Directional migration of Mg2+ in hexagonal Se cathode to unlock high-energy-density Mg metal batteries. - Wang, Kewei; Xu, Tongmin; Zhu, Jie; Chai, Yuming; Bao, Yijiang; Feng, Shiqiang; Yang, Chengkai; Wang, Shiyang; Li, Qi; Xu, Dongsheng (National Science Review, 2026)