A supercapacitor have more excellent performance under ultra-low temperature condition and preparation method thereof

Abstract

The invention relates to a supercapacitor with more excellent performance under ultra-low temperature condition, which is composed of a housing, a positive electrode sheet, a negative electrode sheet,a separator between the positive electrode sheet and the negative electrode sheet and an electrolyte. The positive electrode sheet, the negative electrode sheet and the separator are suspended in theelectrolyte, and are characterized in that the electrolyte is composed of an ionic liquid, an organic solvent and an organic cosolvent, and the concentration of the electrolyte is 0.5 to 2M. The invention also discloses a preparation method of the supercapacitor. The invention not only has the advantages of high charging and discharging speed, high power density, small internal resistance, long cycle life and the like, but also the use temperature of the capacitor can be as low as-90 DEG C, and with the decrease of operating temperature, the operating potential window of the capacitor increases gradually, and the energy density also increases, which is expected to meet the technical requirements of high-performance supercapacitors in related civil or military fields.

Description

technical field [0001] The invention relates to the technical field of supercapacitors, in particular to a supercapacitor with better performance under ultra-low temperature conditions and a preparation method thereof. Background technique [0002] With the development of science and technology, the space for human activities continues to expand, such as polar regions, deep space, deserts, plateaus, glaciers, etc. To cope with various unfavorable natural conditions in these spaces, especially the extremely cold climate, it is urgent to develop an energy storage device that can rapidly store and deliver large amounts of electrical energy at very low temperatures. Supercapacitors (supercapacitors) is a new type of energy storage device, which belongs to the standard full range of low-carbon economic core products. Its biggest advantage is that it has excellent pulse charge and discharge performance and fast charge and discharge performance. Its power density is much higher tha...

AI Technical Summary

Problems solved by technology

The freezing point of acetonitrile is -45°C, which makes the lowest tolerable temperature of commercially available supercapacitors only reach -40°C

In addition, the most critical issue is that the potential window of commercially available supercapacitors is generally 2.7V, and it gradually decreases as the temperature decreases, and only a few remain unchanged.

At the same time, the specific capacity, especially the energy density, of commercially available supercapacitors also declines suddenly with the decrease of the operating temperature. The specific capacity and energy density at -40°C are extremely low, which seriously restricts the application prospects of supercapacitors in special fields.

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