•  
  •  
 

Corresponding Author

Xin-ping AI(xpai@whu.edu.cn)

Abstract

Safety concern is a major obstacle hindering the wide applications of large-capacity lithium ion batteries (LIBs) in electric vehicles. In this paper, a polymerizable monomer of 3, 4-ethylenedioxythiophene (EDOT) was proposed and tested as an electrolyte additive for enhancing the safety of LIBs. The electro-oxidative polymerization behaviors and influence of PEDOT additive on the thermal behavior of LiCoO2 cathode, as well as the safety performance and electrochemical properties of LiCoO2-based LIBs were investigated. The results from cyclic voltammetry (CV) and transmission electron microscope (TEM) characterizations indicated that the monomer additive can be electro-oxidatively polymerized to form a dense and uniform conductive polymer film (PEDOT) on the cathode surface during the first battery charging. The analysis results from differential scanning calorimetry (DSC) demonstrated that the heat released from the thermal decomposition of liquid electrolyte on the cathode surface was significantly reduced by 26 % due to the PEDOT barrier layer, which prevents electrolyte from direct contact with highly oxidative cathode. The safety tests revealed that even with a monomer content of only 0.1 wt% in liquid electrolyte, the thermal runaway onset time of LiCoO2-based pouch full cells could be delayed for 13.8 min under high temperature impact at 150 oC, representing a significantly enhanced safety. In addition, it is also found that the use of EDOT monomer as an electrolyte additive did not produce any negative influence on the normal charge-discharge performance of LIBs, showing a prospect for battery application.

Graphical Abstract

Keywords

safety additive, lithium ion battery, electro-oxidative polymerization, conducting polymer, 3, 4-ethylenedioxythiophene monomer.

Publication Date

2016-06-28

Online Available Date

2016-01-25

Revised Date

2016-01-19

Received Date

2015-12-29

References

[1] G. Crabtree. Perspective: The energy-storage revolution[J]. Nature, 2015, 526(7575): 92-92.

[2] M. Armand, J. M. Tarascon. Building better batteries[J]. Nature, 2008, 451(7179): 652-657. [3] J. M. Tarascon, M. Armand. Issues and challenges facing rechargeable lithium batteries[J]. Nature, 2001, 414(6861): 359-367. [4] K. T. Lee, S. Jeong, J. Cho. Roles of Surface Chemistry on Safety and Electrochemistry in Lithium Ion Batteries[J]. Accounts of Chemical Research, 2013, 46(5): 1161-1170. [5] Q. Wang, P. Ping, X. Zhao, et al. Thermal runaway caused fire and explosion of lithium ion battery[J]. Journal of Power Sources, 2012, 208: 210-224. [6] X. Feng, M. Fang, X. He, et al. Thermal runaway features of large format prismatic lithium ion battery using extended volume accelerating rate calorimetry[J]. Journal of Power Sources, 2014, 255: 294-301. [7] Yamaki J, Baba Y, Katayama N, et al. Thermal stability of electrolytes with LixCoO2 cathode or lithiated carbon anode[J]. Journal of power sources, 2003, 119: 789-793. [8] Spotnitz R, Franklin J. Abuse behavior of high-power, lithium-ion cells[J]. Journal of Power Sources, 2003, 113(1): 81-100. [9] M. Baginska, B. J. Blaiszik, R. J. Merriman, et al. Autonomic Shutdown of Lithium-Ion Batteries Using Thermoresponsive Microspheres[J]. Advanced Energy Materials, 2012, 2(5): 532-535. [10]W. Ji, B. Jiang, F. Ai, et al. Temperature-responsive microspheres-coated separator for thermal shutdown protection of lithium ion batteries[J]. RSC Advances, 2015, 5(1): 172-176. [11] H. Zhong, C. Kong, H. Zhan, et al. Safe positive temperature coefficient composite cathode for lithium ion battery[J]. Journal of Power Sources, 2012, 216: 273-280 [12]H. Zhang, J. Pang, X. Ai, et al. Poly(3-butylthiophene)-based positive-temperature-coefficient electrodes for safer lithium-ion batteries[J].Electrochimica Acta, 2016, 187, 173-178. [13]C.-C. Lin, H.-C. Wu, J.-P. Pan, et al. Investigation on suppressed thermal runaway of Li-ion battery by hyper-branched polymer coated on cathode[J]. Electrochimica Acta, 2013, 101, 11-17.

[15]A. Abouimrane, S. A. Odom, H. Tavassol, et al. 3-Hexylthiophene as a stabilizing additive for high voltage cathodes in lithium-ion batteries[J]. Journal of the Electrochemical Society, 2013, 160(2): A268-A271.

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.