China eyes new grip on EV sector with high-performance rare-earth rubber

China is seeking to strengthen its influence in the electric vehicle (EV) and heavy-duty tyre sectors by expanding the use of high-performance rare-earth rubber. This specialized material, known as rare-earth cis-butadiene rubber grade ND9106, commanded a higher price of 22,500 yuan (US$3,400) per tonne in China during the week of October 26 to November 1, compared to conventional synthetic rubber at 16,660 yuan per tonne.

The China Rubber Industry Association's data highlights the material's superior wear resistance, strength, and lower rolling resistance, making it an attractive option for tyre manufacturers. A 100,000-tonne-a-year production facility at Dushanzi Petrochemical Company in Karamay, Xinjiang Uygur autonomous region, successfully tested the premium-grade rare-earth cis-butadiene rubber on June 27, 2023, according to the Chinese Academy of Sciences’ Changchun Institute of Applied Chemistry.

The institute considers this achievement a "major breakthrough" in China's proprietary rare-earth catalytic rubber technology, as core technologies are fully under domestic control. This development is crucial for meeting the urgent demand for high-end grades of rare-earth cis-butadiene rubber, supporting the growth of China's petrochemical new-materials industry, and safeguarding supply-chain security.

The material's benefits are particularly relevant to EV tyres, as electric cars are heavier and demand higher tyre durability. Rare-earth rubber's low rolling resistance can reduce energy loss, while wear and fatigue resistance extend tyre life. Heavier-duty vehicles also benefit from rubber that can endure high loads, repeated deformation, and heat build-up. Furthermore, the same combination of strength, wear resistance, and durability could be pertinent to military tyres and other high-performance rubber components.

The technology behind this rare-earth rubber involves polymerising butadiene using a rare-earth catalyst, which controls the polymer's molecular structure and mechanical properties. The institute's second-generation production technology integrates automated operations and domestically developed equipment, addressing technical challenges like precise catalyst control and integration of long-chain branching and functionalisation.

The institute's rare-earth-catalysed rubber research dates back to 1964, with scientists Ouyang Jun and Shen Zhiquan publishing the first international paper on the topic. In 1982, they won second prize in China's National Natural Science Award for their work on stereospecific polymerisation catalysed by rare-earth complexes. Over the years, the institute has conducted extensive scale-up experiments and pilot trials, transforming six decades of research into a reliable industrial process.