Solid-State technology: A strategic breakthrough in Saft’s battery development

In the race to deliver sustainable energy solutions, solid-state batteries are emerging as a promising innovation that targets unprecedented levels of safety, performance, and longevity. Saft, a global leader in advanced battery technologies, has been actively developing this next-generation approach since 2018. This article outlines Saft’s progress, the technology’s advantages, and the versatility of its applications.
 

What is a solid-state battery?

A solid-state battery replaces the liquid or gel electrolyte used in conventional lithium-ion cells with a solid electrolyte. This fundamental design shift enables several key improvements—chiefly higher energy density and enhanced safety. It also allows the replacement of the standard graphite anode with lithium metal or silicon, which can significantly boost the battery’s energy density. Since 2018, Saft has been pursuing a strategic program to mature, industrialize, and commercialize this innovative technology.

A structured strategic program since 2018

Solid-state technology is a major strategic pillar for the battery industry due to its disruptive potential and technological promise. Since 2018, Saft has reached several milestones, including:

• Launching a dedicated internal program focused on solid-state technologies
• Developing and successfully testing multiple prototypes
• Sustained investments, including an advanced prototyping line

Saft also participates in several European research consortia, strengthening its expertise through collaborative projects such as ELIAS (supported by France 2030 and operated by Bpifrance), SOLVE, and SAFELiMOVE (funded by the European Union under the Horizon Europe programme), all aimed at accelerating the technological maturity of solid-state batteries.

Why is solid-state a strategic leap for Saft?

Solid-state batteries represent a major step forward for energy storage thanks to their disruptive potential—particularly the significantly higher energy density they can offer. Saft is investing in a dedicated prototyping line and other resources to anticipate and overcome the technical and economic challenges associated with future large-scale manufacturing and commercialization.
The expected performance of solid-state batteries addresses several key needs:

• Optimized performance: Higher energy density enables more energy per unit volume or mass—an advantage where integration space is constrained, such as in electric vehicles or satellites.
• Extended lifespan: Longer cycle life can reduce the total cost of ownership (TCO) for customers over time.
• Robust operation in extreme conditions: Early tests indicate improved thermal stability, making them suitable for harsh environments.
• Enhanced safety: Replacing volatile, flammable liquid electrolytes with solid electrolytes can greatly reduce flammability risk, improving overall safety. Over time—and subject to technical and regulatory validation—this could simplify protective systems in certain infrastructures.

Application versatility: beyond energy storage

Solid-state technology is poised to transform numerous battery market segments. Saft—whose track record includes introducing disruptive technologies like lithium-ion in the space sector over 30 years ago—continues to demonstrate a pioneering spirit with solid-state. Several sectors stand to benefit:

• Aerospace and defense: Satellites, military equipment, and aviation—including Advanced Air Mobility (AAM)—demand extreme temperature tolerance and high performance.
• Industrial microgrids and off-grid systems: Solid-state batteries can deliver the robustness and adaptability needed for demanding operational environments, ensuring stable, uninterrupted power in complex industrial settings.
• Grid-scale energy storage: Over time, solid-state could offer the safety, longevity, and performance needed to integrate large shares of renewables and stabilize the grid.
• Transport: Trains, ships, and certain vehicles could gain improved range, safety, and weight advantages.
• Telecommunications and critical infrastructure: Reliable backup power is essential; solid-state batteries should provide stable performance even in challenging conditions to keep vital services running.

Challenges and the road to commercialization

Despite its immense promise, widespread commercialization of solid-state batteries still faces hurdles, including manufacturing, supply chains, and cost reduction.

• Cost and manufacturing: Current production techniques for solid electrolytes often require specialized, costly processes. Saft is investing in innovative production methods to enable high-volume manufacturing at competitive costs.
• Materials innovation: Achieving the right balance among ionic conductivity, mechanical strength, and stability is crucial for commercial viability. Saft’s R&D teams are exploring advanced materials to optimize these properties.
• Supply-chain development: A robust network of suppliers and partners is needed for raw materials, component manufacturing, and recycling programmes. Saft collaborates across the value chain to build a resilient, sustainable supply base for key materials.

Collaboration with experienced manufacturing partners helps ensure thorough testing and compliance with regulatory standards. As outlined in Saft’s perspective on the future of solid-state batteries, innovation and strategic alliances are key to overcoming these obstacles.