Sulfide Solid-State Batteries Gaining Traction

The sulfide-based all-solid-state battery (ASSB) route is seeing two major trends in 2025. First, its superior ionic conductivity has made it a consensus choice among researchers and industry players. Second, the commercialization process is accelerating, especially among startups, with clear progress in funding, production capacity, and market expansion.

Firm Lithium Technology Technology: A Three-Pronged Push

Firm-lithium Technology, a Chinese startup, has recently achieved key milestones:

Funding: Completed Series A round backed by Chaowei Power’s subsidiary and SAIC’s investment arm.

Production Capacity: Signed an agreement to build a sulfide electrolyte and ASSB facility in Changzhou, set to begin production in June. The company plans 26 GWh of total ASSB capacity over five years, requiring ~$9.2 billion RMB (~$1.3B USD).

Market Expansion: Partnered with a Beijing-based high-end electric motorcycle brand, expanding beyond consumer electronics. Yili aims for vehicle integration in 2026 and passenger vehicle scale-up by 2027.

Early-Stage Competition: Carving Out Niches

Competition is emerging among solid-state battery startups. For example, Chunli New Energy, focused on polymer-based ASSBs, launched a 200 MWh production line in late 2024, targeting e-bikes.

Supply Chain Breakthroughs: Electrolyte Production Scaling Up

Key upstream players are also making strides:

  • Zhongke Gu’neng: Received ton-level sulfide orders in 2025. Built a 100-ton/year electrolyte line and 100 MWh pilot line in Changzhou. Uses proprietary gas-phase synthesis and wet coating processes.

  • Tianshi Kefeng: Raised tens of millions in angel funding. Plans a tens-of-ton electrolyte powder line in 2025, expanding to hundred-ton scale by 2026-2027. Samples sent to CATL, Gotion, Ronbay, etc.

  • Idemitsu Kosan : Investing over ¥21.3 billion (~$140M USD) to build 1,000 tons/year of lithium sulfide capacity by June 2027, supporting Toyota’s ASSB EV launch target (2027-2028).

Key Observation: Startups’ “Low-to-High” Strategy

Currently, most sulfide ASSB startups are targeting low-speed, light-duty, or cost-insensitive applications first—a pragmatic move to secure early market share and validate technology on smaller cells before moving to passenger EVs.

Notably, no sulfide-focused startup has yet formed a deep partnership with an automaker in China. In contrast, players using oxide-polymer composite routes (e.g., Tailan, Weilan, Qingtao) have already secured strong EV maker backing through a stepwise “semi-solid to all-solid” strategy.

Whether sulfide-focused startups can overcome this gap and establish a leading position remains a key storyline to watch.

 

Note: This article is adapted and summarized from publicly available reporting by Gaogong Lithium Battery (GGII). The original data and viewpoints belong to GGII.

 

 

 

 

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