储能科学与技术 ›› 2019, Vol. 8 ›› Issue (1): 162-166.doi: 10.12028/j.issn.2095-4239.2018.0170

• 研究及进展 • 上一篇    下一篇

超级电容器用耐压电解液的调制与性能

卢海1,2, 李祥元2, 张伟2, 郝星辰2, 车景锋2, 杜慧玲1   

  1. 1 西安科技大学材料科学与工程学院, 陕西 西安 710054;
    2 西安力能新能源科技有限公司, 陕西 西安 710200
  • 收稿日期:2018-09-02 修回日期:2018-09-18 出版日期:2019-01-01 发布日期:2018-09-20
  • 通讯作者: 卢海(1982-),男,讲师,研究方向为新能源材料与器件,E-mail:lhxust@126.com。
  • 作者简介:卢海(1982-),男,讲师,研究方向为新能源材料与器件,E-mail:lhxust@126.com。
  • 基金资助:
    国家自然科学基金(51604221),陕西省重点科技创新团队项目(2014KCT-04)。

Preparation and performance of high-voltage electrolytes for supercapacitors

LU Hai1,2, LI Xiangyuan2, ZHANG Wei2, HAO Xingchen2, CHE Jingfeng2, DU Huiling1   

  1. 1 School of Materials Science and Engineering, Xi'an University of Science and Technology, Xi'an 710054, Shaanxi, China;
    2 Xi'an Lineng New Energy Technology Co. Ltd., Xi'an 710200, Shaanxi, China
  • Received:2018-09-02 Revised:2018-09-18 Online:2019-01-01 Published:2018-09-20

摘要: 采用咪唑类离子液体1-乙基-3-甲基咪唑四氟硼酸盐(EMIBF4)调制了两款耐压电解液并用于大容量圆柱式超级电容器中,考察了电容器的容量、内阻、循环等性能,分析了高压循环过程中电容器的发热行为。结果表明:相比商用耐压电解液,两款自制电解液均能一定程度提高电容器的能量密度,但是由于内阻的增加而引起功率密度有所下降。商用耐压电解液由于表面温升过快,难以在2.85 V及以上电压正常循环,而两款自制电解液均显著减少了表面温升,改善了电容器的高压循环能力。另一方面,降低电流密度可以有效控制超级电容器的表面温升速度,这使得各款电容器都能维持稳定的3 V限压循环,EMIBF4/AN电解液甚至可以支持3.2 V上限循环,此时基于超级电容器总重量计算的最大能量密度与最大功率密度分别达到8.62 W·h/kg和16.18 kW/kg。

关键词: 超级电容器, 耐压电解液, 限压循环, 发热

Abstract: An ionic liquid of 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIBF4) was employed to fabricate two high-voltage electrolytes for applications in large-capacity cylindrical supercapacitors. The capacity, resistance (ESR) and cycle performance of the devices were investigated, and the heat generation behavior during high-voltage cycling were analyzed. Compared to commercial high-voltage electrolyte, the two as-prepared electrolytes with a suitable ionic conductivity increased the energy density of the device to a certain extent, but the power density decreased due to an increased ESR. It is difficult for the commercial high-voltage electrolyte to cycle normally at a voltage of exceeding 2.85 V due to rapidly-increased surface temperature. However, the two as-prepared electrolytes significantly reduced the temperature rise and improved the high-voltage cycle performance of the device. In addition, decreasing the current density also effectively controlled the temperature rise rate of the supercapacitor. All the supercapacitors maintained stable cycles at a upper voltage of 3V. The electrolyte of EMIBF4/AN even provided a favorable cycle at a upper voltage of 3.2V, with maximum energy density and power density (based on total mass of the device) of 8.62 Wh/kg and 16.18 kW/kg, respectively.

Key words: supercapacitor, high-voltage electrolyte, cycle at limited upper voltage, heat generation

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