From the Hefei Institutes of Physical Science, Chinese Academy of Sciences, it has been learned that the research team led by Researcher Zhao Bangchuan at the Institute of Solid State Physics has recently achieved a significant breakthrough in the development of high-performance sodium-ion battery cathode materials. The team innovatively adopted a multi-scale synergistic modification strategy of "bond structure regulation + interface modification," successfully addressing the industry challenges of low ion transport efficiency and poor cycling stability in sodium vanadium manganese phosphate cathode materials. The related research findings have been published in the top-tier international materials science journal Advanced Functional Materials, laying a key technological foundation for the industrial development of high-stability, long-life sodium-ion batteries.

As an important complement to lithium-ion batteries, sodium-ion batteries hold broad application prospects in large-scale energy storage and commercial vehicles due to their abundant sodium resources, low cost, and high safety. Among them, NASICON-type sodium vanadium manganese phosphate (NMVP) cathode materials have attracted considerable attention for their three-dimensional open framework and high operating voltage. However, issues such as poor intrinsic electronic conductivity and susceptibility to lattice distortion during charge-discharge cycles have severely limited their practical application.

Addressing this critical challenge, Zhao Bangchuan's team proposed a synergistic modification approach of "internal and external refinement": introducing high-valence, small-radius molybdenum ions at the vanadium sites in the material's bulk phase to optimize the local coordination environment of manganese, thereby enhancing chemical bond strength. This effectively suppresses lattice distortion while improving electronic conductivity. Additionally, a uniform alumina coating was constructed on the material's surface to stabilize the electrode-electrolyte interface reaction, reduce metal ion dissolution, and accelerate sodium ion transport. This multi-dimensional modification strategy, spanning from the atomic scale to the micrometer scale, achieves comprehensive optimization of the material's electrochemical performance.

Experimental test data show that the modified Na₃.₉₁MnV₀.₉₇Mo₀.₀₃(PO₄)₃@Al₂O₃ (NMVMP@Al₂O₃) material exhibits outstanding performance: at a 0.1C rate, the initial discharge capacity reaches 99.3 mAh/g; even after 3000 cycles under high-rate charge-discharge conditions at 10C, the capacity retention remains as high as 84.5%. These performance metrics far surpass those of unmodified materials and other reported similar cathode materials. Further analysis confirms that the volume change of the modified material during charge-discharge cycles is only 3.66%, demonstrating extremely high structural reversibility and stability, which provides core assurance for the long-term stable operation of batteries.

"This research not only paves the way for the practical application of sodium vanadium manganese phosphate cathode materials but also offers a novel design approach for other polyanionic electrode materials," stated the team leader. The implementation of this achievement will effectively advance the technological progress of high-stability, long-life sodium-ion batteries and holds significant importance for enhancing China's core competitiveness in the field of new energy storage.

Industry experts point out that the sodium-ion battery industry is currently in a critical transition phase from small-scale production to market-oriented applications. This breakthrough in cathode material technology will further accelerate the industrialization process of sodium-ion batteries. With continuous technological iteration and collaborative efforts across the industrial chain, sodium-ion batteries are expected to enter the large-scale shipment stage within the next 3 to 5 years, with the market size projected to reach the hundred-billion-yuan level.