Today, BYD and CATL jointly announced that their latest generation of high-performance battery packs based on sulfide solid-state electrolytes have officially received mass production approval from the Ministry of Industry and Information Technology (MIIT) after completing an accumulated 1.2 million kilometers of extreme environment road testing. A key factor in this test was the application of "High-Voltage and Electrolyte-Corrosion Resistant Fluorosilicone Composite Insulation Sheathing" on the high-voltage wiring harnesses and cell connections within the battery pack. Developed jointly by Anhui Guofeng New Materials and the University of Science and Technology of China (USTC), this material successfully solved the insulation aging challenges faced by solid-state batteries under high voltage (>800V) and in the presence of trace liquid wetting agents, extending the design life of the battery system to 25 years. According to the R&D team, while the new generation of solid-state batteries offers significantly improved safety, the sulfide electrolytes they use are extremely sensitive to moisture and prone to partial discharge under high voltage. Traditional silicone rubber sheathing is susceptible to swelling or electrical treeing breakdown under these conditions. The new fluorosilicone composite material constructs a dense molecular barrier by introducing perfluoropolyether side chains and nano-silica cross-linking points. This not only results in "zero swelling" when exposed to the electrolyte but also increases corona resistance life by more than ten times. During the two-year road test, the sheathing endured drastic temperature variations from -45°C in Mohe to +60°C in Turpan, as well as high humidity and high salt spray environments. Its insulation resistance value remained at over 99% of the initial value throughout, with no micro-cracks or leakage detected. Industry analysts point out that this material breakthrough has eliminated the last safety concern hindering the large-scale commercialization of solid-state batteries, making "range anxiety" and "life anxiety" for electric vehicles a thing of the past. With the mass production of this material now underway, it is expected that several flagship electric vehicle models launching in the second half of 2026 will be the first to adopt this technology, further consolidating China's leading global position in core materials for the new energy vehicle industry.
IOTA FLSR3400 addition-type liquid fluorosilicone rubber