To provide an ionic liquid which has at least one of properties such as high ionic conductivity, a small reduction in ionic conductivity at a low temperature, a low melting point, and a low viscosity. To provide a power storage device having higher initial charge and discharge efficiency than a power storage device containing a conventional ionic liquid. A cyclic quaternary ammonium salt is liquid at room temperature and contains a quaternary spiro ammonium cation having an asymmetrical structure including two aliphatic rings and one or more substituents bonded to one or both of the two aliphatic rings and an anion corresponding to the quaternary spiro ammonium cation. The power storage device includes a positive electrode, a negative electrode, and a nonaqueous electrolyte containing the cyclic quaternary ammonium salt as a nonaqueous solvent.
提供一种具有高离子导电性、低温下离子导电性小、低熔点和低粘度等性质的
离子液体。提供一种具有比含传统
离子液体的电源储存装置更高的初始充放电效率的电源储存装置。一种环状季
铵盐在室温下为液态,包含一个具有两个脂环和一个或多个取代基连接到两个脂环之一或两者之一的不对称结构的季
铵螺烷阳离子和与季
铵螺烷阳离子对应的阴离子。该电源储存装置包括正极、负极和包含环状季
铵盐作为非
水溶剂的非
水电解质。