Li+ doped layered oxyfluoride cathode for high-rate and long-life potassium-ion batteries

As global reliance on lithium resources intensifies, low-cost and highly safe potassium-ion batteries (PIBs) have emerged as a focal point for next-generation energy storage research. While lithium and potassium share many chemical similarities, directly substituting lithium with potassium is not straightforward. This is because K⁺, being larger than Li⁺, induce significant volume changes during the intercalation and de-intercalation processes.

On June 16, 2025, a research team led by Associate Professor Xuanpeng Wang from Wuhan University of Technology published groundbreaking findings in Nano Research. By employing a lithium-ion doping strategy, the team successfully developed a highly stable manganese-based layered oxyfluoride cathode material, significantly enhancing the cycle life and rate performance of potassium-ion batteries. This achievement provides critical technological support for the commercialization of PIBs.

Manganese-based layered oxides are regarded as ideal cathode materials for PIBs due to their high capacity and low cost. However, their performance has been limited by Mn³⁺-induced Jahn-Teller distortion and sluggish ion diffusion kinetics, leading to structural collapse and rapid capacity degradation during cycling. Associate Professor Wang’s team proposed an innovative strategy combining oxyfluoride design with lithium-ion co-doping, which not only suppresses phase transitions but also dramatically improves potassium-ion transport efficiency.

“The stability and capacity of manganese-based materials have long been a trade-off,” explained Associate Professor Xuanpeng Wang, corresponding author of the study. “By introducing an oxyfluoride framework and trace lithium ions, we restructured the material at the molecular scale, preserving high capacity while addressing the industry’s challenge of short cycle life.”

The team designed a novel cathode material with the chemical formula K_0.45Li_0.045Mn_0.8Co_0.1Fe_0.05Ni_0.05O_1.95F_0.05 (abbreviated as KMCFNOF-Li 4.5%). Experimental results demonstrated that the material delivers a high capacity of 123.7 mAh g⁻¹ at 0.05 A g⁻¹ and retains 83.0 mAh g⁻¹ even at a high rate of 2 A g⁻¹. Notably, a full K-ion battery assembled with this cathode exhibited 75% capacity retention after 1,000 cycles at 0.3 A g⁻¹, far surpassing the performance of existing counterparts.

“Lithium-ion doping not only stabilizes the manganese-oxygen octahedral structure but also inhibits phase transitions through the formation of localized LiMn₆ units,” emphasized Associate Professor Wang. “In situ XRD and XAFS analyses clearly elucidated this mechanism, providing a theoretical foundation for future material design.”

The research team outlined plans to optimize large-scale production processes and explore applications in grid energy storage and low-speed electric vehicles. “Our ultimate goal is to develop a potassium-ion battery system that rivals lithium-ion batteries in cost while offering greater safety and environmental sustainability,” said Associate Professor Wang.

The team’s success underscores the importance of interdisciplinary collaboration in materials science. As Prof. Wang noted, “This study opens new avenues for designing advanced cathodes. By addressing both structural and kinetic challenges, we’re one step closer to making potassium-ion batteries a mainstream energy solution.”

With further development, this innovation could accelerate the global shift toward sustainable energy systems, reducing reliance on lithium and enabling greener technologies.

Other contributors include Yueyue Yu, Meng Huang, Binshuo He, Jiashen Meng, Yu Wang, Meng Zhang and Hao Zhang from the School of Materials Science and Engineering at Wuhan University of Technology in Wuhan, China; and Janwei Li from the Zhongyu Feima New Material Technology Innovation Center (Zhengzhou) Co., Ltd. in Zhengzhou, China.

This work was supported by the National Key Research and Development Program of China (No. 2023YFB3809300 and No. 2023YFB3809303), National Science Foundation of China (No. 52373306 and 22409154), the Key Research and Development Program Project of Hubei Province (grant no. 2023BAB140), the Natural Science Foundation of Hubei Province (No. 2023AFA053 and 2024BAA013), the Key Research and Development Program of Henan Province (no. 251111240100), the Postdoctoral Fellowship Program of CPSF (no. GZB20230553) and Hainan Provincial Joint Project of Sanya Yazhou Bay Science and Technology City (No. 2021CXLH0007).

About the Authors

Wang Xuanpeng is an Associate Professor and doctoral supervisor, a Distinguished Young Scientist of Hubei Province, and the Deputy Director of Science and Technology at Zhongyu Feima New Material Technology Innovation Center. His research focuses on the fine structure regulation of novel potassium-ion battery cathode materials, their intrinsic physical properties, electrochemical energy storage mechanisms, industrial applications, and the recycling and regeneration of power batteries. To date, he has published over 110 SCI papers in internationally renowned journals such as Advanced Materials, Angewandte Chemie, Nature Communications, and Nature Nanotechnology. His papers have been cited more than 9,400 times, with 15 papers selected as ESI top 1% highly cited papers and eight as ESI top 0.1% hot papers. He has an h-index of 50 and holds more than 30 national authorized patents. For more information, please pay attention to his research homepage http://smse.whut.edu.cn/yjspy/dsdw/202402/t20240224_985457.shtml

About Nano Research

Nano Research is a peer-reviewed, open access, international and interdisciplinary research journal, sponsored by Tsinghua University and the Chinese Chemical Society, published by Tsinghua University Press on the platform SciOpen. It publishes original high-quality research and significant review articles on all aspects of nanoscience and nanotechnology, ranging from basic aspects of the science of nanoscale materials to practical applications of such materials. After 18 years of development, it has become one of the most influential academic journals in the nano field. Nano Research has published more than 1,000 papers every year from 2022, with its cumulative count surpassing 7,000 articles. In 2024 InCites Journal Citation Reports, its 2024 IF is 9.0 (8.7, 5 years), and it continues to be the Q1 area among the four subject classifications. Nano Research Award, established by Nano Research together with TUP and Springer Nature in 2013, and Nano Research Young Innovators (NR45) Awards, established by Nano Research in 2018, have become international academic awards with global influence.