Li Auto Reveals Why It Chose Stainless Steel Fuel Tanks: Safer, More Durable, and Better Suited for Range-Extended EVs

On January 19, Ji Chaochao, Head of Materials Technology at Li Auto, revealed that the company has chosen stainless steel over plastic or aluminum alloy for its fuel tanks. He explained that plug-in hybrid and range-extended electric vehicles often operate in pure electric mode for extended periods, leaving the fuel tank sealed. This causes internal fuel vapor to evaporate and build up pressure, demanding higher resistance to pressure and deformation from the tank—areas where stainless steel excels. Moreover, passenger vehicle fuel tanks have complex shapes and limited space underneath, making aluminum alloys difficult to stamp into the required forms, whereas stainless steel is better suited for such applications. Li Auto has also independently developed an ultra-high-strength stainless steel, whose yield strength is 100% higher than the industry-standard 304L grade, offering superior puncture resistance, impact protection, and corrosion resistance—significantly enhancing both safety and durability.