Acta Phys. -Chim. Sin. ›› 2016, Vol. 32 ›› Issue (9): 2293-2300.doi: 10.3866/PKU.WHXB201605201

• ARTICLE • Previous Articles     Next Articles

Nitrile-Modified 2, 5-Di-tert-butyl-hydroquinones as Redox Shuttle Overcharge Additives for Lithium-Ion Batteries

Jing-Lun WANG,Xiao-Dan YAN,Tian-Qiao YONG,Ling-Zhi ZHANG*()   

  • Received:2016-04-12 Published:2016-09-08
  • Contact: Ling-Zhi ZHANG E-mail:lzzhang@ms.giec.ac.cn
  • Supported by:
    the Program of Guangdong Provincial Project for Science & Technology, China(2014A050503050/2015B010135008);Guangzhou Municipal Project for Science & Technology, China(2014Y2-00012/201509010018);Dongguan Municipal Project for Science & Technology, China(2013509104210);K. C. Wang Education Foundation, China

Abstract:

Nitrile-modified 2, 5-di-tert-butyl-hydroquinones were synthesized and investigated as redox shuttle overcharge additives for LiFePO4/Li cells. The cyanoethylation reaction was utilized to synthesize the target molecules 2, 5-di-tert-butyl-1, 4-di(β-cyanoethoxyl)benzene (RS-DCN) and 2, 5-di-tert-butyl-1-(β-cyanoethoxyl)-4-methoxybenzene (RS-MCN) in high efficiency from 2, 5-di-tert-butyl-hydroquinone and acrylonitrile. The solubility, cyclic voltammetric measurements, 5 V overcharge test, 100% overcharge test, high rate performance under 100% overcharge conditions, and cycle performance under normal conditions were studied in detail for the electrolyte with the addition of RS-DCN or RS-MCN. The RS-MCN compounds with the asymmetric structure delivered better solubility (with max. 0.3 mol·L-1 in 1.0 mol·L-1 LiPF6/EC+DEC+EMC, 1 : 1 : 1, in vol.), higher overcharge protection life (over 1200 h for the 5 V overcharge test), and excellent rate performance under 100% overcharge conditions (specific discharge capacity reached 153.5 mAh·g-1 at 2.5C). The addition of RS-MCN also improved the cycling performance of the LiFePO4/Li cell under the charge-discharge voltage range of 2.5-3.8 V.

Key words: Lithium-ion battery, Electrolyte, Overcharge protection additive, Nitrile, 2, 5-Di-tert-butyl-hydroquinone

MSC2000: 

  • O646