High energy density hybrid Mg super(2+)/Li super(+) battery with superior ultra-low temperature performance

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Materials for energy and sustainability, 2016-02, Vol.4 (6), p.2277-2285
• Main Authors: Zhang, Zhonghua, Xu, Huimin, Cui, Zili, Hu, Pu, Chai, Jingchao, Du, Huiping, He, Jianjiang, Zhang, Jianjun, Zhou, Xinhong, Han, Pengxian, Cui, Guanglei, Chen, Liquan
• Format: Article
• Language: English
• Subjects: Accumulators; Collectors; Electric batteries; Electrochemical analysis; Energy density; Lithium batteries; Magnesium; Rechargeable batteries
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/c5ta09591c

The development of high energy density rechargeable Mg-based batteries operating in a wide electrochemical window and ultra-low temperature remains a great challenge owing to parasitic side reactions between electrolytes and battery components when examined at high operating potentials (above 2.0 V vs.Mg super(2+)/Mg). Herein we propose a flexible pyrolytic graphitic film (GF) as a reliable current collector of high-voltage cathodes for a hybrid Mg super(2+)/Li super(+) battery within a pouch cell configuration. The utilization of such a highly electrochemical stable GF unlocks the critical bottleneck of incompatibility among all battery parts, especially parasitic corrosive reactions between electrolytes and currently available current collectors, which takes a big step forward towards the practical applications of Mg-based batteries. With an operating potential of 2.4 V, the hybrid Mg super(2+)/Li super(+) battery designed by us can deliver a maximum energy density of 382.2 W h kg super(-1), which significantly surpasses that of the conventional Mg battery (about 60 W h kg super(-1)), and the Al battery (about 40 W h kg super(-1)) as well as the state-of-the-art hybrid Na/Mg and Li/Mg batteries. The electrochemical property of the hybrid Mg super(2+)/Li super(+) battery is also characterized by higher rate capability (68.8 mA h g super(-1) at 3.0C), higher coulombic efficiency of 99.5%, and better cyclic stability (98% capacity retention after 200 cycles at 1.0C). In addition, the designed hybrid battery delivers excellent electrochemical performance at an ultra-low temperature of -40 degree C, at which it retains 77% capacity compared to that of room temperature. Our strategy opens up a new possibility for widespread applications of graphitic current collectors towards high energy rechargeable Mg-based hybrid batteries, especially applied in polar regions, aerospace, and deep offshore waters.