Synergistic biphasic engineering and dual-site high-entropy doping enable stable sodium storage in layered oxide cathodes
image: The P2/O3 biphasic structure is conducive to optimize Na+ diffusion pathway and improve structural stability. Meanwhile, dual-site high-entropy doping can effectively suppress irreversible phase transitions and enhance Na+ diffusion kinetics. Notably, alkali metal site doping also significantly inhibits the migration of transition metals into the alkali metal layers, thereby preventing transition metal dissolution. Therefore, the designed HEO are expected to achieve highly reversible phase transitions, suppressed transition metal dissolution, and rapid Na+ diffusion kinetics, thereby realizing excellent rate performance and cycling stability.
Credit: Nano Research, Tsinghua University Press
A research team led by scholars from Hebei University of Technology, Wenzhou University, and University of Shanghai for Science and Technology has recently synthesized a novel P2/O3 biphasic high-entropy oxide cathode Na0.88K0.02Ni0.24Li0.06Mg0.07Fe0.1Mn0.41Ti0.1Sn0.02O2, denoted as HEO, with the aim of advancing research in the field of cathodes in sodium-ion battery. This innovative cathode material is designed by integrating biphasic engineering and high entropy strategy, aiming to address the limitations of traditional O3-type layered transition metal oxides, such as sluggish electrochemical reaction kinetics, volume changes during cycling, and irreversible phase transitions.
The research group published their findings in the journal Nano Research, highlighting the exceptional electrochemical performance of the HEO cathode. The HEO cathode exhibits enhanced structural stability, superior particle integrity, suppression of transition metal dissolution, and optimized Na⁺ diffusion kinetics. As a result, it achieves a high reversible capacity of 109.97 mAh g-1 at 5 C and outstanding cycling stability, with a capacity retention of 82.68% after 1000 cycles.
Zhuo Chen, the lead author of the study, stated, "The synergistic effect of the biphasic structure and the high-entropy strategy enables highly reversible phase transitions, suppresses transition metal dissolution, and facilitates rapid Na⁺ diffusion kinetics. These properties are crucial for enhancing the rate capability and cycling stability of sodium-ion batteries. The research team has also demonstrated the practical feasibility of HEO through its excellent air stability and full-cell electrochemical performance, underscoring the potential of the synergy between biphasic engineering and the high-entropy strategy in advanced energy storage materials."
The research group hopes that their findings will facilitate the development of novel sodium-ion battery cathode materials, thereby improving their electrochemical performance and practical applicability. Given its significant advantages in terms of cycling stability and energy density, the HEO cathode material is poised to become an ideal candidate for high-performance sodium-ion batteries, paving the way for the development of more sustainable and efficient energy storage solutions.
Other contributors to the study include Shijian Zheng, Kaixiang Lei, Yaning Wu, Qian Yang, Tingting Huang, Shuang Li, Shuo Shi, Yu Zhang, Mingming Fan, Tongtong Huo, Xuejie Bai, Genliang Yu, Mingyue Li, and Wen Zhang from Hebei University of Technology; Xunzhu Zhou and Lin Li from Wenzhou University; and Shixue Dou from University of Shanghai for Science and Technology.
This work was funded by the National Natural Science Foundation of China (22005082, 52202286, 22309002), Project supported by the Young Scientists Fund of the National Natural Science Foundation of China (12204143), Science Research Project of Hebei Education Department (CXY2024036, QN2024190), Special Project of Local Science and Technology Development Guided by the Central Government of China (226Z4402G, 246Z4410G), Natural Science Foundation of Zhejiang Province (LY24B030006), Science and Technology Plan Project of Wenzhou Municipality (ZG2024055), Basic Research Project of Wenzhou City (G20220016), Natural Science Foundation of Hebei Province (B2024202022, B2024202081), the Tianjin Science and Technology Plan Project (24JCQNJC00750), Anhui Provincial Natural Science Foundation (2308085QB55), Basic Research Program of Shijiazhuang (241790717A), and the Postdoctoral Funding Project of Hebei Province (B2023003015).
About the Authors
Kaixiang Lei is an Associate Professor, a Yuan Guang Scholar, and a Doctoral Supervisor at Hebei University of Technology. He obtained his master's degree (supervised by Fangyi Cheng) in 2016 and his doctoral degree (supervised by Fujun Li) in 2019 from Nankai University. He joined the School of Materials Science and Engineering at Hebei University of Technology in 2019. His research primarily focuses on the development of layered oxide cathodes and electrolytes for sodium/potassium-ion batteries, as well as the study of their interfacial chemistry. He has published over 40 academic papers in prestigious journals such as Angew. Chem. Int. Ed., Nano Lett., Energy Environ. Sci., and Chem, which have been cited more than 4600 times. Five of his papers have been selected as ESI Highly Cited Papers. He has applied for six national invention patents and has been included in the list of the World's Top 2% Scientists in both 2022 and 2023. He has served as the principal investigator for more than 10 projects, including the Young Scientist Fund of the National Natural Science Foundation of China, the Beijing-Tianjin-Hebei Basic Research Program, the Industry-University-Research Collaboration Program of the Hebei Provincial Department of Education, the Central Government's Guidance Fund for Local Science and Technology Development, the General Program and Young Scientist Fund of the Natural Science Foundation of Hebei Province, and the Youth Fund of the Hebei Provincial Department of Education. For more information, please follow the group's homepage: http://www.sjzheng-hebut.com/
Li Lin is an Oujiang Distinguished Professor at Wenzhou University. He has focused on developing functional electrolytes and electrode materials for rechargeable batteries, aiming to construct rechargeable batteries with good temperature tolerance, superior fast charging performance, and high safety. His research output includes over 100 SCI-indexed papers, among which 19 are highly cited, with a total citation count exceeding 8,600 and an H-index of 42. As first author, co-first author, or corresponding author, he has published more than 50 papers in leading international journals such as National Science Review, Proceedings of the National Academy of Sciences of the United States of America, Angewandte Chemie International Edition (10), Advanced Materials (2), and Joule. He has filed 15 national invention patents, with 1 granted. He has led nine research projects, including Young Scientist Fund of the National Natural Science Foundation of China. He also serves as a Youth Editorial Board member for journals such as eScience and Carbon Energy. For more information, please follow the group's homepage: https://chem.wzu.edu.cn/info/2984/56308.htm
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.