GAC-backed Greater Bay Technology starts a 1 GWh solid-state cell line: what is built and what is still promised

What happened on 13 October

Greater Bay Technology (GBT), a battery developer backed by GAC Group and founded in Nansha in 2020, held a ceremony at its Nansha base in Guangzhou to start an all-solid-state cell line. It did not build a new factory. Part of an existing 4 GWh liquid-electrolyte lithium-ion line was converted, giving 1 GWh of solid-state capacity that can switch back to liquid cells.^1,2,3,4

The cells use what GBT calls a deep-eutectic composite solid electrolyte. It is injected as a liquid precursor and solidifies inside the cell, so electrode making, stacking, formation and testing can use conventional equipment. The filling step is done in a dry, oxygen-free environment.^1,2

In production versus announced

In production: first-generation pouch cells for cars, made with established electrode materials, on 1 GWh of converted capacity. Samples are with customers in several industries, and some cells are in validation with carmakers that GBT has not named.^1,3

Announced: converting more of the 4 GWh plant if demand grows, later generations with lithium-metal anodes, a ramp-up to batch deliveries, and agreements with Hubei Liming Lithium and an eVTOL aircraft centre in Shenzhen. In April GBT said it aimed for vehicle installation in 2026. No car model, price or delivery volume has been published.^1,2,3,5

GBT quotes 260 to 480 Wh/kg depending on cell generation and materials, and says cycle life is comparable to conventional lithium-ion without giving figures. It has not said which energy density applies to the cells leaving the line now.^1,2

What the new standard settles

China's national standards register lists GB/T 48093.1-2026, Solid-state batteries for electric vehicles, Part 1: Terminology and classification, as a recommended standard published on 28 August 2026 and taking effect on 1 January 2028. Its draft separated liquid, hybrid solid-liquid and solid-state cells and set a weight-loss limit of 0.5% under vacuum drying, stricter than the 1% in a 2025 industry group standard.^6,7

GBT reports that punctured cells lost less than 0.5% of their mass after six hours of vacuum baking at 120°C in third-party tests, and that a fully charged cell did not catch fire in a nail test. Those are company-reported results; the full test reports have not been published.^1,2,4

How big is 1 GWh?

The IEA counted more than 4 TWh of lithium-ion manufacturing capacity worldwide at the end of 2025, so 1 GWh is about 0.025% of it. Running flat out on solid-state cells, 1 GWh a year would fill roughly 16,700 packs of 60 kWh, close to the average Chinese battery-electric car battery, which the IEA puts below 60 kWh.⁸

The low end of GBT's range, 260 Wh/kg, is similar to the best current NMC cells at up to 265 Wh/kg in IEA figures, and above LFP at up to 205 Wh/kg. The IEA also expects early solid-state batteries to be expensive.^1,8

Rivals are on slower public timelines. CATL plans small-batch all-solid-state production in 2027, and BYD plans demonstration installations in 2027 with large-scale production around 2030. In the United States, Solid Power was still preparing equipment acceptance tests on its continuous electrolyte pilot line in August.^9,10

What to check next

Three facts will show whether this becomes a car battery: a named vehicle with the cells' capacity and price, published cycle-life data, and actual delivery volumes. The claim that these are the world's first certified mass-produced solid-state cells comes from the chairman of China's battery industry alliance and has not been independently established.^1,3,9