China is moving to formalize how solid-state batteries for electric vehicles are defined, tested, and taxed, as domestic pilot lines continue to scale up. Several developments between August 21 and September 1 highlight the difference between batteries described as solid-state and cells that meet an all-solid-state classification.
On August 21, the International Electrotechnical Commission approved a China-led proposal for an international standard covering solid-state traction batteries for electric road vehicles, according to reporting cited by Chinese state outlet Hunan Today. The proposed guide is intended to establish common testing and application parameters. China, France, Japan, and South Korea are participating in the working group, and the drafting process is expected to take 24 to 36 months.
The methodology uses a 0.5% mass-loss threshold. Under the proposed test, a cell is dried in a 120°C vacuum chamber for six hours, and cells losing more than 0.5% of their mass through volatile organic evaporation would not qualify as all-solid-state. A similar 0.5% threshold was included in a Chinese national public-comment draft released in December 2025.
This distinction matters because some products marketed as solid-state use semi-solid designs that contain both solid and liquid electrolyte. Examples include the WeLion battery used by Nio and the QingTao-supplied battery used in the IM L6.
China also introduced new battery consumption-tax rules on September 1. Lithium-ion battery products are subject to a 2% consumption tax from September 1, 2026, rising to 4% from September 1, 2027. Solid-state batteries, sodium-ion batteries, and fuel cells are exempt through December 31, 2028, under the policy directive.
At the same time, domestic pilot activity is advancing. Sunwoda said its dedicated solid-state sample production line reached connectivity in August, while EVE Energy confirmed roll-off of a 60 Ah prototype from its Longquan solid-state battery series. Other reported samples include 20 Ah and 40 Ah cells.
Industry data also points to cost and technical challenges. Shanghai Metals Market assessed Li6PS5Cl, an inorganic sulfide solid electrolyte, at 4,300 yuan per kilogram in August, far above liquid electrolyte pricing. Solid-state cells also require reliable contact between solid materials, making sustained mechanical pressure an important design factor.
Current activity suggests meaningful progress in standards, policy, and sample production, but not yet large-scale commercial deployment.
Source: CarNewsChina
