Solid-State Batteries vs Lithium-Ion 2026: Energy Density, Safety, and Cost Curves

Executive Summary

Solid-state batteries (SSBs) promise higher energy density and improved safety compared with today's advanced lithium-ion (Li-ion) packs. In 2026, however, SSBs remain largely in pilot and early commercial phases. Energy Solutions analysts track cost curves, performance benchmarks, and announced manufacturing roadmaps to help investors and OEMs judge when SSBs may move from R&D to mainstream deployment across electric vehicles and stationary storage. At Energy Solutions, this analysis feeds directly into EV, grid-storage, and second‑life portfolio models.

Download Full Techno-Economic Report (PDF)

Energy Solutions Battery Intelligence

Energy Solutions tracks chemistries from NMC and LFP to solid-state and sodium-ion, spanning EV packs, stationary storage, and second‑life applications. The same datasets that underpin this report power interactive tools for OEMs, utilities, and infrastructure funds.

What You'll Learn

Technology Overview: Solid-State vs Advanced Li-Ion

Conventional Li-ion cells use a liquid electrolyte and separator between the anode and cathode. Solid-state designs replace this liquid with a solid electrolyte—ceramic, sulfide, or polymer-based—often paired with lithium metal or silicon‑rich anodes. The theoretical benefits include higher energy density, improved safety window, and better tolerance of fast charging.

Energy Density, Safety, and Cycle Life Benchmarks

The table below compares indicative performance metrics for high‑nickel Li-ion and three stylised SSB archetypes based on vendor roadmaps and public test data.

Indicative Cell-Level Performance Benchmarks (2025–2026)

Chemistry / Design Gravimetric Energy Density (Wh/kg) Volumetric Energy Density (Wh/L) Cycle Life to 80% SoH Safety Envelope
High-nickel Li-ion (NMC811) 240–280 650–750 1,000–1,500 Requires liquid electrolyte safety systems and strict thermal management.
Polymer-based solid-state (early) 260–300 700–800 1,000–1,800 Improved thermal stability; still sensitive to dendrite formation at high current.
Ceramic solid-state with Li-metal anode (pilot) 320–380 800–950 800–1,200 Non-flammable electrolyte; interface stability and manufacturing yield remain challenges.
Sulfide-based solid-state (R&D) 300–360 780–900 1,000–2,000* Promising fast-charge behaviour; moisture sensitivity complicates production.

*Upper-end figures are from lab-scale cells and may not translate directly to automotive packs.

Illustrative Pack-Level Cost Trajectories (USD/kWh, Real 2025)

Year Advanced Li-ion (NMC/LFP blend) Solid-State – Early Niche Solid-State – Optimistic 2035
2025 110–140 300–450
2030 80–105 160–230
2035 65–85 120–170 80–110

Ranges represent Energy Solutions scenarios rather than firm forecasts.

Indicative Pack Cost Curves: Li-Ion vs Solid-State

Source: Energy Solutions Battery Cost-Curve Explorer (Q4 2025 scenarios).

Cell Energy Density Comparison (2025–2026)

Source: Energy Solutions analysis of vendor roadmaps and public test data.

Illustrative Share of Global EV Battery Capacity by Chemistry (2035)

Source: Energy Solutions modelling; indicative mix only.

Cost Curves, Supply Chains, and Capacity Build-Out

Scaling SSBs requires not only cell design breakthroughs but also new manufacturing processes, supply chains for solid electrolytes, and redesigned pack assembly lines. While Li-ion gigafactories benefit from steep learning curves, SSB lines are closer to first‑of‑a‑kind plants.

Use Cases: EV Packs vs Stationary Storage

In the near term, SSBs are most likely to appear in premium EV segments where higher range and performance justify higher pack costs. For stationary storage, the competition from lower‑cost, lower‑energy‑density technologies is intense. Long‑duration applications may favour chemistries optimised for cycle life and low cost over volumetric density.

Case Studies: OEM Pilots and Grid Demos

Case Study 1 – Automotive OEM Pilot Fleet

Case Study 2 – Stationary Grid Demonstration

Global Perspective: Asia, Europe, and North America

Most announced SSB manufacturing capacity and intellectual property is concentrated in East Asia and parts of Europe, with North American OEMs partnering through joint ventures. Policy support for localised battery supply chains may accelerate SSB projects, but Li-ion and sodium-ion factories are also scaling rapidly.

Devil's Advocate: Risks and Hurdles

Key risks for SSB scale‑up include:

Future Outlook to 2030/2035

Energy Solutions' central scenario treats SSBs as an important but not dominant chemistry by 2035. EV makers may deploy SSBs selectively in long‑range, luxury, or high‑performance models, while Li-ion and sodium-ion continue to serve cost‑sensitive segments. In grid storage, SSBs compete with LFP, sodium-ion, flow batteries, and thermal systems.

For portfolio planning, this means SSBs should be modelled as an option value—a potential upside for range, safety, or form factor—rather than a guaranteed replacement for existing chemistries in the 2020s.

Methodology Note. Performance and cost figures in this report combine public roadmaps, academic literature, and Energy Solutions scenarios as of Q4 2025. Values are indicative, normalised where necessary, and subject to change as more commercial data becomes available.

Frequently Asked Questions

When will solid-state batteries be widely available in mainstream EVs?

Most industry roadmaps point to late-2020s pilot deployments and early commercial volumes, with broader mainstream adoption more likely in the 2030s if technical and manufacturing challenges are resolved.

Are solid-state batteries definitively safer than current lithium-ion packs?

Solid electrolytes are generally less flammable than liquid ones, which can improve the safety envelope. However, overall safety depends on many factors, including cell design, pack engineering, and quality control. Solid-state designs are not automatically risk‑free.

Will solid-state batteries become cheaper than lithium-ion?

In the near term, SSBs are expected to remain more expensive due to new materials and manufacturing processes. In optimistic scenarios, cost parity or an advantage may be possible in the 2030s as volumes increase and learning effects accumulate.

How should SSBs be treated in long-term energy and transport scenarios?

Many analysts treat SSBs as one of several competing chemistries rather than a guaranteed winner. Scenario analysis typically assigns them a growing but minority share of EV and storage capacity by 2035, with sensitivity ranges around adoption timing and cost.

What does this mean for investors in lithium-ion, sodium-ion, and alternative storage?

SSBs are an important technology to track, but current evidence does not justify abandoning investments in advanced Li-ion, sodium-ion, or alternative storage. Instead, diversified portfolios and flexible procurement strategies can accommodate multiple chemistries over time.