Room temperature ionic liquids (RTILs) have shown great potential in a wide range of applications, especially as novel electrolytes for energy generation. Understanding microscopic dynamics under variable environmental conditions provides critical knowledge of the microscopic interactions in RTILs, which are closely linked to their functionality. Here, we investigate a response of a RTIL, EmimTFSI, to application of a high pressure, up to 1.0 GPa, using quasi-elastic neutron scattering, Raman and X-ray scattering. The ionic liquid transitions from a liquid to a solid state at above ∼0.5 GPa and returns to its liquid state following full decompression. However, following such pressure application, the resulting liquid no longer possesses either cations, or anions, as individual entities, as evident from quasi-elastic scattering and Raman scattering results, respectively. We suggest that a possible cause for this behavior could be dimerization of ions, which needs to be considered when designing RTILs for moderate high-pressure applications.

室温离子液体（RTIL）在广泛的应用中显示出巨大的潜力，特别是作为用于产生能量的新型电解质。了解可变环境条件下的微观动力学可提供有关RTIL中微观相互作用的关键知识，这些相互作用与其功能密切相关。在这里，我们使用准弹性中子散射，拉曼光谱和X射线散射研究了RTIL EmimTFSI对高达1.0 GPa的高压施加的响应。离子液体在高于约0.5 GPa时从液态转变为固态，并在完全减压后返回液态。但是，施加这种压力后，所得液体不再具有阳离子或阴离子作为单独的实体，分别从准弹性散射和拉曼散射结果可以看出。我们建议，造成这种现象的可能原因是离子的二聚化，在设计用于中等高压应用的RTIL时需要考虑到这一点。