WeLion New Energy wants to replace the liquid inside your phone’s battery with something solid. The Chinese company is building semi-solid-state cells that could hold more power than today’s lithium-ion batteries, and it has already shown the numbers in lab tests.
The firm’s aim is straightforward — to store energy more safely and densely. It relies on semi-solid-state cells that combine liquid and solid electrolytes, a design that might raise energy density while reducing the danger of fires linked to the flammable fluid inside ordinary lithium-ion batteries.
The Nio Partnership
In 2023, WeLion partnered with Shanghai-based EV-maker Nio to release a battery pack. The pack reached 360 watt-hours per kilogram, far above the 200 wh/kg average for lithium-ion packs today. That translated to a range of over 1,000 kilometers.
The production cost proved too high, so only about 200 of those packs were ever made. Despite that, Nio continues to use them, according to WeLion.
The 824 Record
The real headline comes from a 2025 test. WeLion’s engineers built a semi-solid-state battery that hit 824 wh/kg, more than three times a standard lithium-ion battery. The company calls it a remarkable achievement.
The Cost Problem
WeLion acknowledges that its semi-solid-state batteries carry a higher price tag compared to conventional lithium-ion batteries produced by bigger Chinese battery firms such as CATL. This admission matters because the market is already crowded with cheaper alternatives.
What Is Still Unanswered
The firm refused to offer further particulars on the 2025 prototype, citing that it remains far from being ready for sale. The number of charge and discharge cycles the cell can withstand, along with how its capacity declines over time, have not been disclosed.
The Drone and Car Plans
The company is forging ahead regardless. Its plans include releasing a new drone battery with a semi-solid-state design by the end of this year, carrying an energy density of 410 wh/kg.
The company plans to launch its inaugural all-solid-state battery for vehicles in 2027, with an anticipated energy density of 400 wh/kg.
The Shipping Ambition
Two inland cargo ships powered by WeLion’s batteries are expected to launch in October 2026 in Huzhou, a city in eastern China. Each ship’s battery pack will carry nearly 4,000 kilowatt-hours, enough for up to 250 kilometers of sailing.
Production Capacity
Across its four production bases in China, WeLion now holds a yearly manufacturing capacity of 11 gigawatt-hours. Two further plants, carrying a combined yearly output of 18 GWh, are currently being built.
The Road Ahead
China’s transportation sector accounts for around 10% of the country’s carbon dioxide emissions, and electric ships could help cut that figure. Vessels moving goods along China’s lakes, canals, and rivers are projected to raise their emissions by about 25% this decade, reaching 18.7 million metric tons by 2030.
WeLion’s cofounders include Chen Liquan, a scientist at the Chinese Academy of Sciences who led the development of the country’s first all-solid-state battery back in 1988.
Through its subsidiary, the firm has produced batteries for cargo ships and ferries, while it is working on cells with greater energy density.
“The company declined to give more details about the experimental results from its 2025 prototype, which it says is far from commercialization.”
The numbers show strong promise, yet the road to full-scale manufacturing remains uncertain.
The company understands the problem at hand. What remains to be seen is whether the figures from the research setting will hold up when put into practice on the production line.
Source material: “WeLion New Energy and its semi-solid-state batteries,” MIT Technology Review.
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