Recently, Professor Peng Qiuming's team from the State Key Laboratory of Metastable Materials Science and Technology at Yanshan University has made significant headway in the field of nanotwinned-alloy electrodes. The research team developed a new preparation method of high-pressure solid solution combined with Joule-heating ageing (HPJH), successfully synthesized a variety of nanotwinned-alloy electrodes, and elucidated the microscopic mechanism of enhancing metal deposition dynamics. The related achievements were published online in Nature Communications on February 20, 2025, titled "A nanotwinned-alloy strategy enables fast sodium deposition dynamics".
Illustration: a) Schematic diagram of the preparation process of different Al-Si alloys. The right side shows the HRTEM image of nanotwinned-Si in HPJH-AlSi alloy, revealing the characteristic twinned structure in the sample. b) Relationship between the deposition morphology phase diagram and the nondimensional electrochemical Damköhler number.
The slow kinetics of metal deposition have long plagued the development of battery technology, resulting in uneven metal deposition and dendrite growth, which compromise battery performance and even cause safety accidents. For this challenge, alloying provides a new solution to the problem of uneven metal deposition. Particularly, the introduction of nanotwinned structures into alloy (the nanotwinned-alloys containing active metals serve as negative electrodes, while the nanotwinned-alloys without active metals serve only as current collectors) can significantly reduce the diffusion barrier, promoting uniform metal deposition and inhibiting dendrite growth.
To this end, Professor Peng Qiuming's team adopted the HPJH treatment technology to successfully synthesize an Al-Si alloy electrode containing a high volume fraction (82.7%) of nanotwinned-Si. Such electrode can induce spherical Na deposition and effectively inhibit dendrite growth. In addition, the sodiophilic nanotwinned-Si exhibits a higher Na diffusion rate, which significantly reduces the nondimensional electrochemical Damköhler number, and transforms the deposition from diffusion-controlled process to reaction-controlled process. This strategy of enhancing the Na deposition kinetics through nanotwinned structures has broad applicability and provides a new direction for the deposition of other metals. Furthermore, this synthesis technology can be extended to a variety of alloy systems, providing a new approach for the preparation of bulk nanotwinned-alloys.
This project is funded by the National Natural Science Foundation of China (52331003, 52288102, 52171126, 52202374, 52471050), the Ministry of Education Yangtze River Scholar Professor Program (T2020124), and the Natural Science Foundation of Hebei Province (E2023203255, C2022203003). Zou Guodong from Yanshan University is the first author, and Wang Jinming and Peng Qiuming are the corresponding authors.
