| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the problem in which: in a secondary battery, a gas such as CO, CH<SB POS="POST">4</SB>is generated due to decomposition of a carbonate organic solvent during a forming reaction of a SEI layer and thickness of the battery is expanded when charging; and in a full charge state, the SEI layer is gradually degraded to bring about a side reaction in which an exposed negative electrode surface and the electrolyte react in accordance with the elapse of time during a high-temperature storage; at this time, a battery internal pressure rises due to gas generation, leading to increase in the thickness, expansion and deformation of the battery. <P>SOLUTION: A highly safe and high performance battery which is hard to be decomposed at a high potential and has a wide temperature range and a wide potential window is provided by the electrolyte that includes a material having a relative permittivity at a room temperature of 20 or more and/or a dielectric loss tanδ at 60°C at 1 kHz of 10 or less, and some organic solvents having a nitrile group, lithium bis(trifluoromethanesulfonyl)imide or sodium bis(trifluoromethane sulfonyl)imide and fluorinated cyclic carbonate. <P>COPYRIGHT: (C)2012,JPO&INPIT |
