CATL's Zeng scores solid-state batteries 4 of 9 as rivals race ahead

Solid-state batteries have reached just 4 out of 9 on a readiness scale, CATL Chairman Robin Zeng said at the Summer Davos Forum on June 23, pushing mass production past 2030 as rivals promise commercial output within two years.

"If 1 to 9, with 9 meaning mass production ready, the whole industry is only at 4," Zeng, who also serves as the company's general manager, said. He cited solid-solid interface issues — where two solid materials fail to maintain contact under pressure — as the primary bottleneck.

The 4 score corresponds to Technology Readiness Level 4, meaning lab-scale principle validation under controlled conditions. Five more levels separate that from mass production, each typically requiring one to two years. CATL itself has been developing solid-state technology for a decade and holds the most global patents in the field. Its sulfide-based full solid-state cells have reached 500 watt-hours per kilogram with 15-minute fast charging to 80%, and the company targets 2027 for small-batch production at 5 gigawatt-hours of capacity at readiness level 7 to 8.

The gap between Zeng's public skepticism and CATL's internal investment creates a nuanced picture for investors. While CATL's roughly 1,000-person R&D team pushes toward 2027, competitors including Toyota, Samsung SDI, BYD, and GAC are racing to commercialize their own solid-state lines. The confusion between semi-solid cells — already deployed by Weilani in NIO vehicles since late 2023 — and true full solid-state technology has muddied market expectations, with brokerages offering divergent forecasts for 2030 adoption.

Competitors Push Ahead Despite the Skepticism

Toyota, which has invested more than two decades in solid-state R&D, plans to start production in 2026, supported by a sulfide lithium production facility from Idemitsu Kosan completed in 2025 and recognized under Japan's Ministry of Economy, Trade and Industry subsidy program. Samsung SDI's Shizuoka plant will begin with 0.5 GWh of capacity in 2026, with initial output reserved for Lexus vehicles.

In China, BYD's Pingshan sulfide pilot line has passed vehicle-grade validation, and construction of a 20 GWh mass production line in Chongqing's Bishan district is set to begin in the third quarter of 2026. GAC plans to deploy 400 Wh/kg full solid-state cells in its Haobo models. Chery in March 2026 announced its Rhino S battery with a claimed energy density of 600 Wh/kg. CALB targets delivery of 1,000 robot-grade solid-state products in the fourth quarter of 2026 at above 450 Wh/kg. Gotion High-Tech in May 2026 said its Jinshi full solid-state battery has exceeded 400 Wh/kg, with a 2 GWh production line under construction. Changan, in partnership with Tailan New Energy, is developing a separator-free solid-state battery with a planned 50 GWh base in Chongqing's Liangjiang New Area, targeting small-batch production in 2026.

The 2030 Forecast Gap

Brokerage estimates for solid-state adoption vary widely, reflecting the uncertainty. Dongwu Securities in an April 8 report projected China's full solid-state battery output at 100 GWh by 2030, implying a 150 billion yuan market at 1.5 yuan per watt-hour. CITIC Construction's same-month forecast put global solid-state demand — including semi-solid — at 212 GWh by 2030. Citic Securities on June 2 said semi-solid cells have already entered consumer electronics and energy storage, with power-sector volume expected in the second half of 2026 and full solid-state road tests possible this year.

For investors, the key distinction remains between semi-solid and full solid-state technology. Semi-solid cells, which retain some liquid electrolyte, carry lower technical risk and are already commercial. Full solid-state, which Zeng says is only at 4 of 9, faces years of engineering validation. Publicly listed exposure includes battery material suppliers and automakers with joint-development agreements. The divergence between Zeng's public score and CATL's internal spending suggests the company sees value in managing expectations even as it races to maintain its dominant position in the next battery cycle.

This article is for informational purposes only and does not constitute investment advice.