Sodium-ion batteries are considered a promising technology for large-scale energy storage because sodium is abundant and widely distributed. A major challenge, however, is finding anode materials that combine high capacity, fast reaction kinetics and long cycling stability while remaining practical and low cost.
A research team from Taiyuan University of Technology and Taiyuan University of Science and Technology has reported a strategy that addresses this challenge by using coal tar pitch, an industrial carbon-rich byproduct, as the carbon source for a new composite anode.
Their work was published in Energy Materials and Devices on June 11, 2026.
The team used a zinc-aluminum layered double hydroxide (ZnAl-LDH) as a template to induce the formation of ZnO/ZnSe heterostructures embedded in hierarchical porous carbon. During synthesis, the LDH template serves two functions: it guides the local structure of the active material and helps generate pores in the carbon framework. This produces intimately connected ZnO/ZnSe-carbon interfaces rather than simply mixing active particles with carbon.
The heterostructure is important because ZnO and ZnSe can work together at their interface. The interfacial contact promotes charge transfer, while the mixed oxygen and selenium anion environment, the nanoscale dispersion of ZnO/ZnSe and the conductive carbon network help improve reaction kinetics and reduce the mechanical strain that usually occurs during repeated sodium insertion and extraction.
"Our goal was to turn an inexpensive industrial byproduct into a functional carbon host and then use interface engineering to overcome the kinetic limitations of metal selenide anodes," said Jian Wang, the corresponding authors of this paper, professor in the College of Materials Science and Engineering at Taiyuan University of Technology. "The LDH template allowed us to build the active heterostructure and the porous carbon architecture in one integrated design."
Electrochemical tests showed that the composite anode achieved a reversible capacity of 637.5 mAh g−1 at 100 mA g−1. Under high-rate cycling, it retained 259.7 mAh g−1 after 1000 cycles at 5 A g−1. Kinetic analysis further showed that capacitive storage dominated the response, contributing 93.3% of the total charge storage at 1.2 mV s−1. This behavior explains the material's strong rate capability. The team also assembled a full cell using an Na3V2(PO4)3 cathode to evaluate practical potential. The full cell retained 147.5 mAh g−1 after 100 cycles, indicating that the material design is not limited to half-cell testing.
"This study shows that template-directed heterostructure engineering can be an effective route for developing advanced sodium-ion battery anodes from low-cost carbon resources," the Dr. Wang said. "The next step is to further optimize electrode formulation and evaluate the material under more practical cell conditions."
Other contributors include the Yiming Liu, the professor in the College of Environmental Science and Engineering at Taiyuan University of Technology and deputy dean of School of Chemical Engineering and Technology at Taiyuan University of Science and Technology; Yibo Zhao also from the College of Environmental Science and Engineering at Taiyuan University of Technology and in Taiyuan, China. Peihua Li, Haochen Xie, Yalong Wang and Wanggang Zhang from the College of Materials Science and Engineering at Taiyuan University of Technology; Rufeng Tian and Xiaohong Li from the College of Chemistry and Chemical Engineering at Taiyuan University of Technology.
This work was supported by the National Natural Science Foundation of China (Grant Nos. U25B20110, 22075197 and 22278290), the Shanxi Provincial Central Guidance Fund for Local Science and Technology Development Projects (Grant No. YDZJSX2024D022), and the Key Research and Development (R&D) Projects of Shanxi Province (Grant No. 202102040201003).
DOI Link:
https://doi.org/10.26599/EMD.2026.9370093
