Chemical Sciences and Engineering Division , Argonne National Laboratory , Lemont , Illinois 60439 , United States.
Department of Physics , University of Illinois at Chicago , Chicago , Illinois 60607 , United States.
Inorg Chem. 2018 Jul 16;57(14):8634-8638. doi: 10.1021/acs.inorgchem.8b01417. Epub 2018 Jul 3.
Magnesium-ion batteries are a promising energy storage technology because of their higher theoretical energy density and lower cost of raw materials. Among the major challenges has been the identification of cathode materials that demonstrate capacities and voltages similar to lithium-ion systems. Thiospinels represent an attractive choice for new Mg-ion cathode materials owing to their interconnected diffusion pathways and demonstrated high cation mobility in numerous systems. Reported magnesium thiospinels, however, contain redox inactive metals such as scandium or indium, or have low voltages, such as MgTiS. This article describes the direct synthesis and structural and electrochemical characterization of MgCrS, a new thiospinel containing the redox active metal chromium and discusses its physical properties and potential as a magnesium battery cathode. However, as chromium(III) is quite stable against oxidation in sulfides, removing magnesium from the material remains a significant challenge. Early attempts at both chemical and electrochemical demagnesiation are discussed.
镁离子电池因其较高的理论能量密度和较低的原材料成本，是一种很有前途的储能技术。主要挑战之一是寻找具有与锂离子系统相似的容量和电压的阴极材料。由于具有相互连接的扩散途径和在许多系统中表现出的高阳离子迁移率，尖晶石代表了新型 Mg 离子阴极材料的一个有吸引力的选择。然而，报道的镁尖晶石含有氧化还原不活跃的金属，如钪或铟，或具有较低的电压，如 MgTiS。本文描述了一种新的尖晶石 MgCrS 的直接合成以及结构和电化学特性，该尖晶石含有氧化还原活性金属铬，并讨论了其作为镁电池阴极的物理性质和潜力。然而，由于铬(III)在硫化物中相当稳定，不易被氧化，因此从材料中去除镁仍然是一个重大挑战。本文讨论了早期在化学和电化学方面去除镁的尝试。
