| 摘要 |
PROBLEM TO BE SOLVED: To effectively suppress heat generation so as not to cause thermorunaway of a battery and to secure safety by including a specific amount of metal halide in a nonaqueous electrolyte. SOLUTION: In a nonaqueous electrolyte, metal halide is included by 0.5 to 5 wt.%. As an actual metal halide, AlI3 is especially effective, and AlF3, AlCl3 and PbI2, etc., are also named. For example, ethylenecarbonate is mixed with ethylmethylcarbonate by a prescribed ratio, a suitable amount of LiPF6 as an electrolyte salt is dissolved, and about 1 wt.% of AlI3 is added to this to use as the nonaqueous electrolyte. A battery using this electrolyte provides high safety when overcharged and cycle characteristics at high temperature are also excellent. This is because AlI3 is decomposed when overcharged to form a nonconductor film on the electrode surface and this film effectively suppresses thermorunaway reaction when overcharged. |
