focused on three emerging battery technologies in particular:
- Sodium-ion
- Iron-air
- Flow
Each addresses a different segment of the storage market, and each offers advantages that lithium-ion doesn’t.
Sherman’s analysis of these technologies drew on case studies and market data from his research. His aim wasn’t to pick a single winner, but to understand the strategic role each chemistry can play and the conditions under which each one makes sense.
The Sodium-Ion Approach
Sodium-ion batteries use materials that are over 1,000 times more abundant than lithium in the Earth’s crust. They perform well in cold climates, carry lower fire risk, and cost significantly less per kilowatt-hour to produce.
For residential backup systems and community-scale microgrids, the economics are already competitive. As a result, this emerging technology has attracted serious commercial interest. Natron Energy, for example, announced plans for a $1.4 billion sodium-ion gigafactory in North Carolina but ultimately shut down in 2025 after failing to secure enough capital and commercial traction.
That’s a reminder that the path from promising chemistry to scaled manufacturing isn’t linear and that evaluating these technologies requires looking beyond announcements to actual deployment progress. It also illustrates how tighter capital markets and a less supportive federal clean‑energy policy environment can compound technology and market risks for new storage chemistries.
Iron-Air Technology
Iron-air batteries work on a different principle, using iron, water, and air to store energy for up to 100 hours of continuous discharge. That makes them well-suited for the kind of multi-day grid storage that lithium-ion simply can’t provide at a reasonable cost.
Form Energy broke ground in 2024 on a 1.5 MW/150 MWh commercial pilot in Cambridge, Minnesota in partnership with Great River Energy, the first commercial deployment of its iron-air technology. The system was delivered in 2025 and is expected to be fully online in 2026, after which Great River Energy will evaluate how multi-day storage performs under real grid conditions.
Flow Batteries’ Scalability Solution
Flow batteries, particularly iron-based systems, offer modularity and a lifespan of around 25 years without meaningful capacity degradation. Their design is based on external tank storage of an electrolyte solution that permits independent energy and power scaling.
ESS Inc. has secured a framework agreement with the Sacramento Municipal Utility District (SMUD) for up to 200 MW/2 GWh of iron-flow storage, targeting long-duration commercial and utility applications in support of SMUD’s goal to reach zero carbon by 2030.
A Portfolio Approach, Not a Silver Bullet
The temptation in any technology transition is to look for a single successor. In his research, Sherman found that approach counterproductive when applied to energy storage. Diversification is both necessary and prudent if the goal is long-term system resilience. The more useful question is not which chemistry wins, but which chemistry fits which need.
“No single chemistry is going to replace lithium-ion across every application,” Sherman explains. “The smarter strategic question is which chemistry fits which use case and how do you build a portfolio that covers the range of needs, from four-hour peak shaving to 100-hour grid backup, without overcommitting to any one technology before the market settles.”
That kind of thinking is less about ideology than sequencing:
- Maintain lithium-ion where it still makes sense
- Scale the alternatives that are ready for commercial deployment
- Keep an eye on longer-term possibilities like green hydrogen and gravity-based storage that could shift the picture again in the next decade
Sherman says the same basic sequencing logic shows up in other parts of the energy transition, from how utilities plan new generation to how developers prioritize community-scale projects.
What This Means for Communities
For Sherman, the conversation about battery technology is ultimately a conversation about community resilience.
Decentralized storage, whether sodium-ion systems paired with rooftop solar or iron-air batteries supporting rural grid stability, has the potential to change who benefits from the energy transition and how.
“The technology decisions being made right now will determine whether clean energy infrastructure is something that gets built for communities or just near them,” Sherman says. “That’s a strategic question as much as a technical one, and it’s where business development, policy, and community engagement all intersect.”
As battery manufacturers, utilities, and policymakers work through what comes after lithium-ion’s current dominance, the hard questions aren’t primarily technical. They’re strategic. Which chemistry fits which grid need? Which markets are ready and which aren’t? Which communities get access to distributed storage, and on what terms?
These are questions Sherman examined in his capstone research and continues to explore through strategy and business development roles across climate, technology, and media.. The energy storage market isn’t waiting for a single breakthrough. It’s moving toward a diversified future and the companies and communities that plan accordingly are the ones likely to benefit when it arrives.
“This article draws on research from Brooks Sherman’s 2025 market report, ‘Next-Generation Battery Strategy in a Post-Lithium Energy Storage Market,’ completed as part of his MBA in Sustainable Innovation program at the University of Vermont’s Grossman School of Business.”
