ELECTROLYTE SOLUTION FOR LITHIUM ION SECONDARY BATTERY

• Main Authors: SASAKI HIRONORI, SUZUKI SHUICHI, MIKI TAKESHI
• Format: Patent
• Language: Chinese; English
• Published: 07.08.2020
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRICITY; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY

The purpose of the present invention is to provide an electrolyte solution for a lithium ion secondary battery, with which the quantity of a cyclic carbonate can be optimized, decomposition reactionsof graphite-based anodes can be suppressed, and battery performance in low temperature regions can be improved. This electrolyte solution for a lithium ion secondary battery is characterized by containing 10-20 vol% of ethylene carbonate (EC) and/or propylene carbonate (PC) as a cyclic carbonate, 0.38-0.75 mol/L of at least one type selected from among lithium hexafluorophosphate (LiPF6), lithiumfluoroborate (LiBF4) and lithium bis(oxalate) borate (LiBOB) as a first lithium salt, and a lithium imide salt, with the total quantity of the lithium imide salt and the first lithium salt being 0.5 -1.5 mol/L, and the cyclic carbonate/first lithium salt molar ratio being 3-5. 本发明的目的在于提供一种锂离子二次电池用电解液，其优化环状碳酸酯的量，能够抑制石墨系负极的分解反应，并且提高低温区域的电池性能。本发明的锂离子二次电池用电解液的特征在于，含有：作为环状碳酸酯的碳酸乙烯酯(EC)和/或碳酸丙烯酯(PC)10体积％～20体积％；作为第一锂盐的选自六氟磷酸锂(LiPF