Hu Yongsheng’s Team Breaks Sodium-ion Battery Mass Production Barriers with Localized Materials

When asked about the biggest challenges in the localization process, Hu Yongsheng admitted: "Behind the fully independent R&D and 100% localization of cathode and anode materials, the primary challenges lie in material performance stability and cost control, with equipment and process issues coming second."

Faced with the technical bottlenecks of sodium-ion batteries—namely low energy density and poor cycle performance—the research team broke away from the nickel-based route that dominated international research at the time. Hu Yongsheng recalled: "In 2014, our team innovatively discovered the efficient reversible reaction mechanism in copper-based layered materials. Later that year, by introducing iron to replace some metal components, we successfully developed the world’s first copper-iron-manganese-based cathode material system for sodium-ion batteries. This system not only eliminated the use of precious metals but also significantly improved the cycle stability of sodium-ion batteries, laying a solid foundation for their commercial application."

For the anode material, the team spent three years screening more than 500 carbon-producing precursors. Ultimately, they innovatively leveraged China’s abundant coal resources to develop the world’s first industrialization technology for coal-based hard carbon. Hu Yongsheng stated: "The carbon anode material produced by this technology features high sodium storage capacity, excellent cycle stability, and outstanding cost performance." This breakthrough not only resolved performance issues but also drastically reduced material costs.

After achieving breakthroughs in material principles, mass production equipment emerged as another major hurdle. Hu Yongsheng explained: "Following the principle breakthroughs in the lab, we were confronted with difficulties in manufacturing. Through joint research with domestic equipment manufacturers, we solved numerous production process issues—such as temperature uniformity control for cathode materials, surface tension problems in anode coating, and pole piece calendering control—all unique processes for sodium-ion batteries. These efforts directly supported the leap of large-capacity battery cells from lab development to large-scale mass production."

The entire process was fraught with challenges. "Scaling up from 2Ah lab-scale battery cells to mass-produced large-capacity ones entailed the aforementioned breakthroughs in cathode and anode materials, as well as research on manufacturing equipment and processes. In hindsight, this process may seem logical and well-defined, but in reality, it involved constant iterations and trials, far less structured than it sounds today."

Hu Yongsheng remarked with emotion: "By abandoning the mainstream nickel-based route for the cathode and replacing coconut shell biomass with coal for the anode, we not only avoided being subject to supply chain constraints but also broadened the development path for sodium-ion batteries."