高濃度電解液の特異性に基づく高性能蓄電デバイスの開発
【研究分野】デバイス関連化学
【研究キーワード】
sodium-ion battery / lithium-ion battery / electrolyte / safety / high voltage
【研究成果の概要】
Severe safety concerns are currently impeding the large-scale employment of lithium/sodium batteries. Conventional electrolytes are highly flammable and volatile, which may cause catastrophic fires or explosions. Efforts to introduce flame-retardant solvents into the electrolytes have generally resulted in compromised battery performance because those solvents do not suitably passivate carbonaceous anodes. We propose a salt-concentrated electrolyte design to resolve this dilemma via the formation of a robust inorganic passivation film on the anode. We demonstrated that a concentrated electrolyte using a salt and a popular flame-retardant solvent (trimethyl phosphate), without any additives or soft binders, realized stable charge-discharge cycling of both hard carbon and graphite anodes for more than 1000 cycles (over one year) with negligible degradation; this performance is comparable or superior to that of conventional flammable carbonate electrolytes. The unusual passivation character of the concentrated electrolyte coupled with its fire-extinguishing property contributes to developing safe and long-lasting batteries, and unlocking the limit toward development of much higher energy-density batteries. Moreover, we found that this concentrated electrolyte potentially enables the battery operation from -20 to 100 °C.
【研究代表者】
【研究種目】特別研究員奨励費
【研究期間】2016-04-22 - 2018-03-31
【配分額】2,300千円 (直接経費: 2,300千円)