镁二次电池是以金属镁或镁合金为负极、允许镁离子嵌入和脱出的材料为正极的二次电池,具有能量密度高、环境友好、价格低廉、操作安全等特点,在新能源、便携式电源、大负荷储能等领域具有良好的应用前景。然而,二价镁离子电荷密度高、极化作用强,在材料中扩散速率较慢,适合其嵌入的正极材料较少,是导致镁二次电池发展和应用缓慢的主要因素之一。近年来,关于镁二次电池正极材料的报道不断增加,对正极材料的探究和改进一直是镁二次电池的研究热点。从微观结构(原子排布)的角度出发,针对目前已经报道的一些镁二次电池正极材料的结构特点进行归纳和总结,主要包括层状结构、尖晶石结构、橄榄石状结构和块状堆积结构等,探讨了镁二次电池正极材料的研究现状和存在问题,并对未来的发展趋势提出了展望,希望可以为镁二次电池的相关研究提供借鉴和参考。
Rechargeable magnesium batteries (RMBs) using pure Mg or Mg alloy as the anode and some materials al- lowed Mgz+ to insert/extract as the cathode,have the characteristic of high energy density, environmentally friend- ly,low cost and safety of handling, and have good application prospects in the new clean energy sources, portable power sources and heavy load energy devices. However,so far there is no suitable cathode materials for RMBs be- cause of the high charge density,strong polarization effect and very slow insertion/extraction speed of Mg ion,which is one of the primary factors for the slow application and development of RMBs. Recently, the reports about the cathode materials of RMBs increase significantly. The research and development of the cathode materials are a hot topic in RMBs field. Based on many reports, the structures of the cathode materials of RMBs were reviewed and classified from the perspective of the microstructure (the arrangement of atoms)characteristics, included layered structure, spinel structure,olivine structure, massive accumulation structure, etc. The status and issues of the cath- ode materials of RMBs were analyzed and discussed. The future development trend was prospected for providing some references for the relevant research about RMBs.