Converging lab-scale breakthroughs in solid-state battery technology are prompting a reassessment across the energy storage industry, as researchers tackle the core technical barriers that have kept the technology out of commercial grid applications.
Background
Grid-scale battery storage is expanding rapidly. In the first nine months of 2025, 49.4 GW/136.5 GWh of grid-scale battery energy storage systems came online, a 36% increase in gigawatt-hours compared to the same period in 2024. That capacity relies almost entirely on conventional lithium-ion chemistry - primarily lithium iron phosphate (LFP). The global lithium-ion battery market topped $150 billion in 2025, marking a 20% year-on-year increase. Yet safety incidents, geographic supply concentration, and energy-density ceilings are driving commercial pressure to develop alternatives. China controls roughly half the global lithium market and dominates EV battery production. Solid-state batteries (SSBs), which replace flammable liquid electrolytes with solid materials such as ceramics, polymers, or sulfides, have long been positioned as the successor technology. SSBs offer energy densities reaching up to 500 Wh/kg compared to approximately 250 Wh/kg in conventional lithium-ion systems. Until recently, slow ion transport within solid electrolytes and manufacturing challenges limited progress beyond the lab.
Details
Researchers at the Department of Energy's Oak Ridge National Laboratory (ORNL) published a materials advance in April 2026 that directly targets the ion-movement problem. ORNL scientists demonstrated that by carefully controlling the chemical composition of a lithium salt-based polymer, they could create a material enabling superfast transport of ions - up to 10 billion times faster than their surroundings - without the brittleness of ceramic electrolytes. The key mechanism involves zwitterionic molecular groups, which carry both positive and negative charges, that self-organize into channel-like structures allowing ions to move with minimal resistance. "We developed a very special polymer in which the segments self-organize to provide a high mobility path for the ions to move through," said Tomonori Saito, a distinguished researcher in ORNL's Chemical Sciences Division, in a laboratory statement. The research was published in Materials Today and conducted under the DOE's Fast and Cooperative Ion Transport in Polymer-Based Materials (FaCT) Energy Frontier Research Center. ORNL researchers noted that flow batteries, fuel cells, and grid-level energy storage applications could all benefit from the newly developed polymers.
The ORNL result is one of several overlapping advances shaping the field. A study published in Nature Sustainability in October 2025 demonstrated "dynamically adaptive interphases" in solid-state lithium batteries through controlled iodide-ion movement, eliminating the need for bulky external pressure equipment - a significant engineering barrier to grid-scale packaging. On the sodium chemistry front, researchers at the A*STAR Institute of Materials Research and Engineering and the University of Chicago developed a sodium-based solid-state battery that performs reliably from room temperature to below freezing, using a metastable sodium hydridoborate electrolyte with ionic conductivity at least one order of magnitude higher than previously reported.
At the commercial scale, ION Storage Systems, backed by $20 million from ARPA-E, achieved a 25x capacity boost and over 1,000 cycles in large-format cells retaining more than 80% capacity in 2025. In April 2025, Stellantis and Factorial Energy validated 77 Ah solid-state cells with an energy density of 375 Wh/kg and more than 600 charge cycles, with charging from 15% to 90% capacity completed in 18 minutes.
The commercial SSB market remains nascent but is growing rapidly. The solid-state battery market is estimated at approximately $3 billion in 2025 and is projected to reach $122 billion by 2037, growing at a compound annual growth rate of more than 35%. Industry analysts report that solid-state battery manufacturing costs have dropped 40% since early 2024, driven by advances in solid electrolyte production and automated assembly. Venture capital funding for solid-state battery startups reached $3.2 billion in 2025.
Despite this momentum, a clear gap persists between the laboratory and grid deployment. Solid-state electrolytes introduce new supply chain dependencies - particularly around sulfide-based electrolytes and high-purity precursor materials - even as they reduce some risks tied to lithium-ion supply concentration. SSBs may reduce risks linked to volatile metal markets, but introduce new dependencies, particularly around specialized electrolyte materials and high-purity precursors. Manufacturing readiness remains a bottleneck: the industry's commercialization trajectory runs from pilot lines in 2024-2025 toward early production in 2026-2027, with mass production and cost parity targeted for 2028-2030.
Outlook
ORNL's research team continues to investigate the fundamental mechanisms behind the new polymer's superionic behavior using AI-driven autonomous chemistry and neutron scattering studies at the Spallation Neutron Source. In late 2025, China launched a public consultation for its first national standard dedicated to solid-state batteries, addressing terminology, classification, and coding rules. For utility procurement teams and project developers, the near-term calculus remains weighted toward proven LFP deployments. SSB performance data from ongoing pilots - and the material cost trajectory - will determine whether grid-scale commercialization accelerates within this decade.
