Directional migration of Mg2+ in hexagonal Se cathode to unlock high-energy-density Mg metal batteries
Year: 2025
Type: article
Abstract: ABSTRACT Conversion-type cathodes have raised much attention in rechargeable Mg metal batteries owing to the low reaction energy barriers and high specific capacities. However, the structural collapse during the charging/discharging cycles often leads to increased electrochemical polarization and capacity degradation. In this work, we demonstrate a directional Mg2+ migration strategy in hexagonal selenium (H-Se) cathodes with 3D interconnected chain structures, enabling the sequential diffusion of Cu and Mg ions along the specific crystal plane and the lattice-matching phase conversions from H-Se (100) to Cu2−xSe (220) and eventually to MgSe (220). As a result, H-Se exhibits both a high specific capacity (630 mAh g−1), excellent rate performance (434 mAh g−1 at 2 C), high specific capacity and areal capacity (>500 mAh g−1 and 5 mAh cm−2) and long lifespan (∼1000 cycles). Finally, a H-Se based prototype pouch cell with a gravimetric energy density of 50 Wh kg−1 is achieved.
Source: National Science Review
DOI: 10.1093/nsr/nwaf485
Authors: Kewei Wang, Tongmin Xu, Jie Zhu, Yuming Chai, Yijiang Bao, Shiqiang Feng, Chengkai Yang, Shiyang Wang, Qi Li, Dongsheng Xu
Institutions: Peking University, Beijing National Laboratory for Molecular Sciences, Fuzhou University, Chinese Academy of Sciences, Fujian Institute of Research on the Structure of Matter, State Key Laboratory of Structural Chemistry, Fujian Science and Technology Innovation Laboratory for Optoelectronic Information of China
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,000
Awards: G1041984945, G5949950567, G616742053
OpenAlex ID: W4416099664