Acta Phys. -Chim. Sin. ›› 2012, Vol. 28 ›› Issue (04): 818-822.doi: 10.3866/PKU.WHXB201201132

• ELECTROCHEMISTRY AND NEW ENERGY • Previous Articles     Next Articles

Reaction Mechanism of 1,4-Dimethoxy Benzene as an Overcharge Protection Additive

LI Tian-Tian1, WANG Chao-Yang1, XING Li-Dan1, LI Wei-Shan1,2,3, PENG Bin1, XU Meng-Qing1,2,3, GU Feng-Long1,2,3, HU She-Jun1,2,3   

  1. 1. School of Chemistry and Environment, South China Normal University, Guangzhou 510006, P. R. China;
    2. Key Laboratory of Electrochemical Technology on Energy Storage and Power Generation of Guangdong Higher Education Institutes, South China Normal University, Guangzhou 510006, P. R. China;
    3. Engineering Research Center of Materials and Technology for Electrochemical Energy Storage (Ministry of Education), South China Normal University, Guangzhou 510006, P. R. China
  • Received:2011-10-31 Revised:2012-01-03 Published:2012-03-21
  • Contact: LI Wei-Shan E-mail:liwsh@scnu.edu.cn
  • Supported by:

    The project was supported by the Joint Project of National Natural Science Foundation of China and Natural Science Foundation of Guangdong Province (U1134002) and Natural Science Foundation of Guangdong Province, China (10351063101000001).

Abstract: The reaction mechanism of 1,4-dimethoxybenzene (p-DMOB) as an overcharge protection additive for lithium ion batteries was determined by theoretical calculation of density functional theory (DFT) at the level of B3LYP/6-311+G(d,p) and MP2/6-311+G(d,p). It was found that p-DMOB is oxidized prior to the solvents, ethyl methyl carbonate, dimethyl carbonate, and ethylene carbonate, when the lithium ion battery is overcharged. The calculated oxidative potentials of p-DMOB by B3LYP and MP2 methods are well in agreement at 4.12 and 4.05 V (vs Li/Li), respectively. The initial oxidation of p-DMOB involves a one-electron transfer resulting in a radical cation p-DMOB. The corresponding energy variations were 701.24 and 728.27 kJ·mol-1 from B3LYP and MP2 calculations, respectively. The p-DMOB species then loses one proton forming a radical p-DMOB·through the breaking of a C―H bond on the benzene ring, with the corresponding energy variations of 1349.78 and 1810.99 kJ·mol-1 for B3LYP and MP2, respectively. The p-DMOB·species is unstable and copolymerizes forming an insulated polymer with the corresponding energy variations of -553.37 and -1331.20 kJ·mol-1 for B3LYP and MP2, respectively.

Key words: Lithium ion battery, Overcharge protection additive, 1,4-Dimethoxy benzene, Reaction mechanism, Density functional theory

MSC2000: 

  • O646